Against the Mathematicians


Sometimes, Against the Mathematicians Books I-VI are referred to as Against the Professors and Against the Mathematicians Books VII-XI are referred to as Against the Dogmatists.

Book VII: Against the Logicians

1. The general character of Scepticism has now been set forth by the appropriate method of description, as an Outline of it has been given partly by means of direct exposition and partly by distinguishing it from the philosophies which stand next to it. “It remains for us, in the next place, to explain how we apply it to the particular divisions of philosophy, so that we may be less prone to rashness either in our own sceptical investigations of things or in our contradictions of the Dogmatists. 2. Since, however, Philosophy is a complex affair, for the sake of an orderly and methodical inquiry into all its parts, we must first discuss briefly the question what its parts are.

Some, then, hold that it has but one part, others that it has two, and others that it has three parts; and of those who have supposed it to consist of one part, some have supposed this to be physics, others ethics, others logic; 3. and so likewise of those who divide it into two, some have made the divisions physics and logic, others physics and ethics, others logic and ethics; 4. while those who divide it into three parts are all agreed on the division into physics, logic, and ethics. 5. “It has been supposed to consist of physics, as its sole part, by Thales, Anaximenes, Anaximander, Empedocles, Parmenides, Heracleitus”: and of these, as regards Thales, Anaximenes, and Anaximander, all agree and there is no dispute, but all do not agree about Empedocles and Parmenides, nor yet Heracleitus. 6. Thus Aristotle says that “Empedocles first cultivated the art of rhetoric, to which dialectic is antistrophic (or corresponding),” that is to say is isostrophic (or equivalent), inasmuch as it is strophic of (concerned with) the same subject matter — just as the Poet called Odysseus antitheos (god-like), which means isotheos (god-equal). 7. And it would seem that Parmenides was not unversed in dialectic since Aristotle, again, regarded his friend Zeno as “the pioneer of dialectic.” About Heracleitus, too, it was a question whether he was not merely a physicist but an ethical philosopher as well. 8. But in any case these are the leading exponents of the Physical division. The Ethical division alone was that which engaged Socrates, at least according to the rest of his friends; for Xenophon in his Memorabilia says expressly that “he rejected physics as a subject above our human powers and devoted himself solely to Ethics as the subject which concerns us men.” Timon also knows that this was his practice, for in one place he says —

But by the Stone-cutter, prater of laws, such things were abjured.

That is to say, Socrates turned aside from physics to the study of Ethics; and on this account Timon gave him the name of “prater of laws,” as the discussion of laws is a branch of Ethics. 9. Plato, however, ascribes to him every division of philosophy, — Logic, in so far as he is introduced as an investigator of definitions and divisions and etymology, which are logical themes, — Ethics, because he discusses virtue and government and laws, — 10. Physics, since he is made to philosophize about the Universe and animal creation and the Soul. Hence, too, Timon censures Plato for thus decking out Socrates with a host of sciences: for Plato, he says, “suffered him not to remain a simple teacher of Ethics.”

11. The Cyrenaics, too, are thought by some to embrace the Ethical division only, and to dismiss Physics and Logic as contributing nothing to the happiness of life. Some, however, have supposed that this view is refuted by the fact that they divide Ethics into sections — one dealing with objects of choice and aversion, another treating of the affections, yet another treating of actions, then a further section concerned with causes, and finally one dealing with arguments; for of these, the section treating of causes, they say, belongs to the Physical division of Philosophy, and that treating of arguments to the Logical. 12. Ariston of Chios, also, not only, they say, rejected the study of Physics and Logic on the ground that they are unprofitable and injurious to the philosophers who study them, but also proscribed some branches of Ethics, such as the hortatory and admonitory; for these, he held, are the business of nurses and pedagogues, whereas for securing happiness in life that doctrine is sufficient which attracts men to virtue and alienates them from vice and runs down those intermediate things which excite the admiration of most men and ruin their lives. 13. Logic, on the other hand, was the sole division which was cultivated by Panthoides and Alexinus, and Eubuhdes and Bryson, and Dionysodorus and Euthydemus.

14. Of those who supposed Philosophy to consist of two parts, Xenophanes of Colophon, as some say, pursued both Physics and Logic, but Archelaos of Athens Physics and Ethics; and some set Epicurus beside Archelaos as equally rejecting the study of Logic. 15. But there have been others who say that he did not set aside logic as a whole but merely that of the Stoics, so that he virtually allowed after all the three divisions of Philosophy. Some too — as Sotion has testified — ascribe to the Cyrenaics the expression of the opinion that both Ethics and Logic are parts of Philosophy.

16. These thinkers, however, seem to have handled the question incompletely, and, in comparison with them, the view of those who divide Philosophy into Physics, Ethics, and Logic is more satisfactory. Of these Plato is, virtually, the pioneer, as he discussed many problems of physics and of ethics, and not a few of logic; but those who most expressly adopt this division are Xenocrates “ and the Peripatetics, and also the Stoics. 17. Hence they plausibly liken philosophy to a garden rich in fruits, comparing Physics to the height of the plants. Ethics to the richness of the fruits, Logic to the strength of the walls. 18. And others say that Philosophy resembles an egg. Ethics being like the yolk, which some identify with the chick. Physics like the white, which is nutriment for the yolk, and Logic like the outside shell. 19. But on the ground that the parts of Philosophy are inseparable one from another, whereas plants appear different from fruits and walls separated from plants, Poseidonius “preferred the comparison of Philosophy with an animal — Physics with the blood and flesh, Logic with the bones and sinews, Ethics with the soul.

20. Regarding Philosophy, then, as tripartite, some put Physics as its first division since it holds first place both in point of time — seeing that even up till now the earliest philosophers have been called “physicists” — and also in natural order, as it is fitting to begin by discussing the Whole before we go on to investigate the particulars and Man himself. 21. Others have begun with Ethics, as a more necessary subject and one which invites to happiness; just as Socrates gave out that his only subject of inquiry was

Whatso of evil and good within these homes is enacted.

22. The Epicureans start off with Logic, for they expound “Canonics” first, treating of things evident and non-evident and allied matters. The Stoics themselves, too, say that Logic comes first, and Ethics second, while Physics occupies the last place. 23. For the mind must first be fortified for the task of guarding its heritage impregnably, and what thus makes the intellect secure is the Dialectical section; secondly we must subjoin Ethical doctrine for the bettering of morals; for when this is laid upon an existing basis of logic, its reception is without danger; and finally we must add Physical doctrine, it being a more divine subject and one which requires more profound attention.

24. Such, then, are the views of these thinkers. We, however, are not at present investigating this matter with exactness; but this we do affirm — that if truth is to be sought in every division of Philosophy, we must, before all else, possess trustworthy principles and methods for the discernment of truth. Now the Logical branch is that which includes the theory of criteria and of proofs; so it is with this that we ought to make our beginning. 25. And in order to facilitate our inquiry, in its criticism of the Dogmatists, seeing that things evident are held to be directly cognized by means of a criterion, whereas the non-evident things are discovered by means of signs and proofs through inference from the evident, we shall take them in this order, inquiring first whether there exists a criterion of things directly perceived either by sense or by reason, and, in the next place, whether there exists a method capable of either signifying or proving things non-evident. 26. For I suppose that if these shall be abolished there will no longer be any question as to the duty of suspending judgment, seeing that no truth is discovered either in things plainly obvious or in things obscure. Let us begin, then, with the discussion of the criterion, since it is held to embrace all the modes of apprehension.

Does a Criterion of Truth Exist?

27. The problem of this Criterion is everywhere a subject of controversy, not only because Man is by nature a truth-loving animal, but also because the most extensive systems of Philosophy pronounce judgment on the weightiest matters. For either the great and sublime theme of the Dogmatists’ boasts will necessarily be utterly abolished if no Canon of the veritable existence of things is discovered, or conversely, if something appears which is able to point us to the apprehension of the truth, the Sceptics will be convicted of rashness and of defiant disregard for the general belief. It would indeed be monstrous if, while spending the utmost pains in investigating the external criteria — such as rules and compasses, weights and scales — we should neglect the Criterion within us — itself the accepted test of those very externals. 28. As our inquiry, then, has to do with the whole subject, we shall proceed in an orderly way, and since two terms are involved in the proposition — namely, “the Criterion” and “Truth” — we shall discuss each of these separately, of treatment consisting partly of an exposition of the various senses of the terms “Criterion” and “Truth” and of the kind of reality ascribed to them by the Dogmatists, and partly of a more critical inquiry as to the possibility of the real existence of any such things.

Concerning the Criterion

29. Well, then, the Criterion (for with it we must begin) has, in the first place, two senses; in the one sense it is used of that in view of which we do these things and not those; in the other, it means the thing in view of which we assert that these things exist and those do not exist, and that these are true, those false. The former of these we have dealt with in our section “Concerning the Sceptic Way.” 30. For the sceptical philosopher, if he is not to be entirely inert and without a share in the activities of daily life, was necessarily obliged to possess some Criterion both of choice and of aversion — that is to say, the Appearance; even as Timon also testified m his saying —

Yea, the Appearance is ev’rywhere strong, where’er it approacheth.

31. “Criterion,” in the second of the two senses — that of existence, I mean, which is the theme of our present inquiry — seems to be used with three meanings; the general, the special, and the most special. As general it is used of every measure or standard of apprehension, and in this sense the physical criteria also — such as sight, hearing, taste — are thought worthy of the title; 32. as special it includes every technical measure of apprehension, so that in this sense one would call the cubit, the balance, the rule and the compass “criteria” inasmuch as they are technical, but not sight nor hearing nor in general the rest of the common sense-organs, the construction of which is natural; 33. in the more special sense the Criterion is every measure of apprehension of a non-evident object, and in this sense the ordinary standards are no longer called criteria but only logical standards and those which the dogmatic philosophers introduce as means for the discovery of truth.

34. The term “Criterion,” then, being used in many senses, we again propose to examine in the first place the logical criterion, which the philosophers harp on, and subsequently each of the criteria of ordinary life. 35. One may, however, subdivide this logical criterion as well, by calling one form of it that of the agent, another the instrument, and a third the application and use. The agent, for instance, may be a man, the instrument sense-percepition, and the third form of criterion the application of the sense-unpression. 36. For just as in the process of examining heavy and light objects there are three criteria, the man who weighs, the scales, and the act of weighing, and of these the weigher is the criterion of the agent, the scales that of the instrument, and the act of weighing that of the use; and again, just as for the determination of things straight and crooked there is need of a craftsman and a rule and the application of the rule; so, in the same way, in philosophy also, for the determination of things true and false, we require the three criteria we have mentioned above; 37. and here the man, who is the agent in the judgment, corresponds to the weigher or carpenter; sense-perception or intelligence, as the instrument by which the judgment is effected, corresponds to the scales and the rule; and the application of the sense-impression, according to which the man proceed.s to judge, corresponds to the use of the aforesaid instruments.

It was, in fact, necessary for our present purpose to begin with this explanation of the criterion.

Concerning Truth

38. It is supposed by some, and especially by the Stoics, that “truth” differs from “the true” in three ways, in essence and composition and potency, — in essence in so far as truth is a body whereas the true is incorporeal.” And naturally so, they say; for the latter is “judgment,” and the judgment is “expression,” and the expression is incorporeal. On the other hand, truth is a body in so far as it is held to be “knowledge declaratory of all true things?,” 39. and all knowledge is “a particular state of the regent part,” just as the fist is conceived as a particular state of the hand, and, according to these thinkers, the regent part is a body, so that truth also will belong to the genus body. 40. They differ in composition, inasmuch as the true is conceived as uniform and simple in its nature, — as for instance, at the present moment, the propositions “It is day” and “I am conversing,” — whereas truth, as consisting in knowledge, is on the contrary conceived to be of composite nature and a collection of several elements. 41. Thus, just as “the people,” is one thing and “the citizen” another, — the collection composed of many citizens being “the people,” the one individual “the citizen,” — so, by the same reasoning, truth is distinguished from the true, and whereas truth corresponds to “the people,” the true corresponds to “the citizen,” because the former is composite but the latter simple. 42. And they are distinct from one another in potency, since the true is not altogether dependent on knowledge (for in fact the fool and the infant and the madman at times say something true, but they do not possess knowledge of the true), whereas truth is considered to involve knowledge. Hence, too, its possessor is a Sage (for he possesses knowledge of things true), and he never speaks falsely, even if he says what is false, because he does not utter it from an evil but from a kindly disposition. 43. For just as the doctor who says something false respecting the cure of his patient, and promises to give him something but does not give it, is not lying though he says something false (for in saying it he has regard to the cure of the person in his charge), — and just as the best commanders, when, as often, they concoct messages from allied States for the eneouragenient of the soldiers under their command, say what is false yet are not liars because they do not do this with a bad intention, 44. &mdash and just as the grammarian, although when giving an example of a solecism he utters a solecism, is not guilty of bad grammar (for it is not through ignorance of correct speech that he makes the mistake), — so also the Sage (I mean the man who possesses the knowledge of the true) will at times say something false but will never lie because his mental disposition is not assenting to what is false. 45. For, as they assert, the fact that the liar must be judged by his disposition and not by his mere utterance may be learnt from the examples now to be adduced. Thus the name “grave-digger” is applied both to the man who so acts in order to plunder the dead and to the man who digs graves for the dead; but whereas the first is punished as doing this from an evil disposition, the second receives pay for his service for the opposite cause. So then it is quite plain that uttering a falsehood is vastly different from lying, in that the former proceeds from a kindly intention but lying from an evil intention.

46. Having thus stated the views held by some concerning truth, let us next consider the divergent opinions which have arisen among the dogmatic philosophers concerning the criterion; for while we are investigating its existence we must also consider at the same time what, in its essence, it is. 47. Now many divergent opinions of all sorts are propounded regarding this subject, but for the present it is sufficient for us to say that some have rejected, others retained the criterion. Of those who have retained it the main views are three; some have retained it in rational discourse, some in non-rational self-evident facts, some in both. 48. Moreover, it has been rejected by Xenophanes of Colophon and Xeniades of Corinth and Anacharsis the Scythian and Protagoras and Dionysodorus; and besides these, by Gorgias of Leontini and Metrodorus of Chios and Anaxarchus “the Eudaemonist”” and Monimus the Cynic. [And among these are also the Sceptics.] 49. And of these Xenophanes, according to some, took up this position by declaring all things to be non-apprehensible, as in this passage;

Yet, with respect to the gods and what I declare about all things.
No man has seen what is clear nor ever will any man know it.
Nay, for e’en should he chance to affirm what is really existent,
He himself knoweth it not; for all is swayed by opining.

50. For here he seems to mean by “clear” what is true and known, just as in the saying

By nature simple is the word of truth.

And by “man” he seems to mean “human being,” using the special term instead of the general; for man is a species of human being. The use of this mode of speech is customary also in Hippocrates, as when he says “A woman is not produced right-handed,” — that is to say, “a female is not compounded in the right-hand parts of the womb.” The words “with respect to the gods” are used, by way of example, for “concerning any non-evident object”; and “opining” stands for surmise and opinion. 51. Consequently his statement, when simplified, amounts to this — “Yet the true and known — at least in respect of non-evident things — no human being knows; for even if by chance he should hit upon it, still he knows not that he has hit upon it but imagines and opines.” 52. For just as, if we were to suppose that certain people are searching for gold in a dark room containing many treasures, what happens will be that each of them whenever he lays hold of some one of the treasures in the room will imagine that he has grasped the gold, though none of them will be convinced that he has lighted on ihe gold, even though, in fact, he has lighted upon it; so also into this Universe, as into a great house, there has entered a host of philosophers bent on the search for truth, and it is quite likely that the one who has laid hold of it disbelieves that he has achieved his aim.

Thus Xenophanes denies that a criterion of truth exists because there is nothing apprehensible existing in the nature of the objects of inquiry. 53. And Xeniades the Corinthian — who is mentioned by Democritus — inasmuch as he asserts that all things are false, and that every impression and opinion is false, and that all that becomes becomes out of the non-existent, and all that perishes perishes into the non-existent, virtually adopts the same position as Xenophanes. 54. For if nothing true, as opposed to false, exists, but all things are false and therefore inapprehensible, neither will there exist any criterion capable of judging between things. And the fact that all things are false and therefore inapprehensible is proved by disparagement of the senses; for if the supreme criterion of all things is false, all things also are of necessity false. But the senses are the supreme criterion of all things, and they are proved to be false; therefore all things are false.

55. Anacharsis the Scythian also, as they say, destroys the apprehension which judges concerning every art, and strongly censures the Greeks for accepting it. “For who,” says he, “is the man who judges a thing by rules of art? Is he the non-expert or the expert artist?” But surely we could not say that he is the non-expert; for he is lacking in knowledge of the special features of the art, and just as the blind man does not perceive the effects of vision, nor the deaf those of hearing, so neither is the non-expert keen of sight to apprehend the result produced by artistic methods; since in fact, were we to entrust to him the judgment of any product of art, there will be no difference between lack of art and art, which is absurd. So that the non-expert is not the judge of the special features of art. 56. It remains, then, to say that the expert artist is the judge; and this again is improbable. For either the fellow-craftsman judges the fellow-craftsman, or the man of one craft the man of another craft. But the man of one craft is incapable of judging the man of another craft; 57. for he is learned in his own art, but in regard to another man’s he is in the position of a non-expert. Nor in fact can the fellow-craftsman pass judgment on his fellow-craftsman: for precisely this was our question — Who is he that judges those who stand on the same level inasmuch as they are engaged in the same art? And besides, if this fellow-craftsman judges that one, the same thing will be both judging and judged, both trusted and distrusted; 58. for in so far as the other man is a fellow-craftsman of the man who is being judged, he himself also will be subject to judgment and distrusted, whereas, in so far as he is giving judgment, he will be trusted. But it is not possible for the same thing to be both judging and judged, trusted and distrusted. Therefore there is none who judges by rules of art. 59. And because of this there is no criterion either; for of criteria some are technical, others non-technical, but, for the reasons already stated, neither the non-technical criteria judge any more than the non-expert, nor the technical any more than the expert artist. So then no criterion exists.”

60. Some, too, have counted Protagoras of Abdera among the company of those philosophers who abolish the criterion, since he asserts that all sense-impressions and opinions are true and that truth is a relative thing inasmuch as everything that has appeared to someone or been opined by someone is at once real in relation to him. Certainly, at the opening of his book The Down-Throwers he has proclaimed that “Of all things the measure is man, of existing things that they exist and of non-existing things that they exist not.” 61. And to this statement even the opposite statement appears to bear witness. For if anyone shall assert that man is not the criterion of all things he will be confirming the statement that man is Lhe criterion of all things; since the very person who makes the assertion is himself a man, and in affirming what appears relatively to himself he confesses that this very assertion of his is one of the appearances relative to himself. Hence also the madman is a trustworthy criterion of the appearances which occur in madness, and the sleeper of those in sleep, and the infant of those in infancy, and the ancient of those in old age. 62. Nor is it appropriate to disallow one set of circumstances because of a different set of circumstances — that is to say, the appearances which occur in the state of madness because of the impressions received in the sane state of mind, and those of sleep because of those of the waking state, and those of infancy because of those of old age. For as the latter percepts do not appear to the former percipients, so also conversely the appearances perceived by these do not affect those. 63. Consequently, if the madman or the sleeper is not a reliable judge of the appearances he perceives because he is found to be in a certain state of mind, then since both the sane and the waking man are also in a certain state, they again will not be trustworthy for the determining of their percepts. Seeing, then, that no impression is received apart from circumstances, each man must be trusted regarding those received in his own circumstances. 64. And this man, as some have supposed, rejects the criterion, seeing that it purports to be a test of absolute realities and to discriminate between the true and the false, whereas the man just mentioned does not admit the existence either of anything absolutely real or of falsehood. Euthydemus and Dionysodorus also are said to have shared these views; for they too regarded both the existent and the true as relative things.

65. Gorgias of Leontini belonged to the same party as those who abolish the criterion, although he did not adopt the same line of attack as Protagoras. For in his book entitled Concerning the Non-existent or Concerning Nature he tries to establish successively three main points — firstly, that nothing exists; secondly, that even if anything exists it is inapprehensible by man; thirdly, that even if anything is apprehensible, yet of a surety it is inexpressible and incommunicable to one’s neighbor. 66. Now that nothing exists, he argues in the following fashion: If anything exists, either it is the existent that exists or the non-existent, or both the existent and the non-existent exist. But neither does the existent exist, as he will establish, nor the non-existent, as he will demonstrate, nor both the existent and the non-existent, as he will also make plain. Nothing, therefore, exists. 57. Now the non-existent does not exist. For if the non-existent exists, it will at one and the same time exist and not exist; for in so far as it is conceived as non-existent it will not exist, but in so far as it is non-existent it will again exist. But it is wholly absurd that a tiring should both exist and exist not at one and the same time. Therefore the non-existent does not exist. Moreover, if the non-existent exists, the existent will not exist; for these are contrary the one to the other, and if existence is a property of the non-existent, non-existence will be a property of the existent. But it is not the fact that the existent does not exist; neither, then, will the non-existent exist.

68. Furthermore, the existent does not exist either. For if the existent exists, it is either eternal or created or at once both eternal and created; but, as we shall prove, it is neither eternal nor created nor both; therefore the existent does not exist. For if the existent is eternal (the hypothesis we must take first), it has no beginning; 69. for everything created has some beginning, but the eternal being uncreated had no beginning. And having no beginning it is infinite. And if it is infinite, it is nowhere. For if it is anywhere, that wherein it is is different from it, and thus the existent, being encompassed by something, will no longer be infinite; for that which encompasses is larger than that which is encompassed, whereas nothing is larger than the infinite; so that the infinite is not anywhere. 70. Nor, again, is it encompassed by itself. For, if so, that wherein it is will be identical with that which is therein, and the existent will become two things, place and body (for that wherein it is is place, and that which is therein is body). But this is absurd; so that the existent is not in itself either. Consequently, if the existent is eternal it is infinite, and if it is infinite it is nowhere, and if it is nowhere it does not exist. So then, if the existent is eternal, it is not even existent at all.

Nor, again, can the existent be created. 71. For if it has been created, it has been created either out of the existent or out of the non-existent. But it has not been created out of the existent; for if it is existent it has not been created but exists already; nor out of the non-existent; for the non-existent cannot create anything because what is creative of anything must of necessity partake of real existence. Neither, then, is the existent created.

72. In the same way, it is not both together — at once eternal and created; for these are destructive the one of the other, and if the existent is eternal it has not been created, while if it has been created it is not eternal. So then, if the existent is neither eternal nor created nor both at once, the existent will not exist.

73. Moreover, if it exists, it is either one or many; but, as we shall show, it is neither one nor many; therefore the existent does not exist. For if it is one, it is either a discrete quantity or a continuum or a magnitude or a body. But whichever of these it be, it is not one; but if it be a discrete quantity it will be divided, and if it be a continuum it will be cut in sections; and similarly, if it be conceived as a magnitude it will not be indivisible, while if it is a body it ivill be threefold, for it will possess length and breadth and depth. But it is absurd to say that the existent is none of these; therefore the existent is not one. Yet neither is it many. 74. For if it is not one, neither is it many; for the many is a sum of the ones, and hence if the one is destroyed the many also are destroyed with it.

Well, then, it is plain from this that neither does the existent exist nor the non-existent exist; 75. and that they do not both exist — both the existent and the non-existent — is easy to prove. For if the non-existent exists and the existent exists, the non-existent will be identical with the existent so far as regards existing; and for this reason neither of them exists. For it is admitted that the non-existent does not exist; and it has been proved that the existent is identical therewith; therefore it too will not exist. 76. And what is more, if the existent is identical with the non-existent, both of them cannot exist; for if the pair of them both exist, there is no identity, and if there is identity, there is no longer a pair. From which it follows that nothing exists; for if neither the existent exists nor the non-existent nor both, and besides these no other alternative is conceived, nothing exists.

77. In the next place it must be shown that even if anything exists it is unknowable and inconceivable by man. If, says Gorgias, the things thought are not existent, the existent is not thought. And this is logical; for just as, if it is a property of the things thought to be white it would be a property of white things to be thought — so, if it is a property of things thought not to be existent, it will necessarily be a property of things existent not to be thought. 78. Consequently, this is a sound and consistent syllogism — “If the things thought are not existent, the existent is not thought.” But the things thought (for we must take them first) are not existent, as we shall establish; therefore the existent is not thought. And, in fact, that the things thought are not existent is plain; 79. for if the things thought are existent, all the things thought exist, and in the way, too, in which one has thought them. But this is contrary to sense. For if someone thinks of a man flying or of a chariot running over the sea, it does not follow at once that a man is flying or a chariot running over the sea. So that the things thought are not existent. 80. Furthermore, if the things thought are existent, the non-existent things will not be thought. For opposites are properties of opposites, and the non-existent is the opposite of the existent; and because of this, if “to be thought” is a property of the existent, “not to be thought” will most certainly be a property of the non-existent. But this is absurd; for Scylla and Chimaera and many non-existent things are thought. Therefore the existent is not thought. 81. And just as the things seen are called visible because of the fact that they are seen, and the audible termed audible because of the fact that they are heard, and we do not reject the visible things because they are not heard, nor dismiss the audible things because they are not seen (for each object ought to be judged by its own special sense and not by another), — so also the things thought will exist, even if they should not be viewed by the sight nor heard by the hearing, because they are perceived by their own proper criterion. 82. If, then, a man thinks that a chariot is running over the sea, even if he does not behold it he ought to believe that there exists a chariot running over the sea. But this is absurd; therefore the existent is not thought and apprehended.

83. And even if it should be apprehended, it is incommunicable to another person. For if the existent things are objects, externally existing, of vision and of hearing and of the senses in general, and of these the visible things are apprehensible by sight and the audible by hearing, and not conversely, — how, in this case, can these things be indicated to another person? 84. For the means by which we indicate is speech, and speech is not the veal and existent things; therefore we do not indicate to our neighbors the existent things but speech, which is other than the existing realities. Thus, just as the visible thing will not become audible, and vice versa, so too, since the existent subsists externally, it will not become our speech; 85. and not being speech it will not be made clear to another person.

Speech moreover, as he asserts, is formed from the impressions caused by external objects, that is to say the sensibles; for from the occurrence of flavor there is produced in us the speech uttered respecting this quality, and by the incidence of color speech respecting color. And if this be so, it is not speech that serves to reveal the external object, but the external object that proves to be explanatory of speech. 86. Moreover, it is not possible to assert that speech subsists in the same fashion as the visible and audible things, so that the subsisting and existent things can be indicated by it as by a thing subsisting and existent. For, says he, even if speech subsists, yet it differs from the rest of subsisting things, and the visible bodies differ very greatly from spoken words; for the visible object is perceptible by one sense-organ and speech by another. Therefore speech does not manifest most of the subsisting things, just as they themselves do not make plain one another’s nature.

87. Such, then, being the difficulties raised by Gorgias, if we go by them the criterion of truth is swept away; for there can be no criterion of that which neither exists nor can be known nor is naturally capable of being explained to another person.

As I said above, there have been not a few who have asserted that Metrodorus and Anaxarchus, and also Monimus, abolished the criterion — 88. Metrodorus because he said “We know nothing, nor do we even know the very fact that we know nothing”; and Anaxarchus and Monimus because they likened existing things to a scene-painting and supposed them to resemble the impressions experienced in sleep or madness.

89. Such, then, was the view in which all these men shared; but it is held that the Physicists, from Thales down, were the first to introduce the inquiry regarding the criterion. For when they had condemned sensation as being in many cases untrustworthy, they set up reason as the judge of the truth in existing things, and starting out from this they arranged their doctrines of principles and elements and the rest, the apprehension of which is gained by means of the faculty of reason. 90. Hence the greatest of the Physicists, Anaxagoras, in disparaging the senses on the ground of their weakness, says, “Owing to their infirmity we are unable to judge what is true.” And as an assurance of their lack of sureness he alleges the gradual change in colors; for if we were to take two colors, black and white, and pour some of the one into the other drop by drop, our sense of sight will be unable to distinguish the gradual alterations although they subsist as actual facts. 91. Asclepiades, too, is found using virtually the same argument in the First Book of his Concerning Wine-giving, where he is dealing with the pale and the dark — “For when these,” he says, “are mixed, the sense is unable to discern whether what subsists is a single and simple color or not.”

92. Anaxagoras, accordingly, declared that reason in general is the criterion. But the Pythagoreans declare that it is not reason in general but the reason which is attained from the sciences; even as Philolaus said that “It, being conversant with the nature of all things, possesses a certain kinship thereto, since it is the nature of like to be apprehended by like”:

Verily earth by earth we behold, and water by water,
Aether divine by aether, and fire the destructive by fire,
Love, moreover, by love, and hate by dolorous hatred.

93. And as Poseidonius says in his exposition of Plato’s Timaeus, “Just as light is apprehended by the luciform sense of sight, and sound by the aeriform sense of hearing, so also the nature of all things ought to be apprehended by its kindred reason.” But the principle of the structure of all things is number; wherefore also the reason that is judge of all things may be called “number,” seeing that it is not devoid of the potency thereof. 94. And by way of indicating this the Pythagoreans are wont at one time to declare that “All things are like unto number,” and at another time to swear the most natural of oaths in this form:

Nay, by the man I swear who bequeathed to our head the Tetraktys,
Fount containing the roots of Nature ever-enduring.

By “the man who bequeathed” they mean Pythagoras (for him they deified); and by “the Tetraktys” a certain number which, being composed of the four primary numbers, makes up the most perfect number, namely the Ten; for one plus two plus three plus four amount to ten. 95. And this number is the first Tetraktys, and it is termed the “fount of Nature ever-enduring” in so far as the whole Universe, according to them, is arranged according to harmony, and harmony is a system composed of three symphonies — that of the “By-Fours,” and that of the “By-Fives,” and that of the “By-Alls”; and the proportions of these three symphonies are found in the four numbers just mentioned — in the one and in the two and in the three and in the four. 96. For the “By-Fours” symphony consists in the “epitrite” (4 : 3) ratio, the “By-Fives” in the ratio 3 : 2, and the “By-Alls” in the ratio 2 : 1. Hence the number four being “epitrite” in relation to three (since it is composed of three plus a third part of three) comprises the symphony “By-Fours”; 97. and the number three, being one and a half times two (in that it comprises both the two and the half of the two), discloses the “By-Fives” symphony; and the four which is double of two, and the two double of one, are fitted to comprise the “By-Alls.” 98. Seeing, then, that the Tetraktys supplies the proportion of the symphonies mentioned, and the symphonies serve to make up the perfect harmony, and according to the perfect harmony all things are arranged, on this account they have described it as “the fount containing the roots of Nature ever-enduring.”

99. Again, they argue that it is according to the ratios of these four numbers that both body and the incorporeal are conceived — for it is by the flow of a point that we form a notion of a line, which is length without breadth, and by the flow of a line we conceive breadth, which is surface without depth, and by the flow of surface solid body is produced. 100. But over the point stands the monad which is indivisible, as is also the point, and over the line the number two; (and over the surface stands the number three) (for the line has come from somewhere to somewhere), that is to say (the movement) from one point to another, and from this again to a third; and over the solid body stands the number four; for if upon the top of three points we place a fourth, there is formed a pyramid, which is in fact the first form of a solid body. Thus it is reasonable to hold that the Tetraktys is the fount of universal Nature.

101. Again, everything apprehended by man is, they say, either body or incorporeal; but whether it be body or whether it be incorporeal, it is not apprehended apart from the conception of numbers, since, in the case of body, as it has three dimensions it involves the number three. 102. Moreover, of bodies some are composed of things joined together, like ships and cables and turrets, others of things unified, which are held together by a single mode of connection, like plants and animals, others of separate units, like choruses and armies and herds. But whether they consist of things joined or of things unified or of things separate, they contain numbers in so far as they are composed of a plurality of things. 103. And further, some bodies are substances with single qualities, others with numerous qualities, as is the apple; for it possesses a certain quality of color to the sight and of flavor to the taste and of odor to the smell and of smoothness to the touch; and these belong to the nature of numbers.

104. The same argument applies to the case of incorporeals also, seeing that time, which is incorporeal, is perceived by number, as is plain from the years and months and days and hours. So likewise are the point and line and surface and the rest of the things we were discussing a moment ago, when we traced back the notions of them to numbers.

105. The practice of ordinary life too, they assert, is in unison with the views thus stated, as is also the practice of the arts. For ordinary life judges each thing by criteria, and these are numerical standards. And certainly, if we abolish number, the cubit will be abolished, which consists of two half-cubits and six palms and twenty-four fingers, and the bushel will be abolished and the talent and the rest of the criteria; for all these, as composed of a plurality of elements, are at once species of number. 106. Hence all the other things, too, are bound up with number — loans, evidences, votes, contracts, times, periods. And in general, it is impossible to find anything in ordinary experience that does not participate in number.

And assuredly there is no art or craft that has been built up without proportion, and proportion is based on number; so that every art is built up by means of number. 107. Thus the Rhodians, it is said, asked Chares the architect how much money it would cost to construct the Colossus. And when he had named a figure, they asked again how much it would be if they wished to construct it twice that size. And when he asked double the sum, they gave it to him; but he, when he had spent the sum given on the first stages of the work and the preliminary expenses, slew himself. 108. And when he was dead the craftsmen became aware that he ought to have asked not double but eight times the sum, for he was bound to enlarge not only the length but also every other dimension of the structure. So that there exists in the plastic art, and likewise in painting, a certain proportion whereby unvarying resemblance is preserved. 109. And, to speak generally, every art is a system composed of apprehensions, and system is number. Hence it is a sound saying that “all things are like unto number,” — that is, like unto the reason that judges and is alun to the numbers which compose all things.

110. Such is the doctrine of the Pythagoreans. But Xenophanes, according to those who interpret him differently, when he says —

Yet, with respect to the gods and what I declare about all things.
No man has seen what is clear nor ever will any man know it,
Nay, for e’en should he chance to affirm what is really existent,
He himself knoweth it not; for all is swayed by opining, —

does not appear to be abolishing every apprehension, but only that which is cognitive and inerrant, while admitting that which is opinionative; for this is what the sentence “all is swayed by opining” indicates. So that according to him the opinionative reason — that is to say, the reason which holds to the probable but not to the certain — is the criterion.

111. But his friend Parmenides rejected the opinionative reason — I mean that which has weak conceptions, — and assumed as criterion the cognitive — that is, the inerrant — reason, as he also gave up belief in the senses. Thus in the opening of his work On Nature he writes in this fashion:

Far as the soul can aspire have the steeds that hurry me forward
Brought me, seeing that now on the far-famed road they have set me.
Road of the Daemon which all-whither leadeth the truth-witting mortal.
By that road was I drawn; for the fam’d steeds drew me by that road
Pulling the chariot amain; and damsels guided my going.
Glowing within its nave the axle sang like a reed-pipe —
Furnish’d on either side with a pair of wheels well-rounded —
Whenas the Sun-born damsels in haste proceeded to bring me
Into the sun-light, leaving behind them the chambers of Darkness,
When with their hands they had stript from their heads the mantles that veiled them.
There are the gates dividing the ways of Day-time and Night-time,
Gates which are holden around by a lintel and threshold of marble;
High in the air they stand and with doors immense are they furnish’d:
Justice, dealer of dooms, doth keep the keys which unlock them.
Her the damsels addressing with soft and flattering speeches
Artfully won her consent to push the bolted cross-bar
Back from the gates; and whenas the gates swung wide in the door-way,
Vast was the chasm they caused as they set the hinges revolving.
Each in its socket on either side, — of bronze were the hinges.
Fitted with bolts and with nails of bronze. So then through the gateway
Straight did the damsels drive their horses and car on the high-road,
Graciously then did the goddess receive me, taking my right hand
Clasp’d in her own, and this was the speech wherewith she address’d me;
“Youth, who hast for thy fellows immortal chariot-drivers.
Now thou hast come to our halls, both thou and the horses that speed thee,
Hail! since the doom was no evil doom that prompted thy journey
Hither (for far does it lie from the ways that are trodden of mortals),
Nay, but justice and right. Thy task is now to discover
Truth’s unshakable heart, which fitly induces persuasion.
Mortals’ opinions, to boot, which are empty of true conviction.
Nay, but I bid thee restrain thy mind from this path of inquiry,
Nor let habit oft-tried along this pathway impel thee,
Eye unobservant to ply and tongue and echoing ear-drum.
But use reason to judge the oft-tried proof which refutes them
Utter’d by me. For the heart when alone still misseth the pathway.”

112. In these verses Parmenides means that the steeds which take him along are the irrational impulses and appetites of the soul, and that “the far-famed road of the Daemon” they travel is that of investigation according to philosophical reason, which reason, like a Divine conductor, points the way to the knowledge of all things. And the damsels that lead him on are the senses, the reports of which he indicates in riddling wise by saying “It was furnish’d with a pair of well-rounded wheels,” that is with those of the ears, by means of which they receive sound; 113. and the acts of vision he calls “Sun-born damsels,” which “leave the chambers of Darkness” and “thrust into the light” because it is impossible to make use of them without light. And the approach to “Justice, dealer of dooms,” which holds “the keys wluch unlock them,” is that to intelligence which holds safe the apprehensions of things. 114. And she, after welcoming him, promises to teach him two things — “Truth’s unshakable heart which fitly induces persuasion,” which is the immovable seat of knowledge, and secondly “mortal men’s opinions which are empty of true conviction,” that is to say everything which consists in opinion because all such things are unsure. And at the end he again makes it clear that one must not pay attention to the senses but to the reason; for he says “Let not habit oft-tried along this pathway impel thee, Eye unobservant to ply and tongue and echoing ear-drum. But use reason to judge the oft-tried proof which refutes them Utter’d by me.”

This man himself, then, as is plain from his statements, proclaimed the cognitive reason to be the standard of truth in things existing and gave up paying attention to the senses. 115. But Empedocles of Acragas, according to those who seem to interpret him most simply, offers us six criteria of truth. For having laid down two efficient principles of all things, Love and Strife, and having at the same time designated as material principles the four — earth and water and air and fire, — he declared that all these are criteria. 116. For, as I said before,” there is an old opinion, dating from far back, which is prevalent among the Physicists to the effect that like things are cognitive of like; Democritus too seems to have brought a confirmation of this opinion, and Plato also seems to have introduced it in his Timaeus. 117. But, on the one hand, Democritus bases his argument on both animate and inanimate things. “For animals,” he says, “flock together with animals of a like species, as doves with doves and cranes wdth cranes, and so too all other irrational animals.” And it is the same with things inanimate, as one may see in the case of seeds that are being winnowed and in the case of pebbles along the beaches; for in the one case, by the whirling of the sieve lentils are ranged separately with lentils, barley with barley, and wheat with wheat; 118. and in the other case, owing to the motion of the waves, the oblong pebbles are pushed into the same place as the oblong, and the round as the round, as though the similarity in things had a certain force of attraction for them.

119. So says Democritus. But Plato, on the other hand, in his Timaeus, uses the same kind of proof to establish the fact that the soul is incorporeal. For if, says he, the sense of sight as perceiving light is thereby light-like, and hearing as discerning smitten air, which is sound, is thereby seen to be air-like, and smell as recognizing vapors is indisputably vapor-like, and taste as recognizing flavors flavor-like, then the soul also must of necessity be incorporeal as perceiving the incorporeal Ideas, those in numbers, for instance, and those in the limits of bodies.

120. Such, then, being the opinion held by the earlier thinkers, Empedocles also seems to be carried away by it, and to assert that as the principles which compose the Universe are six, so the criteria are equal to them in number, inasmuch as he writes —

121. Verily earth by earth we behold, and water by water,
Aether divine by aether, and fire the destructive by fire,
Love, moreover, by love, and hate by dolorous hatred.

For thereby he indicates that we apprehend earth by participation in earth and water by partaking in water, and air by participation in air, and similarly in the case of fire. 122. But there have been others who have asserted that according to Empedocles the criterion of truth is not the senses but right reason, and of right reason one sort is divine, the other human. And of these the divine sort is inexpressible, but the human sort expressible. 123. As regards the fact that the judgment of truth does not reside in the senses he speaks thus;

Straiten’d in sooth are the powers which lie dispersed in our members,
Many the plagues which thwart them, and blunt the edge of our thinking.
Short is the span of unlivable life beholden by mortals,
Swift is their doom, as, whirl’d like smoke, they are lifted and vanish,
Each persuaded only of what himself has encounter’d,
Carried about all ways; yet each keeps foolishly boasting
How he has found the Whole. So far from human perception
Lie these things, out of reach of the sense of vision or hearing.
And of the grasp of the mind.

124. And as regards the fact that truth is not altogether unattainable, but is really attainable so far as the reason of man can reach, he makes this clear when to the foregoing verses he adds this:

  But since thou hast hither retreated.
Thou shalt be told not more than mortal wit has discovered.

And in what follows, after rebuking those who profess they know more, he tries to establish that the thing perceived by each sense is trustwortliy, as the reason is in control of them, although he had previously run down the evidence supplied by them. 125. For he says:

Nay, ye gods, avert from my tongue the madness of those men.
And make flow pure rivers of speech from lips that are holy.
There, too, now I beseech, O Muse white-armed and virgin,
Courted by many; thy car well-reined from Piety's dwelling
Drive, and bring to me all that is meet to be told unto mortals;
Nor shall thou ever he forced to receive from hands that are mortal
Flowers of glorious honor for uttering more than is holy
Over-bold, and to gain thus a seat on the summits of wisdom.
Come, then, with each of thy powers discern each manifest object,
Putting no greater trust in the sight of the eye than in hearing.
Nor in the echoing car above the clear witness of tongue’s taste;
Nor from the rest of the parts wherein are the channels of knowledge
Hold thou back thy trust, but mark each manifestation.

126. Such, then, are the views of Empedocles. And Heracleitus — since he again supposed that man is furnished with two organs for gaining knowledge of truth, namely sensation and reason — held, like the Physicists mentioned above, that of these organs sensation is untrustworthy, and assumes reason as the criterion. Sensation he convicts by saying expressly, “Ill witnesses for men are eyes and ears when they have barbarous souls,” which is equivalent to saying “To trust in the irrational senses is the part of barbarous souls.” 127. And he declares reason to be the judge of truth — not, however, any and every kind of reason, but that which is “common” and divine. But what this is must be explained concisely. It is a favorite tenet of the Physicist that “What encompasses us is rational and intelligent.” 128. And, long before, Homer had expressed this when he says:

As is the day which upon them is brought by the sire immortal,
So are the minds of mortal men,

Archilochus, too, says that the thoughts men think are “Such as the day which Zeus doth bring about.” And the same thing has also been said by Euripides:

To see and know thee, who thou art, O Zeus,
Doth baffle wit! Art thou Necessity
Of Nature? Or mankind’s Intelligence?
Howbeit, I invoke thee.

129. It is then by drawing in by inspiration this divine reason that, according to Heracleitus, we become intelligent, and while forgetful during sleep become sensible again on waking. For during sleep, as the passages of the senses are closed, the mind wthin us is cut off from its natural union with the enveloping substance — only the connection by way of respiration, like that of a root, being preserved — and being thus parted it loses the power of memory which it previously possessed; 130. but on waking it stretches out again through the passages of sense, as it were through windows, and by junction with the enveloping substance is invested with the power of reason. Thus, just as cinders when put close to the fire are altered and become ignited, but are extinguished when put at a distance, in like manner the fraction of the enveloping substance that stays as a stranger in our bodies becomes well-nigh irrational owing to the separation, but through its union by means of its numerous passages it is made like in kind to the Whole. 131. Heracleitus, then, asserts that this common and divine reason, by participation in which we become rational, is the criterion of truth. Hence, that which appears to all in common is trustworthy (for it is perceived by the common and divine reason), but that which affects one person alone is, for the opposite cause, untrustworthy. 132. Thus the man above-mentioned declares at the beginning of his work On Nature, pointing in a fashion to the enveloping substance —

“Of this existent Reason men are without comprehension, both before they have heard of it and when they have heard of it for the first time; for they are like unto men without experience of the things which happen according to this reason when they experience such words and deeds as I relate, when I define each thing according to its nature and declare what its condition is. But as to the rest of mankind, all the things which they do when awake escape their notice, even as they forget all when asleep.” 133. For having in these words expressly argued that we do and think everything through participation in the divine reason, after proceeding a little further, he adds, “Wherefore one must follow the comprehensive,” that is the “common” (for “comprehensive” means “common”); “and though reason is comprehensive most people live as though they possessed a private intelligence of their own.” And this is nothing else than an explanation of the mode of arrangement of the Whole. Therefore in so far as we share in the memory of that reason we say what is true, but whenever we utter our own private thoughts, we lie. 134. So here and in these words he most expressly declares that the common reason is the criterion, and that the things which appear in common are trustworthy as being judged by the common reason, whereas those which appear privately to each man are false.

135. Such, then, is the attitude of Heracleitus. And Democritus in some places abolishes the things that appear to the senses and asserts that none of them appears in truth but only in opinion, the true fact in things existent being the existence of atoms and void; for “By convention,” he says, “is sweet, by convention bitter, by convention hot, by conveirtion cold, by convention color; but by verity atoms and void.” (This means: Sensible objects are conventionally assumed and opined to exist, but they do not truly exist, but only the atoms and the void.) 136. And in his Confirmations, although he had promised to ascribe the confirmatory evidence to the senses, yet none the less he is found condemning them. For he says: “But we in reality comprehend nothing invariable, but what shifts about according to the disposition of the body and of the things which enter into it and the things which oppose it.” And again he says: “Now verily that we do not comprehend what the nature of each thing is or is not, has been oft-times made plain.” 137. And in his book Concerning Forms he says, “Man must learn by this rule that he is divorced from verity”; and again, “This argument also makes plain that we know nothing verily about anything, but each man’s opinion is due to influx”; and yet again, “It will, however, be plain that it is impracticable to learn the veritable nature of each thing.”

Now in these passages he almost rejects apprehension altogether, although it is the senses only that he specially attacks. 138. But in his “Canons” he says that there are two kinds of knowledge, one by means of the senses, the other by means of the intelligence; and of these he calls that by means of the intelligence “genuine,” ascribing to it trustworthiness in the judgment of truth, but that by means of the senses he terms “bastard,” denying it inerrancy in the distinguishing of what is true. 139. He expressly declares — “Of knowledge there are two forms, the genuine and the bastard; and to the bastard belong all these — sight, hearing, smell, taste, touch; but the other form is distinct from this and genuine.” Then, while thus preferring the genuine to the bastard, he proceeds: “Whenever the bastard kind is unable any longer to see what has become too small, or to hear or smell or taste or perceive it by touch, (one must have recourse to) another and finer (instrument).” Thus, according to this man also, reason is the criterion, and he calls it “genuine knowledge.” 140. But Diotimus used to say that according to Democritus there are three criteria — namely, the criterion of the apprehension of things non-evident, which is the things apparent; for, as Anaxagoras says (and Democritus commends him for it), the things apparent are the vision of the things non-evident; and the criterion of investigation, which is the conception — “for in every case, my child, the one starting-point is to know what the subject of investigation is”; and the criterion of choice and aversion, which is the affections — for that which we feel is congenial to us is choiceworthy, but that which we feel is alien is to be regarded with aversion.

Such, then, was the account given by the old philosophers concerning the criterion of truth. 141. Next let us treat of those who came after the Physicists.

Plato, then, in his Timaeus, after dividing things into intelligibles and sensibles and stating that the intelligibles are apprehensible by reason whereas the sensibles are objects of opinion, plainly specified reason as the criterion of the knowledge of things, though he included along with it the clear evidence of sense. 142. These are his words; “What is that which is Existent always and has no Becoming? And what is that which is Becoming always and never is Existent ? Now the one of these is apprehensible by thought with the aid of reasoning, but the other by opinion with the aid of sensation.” 143. And the Platonists say that the reason which embraces both sensible evidence and truth is termed by him “comprehensive reason.” For in the act of judging truth the reason must set out from the sensible evidence, if it be so that the judgment of things true is effected by means of things evident.

But this evidence is not self-sufficient for knowledge of the true; for if a thing appears evidently, it does not therefore exist truly; but there must also be present an instrument which judges what thing merely appears and what, in addition to appearing, also subsists in truth — that is to say, reason. 144. Thus it will be necessary for both to come together — both the sensible evidence as forming the starting-point for the reason in its judging of the truth, and the reason itself for estimating the evidence. Yet for getting in touch with the evidence and estimating the truth it contains, the reason in turn needs sensation as a colleague; for it is through it that the reason receives the presentation and produces the thought and the knowledge of what is true, so that it really is “comprehensive” both of evidence and of truth, which is equivalent to being “apprehensive.”

145. Such, then, was the view of Plato. But Speusippus declared that, since some things are sensible, others intelligible, the cognitive reason is the criterion of things intelligible and the cognitive sense of things sensible. And cognitive sense he conceived as being that which shares in rational truth. 146. For just as the fingers of the flute-player or harper possess an artistic activity, which, however, is not primarily brought to perfection by the fingers themselves but is fully developed as a result of joint practice under the guidance of reasoning, — and just as the sense of the musician possesses an activity capable of grasping the harmomous and the non-harmonious, this activity, however, not being self-produced but an acquisition due to reasoning, — so also the cognitive sense naturally derives from the reason the cognitive experience in which it shares, and which leads to unerring discrimination of subsisting objects.

147. But Xenocrates says that there are three forms of existence, the sensible, the intelligible, and the composite and opinable; and of these the sensible is that which exists within the Heaven, and the intelligible that which belongs to all things outside the Heaven, and the opinable and composite that of the Heaven itself; for it is visible by sense but intelligible by means of astronomy. 148. This, then, being the condition of things, he declared that the criterion of the existence which is outside the Heaven and intelligible is knowledge; and the criterion of that which is within the Heaven and sensible is sense; and the criterion of the mixed kind is opinion. And of these generally the criterion afforded by the cognitive reason is both firm and true, and that by sense is true indeed but not so true as that by the cognitive reason, while the composite kind shares in both truth and falsehood; for opinion is partly true and partly false. 149. Hence, too, we have by tradition three Fates — Atropos, the Fate of things intelligible, she being unchangeable, and Clotho of things sensible, and Lachesis of things opinable.

150. Arcesilaus did not, to begin with, lay down any definite criterion, and those who are thought to have laid one down produced it by way of counter-blast to that of the Stoics. 151. For the latter assert that there are three criteria — knowledge and opinion and, set midway between these two, apprehension; and of these knowledge is the unerring and firm apprehension which is unalterable by reason, and opinion is weak and false assent, and apprehension is intermediate between these, being assent to an apprehensive presentation; 152. and an apprehensive presentation, according to them, is one which is true and of such a kind as to be incapable of becoming false. And they say that, of these, knowledge subsists only in the wise, and opinion only in the fools, but apprehension is shared alike by both, and it is the criterion of truth. 153. It was these statements of the Stoics that Arcesilaus controverted by proving that apprehension is not a criterion intermediate between knowledge and opinion. For that which they call “apprehension” and “assent to an apprehensive presentation” occurs either in a wise man or in a fool. But if it occurs in a wise man, it is knowledge, and if in a fool, opinion, and nothing else is acquired besides these two save a mere name. 154. And if apprehension is in fact assent to an apprehensive presentation, it is non-existent — firstly, because assent is not relative to presentation but to reason (for assents are given to judgments), and secondly, because no true presentation is found to be of such a kind as to be incapable of proving false, as is shown by many and various instances. 155. But if the apprehensive presentation does not exist, neither will apprehension come into existence, for it was assent to an apprehensive presentation. And if apprehension does not exist, all things will be non-apprehensible. And if all things are non-apprehensible, it will follow, even according to the Stoics, that the wise man suspends judgment. Let us consider the matter thus: 156. — Since all things are non-apprehensible owing to the non-existence of the Stoic criterion, if the wise man shall assent the wise man will opine; for when nothing is apprehensible, if he assents to anything he will be assenting to what is non-apprehensible, and assent to the non-apprehensible is opinion. 157. So that if the wise man is in the class of assenters, the wise man will be in the class of those who opine. But the wise man, to be sure, is not in the class of those who opine (for, according to them, opinion is a mark of folly and a cause of sins); therefore the wise man is not in the class of assenters. And if this be so, he will necessarily refuse assent in all cases. But to refuse assent is nothing else than to suspend judgment; therefore the wise man will in all cases suspend judgment. 158. But inasmuch as it was necessary, in the next place, to investigate also the conduct of life, which cannot, naturally, be directed without a criterion, upon which happiness — that is, the end of life — depends for its assurance, Arcesilaus asserts that he who suspends judgment about everything will regulate his inclinations and aversions and his actions in general by the rule of “the reasonable,” and by proceeding in accordance with this criterion he will act rightly; for happiness is attained by means of wisdom, and wisdom consists in right actions, and the right action is that which, when performed, possesses a reasonable justification. He, therefore, who attends to “the reasonable” will act rightly and be happy.

159. Such was the doctrine of Arcesilaus. Carneades arrayed his arguments concerning the criterion not only against the Stoics but against all his predecessors. In fact his first argument, aimed at all alike, is that by which he establishes that there is absolutely no criterion of truth — neither reason, nor sense, nor presentation, nor anything else that exists; for these things, one and all, play us false. 160. Second comes the argument by which he shows that even if a criterion exists, it does not subsist apart from the affection produced by the evidence of sense. For since the living creature differs from lifeless things by its faculty of sense, it will certainly become perceptive both of itself and of external things by means of this faculty. But when the sense is unmoved and unaffected and undisturbed, neither is it sense nor perceptive of anything; 161. but when it is disturbed and somehow affected owing to the impact of things evident, then it indicates the objects. Therefore the criterion must be sought in the affection of the soul caused by the sensible evidence. And this affection must be indicative both of itself and of the appearance which caused it, which affection is nothing else than the presentation. 162. Hence we must say that the presentation is an affection of the living creature capable of presenting both itself and the other object. Thus for example, says Antiochus, when we have looked at an object we have our sense of sight in a certain condition, and not in the same condition as that in which we had it before we looked; and owing to such an alteration we perceive, in fact, two things, one the alteration itself, which is the presentation, and, secondly, that which produced the alteration, which is the visible object. And similarly in the case of the other senses. 163. So then, just as light shows both itself and all things within it, so also presentation, which is the primary factor in the cognition of the living creature, must, like light, both reveal itself and be indicative of the evident object which produced it. But since it does not always indicate the true object, but often deceives and, like bad messengers, misreports those who dispatched it, it has necessarily resulted that we cannot admit every presentation as a criterion of truth, but — if any — only that which is true. 164. So then, once more, since there is no true presentation of such a kind that it cannot be false, but a false presentation is found to exist exactly resembling every apparently true presentation, the criterion will consist of a presentation which contains the true and the false alike. But the presentation which contains them both is not apprehensive, and not being apprehensive, it will not be a criterion. 165. And if no presentation capable of judging exists, neither will reason be a criterion; for it is derived from presentation. And naturally so; for that which is judged must fost be presented, and nothing can be presented without sense which is irrational. Therefore neither irrational sense nor reason is the criterion.

166. These were the arguments which Carneades set forth in detail, in his controversy with the other philosophers, to prove the non-existence of the criterion; yet as he, too, himself requires a criterion for the conduct of life and for the attainment of happiness, he is practically compelled on his own account to frame a theory about it, and to adopt both the probable presentation and that which is at once probable and irreversible and tested. 167. What the distinction is between these must be briefly indicated. The presentation, then, is a presentation of something — of that, for instance, from which it comes and of that in which it occurs; that from which it comes being, say, the externally existent sensible object, and that in which it occurs, say, a man. 168. And, such being its nature, it will have two aspects, one in its relation to the object presented, the second in its relation to the subject experiencing the presentation. Now in regard to its aspect in relation to the object presented it is either true or false — true when it is in accord with the object presented, but false when it is not in accord. 169. But in regard to its aspect in relation to the subject experiencing the presentation, the one kind of presentation is apparently true, the other apparently false; and of these the apparently true is termed by the Academics “emphasis” and probability and probable presentation, while the not apparently true is denominated “ap-emphasis” and unconvincing and improbable presentation; for neither that which itself appears false, nor that which though true does not appear so to us, is naturally convincing to us. 170. And of these presentations that which is evidently false, or not apparently true, is to be ruled out and is not a criterion whether (it be derived from a non-existent object or) from an object which exists, but not in accord with that object and not representing the actual object — such as was the presentation derived from Electra which Orestes experienced, when he supposed her to be one of the Furies and cried out —

Avaunt! For of my Furies thou art one.

171.And of the apparently true kind of presentation, one sort is obscure — the sort, for instance, that is found in the case of those who have a perception that is confused and not distinct owing to the smallness of the object viewed or owing to the extent of the interval or even owing to the weakness of the sense of sight, — while the other sort, in addition to being apparently true, possesses this appearance of truth to an intense degree. 172. And of these, again, the presentation which is obscure and vague will not be a criterion; for because of its not indicating clearly either itself or that which caused it, it is not of such a nature as to persuade us or to induce us to assent. 173. But that which appears true, and appears so vividly, is the criterion of truth according to the School of Carneades. And, being the criterion, it has a large extension, and when extended one presentation reveals itself as more probable and more vivid than another. 174. Probability, in the present instance, is used in three senses — in the first, of that which both is and appears true; in the second, of that which is really false but appears true; in the third, of that which is at once both true and false. Hence the criterion will be the apparently true presentation, which the Academics called “probable”; 175. but sometimes the impression it makes is actually false, so that we are compelled at times to make use of the presentation which is at once both true and false. But the rare occurrence of this kind — the kind I mean which imitates the truth — should not make us distrust the kind which “as a general rule” reports truly; for the fact is that both our judgments and our actions are regulated by the standard of “the general rule.”

176. Such then is the first and general criterion according to Carneades. But since no presentation is ever simple in form but, like links in a chain, one hangs from another, we have to add, as a second criterion, the presentation which is at once both probable and “irreversible.” For example, he who receives the presentation of a man necessarily receives the presentation both of his personal qualities and of the external conditions — 177. of his personal qualities, such as color, size, shape, motion, speech, dress, foot-gear; and of the external conditions, such as air, light, day, heaven, earth, friends, and all the rest. So whenever none of these presentations disturbs our faith by appearing false, but all with one accord appear true, our belief is the greater. 178. For we believe that this man is Socrates from the fact that he possesses all his customary qualities — color, size, shape, converse, coat, and his position in a place where there is no one exactly like him. 179. And just as some doctors do not deduce that it is a true case of fever from one symptom only — such as too quick a pulse or a very high temperature — but from a concurrence, such as that of a high temperature with a rapid pulse and ulcerous joints and flushing and thirst and analogous symptoms; so also the Academic forms his judgment of truth by the concurrence of presentations, and when none of the presentations in the concurrence provokes in him a suspicion of its falsity he asserts that the impression is true. 180. And that the “irreversible” presentation is a concurrence capable of implanting belief is plain from the case of Menelaus; for when he had left behind him on the ship the wraith of Helen — which he had brought with him from Troy, thinking it to be the true Helen — and had landed on the island of Pharos, he beheld the true Helen, but though he received from her a true presentation, yet he did not believe that presentation owing to his mind being warped by that other impression from which he derived the knowledge that he had left Helen behind in the ship. 181. Such then is the “irreversible” presentation; and it too seems to possess extension inasmuch as one is found to be more irreversible than another.

Still more trustworthy than the irreversible presentation and supremely perfect is that which creates judgment; for it, in addition to being irreversible, is also “tested.” 182. What the distinctive feature of this presentation is we must next explain. Now in the case of the irreversible presentation it is merely required that none of the presentations in the concurrence should disturb ns by a suspicion of its falsity but all should be apparently true and not improbable; but in the case of the concurrence which involves the “tested” presentation, we scrutinize attentively each of the presentations in the concurrence, — just as the practice is at assembly-meetings, when the People makes inquiry about each of those who desire to be magistrates or judges, to see whether he is worthy to be entrusted with the magistracy or the judgeship. 183. Thus, for example, as there are present at the scat of judgment both the subject that judges and the object that is being judged and the medium through which judgment is effected, and distance and interval, place, time, mood, disposition, activity, we judge the distinctive character of each of these factors — as regards the subject judging, whether its vision be not dimmed (for vision of that Icind is unfitted for judging): and as regards the object judged, whether it be not excessively small; and as regards the medium through which the judgment is effected, whether the atmosphere be not dark; and as to distance, whether it be not excessively great; and as to interval, whether it be not too short; and as to place, whether it be not immense; and as to time, whether it be not brief; and as to disposition, whether it is not found to be insane; and as to activity, whether it be not unacceptable.

184. For all these factors together form the criterion — namely, the probable presentation, and that which is at once both probable and irreversible, and besides these that which is at once probable and irreversible and tested. And it is because of this that, just as in ordinary life when we are investigating a small matter we question a single witness, but in a greater matter several, and when the matter investigated is still more important we cross-question each of the witnesses on the testimony of the others, — so likewise, says Carneades, in trivial matters we employ as criterion only the probable presentation, but in greater matters the irreversible, and in matters which contribute to happiness the tested presentation. 185. Moreover, just as they adopt, they say, a different presentation to suit different cases, so also in different circumstances they do not cling to the same presentation. For they declare that they attend to the immediately probable in cases where the circumstances do not afford time for an accurate consideration of the matter. 186. A man, for example, is being pursued by enemies, and coming to a ditch he receives a presentation which suggests that there, too, enemies are lying in wait for him; then being carried away by this presentation, as a probability, he turns aside and avoids the ditch, being led by the probability of the presentation, before he has exactly ascertained whether or not there really is an ambush of the enemy at the spot. 187. But they follow the probable and tested presentation in cases where time is afforded for using their judgment on the object presented with deliberation and thorough examination. For example, on seeing a coil of rope in an unlighted room a man jumps over it, conceiving it for the moment to be a snake, but turning back afterwards he inquires into the truth, and on finding it motionless he is already inclined to think that it is not a snake, 188. but as he reckons, all the same, that snakes too are motionless at times when numbed by winter’s frost, he prods at the coiled mass with a stick, and then, after thus testing the presentation received, he assents to the fact that it is false to suppose that the body presented to him is a snake. And once again, as I said before, when we see a thing very plainly we assent to its being true when we have previously proved by testing that we have our senses in good order, and that we see it when wide awake and not asleep, and that there exists at the same time a clear atmosphere and a moderate distance and immobility on the part of the object perceived, 189. so that because of these conditions the presentation is trustworthy, we having had sufficient time for the scrutiny of the facts observed at the seat of the presentation. The same account is to be given of the irreversible presentation as well; of controverting it, as was said in the case of Menelaus.

190. But now that we have set forth the Academic doctrine from Plato down, it is not, I fancy, out of place to deal also with the Cyrenaic position; for the Cyrenaic School appears to have arisen from the teaching of Socrates, from which also arose the School of Plato and his successors. 191. The Cyrenaics, then, assert that the affections are the criteria, and that they alone are apprehended and are infallible, but of the things that have caused the affections none is apprehensible or infallible. For, say they, that we feel whiteness or sweetness is a thing we can state infallibly and incontrovertibly; but that the objet productive of the affection is white or is sweet it is impossible to affirm. 192. For it is likely that a man might be made to feel whiteness by what is not white and sweetness by what is not sweet. For just as the sufferer from vertigo or jaundice receives a yelloulsh impression from everything, and the sufferer from ophthalmia sees things red, and he who pushes his eye sideways gets as it were a double impression, and the madman beholds a “doubled Thebes,” and sees the image of a doubled sun, 193. and in all these cases, while it is true that they have this particular affection (have, for instance, a feeling of yellowness or of flushing or of douhleness), yet it is supposed to be false to say that the object which impresses them is yellow or reddish or double, — so also it is most reasonable to hold that we are not able to perceive anything more than our own immediate affections. Hence we must posit as apparent either the affections or the things productive of the affections. 194. And if we assert that the affections are apparent, we must declare that all apparent things are true and apprehensible; but if we term the things productive of the affections apparent, all the apparent things are false and all non-apprehensible. For the affection which takes place in us reveals to us nothing more than itself. Hence too (if one must speak the truth) our affection alone is apparent to us, and the external object which is productive of the affection, though it is perhaps existent, is not apparent to us. 195. And in this way, whereas we are all unerring about our own affections, as regards the external real object we all err; and whereas the former are apprehensible, the latter is non-apprehensible, the soul being far too weak to discern it, owing to the positions, the intervals, the motions, the changes, and a host of other causes. Hence they assert that there exists no criterion common to mankind, but common names are given to the objects. 196. For all in common use the terms “white” or “sweet,” but they do not possess in common anything white or sweet. For each man perceives his own particular affection, but as to whether this affection is produced by a white object both in himself and in his neighbor, neither the man himself can affirm without experiencing his neighbor’s affection, nor can the neighbor without experiencing that of the man. 197. But since there is no affection which is common to us all, it is rash to assert that the thing which appears of this kind to me appears to be of this kind to the man next me as well. For possibly while I am so constituted as to get a feeling of whiteness from that which impresses me from without, the other man has his sense so constructed as to be otherwise affected. So what appears to us is not always common to all. 198. And that we do not, in fact, receive identical impressions, owing to the different constructions of our senses, is obvious in the case of sufferers from jaundice and ophthalmia and of those who are in a normal condition. For just as some have an affection of yellow, others of crimson, others of white, caused by the same object, so also it is likely that those who are in a normal condition will not receive identical impressions from the same objects owing to the differing construction of their senses, but the grey-eyed one kind, the blue-eyed another, and the black-eyed a different kind. So that we give to things names that are common, but the affections we have are peculiar to each of us.

199. Corresponding to the statements made by these men regarding criteria are, as it seems, their statements regarding Ends. For the affections reach even as far as the Ends. For of the affections some are pleasant, some painful, some intermediate; and the painful, they say, are evils, whereof the End is pain, and the pleasant are goods, whereof the infallible End is pleasure, and the intermediate are neither goods nor evils, whereof the End is neither good nor evil, this being an affection intermediate between pleasure and pain. 200. Of all things, therefore, that exist the affections are the criteria and Ends, and we live, they say, by following these, paying attention to evidence and to approval — to evidence in respect of the other affections, but to approval in respect of pleasure.

Such are the views of the Cyrenaics, who thus, as compared with the Platonists, restricted the nature of the criterion more closely; for whereas the latter made it to be a compound of both evidence and reason, the former confine it to evidences and affections.

201. Not far removed, it would seem, from the opinion of the Cyrenaics are those who declare the senses to be the criterion of truth. For that there have been some who have maintained this view has been made clear by Antiochus the Academic, when in the Second Book of his Canonics he writes thus: “But a certain other man, second to none in the art of medicine and a student also of philosophy, believed that the sensations are really and truly perceptions, and that we apprehend nothing at all by the reason.” 202. For in these words Antiochus seems to be stating the view mentioned above and to be hinting at Asclepiades the physician, who abolished the “ruling principle,” and who lived at the same time as himself. But of this man’s attitude we have given a more circumstantial and particular account in our Medical Memoirs, so that there is no need to repeat the story.

203. Epicurus asserts that there are two things which are correlative — namely, presentation and opinion, — of which the presentation, which he also terms “evidence,” is constantly true. For just as the primary affections — that is to say plea, sure and pain — come about owing to certain agents and in accord with those agents (pleasure, for instance, from things pleasant and pain from things painful), and it is impossible for the agent productive of pleasure ever to be not pleasant, or that which is creative of pain to be not painful, but of necessity that which gives pleasure must in its real nature be pleasant and that which gives pain painful, — so also in the case of the presentations, which are affections of ours, the agent which is productive of each of them is always entirely presented, and, as being presented, it is incapable of being productive of the presentation without being in very truth such as it appears.

204. In the case, also, of the particular sensations one must argue in like manner. Thus the visible object not only appears visible but actually is such as it appears; and the audible object not only appears audible but also really is so in truth; and so on with the rest. The presentations, then, which occur are all true. And reasonably so; 205. for, say the Epicureans, if a presentation is termed “true” whenever it arises from a real object and in accord with that real object, and every presentation arises from a real presented object and in accord with that object, then every presentation is necessarily true. 206. But some are deceived by the difference in the presentations which seem to be derived from the same object of sense — for instance a visible object — because of which the object appears of another color or of another shape, or altered in some other way. For they have supposed that, of the presentations thus differing and conflicting, one kind must be true and the kind derived from an opposite source false. But this is silly, and the notion of men who do not fully consider the real nature of things. 207. Thus — to base our argument on objects of sight — it is not the whole of the solid body that is seen, but the color of the solid body. And of the color, one part is on the solid (as in the case of objects seen close at hand or at a moderate distance), and another part outside the solid and existent in the spaces adjacent (as in the case of things viewed at a great distance). And this being altered in the intervening space and receiving a special shape of its own gives rise to a presentation which is similar to its own real nature. 208. For just as neither the sound in the brass instrument that is struck, nor the sound in the mouth of the man who shouts, is heard but the sound which strikes on our own sense; and just as no one says that he who hears a faint sound from a distance hears falsely because the same man, on coining close, perceives it as loud; — just so I should decline to say that the eyesight is false because at a long distance it sees the tower as small and round but from close at hand as large and square, 209. but I should say rather that it reports truly because, when the object of sense appears to it small and of a certain shape, it really is small and of a certain shape, as the limits belonging to the images are rubbed away by their passage through the air; and again when ih appears large and of a different shape it is correspondingly large and of a different shape, since it is no longer the same object that is both at once. For it is left to the distorted opinion to imagine that the presented object seen from close at hand is the same as that seen from a distance. 210. But it is the special function of sense to perceive only that which is present and affects it — color, for instance — but not to discern that the object here is one thing and the object there another. Hence, for these reasons, presentations are all true, (but opinions are not all true) but possess certain distinctions. For some of them are true, others false, since they are judgments of ours concerning the presentations, and we judge sometimes rightly and sometimes wrongly either because of adding and attaching something to the presentations or because of subtracting something from them and, in either case, falsifying the irrational sensation. 211. Of opinions, then, according to Epicurus, some are true, others false; the true being those which testify for, and not against, the evidence of sense, and the false those which testify against, and not for, that evidence. 212. And confirmatory testimony is apprehension by means of evidence that the thing opined is of such a sort as it was opined to be — as when, for example, on the approach of Plato from afar I guess and opine, because of the distance, that it is Plato, and when he has drawn near the fact that he is Plato is further testified — the distance being reduced — and is confirmed by actual evidence of sense. 213. And lack of contrary testimony is the congruity of the supposed and opined non-evident object with the apparent — as when Epicurus says that void exists, which is a thing non-evident, and this is supported by an obvious fact, namely motion; for if void does not exist, neither ought motion to exist, the moving body having no place into which to pass over, owing to the fact that all things are full and close-packed; 214. so that, since motion exists, the apparent does not give testimony that contradicts the opined non-evident fact. But contrary testimony is something which conflicts with lack of contrary testimony; for it is the joint-refutation of the apparent fact and the supposed non-evident fact, — as when, for instance, the Stoic says that void does not exist, asserting something non-evident, and jointly with this supposed fact the apparent fact, by which I mean motion, is necessarily refuted; for if void does not exist, of necessity motion does not exist either, according to the argument we have already set out. 215. So likewise lack of confirmatory testimony is opposed to confirmatory testimony; for it is the impression due to sense-evidence that the thing opined is not such as it was opined to be; as, for instance, when someone is approaching from afar and we guess, because of the distance, that it is Plato, but when the distance is reduced we learn by evidence that it is not Plato. Such an occurrence is lack of confirmatory testimony; for the thing opined was not confirmed by the apparent fact. 216. Hence confirmatory testimony and lack of contrary testimony form a criterion of the truth of a thing, but lack of confirmafory testimony and contradictory testimony of its falsehood. And the base and foundation of all is the evidence of sense.

217. Such, then, is the criterion according to Epicurus. But Arisfotle and Theophrastus and the Peripatetics in general, seeing that the nature of things falls into two main classes, — since, as I said before, some things are sensible, others intelligible, — themselves also admit a twofold criterion, sense of things sensible and intellect of things intelligible, 218. while common to both, as Theophrastus said, is the plainly evident. First, then, in order comes the irrational and non-demonstrable criterion, sense, but first in potency intellect, although it appears to come second in order as compared with sense. 219. For the sense is affected by things sensible, and as a result of the affection of the sense in an evident way there supervenes an affection of the soul in such creatures as are superior and better and able to move of themselves; and this is termed by them memory and presentation — memory of the affection felt by the sense, and presentation of the sensible object which has produced the affection in the sense. 220. Hence they say that an affection of this kind is comparable to a foot-mark; and just as that (I mean the foot-mark) is made both by something and from something — by something as, for example, by the pressure of the foot, and from something, as, say, from Dion, — so also the affection of the soul mentioned above is generated by something, as, say, the affection of the sense, and from something, such as the sensible object, to which also it preserves a certain similarity. 221. And this affection, again, which is termed both memory and presentation, possesses within itself a third and separate supervenient affection — that of rational presentation, which is an after-result consequent on our judgment and preference; and this affection is called mind and thought; as for example, when someone, on receiving an evident impression of Dion, suffers a certain affection of sense and a certain disturbance, and by the affection of his sense there is produced in his soul a presentation (which is also, as we said above, memory and similar to a foot-mark), 222. and from this presentation there is voluntarily limned and represented by him an imagined object, such as generic Man. Now this kind of affection of the soul the Peripatetic philosophers call either mind or thought according to the different ways in which it occurs — mind in so far as it is a potency, thought in so far as it is an actuality; 223. for whenever the soul is potentially able to form this representation — that is to say, whenever it is of a nature to do so — it is called mind, but whenever it is already actually doing so, it is termed thought. Moreover, from thought and the action of mind arise comprehension and science and art. For mental action deals at one time with particulars, at another with both particulars and genera; 224. but the aggregation of such images of the thought and the summing-up of the particulars in the universal is termed comprehension, and in this process of aggregation and summing-up the last stage constitutes science and art — science being that which possesses accuracy and inerrancy, art that which does not always possess them. 225. And as the sciences and arts are of later origin, so also is what is termed “opinion”; for whenever the soul yields to the presentation produced in it by sense and inclines and assents to the object which has appeared, this is called “opinion.” 226. It appears, then, from what has been said that the primary criteria of the knowledge of things are sensation and thought, the former playing the part of the instrument, the latter that of the craftsman. For just as we are unable to carry out a test of things heavy and light without a balance, or to grasp the difference between things straight and crooked without a rule, so likewise thought is naturally incapable of estimating objects when divorced from sense.

Such, then, summarily stated, are the views of the Peripatetics; 227. and as there still remains the Stoic doctrine, let us deal with it also in the next place. These men, then, assert that the criterion of truth is the apprehensive presentation. What this is we shall understand when we have first learnt what, in their view, presentation is and what are its specific differences. 228. Presentation then, according to them, is an impression on the soul. But about this they at once began to quarrel; for whereas Cleanthes understood “impression” as involving eminence and depression, just as does the impression made in wax by signet-rings, 229. Chrysippus regarded such a thing as absurd. For in the first place, he says, when the mind imagines at one and the same moment a triangular object and a quadrangular, the same body must needs be circumscribed by different forms at the same time and become simultaneously both triangular and quadrangular, or even circular, which is absurd; and further, when many presentations occur in us simultaneously, the soul will also receive innumerable formations, which result is worse than the former. 230. He himself, therefore, suspected that the term “impression” was used by Zeno in the sense of “alteration,” so that the definition runs like this — “presentation is an alteration of the soul for it is no longer absurd that, when many presentations co-exist in us at the same moment, the same body should admit of innumerable alterations; 231. for just as the air, when many people are speaking simultaneously, receives in a single moment numberless and different impacts and at once undergoes many alterations also, so too when the regent part is the sunject of a variety of images it will experience something analogous to this.

232. But others assert that not even the definition thus put forth in accordance with the amendment of Chrysippus is correct. For if a presentation exists, it is an impression and alteration of the soul; but if an impression of the soul exists, it is not in all cases a presentation. For in fact when a knock happens to the finger, or a scratch occurs in the hand, there is produced indeed an impression and alteration of the soul, but not a presentation as well; seeing that this is a result which occurs not in any chance part of the soul but only in the mind and the regent part. — 233. By way of meeting their objection the Stoics declare that in the phrase —impression of the soul” there is implied also the words “in so far as it is soul.” so that the full statement is this — “presentation is an impression in the soul in so far as it is soul.” For just as “ephelotes” is defined as “whiteness in the eye,” wherewith we also imply that “in so far as it is eye” (that is to say, “in a certain portion of the eye”) there exists whiteness, in order that all of us men may not have “ephelotes,” seeing that we all naturally have whiteness in the eye, — so when we define presentation as “impression in the soul,” we also imply therewith that it occurs in a certain part of the soul, to wit, the regent part, so that, stated explicitly the definition is this — “presentation is alteration in the regent part.” 234. — Others, starting with the same line of argument, have made a more subtle defence. For they say that soul is used in two senses, as denoting both that which holds together the whole framework and, in especial, the regent part. For when we say that man is composed of soul and body, or that death is a separation of soul from body, we are speaking specially of the regent part. 235. So likewise, when we are classifying goods and say that some are goods of the soul, some of the body, and some external, we do not mean the whole soul but the regent part of it, for it is to this that the affections and the goods belong. 236. Hence, when Zeno says that “presentation is an impression on the soul,” we must understand by “soul” not the whole but that part of it, so that the statement may be in this form, “presentation is alteration of the regent part.” — 237. But even when put in this form some say that it is wrong again. For, in fact, impulse and assent and apprehension are alterations of the regent part, but are different from presentation. For whereas this is a passivity of ours and a condition, the former are much rather activities. The definition, therefore, is a bad one, as it suits many different things; 238. and just as he who defines “man” and says that “man is a rational animal” does not give a sound description of the notion of “man” because “god” also is a rational animal, so also he who declares presentation to be “an alteration of the regent part” is at fault, since this is no more an account of presentation than of any one of the motions enumerated. — 239. Such being this further objection, the Stoics resort once again to their “implications,” saying that we must understand, as implied in the definition, the words “by way of passivity.” For just as he who says that love is “an impulse to win affection” implies therewith “of youths in their bloom,” even though he does not state this expressly (for no one loves old men and those who are not in their first bloom), so when we describe presentation as “alteration of the regent part,” we imply therewith, they say, that the alteration occurs “by way of passivity” and not by way of activity. 240. — But not even so do they seem to have escaped the charge; for when the regent part is being nourished and, in sooth, increased, it is altered by way of passivity, but this kind of alteration, although it is by way of passivity and condition, is not presentation — unless they should say once again that presentation is a special form of passivity which is distinct from the passive conditions, or else say this 241. — that, since presentation is either of things external or of our own internal affections (this being more precisely termed by them “vacuous attraction”), there is always implied in the definition of presentation that the “passivity” is either in respect of external impact or in respect of our internal affections; but this additional implication is no longer possible in the case of alteration due to processes of increase or nutrition.

Thus presentation, in the doctrine of the Stoics, is hard to define. In presentations, also, there are many and various distinctions, of which it will be enough to record the following. 242. Some of them are probable, some improbable, some at once both probable and improbable, some neither probable nor improbable. “Probable,” then, are those which produce a smooth motion in the soul — as, at the present moment, the impression that “it is day” and that “I am discoursing,” and everyone which attains a similar degree of obviousness; “improbable” are those which do not do so but make us decline to assent, 243. such as the judgment “if it is day, the sun is not above the earth,” “if it is dark, it is day.” “Both probable and improbable” are those which, according to the relation in which they stand, are at one time of this kind and at another time of that kind, as for instance presentations of problematic statements. “Neither probable nor improbable” are such as are concerned with judgments of this sort — “the stars are even in number,” “the stars are odd.” And of the probable presentations some are true, some false, 244. some both true and false, some neither true nor false. True, then, are those about which it is possible to make a true affirmation, as, at the present moment, “it is day” or “it is light”; false are those about which it is possible to make a false affirmation, as that the oar under the water is bent or that the porch is dilapidated; an example of both true and false is the impression of Electra experienced by Orestes in his madness 245. (for in so far as his impression was of an existing object it was true, for Electra existed, but in so far as it was that of a Fury it was false, for there was no Fury); and again when a man experiences a false and “vacuous attraction” in his dreams, imagining that Dion is standing beside him when Dion is alive. 246. Neither true nor false are the generic presentations; for the genera of things of which the particulars are of this kind or of that are neither of this kind nor of that kind; as, for instance, whereas some men are Greeks, others barbarians, the generic Man is neither a Greek (for then all particular men would have been Greeks), nor yet a barbarian (for the same reason) 247. — And of true presentations some are apprehensive, others not, — not apprehensive being those which are experienced by persons in a morbid condition; for countless sufferers from frenzy and melancholia receive a presentation which though true is not apprehensive but occurs externally and fortuitously, so that often they make no positive affirmation about it and do not assent to it. 248. An apprehensive presentation is one caused by an existing object and imaged and stamped in the subject in accordance with that existing object, of such a kind as could not be derived from a non-existent object. For as they deem that this presentation is eminently perceptive of real objects and reproduces with artistic precision all their characteristics, they declare that it possesses each one of these as an attribute. 249. Of these the first is derivation from an existing object; for many presentations occur from what is non-existent, as in the case of madmen, and these will not be apprehensive. Second is derivation both from an existing object and according to that existing object; for some again, though they are derived from an existing object, do not resemble that object, as we showed a little while ago in the case of the mad Orestes. For though he derived a presentation from an existing object, Electra, it was not in conformity with that object; for he supposed that she was one of the Furies, and accordingly repulses her, as she approaches and eagerly seeks to tend him, with the words —

Avaunt! For of my Furies thou art one.

Heracles, too, derived an impression of Thebes from an existing object, but not according to that object; for the apprehensive presentation must also be in accoid with the object itself. 250. Moreover, it must also be imaged and stamped in the subject, in order that all the characteristics of the presented objects may he reproduced with artistic exactitude. 251. For just as carvers set their hands to all the parts of the works they are completing, and as the seals on rings always imprint all their markings exactly on the wax, so likewise those who experience apprehension of real objects ought to perceive all their characteristics. 252. And they added the clause “of such a kind as could not be derived from a non-existent object” because the Academics did not, like the Stoics, suppose it to be impossible that a presentation exactly similar in all respects should be found. For the Stoics assert that he who has the apprehensive presentation discerns with artistic exactitude the difference subsisting in the objects, since a presentation of that kind as compared with all other presentations has a special characteristic of its own, like the horned serpents as compared with all other serpents; but the Academics assert on the contrary that a false one exactly similar to the apprehensive presentation can be found.

253. But whereas the older Stoics declare that this apprehensive presentation is the criterion of truth, the later Stoics added the clause “provided that it has no obstacle.” 254. For there are times when an apprehensive presentation occurs, yet is improbable because of the external circumstances. When, for instance, Heracles presented himself to Admetus bringing back Alcestis from the grave, Admetus then received from Alcestis an apprehensive presentation, but disbelieved it; 255. and when Menelaus on his return from Troy beheld the true Helen at the house of Proteus, after leaving on his ship that image of her for which the ten years’ war was waged, though he received a presentation which was imaged and imprinted from an existing object and in accordance with that object, he did not accept it as valid. 256. So that, whereas the apprehensive presentation is the criterion when it has no obstacle, these presentations, although they were apprehensive, yet had obstacles. For Admetus argued that Alcestis was dead and that he who is dead does not rise again, but certain daemons do rove about at times; and Menelaus also reflected that he had left Helen under guard in his ship and that it was not improbable that she who was discovered in Pharos might not he Helen but a phantom and supernatural. 257. Hence the apprehensive presentation is not the criterion of truth unconditionally, but only when it has no obstacle. For in this latter case it, being plainly evident and striking, lays hold of us, almost by the very hair, as they say, and drags us off to assent, needing nothing else to help it to be thus impressive or to suggest its superiority over all others. 258. For this reason, too, every man, when he is anxious to apprehend any object exactly, appears of himself to pursue after a presentation of this land — as, for instance, in the case of visible things, when he receives a dim presentation of the real object. For he intensifies his gaze and draws close to the object of sight so as not to go wholly astray, and rubs his eyes and in general uses eveiy means until he can receive a clear and striking presentation of the thing under inspection, as though he considered that the credibility of the apprehension depended upon that. 259. Moreover it is impossible to affirm the opposite, and he who abstains from asserting that presentation is the criterion, since he does so owing to the existence of another presentation, thereby of necessity confirms the fact that presentation is the criterion, — nature having kindled as it were a light for us, to aid in the discernment of truth, in the faculty of sense and the presentation which takes place by means thereof. 260. It is absurd, then, to set aside so great a faculty and to rob ourselves as it were of our own daylight. For just as the man who allows colors and the differences in them but abolishes vision as unreal or improbable, and while affirming the existence of sounds asserts the non-existence of hearing, is utterly illogical (for if the organs by which we perceive colors and sounds were absent we should be unable to experience colors or sounds), — so also he who admits the existence of objects, but inveighs against the presentation of sense by means of which he apprehends the objects, has completely lost his wits and puts himself on a level with things that have no soul.

261. Such, then, is the doctrine of the Stoics; and now that practically all the controversy regarding the criterion lies before our view, it will be a fitting time to commence our counter-argument and to apply it to the criterion. This, as I said above, some have supposed to reside in reason, some in the irrational senses, some in both; and some have named “Man” as the agent “by which”; some the sense and intellect as the instrument “by means of which”; some the impact as, for instance, the presentation. 262. We shall endeavor, then, so far as possible to state the difficulties appropriate to each of these rival views, that we may not be compelled to repeat ourselves by assailing one by one all the philosophers enumerated.

Concerning Man

263. First in order, then, let us examine the criterion “by whom,” or agent, that is to say Man; for I suppose that when we have cast doubt on this, to begin with, there will no longer by any need to proceed to further discussion of the other criteria; for these are either parts or actions or affections of Man. If, then, this criterion is to be apprehended, it must be conceived long before, inasmuch as conception in every case precedes apprehension. But up till now Man has proved to be inconceivable, as we shall establish; 264. therefore Man is certainly not apprehensible; and from this it follows that the knowledge of truth is indiscoverable, seeing that the subject who knows it is inapprehensible. Thus, for instance, of those who investigated the conception, Socrates was a doubter, remaining undecided and declaring himself ignorant both of what he himself is and in what relation he stands to the Universe — “for I do not know,” he says, “whether I am a man or some other kind of beast more complex than Typhon.” 265. But Democritus, who likened himself to the voice of Zeus, and spoke so about the sum of all things, attempted indeed to explain the conception, but was able to produce nothing more than a crude statement, in the words “Man is what we all ken.” 266. For, in the first place, we all know Dog as well, but Dog is not Man. And Horse we all know and Plant, but none of these is Man. And further, he has begged the question; for no one will grant otf-hand that the nature of Man is known, seeing that the Pythian propounded “Know thyself” as Man’s chief problem. And even were one to grant this, one would not ascribe the knowledge of Man to all but only to the most exact philosophers. 267. — Epicurus and his followers supposed that the conception of Man could be conveyed by indication, saying that “Man is this sort of a shape combined with vitality.” But they did not notice that if the thing indicated is Man, the thing not so indicated is not Man. And again, such an indication is made in the case of either a man or a woman, an elder or a youth, snub-nosed or hook-nosed, straight-haired or curly-haired, and all the other differences; 268. and if it is made in the case of a man, a woman will not be Man, and if in the case of a woman, the male will be ruled out, and if in the case of a youth, all the remaining ages will be debarred from Manhood.

269. Some philosophers there have been who have defined by logic the generic Man, imagining that from this the conception of particular men will also emerge. Of these philosophers some have given this definition — “Man is a rational mortal animal, receptive of thought and knowledge.” So they too have presented to us not Man but the properties of Man. 270. But the property of a thing is different from the thing of which it is a property, since of course if it were not different it would not have been a property but the actual thing itself. And, to be sure, while some properties are inseparable from the things to which they belong — as are length, breadth and depth from bodies, for without their presence it is impossible to conceive Body, — 271. others are separated from the thing to which they belong, and it still remains when they are removed — as, for instance, in the ease of Man, running, talking, sleeping, waking; for all these properties belong to us, but not continuously; for we remain the same when we are not running and when we are silent, and so likewise as regards the rest of these properties. As, then, there are two distinct kinds of properties, we shall find that neither of them is the same as the substantial thing but always distinct. 272. So then those who define Man as “a rational mortal animal,” and so on, achieve nothing; for they have not given a definition of Man but merely enumerated his properties. And of these “animal” is one of his constant properties, for it is impossible to be Man without being animal. But “mortal” is not even a property but something supervenient which occurs to Man; for when we are men we are alive and not dead. 273. “Reasoning and possessing knowledge” is indeed a property of his, but not constantly; for in fact some who are not reasoning are men, as for instance those that are by slumber sweet o’orcome,” and those who are not “possessing knowledge” have not lost manhood, as for instance madmen. Thus while we have been seeking one thing, they have offered us another.

274. Again, “Animal” is not “Man,” since in that case every animal would be a man. And if “rational” is put in place of “exercising reason,” then the gods, too, when they reason will become men, and possibly some of the other animals as well; while if “rational” stands for “uttering significant sounds,” we shall be saying that crows and parrots and the like are men, which is absurd. 275. Moreover, if one should say that “mortal” is Man, it will follow that the irrational animals also, being mortal, are men. And one must take a similar view of the words “receptive of thought and knowledge.” For, firstly, thts applies to gods as well; and secondly, if Man is receptive of these, Man is not these things but he who is receptive of these things, the real nature of whom they have, not explained.

276. Some, however, of those who have a reputation for cleverness in the Dogmatic School say, by way of reply to this, that it is not each of the properties enumerated that is “Man,” but all of them combined together compose “Man” — the sort of thing we see happening in the case of parts and a whole. 277. For just as a hand by itself is not a man, nor is a head, nor a foot, nor any other such part, but the compound made up of them is conceived as a whole, — so also “Man” is not barely “animal,” nor solely “rational,” nor “mortal” alone, but the aggregate of all these — that is to say, at once ananimal and mortal and rational. 278. But to this also there is an answer ready to hand. For, firstly, if each of those things separately is not “Man,” how can they make “Man” when combined together so as neither to extend beyond what he is nor to fall short of his real extent nor to diverge in any other way? And, next, they cannot so much as congregate all together so that the sum of them all should form “Man.” 279. Thus “mortal,” for instance, is not a property of ours when wo are men but is derived from concurrent recollection. For from seeing that Dion and Theon and Socrates, and in general individuals similar to ourselves, have died we reason that we also are mortal, even though death is not yet present with us — for, to be sure, we are alive. 280. Moreover, reasoning, too, is at one time present with us, at another time not present: and “possessing knowledge” again, as we have already explained,” is not one of the constant properties of Man. It must be said, then, that not even the union of all these properties is “Man.”

281. Plato gives a worse definition of Man than the others when he states that “Man is a wingless animal, with two feet and broad nails, receptive of political science.” Hence the objections which should be brought against him are obvious. For, once again, he has not explained Man but has enumerated the positive and negative attributes of Man; 282. for “wingless” is a negative attribute of his, while “animal” and “with two feet” and “with broad nails” are positive attributes, and “receptive of political science” is at one time a positive, at another a negative attribute. So that while we are seeking to learn one thing, he offers us another.

Well, then, let us grant that it is thus proved that it is not possible to form off-hand a conception of Man. 283. In like manner one must declare that the apprehension of Man is a thing impracticable, especially since this has been partially established already (for what is not conceived is not capable of being apprehended; and it has been shown that Man, so far as the conceptions of the Dogmatists are concerned, is inconceivable, and therefore also non-apprchensible). 284. All the same, it will be possible to establish this point by another line of argument as well. If Man is apprehensible either he as a whole wholly seeks and apprehends himself, or as a whole he is the object sought and coming under apprehension, (or he is partly the subject, partly the object of apprehension,) just as if one were to imagine the sense of sight seeing itself; for either it will be wholly seeing or seen, or partly seeing itself and partly seen by itself. 285. But if man as a whole should wholly seek himself and should be conceived therewith (that is, with the fact that he as a whole wholly conceives himself), there will no longer be any object that is apprehended, which is absurd. And if, on the other hand, he as a whole is the object sought and as a whole is conceived therewith (that is, with the fact that he is sought), then again we shall be left with no subject that seeks or is about to effect the apprehension. 286. Moreover it is not possible to take him in parts so that at one time he should be wholly the subject seeking, and at another wholly the object sought. For when us a whole he is seeking and as a whole is conceived therewith (that is, with the fact that as a whole he is seeking), no object will be left for him to seek; and conversely, when as a whole he is wholly the object sought, the subject which seeks will not exist.

287. We are left, then, with the alternative that Man does not as a whole perceive himself but forms the apprehension of himself by means of some part of himself. But this again is a thing impracticable. For Man is nothing more than his substance and senses and intellect, so that, 288. if he is to apprehend himself with one of his parts, either he will perceive his senses and intellect with his body, or conversely he will apprehend his body with his senses and intellect. It is, however, impossible for him to perceive his senses and intellect with his body; for it is irrational and senseless and unsuited for suchlike investigations. 289. And besides, if the body is capable of perceiving the senses and the intellect, as apprehending these it must be similar to them, that is, it must be in a similar condition and become both sense and intellect. For when it perceives the sense of sight, in so far as it sees it will be sight, and when it is apprehensive of taste in the act of tasting it will become taste, and similarly with the other senses. 290. For just as that which perceives a hot thing as hot perceives it by being heated, and being heated is at once hot, and as that which acquires knowledge of a cold thing as cold by feeling cold is at once cold, so also if the fleshly substance perceives the senses as senses it has sense-perception, and having sense-perception it certainly will become sense, 291. and in this way the seeking subject will no longer subsist but it will be the object sought, — besides the fact that it is perfectly ridiculous to suppose that the body’s substance does not differ from the senses and the intellect, when practically all the dogmatic philosophers have made mention of the difference between them.

292. The same argument applies also to the intellect; for if the bodily substance perceives it as intellect — that is, as thinking — the substance will be intellect, and being intellect it will be not the seeker but the sought. So, then, the body is not capable of apprehending Man.

293. Nor indeed are the senses. For these are solely passive and are stamped like wax, and not a single thing else do they know, sinee, to be sure, if we ascribe to them a seeking for anything they will become no longer irrational but rational and endowed with the nature of intellect. But this is not the case; for if feeling the white and the black and the sweet and the bitter and the odorous, and passive feeling in general, is a peculiar property of theirs, active seeking will not be a peculiar property of theirs. 294. — Further, how is it possible for the bodily substance to be apprehended by them when they do not possess a corporeal nature? Thus the sense of sight, for instance, is perceptive of form and size and color, but the substance is neither form nor size nor color but, if anything, that whereof these are properties; and because of this sight is not able to perceive the substance and only sees the properties of the substance, such as its form, size, color. 295. “Yes,” someone will say, “but the aggregate made up of these is the substance.” But this is fatuous. For, in the first place, we have shown that not even the united combination of the properties of a thing is the thing of which they are properties. 296. And further, even were it so, it is again an impossibility for the body to be perceived by the sense of sight. For if neither bare length, nor form by itself, nor color in isolation, is the body, but the compound made up of them, it will be necessary for the sight which apprehends the body to put these together one by one in itself, and thus to call the general aggregate of them all “body.” 297. But the act of putting together one thing with another, and of perceiving such and such a size together with such and such a form, belongs to the rational faculty. And the sense of sight is irrational, so that it is not its task to perceive the body — 298. Moreover, it is not only iinsuited by nature to conceive the general aggregate as body, but it is also disabled for the apprehension of each of the body’s properties. That of length, for instance; for this is naturally perceived by passing over its parts, as we commence at a point and proceed through a point and end up at a point, which an irrational nature cannot do. Again, take the property of depth; 299. for sight roams over the actual surface and does not penetrate to the depth. Thus it fails to discover the copper in coins that are gilded over. And when we overthrew the Cyrenaic theory it was stated that sight is also unfitted for the discerning of color. 300. Consequently, if the sense of sight is not even perceptive of the properties of the body, much less will it be capable of discerning the body itself. Nor, indeed, is this a task for hearing or smell or taste or touch; for each of these senses is only aware of the percept proper to itself, and this will not be the bodily substance. For hearing is perceptive of sound only, and sound is not the substance. And smell is a judge only of the odorous or mal-odorous; but no one is so witless as to class the substance of our body among things odorous or mal-odorous. And — not to make a long story of it — the same may be said regarding the rest of the senses. So that the senses do not apprehend the bodily substance.

301. Nor indeed do they apprehend themselves. For who has beheld sight by sight? Or who has heard hearing by hearing? And who ever tasted taste by taste, or smelt smell by smell, or touched touch by touch? For these are objects for the intellect. Hence it must be declared that the senses are not even perceptive of themselves; nor, in consequence, of one another. For sight cannot see hearing as it hears, and conversely hearing is incapable of hearing sight as it sees, — and the same method of criticism applies to the other senses, — since, of course, if we assert that hearing as hearing (that is, as in act of hearing) is perceptible by sight, we shall be admitting that sight is like to the former in quality, so that it is no longer sight but hearing; 302. for how can it discern hearing in act of hearing unless it possesses itself a nature capable of hearing? And conversely, in order that hearing may perceive sight as in act of seeing it must itself have become vision long before. But this, it would seem, reaches the very height of absurdity. One must, therefore, declare that the senses do not perceive either the body or themselves or one another.

303. “Yes,” say the Dogmatists, “but the intellect discerns both the bodily substance and the senses and itself.” But this, too, is a thing impracticable. For when they claim that the intellect is perceptive both of the whole body and of its contents, we shall inquire whether it apprehends by making contact all at once with the substance as a whole, or with its parts, and by combining these it apprehends the whole. 304. That it is with the whole they will not agree, as will be evident from what follows; and if they should say that it combines the parts and therefrom discerns the whole, they will be plunged into difficulties. For of the parts of the substance some are irrational, and those that are irrational move us irrationally. The intellect, therefore, being irrationally moved by these will become irrational, and being irrational it will not be intellect. So that the intellect will not apprehend the substance. 305. — Nor, in fact, can it distinguish the senses, according to the same argument. For just as it is unable to apprehend the body owing to the fact that it has itself a share of rational power whereas the body is irrational, so also it will be unable to apprehend the senses since they are irrational and therefore move what apprehends them irationally. Further, in perceiving the senses it will certainly be sense itself. For in order that it may perceive the senses as senses (that is, as exercising sense-perception) it will itself become of like nature with them; for when it apprehends sight as in act of seeing it will, long before, become sight, and in discerning hearing in act of hearing it will become no different from hearing. The same argument applies to both smell and taste and touch. 306. — But if the intellect that discerns the senses is found to have passed over into their nature, there will no longer exist any subject which seeks to know the senses; for that which we assumed to be seeking has turned out to be identical with the senses sought, and consequently in need of something to apprehend it. 307. “Yes,” they say, “but the same thing is both intellect and sense, but not in the same aspect, it being in one aspect intellect but in another sense; and just as the same drinking-cup is said to be both concave and convex, though not in the same aspect, but in one aspect concave, as is the inside part, and in another convex, as is the outside, — and as the same road is conceived as being both an incline and a decline, an incline for those ascending by it but a decline for those descending, — so likewise the same faculty is in one aspect thought but in another sense, and being the same it is not precluded from the aforementioned apprehension of the senses.” 308. But they are utterly simple-minded, and only make empty replies to the difficulties propounded. For we assert that, even if it be granted that these different faculties really belong to the same substance, there still remains the difficulty raised by us a little while ago. 309. For I ask, as regards this thing which is said to be thought in one aspect and sense in another, how by its aspect as thought can it perceive its aspect as sense? For it being rational and apprehending an irrational thing will be moved irrationally, and being moved irrationally it will be irrational, and being this it will not be apprehending but apprehended. And this again is absurd.

310. Let it be established, then, by these arguments that Man is unable to perceive either the senses by means of the body or, conversely, the body by means of the senses, seeing that these cannot perceive either themselves or one another. Next we have to show that the intellect is not cognizant of itself, as the Dogmatic philosophers claim. For if the mind apprehends itself, either it as a whole will apprehend itself, or it will do so not as a whole but employing for the purpose a part of itself. 311. Now it will not be able as a whole to apprehend itself. For if as a whole it apprehends itself, it will be as a whole apprehension and apprehending, and, the apprehending subject being the whole, the apprehended object will no longer be anything; but it is a thing- most irrational that the apprehending subject should exist while the object of the apprehension does not exist. 312. Nor, in fact, can the mind employ for this purpose a part of itself For how does the part itself apprehend itself? If as a whole, the object sought will be nothing; while if with a part, how will that part in turn discern itself? And so on to infinity. So that apprehension is a thing without beginning, as either no first subject is found to apprehend or no object exists to be apprehended. 313. — Further, if the mind apprehends itself it will also apprehend therewith the place in which it exists; for everything that is apprehended is apprehended together with some place. And if the mind apprehends together with itself the place also wherein it exists, this ought not to have been a matter of dispute among the philosophers, some of them declaring it to be the head, others the breast, and, in particular, some the brain, others the pia mater, some the heart, others the portals of the liver or some such part of the body. Regarding this the Dogmatic philosophers do actually dispute among themselves; therefore the mind does not apprehend itself.

314. Let this, then, stand as a statement of the difficulties which beset the inqiury about the criterion, in its larger aspect as Man in general. But inasmuch as the Dogmatists, in their self-conceit, do not pass over to others the judgment of truth but assert that they themselves alone have discovered it, come and let us base our argument upon them and demonstrate that not even so is it possible for any criterion of truth to be discovered. 315. Now each of those who claim to have discovered the truth either makes this declaration by merely asserting it or adduces a proof. But he will not utter it by assertion; for one of those who belong to the opposite side will utter an assertion claiming the opposite, and in this case the former will be no more trustworthy than the latter; for a bare assertion counterbalances a bare assertion. 316. But if his declaration of himself as criterion is accompanied by proof, it must be sound proof. But in order to ascertain that the proof which he employs in declaring himself as criterion is sound, we must possess a criterion, and one that is already agreed upon; but we do not possess an undisputed criterion, it being the object of inquiry; therefore it is not possible to discover a criterion. 317. — Again, since those who call themselves criteria of truth derive from discordant Schools of thought, and just because of this disagree with one another, we need to possess a criterion which we can employ to pronounce upon their disagreement so as to give assent to the one party and not to the other. 318. This criterion, then, is either in disagreement with all those who disagree or in agreement with only one. But if it disagrees with all, it will itself also be a party in the disagreement, and being a party in this it will not be a criterion but itself also, like the whole of the disagreement, in need of a judgment; for that the same thing should be at once both examining and examined is a thing impracticable. 319. And if it does not disagree witli all but agrees with one, the one with whom it agrees, as being involved in the disagreement, requires an examiner. And on this account the criterion which agrees with that one, being no different from it, will need judgment, and needing judgment it wll not be a criterion. 320. — But the most important argument of all is this; — if we say that some one particular Dogmatist is the judge of truth, and that this attribute belongs to him alone, we shall make this statement after looking intently either at his age, or not at his age but at his labors, or not at these hut at his sagacity and intellect, or not at his sagacity but at the testimony of the multitude. But in our inquiry into the truth it is not appropriate, as we shall show, to give attention either to age or to industry or to any other of the points mentioned above; therefore it should not be asserted that any one of the philosophers is the criterion of truth. 321. Now one should not attend to age, seeing that most of the Dogmatists were pretty much of the same age when they declared themselves to be criteria of truth; for it was when they had all become old — take Plato, for instance, and Democritus and Epicurus and Zeno — that they testified to their own discovery of truth. 322. Further, it is not unlikely that, just as in ordinary life and common intercourse the young are often found to be more intelligent than the old, so likewise in philosophy the young may be more keen-witted than the old. 323. For some people, including Asclepiades the physician, have asserted expressly that the old fall far short of the young in intelligence and mental acumen, although the opposite was supposed to be the fact owing to the false opinion held by most thoughtless people. For the young are believed to fall short in intelligence because of the great experience of the old, though the opposite is the fact; for while the aged are, as I said, more experienced, they are not more intelligent than the young. So, then, one must not say that, on the ground of age, any of the Dogmatists is the criterion. 324. — Nor yet, surely, on the ground of industry. For they are all equally industrious, and there is none who, after competing in the race for truth and asserting that he has found it, conducts himself indolently. And when all give evidence of equality in this respect, it is a thing unjust to give the preference to one only. 325. — So likewise no one could prefer one as superior to another on the ground of intelligence. For, in the first place, they are all intelligent, nor are some obtuse and others not so. Further, those who are reputed to be intelligent are frequently advocates not of truth but of falsehood. Thus we call those orators who ably support what is false, and raise it to equal the true in credibility, competent and brainy, and those who are not of this class we call, on the contrary, slow of wit and unintelligent. 326. Possibly, then, in philosophy also the most sharp-witted of the seekers after truth seem to be convincing, even if they advocate what is false, owing to their natural ability, whereas those lacking this ability are unconvincing even when they contend for what is true. So, then, neither on the ground of age, nor of industry, nor of intelligence, is it proper to prefer anyone to another and to say that this man has discovered the truth and that man has not. 327. — It remains, then, that we should attend to the majority of those in agreement; for possibly someone will assert that he is the best judge of truth with whom the testimony of the majority is m agreement. But this is nonsensical and worse than the criteria which we have already rejected. For, to pass over all other points, those who disagree about any facts are equal in number to those who agree about the same facts — the Epicureans, for example, are equal to the Aristotelians, and the Stoics to the Epicureans, and so on with the rest. 328. If, then, he that has discerned the truth is the best because all those who derive from him maintain the same view, why should we say that this man rather than that man is the best and the criterion of truth? If, for instance, we name Epicurus because those who agree about him that he has found the truth are many in number, why Epicurus rather than Aristotle, since those who side with the latter are no less numerous? 329. But, notwithstanding, just as in the ordinary affairs of life it is not impossible that one intelligent person should be better than many unintelligent persons, so, once again, in philosophy it is not unlikely that one man should be sensible and on that account trustworthy, and many be like geese and on that account untrustworthy, even though they testify with one voice in someone’s favor; for the intelligent man is rare, the thoughtless common. 330. — Moreover, even if we attend to general agreement and the testimony of the majority, we are brought round again to a position which contradicts our assumption; for of necessity those who disagree about a thing are more numerous than those who agree about it. What I mean will become clearer if we take a familiar example. 331. Let us suppose, for the sake of argument, that those who belong to the Stoic School of philosophy are more numerous than those who belong to each of the other Schools, and that the former agree in saying that Zeno alone has discovered the truth and no one else. Then the Epicureans will contradict them, and the Peripatetics will declare that they are liars, and the Academics will gainsay them, as will also all the members generally of the other Schools, 332. so that once again those who have unanimously given the preference to Zeno, when compared with those who unanimously declare that Zeno is not the criterion, are found to be far fewer in number. Here, too, is another reason; If one ought to vote for those who make an unanimous statement about any matter when they are numerous, it must be asserted that no one has found the truth; for everyone who is commended by a certain number has a multitude from the other Schools who cry out against him. 333. But the most convincing argument of all is this; Those who agree together about a certain person that he has found the truth are in a condition with respect to their agreement which is either different or not different at all but one and the same. But they will by no means be in a different condition since then they must certainly disagree; while if they are in one condition they are brought round into a state of equality with him who states the opposite. For just as the latter is in one condition in respect of which he has opposed them, 334. so also the former are in a condition equal to his, their large numbers being henceforward redundant for ensuring belief; for, in fact, if it had been but one of them who was supposed to have made this statement, he would have had as much weight as all of them.

335. But if he that has discovered the truth in philosophy is said to have succeeded either because of his age or his industry or his intelligence, or through having many to testify for him, whereas we have established that for none of these reasons ought it to be said that he is really the criterion of truth, then it is evident that the criterion in philosophy is undiscoverable.

336. Further, he who declares himself to be the criterion of truth says what appears to himself and nothing more. So then, since each of the other philosophers also says what appears to himself and is contrary to the previous statement, it is plain that, as each of them is on a level with all the others, we shall be unable to state definitely that any one of them is a criterion. For if the first man is trustworthy because it appears to him that he is the criterion, the second man too will be trustworthy, since to him also it appears that he himself is the criterion, and so likewise with the third, and the rest; wherefrom it follows that no one is definitely the criterion of truth. 337. — Furthermore, a man says he is the criterion either by mere assertion or by employing a criterion. But if it be by assertion, he will be checked by assertion, while if it be by employing a criterion, he will be overthrown. For this criterion is either in disagreement with him or in agreement. And if it be in disagreement it is untrustworthy, since it is in disagreement with him who believes himself to be the criterion; 338. and if it be in agreement, it will stand in need of a judge. For just as the man who declares himself to be the criterion is not to be trusted, so also the criterion in agreement with him, since it possesses in a fashion the same quality as he, will require some second criterion. And if this be so, one must not assert that each of the philosophers is the criterion; for everything which requires judging is of itself untrustworthy 339. — Once again, he who declares himself to be the criterion makes this claim either by assertion or by demonstration. Yet, for the reasons I have already given, he cannot do so by assertion; and if he does so by demonstration, it must by all means be a valid one. But the fact that such a demonstration is valid is stated either by assertion or by demonstration, and so on ad infinitum. So, then, on this ground also it must be declared that the criterion of truth is undiscoverable.

340. this argument also is propounded: — Those who claim for themselves to judge the truth are bound to possess a criterion of truth. This criterion, then, either is without a judge’s approval or has been approved. But if it is without approval, whence comes it that it is trustworthy? For no matter of dispute is to be trusted without judging. And if it has been approved, that which approves it, in turn, either has been approved or has not been approved, and on ad infinitum. 341. — Again, the criterion being a matter of dispute requires a proof. But since some proofs are true, some false, the proof which is adduced to confirm the criterion must needs be supported by a criterion; so that we are plunged into circular reasoning, the criterion on the one hand awaiting confirmation by the proof, and, on the other hand, the proof waiting for the support of the criterion, 342. and neither of them being able to be confirmed by the other. And besides, the same thing becomes both trustwortliy and untrustworthy — the criterion trustworthy because it judges the proof, and the proof because it proves the criterion; but the criterion untrustworthy because it is proved by the proof, and the proof because it is judged by the criterion.

343. Well, then, it is by all these arguments that the obscurity of the first criterion — that of the agent “By which” — is criticized among the Sceptics; and the argument regarding the second — I mean that “By means of which” or Instrument — is easy to set forth. For if Man discovers the truth, he discovers it by employing either the senses only or the intellect or the combination of both the senses and the intellect; but, as we shall establish, he cannot discover the truth by employing either the senses only or the intellect by itself or both the senses and the intellect conjointly; therefore Man is not capable of discovering the truth. 344. Now he is not able to grasp the truth by the senses alone, as we have shown above, and shall now briefly rehearse. For they are by nature irrational, and having no farther capacity beyond that of being impressed by the objects imaged, they are wholly disqualified for discovering the truth. For that which is to perceive what is true in the real objects must not only be moved by a whitish or sweetish feeling but also must be brought to have an impression regarding such an object that “this thing is white” and “this thing is sweet.” And similarly with the rest of the senses. 345. But to perceive an object of that kind is no longer the task of sense; for sense is of a nature to grasp only color and flavor and sound, whereas the recognition that “this is white” or “this is sweet,” being neither color nor flavor, is incapable of being experienced by sense. The senses, too, in many cases give false reports and disagree with one another, as we have shown when expounding the Ten Modes of Aenesidemus. 346. But that which is in disagreement and at variance is not a criterion, but is itself in need of a judge. So then the senses are not able by themselves to judge the truth. — There is need, too, of combination and of memory for the perception of real objects such as man, plant, and the like. For man is a combination of color and size and form and certain other peculiarities, 347. whereas sense is unable to combine anything by aid of memory owing to the fact that the combination is neither color nor flavor nor sound, which things alone sense is capable of perceiving.

348. Nor, indeed, is the intellect. For if the intellect is cognizant of the truth, it ought previously to have been cognizant of itself; and just as the architect does not judge of the straight and the crooked without giving attention to the structure of his criteria — such as that of the rule and of the compasses, — so too the intellect, if it is capable of distinguishing falsehood and truth, should have been aware much earlier of its own nature — the substance, for instance, whereof it is composed, the place wherein it exists, and all the rest. 349. But it cannot altogether comprehend such things, seeing that some, like Dicaearchus, say that it is nothing more than a certain condition of body, while others have said that it exists, but have not all agreed that it is contained in the same place — some, like Aenesidemus “according to Heracleitus,” placing it outside the body, others in the whole of the body (like some “according to Democritus”), and others in a part of the body, and the views of these last, again, are very diverse. 350. Also, while some assert, as do the majority, that it is distinct from the senses, others say that it is the senses, — it peering out through the sense-organs as though through peep-holes, — which theory was first held by Strato the physicist and Aenesidemus. Therefore the intellect is not the criterion. 351. — Intellects, too, are many in number, and being many they are in disagreement, and as disagreeing they have need of one to pronounce judgment upon them. This, then, is either intellect again or something different from it. Now it will not be intellect; for if so, as being a party to the disagreement it will require judging and will no longer be a criterion; and if it be something different from intellect, it supports the view that the intellect is not the criterion. 352. It would also be possible now to make use of the conclusions stated by the Dogmatists; for there is no necessity for us to repeat ourselves. — Furthermore, since there exists in us, according to most of the philosophers, not only an intellectual part but along with this also a sensitive part which is set in front of the intellectual, this, being set in front of the other, will of necessity prevent the intellect from perceiving the external objects. 353. For just as the body which lies between the sight and the object of sight prevents the sight from perceiving the object of sight, so if the irrational sense of sight intervenes between the intellect and the external object of sight, the sight will prevent the intellect from perceiving the external object of sight, and if the hearing intervenes between the intellect and the external object of hearing, it will not permit the intellect to become cognizant of the object of hearing; and similarly with the rest of the senses. The intellect, then, being locked away inside, and being kept in the dark by the senses, will not be capable of perceiving any of the external objects. Neither, then, can it be said that it, taken by itself, is the criterion.

354. It remains, therefore, to say “both of them,” — meaning that the intellect, by employing sense as assistant, grasps external objects. But this again is impossible. For sense does not furnish the intellect with the external objects, but each sense reports its own peculiar affection — touch, for instance, when warmed by fire, does not supply to the intellect the external and burning fire but the warmth therefrom, that is to say, its own peculiar affection. 355. And yet not even this. For if thought shall reeeive the affection of sense, it will be sense. For that which is receptive of visual affection is visually moved, and that which is visually moved is vision; that also which is receptive of acoustic affection is acoustically moved, and that which is acoustically moved is the sense of hearing; and similarly with the other senses. 356. Wherefore the intellect also, if it receives the affection of each sense, is sensitively moved, and being sensitively moved it is sense, and being sense it is irrational, and having become irrational it will cease from being any longer thought, and not being thought it will not receive as thought the aifection of sense. 357. — But even if it receives the affection of the senses it will not know external objects. For external objects are unlike our affections, and the presentation is far different from the thing presented, — that of a fire, for instance, from the fire, for the latter burns whereas the former is not capable of burning. Besides, even if we grant that external objects are similar to our affections, it is not certain that by receiving our affections the intellect will apprehend external objects. For things similar to certain things are other than those things to which they are similar. 358. Wherefore if the intellect is cognizant of things similar to the external objects, it is not cognizant of the external objects but of things similar to them. And just as he who does not know Socrates but is looking at the likeness of Socrates does not know whether Socrates resembles the apparent likeness, so the intellect, when it perceives the affections without having discerned the external objects, will not know either the nature of these objects or whether they resemble the affections. And not knowing the apparent things, neither will it understand the non-evident things which are assumed to be known by transition therefrom; and, consequently, it will not be the criterion of truth.

359. But some of the Dogmatists keep repeating in this case also the rejoinder which was mentioned above, saying that these different parts of the soul — that is, the rational and the irrational — are not separated, but just as honey is at once, through and through, both liquid and sweet, so also the soul possesses through and through these two faculties, co-extensive with each other, of which the one is rational, the other irrational; 360. and that the rational is affected by intelligible objects, while the irrational is perceptive of sensible objects. Hence, too, it is vain to say that the intellect, or the soul in general, is unable to apprehend the other distinct class of such objects; for as the apparatus it possesses is twofold, it will inevitably be capable of apprehending both sorts of object. — But they are extremely silly. 361. For even if these faculties seem ever so much to be combined in the same substance and to be co-extensive with each other and to range throughout the whole soul, none the less they are generically different from each other, this being one thing and that quite another. This one can learn from facts which seem especially obvious; 362. for there are frequent instances of things which are found attached to the same matter but which have not the same nature. Thus weight and color are both attached to the same body but are different from each other; and again, shape and size are attributes of the same substance but have separate natures, size being conceived as one thing, shape as another. In this way, then, the aforementioned rational faculty, even though it subsist in fusion with the irrational faculty, yet will differ from it. 363. And this involves the further consequence that the one faculty is not able to be moved like the other and to have similar affections, for the reasons enumerated above; since otherwise it would be necessary for both to become one, the rational irrational, if it has irrational affections, and the irrational rational, if it has rational motions. 364. — And even if we assume that the intellect peers through the sensitive passages as through peep-holes and makes contact with the external objects apart from the senses placed in front of it, — even on this assumption the theory will be found no less untenable. For the intellect which apprehends the real objects in this way must apprehend the real objects as self-evident; but, as we shall establish, nothing is self-evident; therefore it is not possible to grasp the truth of the real objects. For it is laid down by our opponents that the “self-evident” is “that which is perceived of itself and needs no second thing to establish it.” 365. But nothing is of a nature to be perceived of itself, but all things through affection, and this is other than the object of presentation which produces it; for when I feel sweetness through the application of honey I guess that the external substance of honey is sweet, and when I feel warm through the approach of fire I take my own condition as a sign that the external substance of fire is warm, and the same may be said of the other objects of sense. 366. Since, then, that which is perceptible through another is by universal agreement non-evident, and all things are perceived through our affections, than which they are other, all external objects are non-evident and on this account unknowable by us; for to ensure knowledge of things non-apparent there must be some self-evident fact present, and if this is not present, the apprehension of those things likewise vanishes. 367. Nor is it possible to say that, though those things are, so far as that goes, non-evident, yet they are apprehended by us owing to the fact that the indication derived from the affections is firm. For honey is not necessarily sweet if I have a feeling of sweetness when honey is applied to my sense of taste, nor is gall bitter if I have a bitter feeling on tasting it, as though the feelings which belong to us ought necessarily to belong also to the causes which produce them. 368. For just as the lash that falls upon the flesh gives pain to the flesh but is not also pain, and as the food or the drink gives pleasure to him that eats or drinks but is not pleasure, so also the fire is able to give warmth and yet not be necessarily warm, and the honey to sweeten and yet not be sweet; and the same argument applies to the other objects of sense. But if, in order that we may know the truth, there must be something self-evident in existence, and it has been proved that all things are non-evident, it must be acknowledged that truth is unknowable.

369. And can it be denied that the controversy among the philosophers regarding the highest matters does away with the knowledge of truth? For if some of the physicists, like Democritus, have abolished all phenomena, and others, like Epicurus and Protagoras, have established all, while others again, like the Stoics and Peripatetics, have abolished some and established others, — then, whether one assumes as criterion the intellect or the sense or both together, in every case it is by all means necessary that either some apparent or some non-evident thing should be adopted to judge between these thinkers. But to adopt an apparent thing is impossible; for as it is derived from the controverted matter it will be controverted and on this account not a criterion. While if a non-evident thing be adopted, things are turned upside down, when that which seems to be known is confirmed by what is not known — which is absurd.

370. However, let the substantiality of Man and of the senses and the intellect be granted, so that the thesis of the Dogmatists may go forward. Yet in order that anything should be known even by means of these, one must needs agree about the third criterion, that is, presentation; for neither sense nor thought can possibly be aware of things without presentative alteration. 371. But this criterion too is beset by manifold doubts, as we may see in detail when we have discussed it in a systematic way right from the beginning. For since some of those who make presentation the rule of things have had regard to the “apprehensive,” others to the “probable” presentation, we shall select the generic form that is common to both kinds — namely, presentation itself — and abolish it; 372. for when this is abolished, the particular differences of the presentations are also abolished; and just as when Animal is non-existent Man does not exist either, so if presentation is non-existent neither does any apprehensive or probable presentation subsist. For if the presentation is “an impression on the soul,” it is an impression either “by way of depression and eminence,” as Cleanthes supposes, or “by way of mere alteration,” as Chrysippus thought. 373. And if it subsists by way of depression and eminence, those absurd results will follow which are alleged by Chrysippus. If the soul when presentatively affected is impressed like wax, the last motion will always keep overshadowing the previous presentation, just as the impression of the second seal is such as to obliterate that of the first. But if this be so, memory is abolished, it being “a treasury of presentations,” and every art is abolished; for art is “a system and aggregation of apprehensions; but it is not possible for many and different presentations to subsist in the regent part, when its mental impressions vary from time to time. So then the impression foremost in the mind is not a presentation. 374. — Again, if the things apparent are “a vision of the things non-evident,” and we find that the bodies of things apparent which are composed of far denser parts than is breath are unable to retain any impression at all that is made upon them, it is reasonable to infer that neither does breath conserve any one single impression derived from a presentation. Moreover, water is of denser parts than breath, but when a finger is pressed upon it it is never found to conserve the impression made by the pressure. 375. Yet why do I speak of water, when even very soft wax, which by comparison is already firm, although because of its elasticity it takes an impression instantaneously, yet does not retain the impression? If, then, such a body as this — which, as compared with water, is in a solid state — is quite incapable of conserving any impressions made upon it, it is surely apparent that neither is breath endowed with a nature suited for this purpose, it being of finer parts and fluid as compared with those other bodies.

376. “Yes, but the presentation is not precisely an impression, but a mere alteration of the intellect.” But this again is worse than the previous definition. For of alterations one sort is by way of affection, the other consists in a change in the substance; and it is by way of affection when, for instance, the statue that remains the same in respect of substance and shape is alternately heated at one time by the sun shining upon it, and at another time chilled by dew falling upon it at night; but it consists in change in the substance, if, for example, this statue were to be melted and become a brazen sphere. 377. If, then, the presentation is an alteration of the soul, it is an alteration either merely by way of affection or by way of change in the substance. And if it be by way of affection, then since the affection is different according as the presentations are different, the new affection changes the older, and thus there will be no retention of anything in the intellect, which is absurd; while if it consists in change of substance, at the very moment of receiving a presentation the soul through being altered will cease from being soul and will be destroyed, just as also the statue that was melted into a sphere ceased at the same time from being a statue. Neither, then, is the presentation an alteration of the soul; 378. and besides they are crushed by the difficulty about change. For if a thing changes and is altered either what remains changes and is altered or what does not remain. But neither what remains is altered and changes — for it remains by being such as it was, — nor what does not remain, for this has been destroyed and been changed but does not change. For example, if white changes it changes either while remaining or while not remaining white. 379. But it does not change while remaining white, for it remains white, and inasmuch as it is white it does not change; nor while not remaining white, for it has been destroyed and been changed but does not change. Therefore white does not change. Wherefore also, if presentation is a change and alteration of the soul, it is non-existent.

380. And even if alteration be granted, the real existence of presentation will not be admitted right away. For it was declared to be an impression of the regent part, but it is not agreed whether this regent part exists or in what spot it exists, some saying (like Asclepiades) that no regent part has any existence at all, and others believing that it exists though not agreeing as to the place which contains it. Wherefore, in so far as this controversy is unresolved, one must remain in a state of suspension, on the ground that it is not agreed that presentation is an impression of the regent part. 381. But let it be granted also that presentation is an impression of the regent part; yet since such an impression is not announced to the regent part otherwise than through the sense — through sight, for instance, or hearing, or any other such faculty, — I want to know whether the alteration that takes place in the regent part is of the same sort as that of the sense, or different. And if it is the same, since each of the senses is irrational, the regent part too, being altered, will be irrational and in no respect different from sense; 382. while if the alteration is different, it will not receive the presented object exactly as it exists, but the existent object will be one thing and the presentation formed in the regent part something different. And this again is absurd. Neither in this way, then, can it be said that presentation is an impression and alteration of the regent part.

383. Furthermore, the presentation is an effect of the object presented, and the object presented is the cause of the presentation and is capable of impressing the sensitive faculty, and the effect is different from the cause which produces it. Hence, since the mind apprehends the presentations, it will be receiving the effects of the presented objects but not the external objects themselves. 384. And should anyone argue from the feelings and affections it experiences that it apprehends the external objects, we shall adduce the difficulties previously stated. For either the external objects are the same as our presentations, or they will not be the same but similar. (But they are certainly not the same;) for how can a cause and its effect be conceived as the same? 385. And if they are similar, since what is similar to a thing is other than that to which it is similar, the intellect will know things similar to the presented objects but not the presented objects; and besides, this too is beset with difficulties. For how wall the intellect know that the presented objects are similar to the presentations? It will know this either without a presentation or by means of a presentation. But without a presentation it is impracticable, for the intellect is naturally incapable of receiving anything unlessby experiencing presentation. 386. And if it knows it by means of a presentation, this presentation ought certainly to perceive both itself and the presented object in order to ascertain whether it is itself similar to the presented object which produced it. Now the presentation will possibly be able to perceive the presented object, it being a presentation thereof; but how will it perceive itself? For in order that this should happen it will be necessary for the same thing to become both presentation and presented object. 387. And since the presented object is one thing (for it is cause) and the presentation another thing (for it is effect), the same thing will be other than itself (both cause and effect simultaneously); and both these conclusions are illogical.

388. From the difficulties now stated let us pass on and mention other difficulties which occur even after conceding that presentation is of that nature, whatsoever it be, which the Dogmatists desire. If presentation is accepted as the criterion, we must assert either that every presentation is true, as Protagoras asserted, or that every one is false, as Xeniades the Corinthian declared, or that some are true, some false, as the Stoics and Academicians said, and the Peripatetics as well. 389. But (as we shall show) we ought not to assert either that every one is true or every one false or some true and some false; therefore we must not declare that presentation is the criterion. One cannot say that every presentation is true, because this refutes itself, as Democritus and Plato taught in opposing Protagoras; 390. for if every presentation is true, the judgment that not every presentation is true, being based on a presentation, will also be true, and thus the judgment that every presentation is true will become false. — And even apart from self-refutation of this kind, it is contrary to apparent facts and to plain evidence to assert that every presentation is true, when many are very false. 391. For our feelings do not respond in the same way, at the present moment, to the judgment “it is day” and to the judgment “it is night,” or to “Socrates is alive” and “Socrates is dead,” nor do these judgments bring with them equally clear evidence, but “it is now day” and “Socrates is dead” beem to be credible, whereas “it is night” and “Socrates is alive” are not equally credible but appear not to be actual facts. 392. — The same argument also applies to the sequence and conflict belonging to certain things. For the existence of light is plainly consequent on the existence of day, and the fact of your motion on that of your walking, whereas the existence of night obviously conflicts with the existence of day, and the fact of your not moving with that of your walking, and the affirmation of the one is the negation of the other [, if one thing is consequent on another thing, certainly also one thing is in conflict with another thing]. But if anything conflicts with anything, not every presentation is true; for that which conflicts with a thing conflicts as truth with falsehood or as falsehood with truth. 393. — Also, if it is the fact that all presentations are true, nothing is non-evident to us. For it is when one is true and another false, and we do not know which of them is true and which false, that we have a case of the non-evident, and the man who says “it is non-evident to me whether the stars are even in number or odd” is virtually saying that he does not know whether it is true or whether it is false that the stars are even or that they are odd. So that if everything is true and all presentations are true, nothing is non-evident to us. And if nothing is non-evident, all things are quite evident. And if all things are quite evident, there will be no such thing as inquiring and doubting about anything; for a man inquires and doubts about a matter which is to him non-evident, but not about what is apparent. But it is absurd to abolish inquiry and doubt; not every presentation, therefore, is true, nor are all things true.

394. Moreover, if every presentation is true and all things are true, there is no veracity or inerrancy, no instruction, no art, no proof, no virtue, nor any other thing of the kind. Let us consider this statement. If every presentation is true, nothing is false, and nothing being false lying will not exist nor error nor lack of art nor vice; for each of these things is connected with falsehood and derives its existence therefrom. 395. And if no one lies neither will anyone be telling the truth, and if no one is in error neither will anyone be found to be inerrant. In the same way, if there is no one inartistic the artist likewise is abolished, and the sage if no vicious man exists. For these things are conceived by way of correlation, and just as, if there is no right hand neither is there a left, and if there is no below neither is there an above, so, if one of two contraries does not exist, neither will the other subsist. Proof also and sign will vanish. 396. For the former is proof that the true exists but not the false; but if no falsehood exists, there is no need for anything to instruct us that falsehood does not exist. As to the sign and token, it was claimed that they serve to reveal what is non-evident, but if all things are true and self-apparent we do not need anything to indicate either the truth or falsity of a thing not known.

397. Yet why do we dilate on these details when neither animal nor universe in general “will exist if it be agreed that all presentations are true? For if all things are true, all things will be quite evident to us, and if so, it will also be valid and true that all things are non-evident to us, this being one of the “all things”; and if it be true that all things are non-evident we shall not admit that either animal or plant or universe appears to us; which is absurd. 398. For all these reasons, therefore, one must declare that not all presentations are true and credible, and indeed, for analogous reasons, that not all are false. For the statement “all are false” is equipollent with “all are true.” Wherefore also it will be possible for us to adduce against a position of this kind nearly all the objections previously stated. 399. For if all the presentations are false and nothing is true, it is true that “nothing is true.” If, therefore, nothing is true, a truth exists; and in this way Xeniades was driven round to the opposite of his original position, when he said that all presentations are false and that absolutely nothing true exists in the world. For, as a universal rule, it is impossible to assert that any particular thing is false without also affirming a truth. For example, when we assert that A is false, we are predicating the existence of that very falsity of A, and we are affirming that “A is false,” so that what we virtually declare is this — “It is true that A is false.” Simultaneously, then, with asserting a thing to be false we necessarily affirm the existence of truth. 400. And in the same fashion one may here show that the differences in presentations are well-nigh self-evident, owing to which some attract our assent while others repel it, and neither all alike attract nor all without exception repel, since, to be sure, if no difference existed but all were equally untrustworthy or trustworthy, there would exist no art nor lack of art, no praise, no blame, no deceit; for art and approval and lack of deceit are conceived through true presentations, but deceit and blame through false ones. One ought not, then, to assert either that all are true and trustworthy or that all are false and untrustworthy.

401. It remains, therefore, to affirm that some presentations are trustworthy, others untrustworthy, as the Stoics and the Academics have said, the Stoics approving the “apprehensive” presentations, and the Academics those which appear to be “probable.” But, on examining it closely, this view also seems to us more like a pious aspiration than the truth. 402. For an “apprehensive” presentation — to take this first — is one which is “imprinted and impressed by a real object and in accordance with that object itself, and such as could not be produced by anything not real.” As to the rest of this account Carneades says that he will concede it to the Stoics, but the clause “Such as could not be produced by what is not real” should not be conceded. For presentations are produced by non-real objects just as by real ones. 403. And the fact that they are found equally self-evident and striking is a token of their indistinguishability, while the fact that corresponding actions are linked to them is a token of their being equally striking and self-evident. For as in waking life the thirsty man feels pleasure in indulging in drink, and the man who flees from a wild beast or any other object of terror shouts and cries aloud, so also in dreams delight is felt by the thirsty when they think they are drinking from a spring, 404. and similarly fear is felt by those in terror:

  Achilles up-leapt in amazement,
Smiting together his hands, and a doleful word did he utter.

And just as in a normal state we believe and assent to very lucid appearances, behaving for instance, towards Dion as Dion, and towards Theon as Theon, so also in a state of madness some are similarly affected. 405. Thus Heracles, when he was mad and had received a presentation of his own children as though they were those of Eurystheus, followed up this presentation with corresponding action. And the corresponding action was to destroy his enemy’s children, which he did. If, then, presentations are apprehensive in so far as they attract us to assent and to the following of them up with corresponding action, then, since false ones also are seen to be of this kind, we must declare that the non-apprehensive presentations are indistinguishable from the apprehensive. 406. Moreover, just as the hero received a presentation of the bow and arrows, so also he received a presentation of his own children as being the children of Eurystheus. For the pre-existent presentation was one and the same and received by a man in the same condition; yet while that of the bow and arrows was true, that of the children was false. 407. So, since both affected him equally, one must admit that the one was indistinguishable from the other; and if that of the bow is termed “apprehensive,” because it was followed by the corresponding action when he used the bow as a bow, let it be said that the presentation of the children does not differ therefrom, inasmuch as it too was followed up by the corresponding action, — namely, the duty of slaying the enemy’s children. 408. Well then, this form of indistinguishability, in respect of the characteristic of self-evidence and intensity, is established. And that in respect of stamp and impression is proved no less surely by the Academics. They summon the Stoics to face apparent facts. 409. For in the case of things similar in shape but differing in substance it is impossible to distinguish the apprehensive presentation from the false and non-apprehensive. If, for example, of two eggs that are exactly alike I offer each one in turn to the Stoic for him to distinguish between them, will the Sage be able on inspection to declare indubitably whether the egg exhibited is this one or that other one? 410. And the same argument also holds good in the case of twins. For the Good Man will receive a false presentation, though he has that presentation “imprinted and impressed both by a real object and according to that very object,” if the presentation he gets be one of Castor as though it were of Polydeuces. It was this, too, that led to the framing of “the Veiled” argument; when a snake has thrust out its head, if we wish to examine the real object we shall be plunged into great perplexity and shall not be able to say whether it is the same snake that thrust its head out before or another one, as there are many snakes coiled up in the same hole. 411. So then the apprehensive presentation possesses no characteristic whereby it differs from the false and non-apprehensive presentations.

Furthermore, if anything else is apprehensive of anything, the sense of sight is so. But in fact, as we shall establish, sight is not apprehensive of anything; 412. therefore nothing is apprehensive of anything. For sight is thought to perceive colors and sizes and forms and motions, but it perceives none of these things, as will be apparent to us at once if we commence with colors. If then, as the Academics say, sight apprehends any color it will also apprehend that of man; but it does not apprehend this; neither then will it apprehend another color. 413. And that it does not apprehend this is quite evident; for this changes according to the seasons, occupations, natures, ages, circumstances, diseases, health, sleeping, walkng, so that while we know that it is thus varied we are ignorant of what in truth it is. And thus, if this color is not apprehensible neither will any other become known. 414. Moreover, we shall find the same kind of difficulty in the case of form. For the same thing is perceived as both smooth and rough, as in the case of pictures; and as both round and square, as in the case of towers; and as both straight and bent, as in the case of the oar when out of and in the water; and, as regards motion, both in motion and at rest, as in the case of persons seated in a ship or standing on the beach.

415. Again, if the non-apprehensive presentation coincides with the apprehensive presentation, the apprehensive presentation will not be the criterion of truth. For just as that which coincides with the crooked will not be the criterion of the straight, so the apprehensive presentation will not be the criterion if it coincides with false and non-apprehensive presentations. But the apprehensive presentation does coincide with non-apprehensive and false things, as we shall establish; so then the apprehensive presentation is not the criterion of the true and the false. 416. For in the case of the Sorites, when the last apprehensive presentation lies beside the first non-apprehensive one and almost defies distinction therefrom, Chrysippus declares that, in the case of presentations where the difference is so small, the Sage will pause and keep silence, but in cases where it appears greater he will assent to the former one as true, 417. If, then, we shall establish that many false and non-apprehensive things lie beside the apprehensive presentation, it is plain that we shall have shown that one ought not to assent to the apprehensive presentation, lest by approving of it we are driven on, because of their proximity, to give assent also to those which are non-apprehensive and false, even though the greatest possible difference may seem to exist between the presentations. 418. What I mean will be clear by an example. Let us assume as an apprehensive presentation “Fifty is few,” which seems far apart from this other, “Ten thousand is few.” Then, since the non-apprehensive presentation “Ten thousand is few” is very far removed from the apprehensive “Fifty is few,” the Good Man will not suspend judgment on perceiving this great difference but will assent to the apprehensive presentation “Fifty is few” and will not assent to the non-apprehensive “Ten thousand is few.” 419. But if the Sage will not assent to the “Ten thousand is few” inasmuch as it is far apart from the “Fifty is few,” it is plain, I presume, that he mil assent to “Fifty-one is few”; for there is nothing between this presentation and that of “Fifty is few.” But as “Fifty is few” was the apprehensive presentation placed last in order, “Fifty-one is few” is the first non-apprehensive one. The Good Man, therefore, will assent to the non-apprehensive presentation “Fifty-one is few.” And if he will assent to this as being in no wise different from “Fifty is few,” he will assent also to the non-apprehensive “Ten thousand is few”; 420. for every non-apprehensive presentation is equal to every other non-apprehensive presentation. Since, then, the non-apprehensive “Ten thousand is few” is equal to the “Fifty-one is few,” and this was not at all different nor remote from the apprehensive “Fifty is few,” the apprehensive “Fifty is few” will become equal to the non-apprehensive presentation “Ten thousand is few.” 421. And thus the apprehensive presentation, because of its indistinguishability, passes out along with the false and non-apprehensive.

Nor indeed is it possible to argue that not every non-apprehensive presentation is equal to every non-apprehensive presentation, but this one is more, that one less non-apprehensive, 422. since, in the first place, the Stoics will be in conflict both with themselves and with the nature of things. For just, as man, qua man, differs not from man, nor stone from stone, so neither does non-apprehensive presentation, qua non-apprehensive, differ from non-apprehensive presentation, nor false, qua false, from false. Zeno, too, setting out from this standpoint, taught that “Sins are equal.” 423. — Further, let it be granted that this presentation is more and that less non-apprehensive. How can this assist them? For it Mill follow that the Sage will not assent to the more non-apprehensive, but will assent to the less, which is absurd; for, according to them, the Sage possesses an infallible criterion, and is counted in all respects divine because he never opines, that is to say, assents to what is false, for therein consists the height of ill-fortune and the ruin of the foolish.

424. Moreover, in order that a sense-presentation, such as that of sight, should take place, it is necessary, according to them, that five things should concur — the organ of sense, the object of sense, the place, the manner, the intellect — since if one only be absent though all the rest be present (if, for instance, the intellect is in an abnormal state), the perception, they say, will not be safely effected. Hence, too, some have said that the apprehensive presentation is not a criterion universally, but only when it has no obstacle present. 425. This, however, is a thing impossible; for because of differences in the (sensory) passages and because of external circumstances and because of many other conditions things do not appear to us either the same or in the same way, as we argued above; so that while we can say that a thing appears by this particular sense and in this particular circumstance, we cannot be quite sure whether it is in very truth such as it appears, or is of one sort and appears to be of another; and on this account no presentation exists without an obstacle.

426. And of course they fall into the fallacy of circular reasoning. For when we inquire what the apprehensive presentation is, they define it as “That which is imprinted and impressed by a real object and according to that object itself, of such a kind as would not be produced by a non-real object.” Then again, since everything that is definitely explained is explained by things known, when we inquire further what the “real object” is, they turn round and say that “A real object is that which excites an apprehensive presentation.” So that, in order that we may understand the apprehensive presentation, we must first have grasped the real object, while in order to do this we must have recourse to the apprehensive presentation; and thus neither of them becomes clear as each awaits confirmation from the other. 427. — And just as — since some objects of presentation both appear and are real, while others appear but are not also real — we need a criterion that will establish for us which are both apparent and real and which are apparent but unreal, so, since some presentations too are apprehensive and some not, we require a criterion which will discriminate which are of the former kind and which are non-apprehensive and false. 428. This criterion, then, will be a presentation that is either apprehensive or not apprehensive. And if it is not apprehensive, it will follow that the not apprehensive presentation is the criterion once for all of everything, its function being to examine also the apprehensive, a result they will not admit; and if it is apprehensive, in the first place it is silly to say so (for the object of our inquiry was to judge when this particular presentation is apprehensive); 429. and secondly, if we adopt the apprehensive presentation as the criterion for distinguishing the apprehensive and non-apprehensive presentations, it will be necessary also that the fact that the presentation which judges them is really apprehensive should be tested by means of an apprehensive presentation, and this again by means of another, and so on ad infinitum.

430. But perhaps someone wall say that the apprehensive presentation is the criterion both of the presented object, that it truly subsists, and of itself, that it is apprehensive. But this is in nowise different from the converse assertion that the presented object is the test both of itself and of the presentation. For just as, when apparent things are contradictory, the question is by what shall we judge what is real and what not real, so also, when presentations are not in accord, we inquire by what we shall judge which of them is apprehensive and which not so. 431. Wherefore, as the things are similar, if the presentation, although not in accord, can be its own criterion, the presented object also, be it ever so contradictory, will be of itself trustworthy, which is absurd. 432. Or if this latter, in so far as it is contradictory, requires something to judge it, the presentation also will require something to test it, and to certify whether it is really apprehensive.

Again, if every conception of the fool is, according to them, ignorance and only the Sage speaks the truth and possesses firm knowledge of the true, it follows that, since up till now the Sage has proved undiscoverable, the true also is necessarily undiscoverable; and because of this, all things are non-apprehensible, seeing that we all, being fools, do not possess a firm apprehension of existent things. 433. And this being so, it is open to the Sceptics to repeat in turn against the Stoics the objections made by the Stoics against the Sceptics. For since, according to themselves, Zeno and Cleanthes and Chrysippus and the rest of their School are numbered among the fools, and every fool is enslaved to ignorance, Zeno certainly was ignorant whether he was contained in the universe or himself contained the universe, and whether he was a man or a woman; and Cleanthes did not know whether he was a man or a beast more full of wiles than Typhon. 434. Moreover, Chrysippus either knew this dogma, which is a Stoic one (I mean, that “The fool is ignorant of all things”), or he did not know even this. And if he knew it, it is false that the fool is ignorant of all things; for Chrysippus, who was a fool, perceived this very fact that the fool is ignorant of all things. But if he did not even know this very dogma that he is ignorant of all things, how does he dogmatize about many things, laying down that there is one universe, and that this is ordered by providence, and that its substance is to be wholly changed, and a multitude of other things? 435. And it is possible, should anyone so desire, for the opponent to bring against them all the other difficulties which they themselves are accustomed to bring forward against the Sceptics; but now that the character of the argumentation has been made clear, there is no need for a lengthy exposition.

Against those who accept the “probable” presentations the argument is brief. For of these criteria one or other of two things must be true; they are adopted by them as useful either for the conduct of life or tor the discovery of the truth of existing things. 436. And if the first is what they say, they will be absurd; for none of these presentations is able of itself to suffice for the conduct of life, but each of them requires also that observation which certifies that this one is for this reason “probable,” and that one for that reason “scrutinized and irreversible.” 437. But if they should pronounce them useful for the discovery of truth, they will come to grief. For the probable presentation alone is not the criterion of truth; for it is necessary, for the discovery of truth, that it should be scrutinized long before, owing to the fact that in our scrutiny of each of the things observed in connection with it we are certainly brought to suspect that possibly some one of the things that ought to be tested in that connection has been overlooked, because, if a reversal occurs in the intellect, knowledge of the truth is done away. 438. And in general, it seems that they are defeated by their own criticisms. For just as, in their disparagement of the apprehensive presentation, they kept saying that this is not the criterion of truth since other indistinguishable presentations lie beside it which are false, so it is not unlikely that, during our examination of the probable presentation, certain false things lie beside those which have been scrutinized, so that it appears (let us say) that we are in a fit condition of soul but we are not really so, or it appears that the presented object is seen from a measurable distance, whereas the fact is otherwise. 439. However, to sum up, if neither all presentations are trustworthy, nor all untrustworthy, nor some trustworthy, others untrustworthy, the presentation will not be the criterion of truth. Whereupon it follows that no criterion exists because neither that of the agent, nor that of the means, nor that “according to which,” provides knowledge that is secure.

440. But the Dogmatists are accustomed to retort by inquiring “How ever does the Sceptic show that there is no criterion? For he asserts this either without judging or with the help of a criterion; but if it is without judging, he will not be trusted, while if it is with a criterion, he will be self-refuted, and while asserting that there is no criterion he will agree to adopt a criterion in order to confirm that assertion.” 441. Again, when we pose the argument “If a criterion exists it is either judged or unjudged,” and draw one or other of two conclusions — either the regress ad infinitum or the absurdity of the statement that a thing is its own criterion, — they, in hostile array, declare that it is not absurd to admit that a thing is its own criterion; 442. for that which is straight is capable of testing both itself and other things, and the balance is capable of weighing both its own equality and that of other things, and light appears capable of revealing not only other things but itself as well, and consequently the criterion can stand as a criterion both of other things and of itself. 443. But in reply to the first point it should be stated that it is the Sceptic practice not to advocate things that are believed, but in their case to be satisfied with the general presumption as a sufficient ground in itself, but, on the other hand, to advocate the things which seem to be unworthy of belief and to bring each of these into a position of equipollence with the trust accorded to those which are deemed worthy of acceptance. So then, in the present case also, we do not employ the arguments against the criterion by way of abolishing it but with the object of showing that the existence of a criterion is not altogether to be trusted, equal grounds being presented for the opposite view. 444. In the next place, even if we seem to be really helping to abolish the criterion, we are able to use the presentation ready to hand, though not as a criterion; for when we state, in accordance with it, the probable arguments for the non-existence of the criterion that occur to us, we do indeed slate them, but when we do this we do not add our assent, owing to the fact that the contrary arguments are equally probable. 445. “But in sooth,” say they, “a thing can also be its own criterion, as was found in the case of the rule and the balance.” But this is childish. For above each of these there stands a superior criterion, such as sense and mind, because of which we proceed to the task of constructing them; but the Stoics do not allow that anything stands above the criterion which is now under discussion. So then, when it makes any statement about itself and has no evidence for its truthfulness, it is untrustworthy.

446. Thus much, then, concerning the criterion; and as this treatise is now sufficiently long, we shall make a fresh start and endeavor to discuss separately the subject of Truth itself.

Book VIII: Against the Logicians

1. The difficulties that are usually stated by the Sceptics in order to abolish the criterion of truth have now been reviewed by us in the treatise already completed; and after giving their account of the investigation from the time of the early physicists down to the later philosophers, we promised, in addition to all this, to discuss separately the subject of Truth itself. So now in fulfilling our promise let us consider first of all whether anything true exists.

Chapter I: Does Anything True Exist?

2. That, if no clear criterion exists, Truth likewise is rendered non-evident is at once apparent to everyone; none the less it will be possible for us to show also — by way of further confirmation — that, even if we assert nothing directly against the criterion, the dissension which exists about Truth itself is enough to drive us to a position of suspended judgment; 3. and just as, if nothing straight nor crooked exists in the nature of things, neither does there exist a rule capable of testing them; and if no heavy or light body exists, the construction of the balance likewise is abolished; so too, if nothing true exists, the criterion of truth also disappears. And the fact that there is nothing true or false — if we are to judge by the statements of the Dogmatists — we shall learn when we have first set out the controversy which has arisen among them on this subject. 4. — Of those who have inquired concerning Truth, some say that there is not, others that there is, something true; and of the latter, some have said that only intelligibles are true, others that only sensibles, and others that both sensibles and intelligibles alike are true. 5. Thus Xeniades the Corinthian, as we indicated above, declares that nothing is true; and so also, perhaps, Monimus the Cynic when he said that “All things are vanity” (that is to say, a vain fancy that non-existents are existent). 6. Plato and Democritus supposed that only intelligibles are true; but whereas Democritus did so because nothing sensible exists by nature, — since the atoms which compose all things possess a nature which is void of every sensible quality, 7. — Plato did so because sensibles are always becoming and never being, as their substance keeps flowing like a river, so that it does not remain the same for two moments together, and (as Asclepiades said) does not admit of being pointed out twice owing to the speed with which it flows. 8. Aenesidemus “according to Heracleitus” and Epicurus both alike fell back on sensibles but differed as to details. For Aenesidemus says that there is a difference in things apparent, and asserts that some of them appear to all men in common, others to one person separately, and of these such as appear to all in common are true, and the other sort false; whence also that which does not escape the common knowledge is by derivation termed “true.” But Epicurus asserts that all sensibles are true and existent. For there is no difference between saying that a thing is “true” and saying that it is “subsisting.” Hence too, in describing truth and falsity, he says “That is true which is in the state in which it is said to be,” and “False is that which is not in the state in which it is said to be.” And he says that sense, being perceptive of the objects presented to it and neither subtracting nor adding nor transposing aught through being irrational, constantly reports truly and grasps the existent object as it really is by nature. And whereas all the sensibles are true, the opinables differ, and some of them are true, others false, as we showed before. 10. But the Stoics assert that some sensibles and some intelligibles are true, the sensibles, however, not directly so but by reference to the intelligibles associated with them. For according to them the True is “that which subsists and is opposed to something,” and the False “that which is not subsistent and is opposed to something”; and this being an incorporeal judgment is an intelligible.

11. Such, then, was the first disagreement about Truth; but there was also another controversy, and in this some placed truth and falsity in the thing signified, others in the sound, others in the motion of the intellect. The champions of the first opinion were the Stoics who said that “Three things are linked together, the thing signified and the thing signifying and the thing existing”; 12. and of these the thing signifying is the sound (“Dion,” for instance); and the thing signified is the actual thing indicated thereby, and which we apprehend as existing in dependence on our intellect, whereas the barbarians although hearing the sound do not understand it; and the thing existing is the external real object, such as Dion himself. And of these, two are bodies — that is, the sound and the existing thing — and one is incorporeal, namely the thing signified and expressible,” and this too is true or false. But this is not all alike (true or false), it being partly incomplete and partly self-complete. And of the self-complete that (part is true or false) which is termed “judgment,” and which they describe by saying “A judgment is that which is true or false.” 13. But Epicurus and Strato the physicist, as they admit only two of these — the thing signifying and the thing existing, — appear to hold the second view and to ascribe truth or falsity to the sound. The last opinion — that, I mean, which places truth in the motion of the intellect — seems to be merely a Schoolman’s invention.

14. So then, as a summary account has now been given of the investigation of this subject, let us proceed to the particular criticisms, some of which will be directed generally against all the views put forward, others separately against each of those views. 15. And let us discuss the general kind first. He, then, who says that something true exists either only asserts that something true exists or proves it. And if he merely asserts it, he will be told the opposite of his mere assertion, namely, that nothing is true. But if he proves that something is true, he proves it either by a true proof or by one that is not true. But he will not say that it is by one not true, for such a proof is not to be trusted. And if it is by a true proof, whence comes it that the proof which proves that something is true is itself true? If it is true of itself, it will be possible also to state as true of itself that truth does not exist; 16. while if it is derived from proof, the question will again be asked “How is it that this proof is true?” and so on ad infinitum. Since, then, in order to learn that there is something true, an infinite series must first be grasped, and it is not possible for an infinite series to be grasped, it is not possible to know for a surety that something true exists.

17. Moreover, if anything true exists it is either apparent or non-evident or partly apparent and partly non-evident. But it is neither apparent, as we shall establish, nor non-evident, as we shall prove, nor partly apparent and partly non-evident, as we shall demonstrate; therefore, there does not exist anything true. 18. For if it is apparent, either everything apparent is true or something apparent is true. But everything apparent is not true (for what is experienced in sleep or in madness is not true); since otherwise, as things apparent are frequently conflicting, we should have to allow that conflicting things are alike real and are equally true, which is absurd. So, then, not every apparent thing is true. 19. And if something apparent is true and something is false, we ought to have a criterion for discerning which apparent thing is true and which false. This criterion, then, is either apparent to all or non-evident. But if it is apparent, since not every apparent thing is true, this too, being an apparent thing, will need to be tested by another apparent thing, and that again by a different one, and so we go on ad infinitum. 20. And if it be non-evident, it is not the apparent things alone that will be true but the non-evident things as well. For if we accept the non-evident thing which is adopted for confirming the apparent thing, something non-evident must be true; for assuredly the true is not judged by the false. 21. But if something non-evident is true, not the apparent only is true, as was originally assumed. Further, how comes it that this non-evident thing is true? For if it is so of itself, then all things which are non-evident will be true of themselves. But if it is so because of proof, it will certainly be either by means of a non-evident or by means of an apparent proof that it is proved to be true. And if it is by means of a non-evident proof, that in turn will need to be judged by means of some other proof, and the third by a fourth, and so on ad infinitum. 22. But if it is by means of an apparent proof, we shall be wrecked on the fallacy of circular reasoning, when we confirm the apparent by the non-evident, and again conversely establish the non-evident by means of the apparent. 23. But if neither every apparent thing is true nor something apparent, then nothing apparent is true — Nor, indeed, is (the true) non-evident. 24. For, again, if the true is non-evident, either everything non-evident is true, or not everything; but neither is everything non-evident true nor something non-evident, as we shall establish; therefore the true is not non-evident. For if everything non-evident is true, then, in the first place, the Dogmatists ought not to have quarreled — some of them, for example, saying that there is one element, others two, some a definite number, others an infinite number, — nor ought they to have given the lie to one another’s opinions. 25. And if everything non-evident is true, things which conflict will be true — for instance the statement that the stars are even in number and that they are odd; for they are equally non-evident, and all non-evident things are true. But of course conflicting things cannot be true; therefore not all non-evident things are true. 26. — Nor, again, are some non-evident things true. For the statement that this non-evident thing is true and that false is made either of itself and wnthout a criterion or with a criterion. And if it is so stated off-hand, we shall have no answer to make to him who declares that the opposite is true. 27. But if it is stated with a criterion, certainly this criterion is either apparent or non-evident. And if it is apparent the original assumption that only the non-evident is true will be false. 28. Furthermore, whence comes it that the criterion itself whereby we judge the apparent thing is true? If it is so of itself, then the (opponent’s) statement that it is not true will also of itself be trustworthy; and if it is so because of an apparent thing, then that apparent thing too will be derived from another apparent thing, and so on ad infinitum; 29. and if it is so because of a non-evident thing, the argument will take the form of circular reasoning, as we are neither able to count the apparent thing trustworthy apart from the non-evident nor the non-evident well-founded without the apparent. So, then, the non-evident cannot be true either.

30. It remains, therefore, to say that what is partly apparent and partly non-evident is true (; but this is silly). For if we assume that this apparent thing, in so far as it is apparent, is true, we assume it to be true either in so far as every apparent thing, or in so far as not every such thing, is true; and if the non-evident thing, in so far as it is non-evident, is assumed to be true, it is assumed to be true either in so far as every non-evident thing, or in so far as not every such thing, is true. And, for the rest, we shall continue to raise the same difficulties. 31. Hence if neither the apparent thing is true nor the non-evident, nor that which is partly apparent and partly non-evident, and besides these no other alternative exists, then of necessity nothing is true.

32. Some people also bring up the difficulty about the summum genus. For this is a genus which stands above all others and is itself subordinate to no other. This, then, is either true or false or at once both true and false or neither true nor false. 33. And if it is true, all things will be true, inasmuch as they are particular specimens of it; and just as, because the genus of man is Man, the particulars are men, and because it is Rational, all the individuals are rational, and because it is Mortal, they likewise are mortal; — so too, if the all-inclusive genus is True, all existing things will necessarily be true also. 34. And if all things are true, nothing will be false, and if there exists nothing false neither will there be anything true, as we pointed out above when we showed that each of these opposites is conceived as in correlation with the other. Besides, if all things are true we shall be affirming that conflicting things are true, and this is absurd. 35. So then the summum genus is not true. — Nor indeed is it false, because of the like difficulties. For if it is false, all things that partake of it will be false; but all things, both corporeal and incorporeal, partake of it; all things, therefore, will be false. And analogous difficulties will follow on the statement that all things are fake. 36. — It remains, then, to say that it is at once both true and false or that it is neither true nor false. But this is worse than the alternatives already stated, because it results from this that all the particulars are at once both true and false, or neither true nor false, which is absurd. There does not, then, exist anything true.

37. Again, the true is either an absolute and natural thing or a relative thing; but it is neither of these, as we shall establish; therefore the true does not exist. The true does not exist absolutely and by nature inasmuch as what subsists absolutely and by nature moves those who are in a like condition in the same way — the hot, for instance, is not hot to one man and cold to another but hot to all who are in the same condition. 38. But the true does not move all alike, but the same thing in relation to this man seems to be true, but in relation to that other man false. Therefore the true does not belong to the class of things which subsist absolutely and by nature. — And if it belongs to the class of things relative, then, since relatives are only conceived and have no real existence, the true also will certainly be only a concept and will not really exist. 39. Besides, if the true is a relative thing, the same thing will be at once both true and false; for just as the same thing is both right and left — right relatively to this object, left relatively to that, — and just as the same thing is said to be both above and beneath — above relatively to what lies below it, and beneath relatively to what lies above it, — so we shall call the same thing both true and false. And if so, it will be no more true than false, and certainly not true.

40. Aenesidemus, too, virtually states difficulties of a similar kind regarding this topic. If anything true exists it is either sensible or intelligible or both intelligible and sensible. But it is neither sensible nor intelligible nor both at once, as shall be established; therefore there does not exist anything true. 41. Now that it is not sensible, we shall argue in this way; — Of things sensible some are genera, some particulars, and genera are the common qualities which pervade the particulars — as Man is that which ranges through the particular men, and Horse through the particular horses, — whereas particulars are the separate individual qualities — of Dion, Theon, and the rest. 42. If, then, the true is sensible, it too will either be the common property of many or it will constitute an individual quality; but it is neither a common nor an individual property; therefore the true is not sensible. 43. — Again, just as the visible object is perceptible by vision, and the audible is known by hearing, and the odorable by smell, so too what is sensible is known by sense in general. But the true is not known by sense in general, for sense is irrational and the true is not kno\vn irrationally. Therefore the true is not sensible. 44. — Nor, indeed, is it intelligible, for if so none of the sensibles will be true; and this again is absurd. For either it will be intelligible to all in common or to some separately. But the true is not capable of being intelligible either to all in common or to some separately; 45. for it is impossible for it to be thought by all in common, and it becomes untrustworthy and debatable if thought by one or more persons separately. Therefore the true is not intelligible either. — Nor yet is it at once both sensible and intelligible. For either everything sensible and everything intelligible is true or something sensible and something intelligible. 46. But to assert that everything sensible and everything intelligible is true is a thing impracticable; for sensibles conflict with sensibles and intelligibles with intelligibles, and conversely sensibles with intelligibles; and, if all things are true, it will necessarily follow that the same thing both is and is not existent, and that it is both true and false. Nor again is it feasible to hold that something sensible is true and something intelligible true; 47. for this is the point at issue. And besides it is logically consistent either to say that all sensibles are true or to say that all are false; for sensibles are on an equality, not one more and one less sensible, and intelligibles again are equally intelligible and not one more and one less intelligible. But not all sensibles are termed true, nor all false; therefore there is not anything true.

48. “Yes, but the truth is perceived not in so far as it appears but owing to another cause.” What, then, is this cause? Let the Dogmatists state it openly so that it may either attract us to assent or repel us to avoidance. 49. Further, how do they perceive this cause itself? As appearing to them or as not appearing? If as appearing, they lie when they say that truth does not exist in so far as it appears; but if as not appearing, how have they perceived what is not appearing to them? Through itself or by means of another? 50. To perceive it through itself is impossible, for nothing which does not appear is perceptible through itself; while if it is by means of another, is this in turn appearing or not appearing? And as the inquisition thus proceeds ad infinitum, the true becomes undiscoverable.

51. What then? Is that which persuades us, “the probable,” to be termed “true” whatever be the nature it possesses, whether sensible or intelligible or a combination of both sensible and intelligible at once? But neither is this feasible. 52. For if the probable is true, then because the same thing does not convince all men nor the same men always, we shall be granting that the same thing both does and does not exist, and that the same thing is at once both true and false; for in so far as it convinces some it will be true and existent, but in so far as it does not convince others it will be false and non-existent. But it is impossible that the same thing should both exist and not exist, and be both true and false; 53. so, then, the probable is not true either. That is, unless we shall declare that what convinces many is true; thus, honey, which convinces many healthy people of its sweetness but does not convince one man who suffers from jaundice, we truly describe as sweet. But this is nonsensical. For when we are investigating truth we ought not to pay regard to the numbers of those who are in agreement but to their conditions. And the diseased person is in one condition, and all the healthy persons in one bodily state. 54. One ought not, then, to trust the one condition more than the other, since if we assume, conversely, that many get a bitter taste from the honey (feverish people, for instance), while one man who is healthy gets a sweet taste, it will certainly follow that we must call the honey bitter, which is absurd. As, then, in this case we set aside the evidence of the multitude and none the less declare honey to be sweet, so also when many taste it sweet and one tastes it bitter, let us give up calling honey sweet because of the numbers of those who experience it as such, and let us investigate the truth in another way.

55. Of some such kind are the general difficulties raised about “the true”: let us pass on next to the particular difficulties. Now as to those who assert that all things are false, we proved above that they are confuted. For if all things are false, the statement “All things are false,” being one of the “all things,” will be false. And if the statement “All things are false” is false, its contradictory, “Not all things are false,” will be true. Therefore, if all things are false, not all things are false. 56. And Democritus and Plato, by rejecting the senses and abolishing sensibles and following intelligibles only, throw things into confusion and shake to pieces not only the truth of existing things but even the conception of them. For every thought occurs either owing to sensation or not apart from sensation, and either owing to experience or not without experience. 57. Hence we shall find that not even the so-called false presentations — such as those in dreams or madness — are detached from things known to us by experience through sense. And in fact when the hero in his madness imagines as his Furies

Maids shaped like dragons and all blood-besprent,

he is conceiving a shape compounded of things that have appeared to his senses. And in the same way he who in his sleep dreams of a winged man does not dream so without having seen some winged thing and a man. 58. And in general it is impossible to find in conception anything which one does not possess as known by experience. For such a thing will be grasped either by way of resemblance to things which have been presented in experience, or by way of enlargement thereof, or of diminution, or of composition. 59. Thus, by way of resemblance, as when because of the likeness of Socrates which has been seen we conceive Socrates who has not been seen; and by way of enlargement, when starting from the common man we move on to a conception of one of such a kind that he was

Less like a corn-eating man than a forest-clad peak of the mountains
Towering high;

and by way of diminution, 60. when, on the contrary, we decrease the size of the common man and grasp a conception of the pygmy; and by way of composition, when from man and horse we derive the conception of a thing we have never perceived — the Hippo-centaur. Every conception, then, must be preceded by experience through sense, and on this account if sensibles are abolished all conceptual thought is necessarily abolished at the same time. 61. — Further, he who declares that all apparent things are false and that only intelligibles exist “in sooth” — that is, in truth — will, in saying so, either use mere assertion or will prove it. But if he is stating it by assertion he will be checked by assertion, and if he tries to adduce proof he will be overthrown. 62. For he will show that only intelligibles exist “in sooth” by means of either an apparent thing or a non-evident. But he will show this neither by an apparent thing, for such does not exist, nor by a non-evident, for the non-evident must be confirmed beforehand by an apparent. So, then, the view of Democritus and Plato is not logically sound.

63. Epicurus asserted that “All sensibles are true and every presentation is of a real object and is of the same kind as is the object which excites the sensation, and those who say that some presentations are true, others false, are led astray orving to their inability to separate opinion from clear evidence. Thus in the case of Orestes, when he fancied he saw the Furies, his sense excited by images was true (for the images really existed), but his mind, in thinking that the Furies were solid, formed a false opinion. 64. And besides,” he says, “the persons mentioned above, when introducing a difference in the presentations, are not capable of confirming the view that some of them are true, others false. For neither by means of an apparent thing will they prove such a statement, since it is apparent things that are in question, nor yet by a non-evident, since the non-evident must needs be proved by means of an apparent.” 65. In saying this Epicurus has unwittingly fallen into a similar difficulty. For if he allows that some presentations come from solid bodies and others from images, and grants that clear evidence is one thing, opinion another, how, I ask, does he distinguish the presentations which occur from a solid body and those from an image? For he can do so neither by evidence, this being in question, nor by opinion, for this must be confirmed by means of evidence. 66. Besides, it is absurd of him to try to prove the less questionable things by the more questionable. For when we are inquiring about the trustworthiness of things apparent, he introduces that marvelous and mythical doctrine of his about the images.

67. Nor, indeed, is the Stoic theory free from difficulty. For while they urge that a difference exists in both sensibles and intelligibles, by which some of them are true, others false, they are unable to deduce this by logic. For they have allowed that some presentations are “vacuous” — such as those which Orestes received from the Furies, — and that others are “distorted,” being derived from real objects but not in conformity with those objects themselves, — as was that which came to Heracles in his madness from his own children as though from those of Eurystheus; for it came from the children who really existed, but not in conformity with the actual real objects; for he did not see the children as his own, but declares —

This nestling of Eurystheus slain by me
Pays for his father’s ennuty by death.

68. And this being so, the presentations are indistinguishable and the Stoics are unable to say which are in truth apprehensive and are derived from real objects and in conformity with those objects themselves, and which are not of this kind, as we have already shown more at length.

69. What we have said regarding this view is very much the same as what we have to say about the remaining view, according to which some assume truth and falsity to lie in the thing signified — that is to say in the incorporeal “expression,” — others in the sound, others in the motion of the intellect. 70. Thus, for instance, to start with the first view, the Stoics maintained that truth and falsity exist in the “expression.” And they say that “expression” is “that which subsists in conformity with a rational presentation,” and that a rational presentation is one in which it is possible to establish by reason the presented object. And of expressions they term some “defective,” others “self-complete”; the defective we may now pass over, but of the self-complete there are, as they assert, several varieties; 71. for in fact they call some “jussive,” such as we utter in giving an injunction, as for example —

Come thou hither, O lady dear;

others “declaratory,” such as we utter when making a statement, as for example — “Dion is walking about”; and others “interrogations,” which we utter when asking a question, as for instance — “Where does Dion dwell?” 72. And some, too, are named by them “imprecatory,” which we utter when we curse —

E’en as this wine is spilt, so may their brains be spilt earthwards;

also “precatory,” which we utter in prayer, of which this is an example —

Zeus, my Father, who rulest from Ida, majestic and mighty,
Victory grant unto Ajax and crown him with glory and honor.

73. And they also term some of the self-complete expressions “propositions,” in uttering which we either speak the truth or lie. Some, too, are more than propositions. The following, for instance, is a proposition —

The cowherd doth resemble Triam’s sons;

for in uttering it we are either telling the truth or lying; but a phrase like this —

How like to Priam’s sons the cowherd is,

is somewhat more than a proposition and is not a proposition. 74. As, however, there is considerable difference in the expressions in order that a thing may be true or false it must first of all, they say, be an expression, and next self-complete, and that, too, not of any and every kind but a proposition; for, as I said before, it is only when we utter this that we speak a truth or a falsehood. 75. How then, say the Sceptics, can they establish that there exists any incorporeal expression which is separate both from the signifying sound, such as “Dion,” and from the actual object, such as Dion himself? For the Stoics will either declare offhand that this subsists or they will demonstrate its existcnce by proof. 76. And if they shall declare offhand that this incorporeal expression subsists, it will be possible for us also to declare offhand that it does not exist; for just as they are to be trusted without proof, so likewise the Doubters are to be trusted when by means of bare assertion they maintain the opposite, or, if they are distrusted, the Stoics also will become similarly distrusted. 77. And if they shall support the statement by proof, they will find themselves faced in consequence with a worse difficulty. For proof is speech, and speech is composed of expressions. The Stoics, then, will be establishing by expressions the existence of an expression, which is nonsensical, since the man who does not grant that any expression exists will not grant either that many expressions exist. 78. Also, when the existence of the expressions of the proof is in question, if they shall perceive their existence directly, the Doubters also will perceive their non- existence directly, and if they perceive it as a result, of proof, they will fall into the fallacy of regress ad infinitum; for they will be asked for a proof of the expressions contained in the second proof, and of those in the third when they bring forward a third, and of those in the fourth when they bring forward a fourth, so that their proof of the existence of expression is without a starting-point.

79. Many other arguments regarding this topic might be adduced, but it will he more opportune to go through them in our chapter “Concerning Proof.” For the present, let this one be stated; They hold that the self-complete proposition is a compound — “day exists,” for example, is compounded of both “day” and “exists.” But no incorporeal thing can be either compounded or divided; for these are things peculiar to bodies. So, then, there is no self-complete [object or] proposition. 80. — Further, every expression must be expressed, since from this it has got its name; but no expression is expressed, as the Doubters establish; therefore no expression exists. Whereupon it follows that no proposition, true or false, exists. For “to express” is, as the Stoics themselves declare, “to utter the sound capable of signifying the object conceived” — this verse, for instance,

Sing, O goddess, the fury of Peleus’ offspring Achilles.

81. But it is not feasible to utter the sound capable of signifying this, because that object whose parts do not co-exist does not exist itself, and the parts of this object do not co-exist, so that neither is it capable of existing itself. And the fact that its parts are not capable of co-existing is proved directly. For when we utter the first half-verse, the second is not yet in existence; and when we utter the second, the first is no longer in existence; so that we do not utter the whole verse. 82. Nor, indeed, even the half-verse. For when, once more, we are saying the first part of the half-verse, we are not then uttering as yet the second part of it; and when we utter the second, we are no longer saying the first; so that the half-verse does not exist either. Nor, if we consider it, does even a single expression, such as “fury.” exist; for when we are saying the syllable “fu” we are not as yet uttering the “ry,” and when we utter the “ry” we are no longer saying the “fu.” 83. If, then, it is impossible for anything to exist if its parts are incapable of co-existence, and it has been proved in the case of one locution that its parts are incapable of co-existence, we must declare that no locution exists. And for the same reason, also, no proposition exists either; for they assert it to be a compound, as for instance “Socrates exists.” For when “Socrates” is being said, “exists” does not yet exist; and when “exists” is being said, “Socrates” is not being said. Therefore the whole proposition never exists, but parts of the whole; and its parts are not propositions. Therefore no proposition exists. 84. Yet why should we discuss the whole proposition “Socrates exists,” when even its nominative case, “Socrates,” taken by itself cannot be conceived as in existence for the same reason — I mean, for the reason that its component parts do not co-exist?

85. But if it be granted that a proposition exists, the Sceptics will not admit that a true or a false proposition exists, because this is not easy of explanation for those with whom they are arguing. For these assert that a true proposition is that which subsists and is opposed to something, and a false one that which is not subsisting but is opposed to something. And when asked “What is that which subsists?” they reply “That which excites an apprehensive presentation”; 86. next, when examined concerning the apprehensive presentation they have recourse again to “the subsistent,” which is equally unknown, saying “An apprehensive presentation is that derived from a subsisting object in conformity with that object itself.” And this is equivalent to teaching the unknown thing by means of an unknown thing and falling into the fallacy of circular reasoning. For in order that we may learn the subsistent they send us off to the apprehensive presentation, saying that the subsistent is that which excites an apprehensive presentation; and in order that we may get to know the apprehensive presentation they send us back to the subsistent. As we know, then, neither the latter nor the former, neither shall we understand the true or false proposition which is explained through them.

87. And even if one sets aside this difficulty, another will pop up, greater than this, for those who accept the logical system of Stoicism. For just as, if we wish to learn what Man is, we ought to know first what Animal is, and what Rational is, and what Mortal is (for the concept of Man is compounded of these), — and just as, if we desire to know what Dog is, it will first be necessary for us to have grasped again what Animal is, and what “Capable of barking” is (for out of these was formed the concept of Dog), 88. — so likewise if the True is, according to the Stoics, that which subsists and is opposed to something, and the false that which is not subsistent but is opposed to something, in order to conceive these things we must necessarily know what the “opposed” thing is. But the Stoics are certainly not able to explain to us the “opposed”; neither, then, will the true or the false become known. 89. For they say that “Opposed things are those of which the one exceeds the other by a negative.” — for instance “It is day — it is not day.” For the proposition “It is not day” exceeds the proposition “It is day” by the negative “not,” and because of this it is opposed thereto. But if this is “opposed,” such propositions as the following will also be opposed — “It is day and it is light” and “It is day and it is not light”; for the proposition “It is day and it is not light” exceeds “It is day and it is light” by the negative. But in fact, according to them, these are not “opposed”; therefore things are not “opposed” through the one exceeding the other by the negative. 90. “Yes,” they reply, “but they are opposed with this (added condition) that the negative is prefixed to one of the propositions; for then it controls the whole proposition, whereas in the case of “It is day and it is not light,” the negative, being a part of the whole, does not control the whole so as to render it negative. In that case, we will reply, to the concept of “things opposed” it should have been added that they are opposed not when the one simply exceeds the other by the negative, but when the negative is prefixed to the proposition.

91. Some other man, too, will adopt the argument of Plato, which he uses in his book On the Soul, and will show that it is not possible for the proposition by participation in the negative to exceed that which has no negative. For as nothing becomes cold by participation in the hot, so nothing becomes great, but small, by participation in the small; and as a thing becomes great by participation in the greater, so also a thing will be small by participation in the small. And because of this, too, the nine does not become greater through the addition of the monad. 92. For the one is less than the nine; so by the addition of it the nine will not become more than nine, but rather less. Since, then, the negative “not” is a smaller thing than the proposition, it will not make the proposition greater, seeing that, just as a thing becomes greater by participation in a magnitude, so also it is rendered smaller by participation in a smaller thing.

By some, then, the argument of Plato ivill be transferred in this wise to our topic; 93. but let us supplement the arguments already put forward by stating this further argument: If the true is a proposition, it certainly is either a simple proposition or a not simple or both a simple and a not simple. For the Dialecticians proclaim that almost the first and most important distinction in propositions is that by which some of them are simple, others not simple. And simple are all those which are neither compounded of one proposition twice repeated, nor of different propositions, by means of some one or more conjunctions; as for example “It is day,” “It is night,” “Socrates is conversing,” and every proposition of similar form. 94. For just as we call the web “simple,” although it is composed of threads, since it is not woven of webs, which are homogeneous with itself, so propositions are called “simple” since they are not compounded of propositions but of certain other things. For example, “It is day” is a simple proposition inasmuch as it is neither formed from the same proposition twice repeated nor compounded of different propositions, but is constructed of certain other elements, namely “day” and “it is.” 95. Moreover, there is no conjunction in it either. And “not simple” are those which are, so to say, double, and all such as are compounded of a proposition twice repeated, or of different propositions, by means of one or more conjunctions, as for example — “If it is day, it is day”; “If it is night, it is dark”; “Both day exists and light exists”; “Either day exists or night exists.” 96. — And of the simple some are “definite,” some “indefinite,” some “intermediate”; the definite are those uttered indicatively, for example “This man is walking,” “This man is sitting” (for I am indicating some particular person). 97. “Indefinite,” according to them, are those in which some indefinite part is dominant, as for example “Someone is sitting”; and “intermediate” those like this, “A man is sitting” or “Socrates is walking.” Now “Someone is walking” is indefinite since it does not define any one of the individuals who are walking; for it can be applied in common to each one of them; but “This man is sitting” is definite because it defines the person indicated. And “Socrates is sitting” is intermediate, because it is neither indefinite (for it defines the particular object), nor definite (for it is not uttered indicatively), but seems to be intermediate between these two, the indefinite and the definite. 98. And they say that the indefinite — “Someone is walking” or “Someone is sitting” — becomes true when the definite — “This man is sitting” or “This man is walking” — is found to be true; for if no one particular person is sitting the indefinite proposition “Someone is sitting” cannot be true.

99. Such then, to speak summarily, are the statements made by the Dialecticians regarding the “simple” propositions. But the Doubters inquire, firstly, whether the “definite” can be true; for if this is abolished, the “indefinite” cannot be true either; and if the indefinite also is abolished, neither will the “intermediate” subsist. But these are elements, as it were, of the simple propositions; so that if they are rejected the simple propositions also will disappear, and it will not be possible to assert that the true exists in the simple propositions. 100. — Now as to this definite proposition “This man is sitting” or “This man is walking,” they declare that it is true when the thing predicated, such as “sitting” or “walking,” belongs to the object indicated. But when, in the statement “This man is walking,” some one particular man is indicated, the person indicated is either (let us say) Socrates or a part of Socrates; but the person indicated is neither Socrates nor a part of Socrates, as we shall establish; therefore the definite proposition cannot be true. 101. Now Socrates is not the object indicated inasmuch as (he being compounded of soul and body) neither his soul nor his body is indicated, so that he will not be indicated as a whole either. Nor yet is a part of Socrates the object indicated; for if they assert that the thing predicated (walking or sitting) belongs to the object indicated, while the thing predicated, such as walking or sitting, never belongs to the part indicated, it being very small, it necessarily follows that the part will not be the object indicated. 102. But if neither this nor Socrates (is indicated), and besides these there is no other alternative, then the definite proposition as indicatively stated disappears — in addition to the fact that it also becomes practically indefinite. For if the thing indicated admits of being this part of Socrates, and admits also of being not this part but another, then the whole necessarily becomes indefinite. If, then, the definite proposition is non-existent, neither will the indefinite exist. And because of this the intermediate will not subsist either.

103. Furthermore, when they say that the proposition “It is day” is at present true but “It is night” false, and “It is not day” false but “It is not night” true, one will ponder how a negative, which is one and the same, when attached to things true makes them false, and attached to things false makes them true. For this is like the Silenus in the riddle of Aesop who, on seeing the same man in the winter season blowing with his mouth both to save his hands from being cold, and to save himself from being burnt, declared that he could not endure to live with a beast of a kind such that out of him proceed things most opposite. 104. Thus, too, the negative itself, by making existing things non-existent and non-existents existent, partakes of the miraculous. For they claim that it either exists or exists not, or (neighter exists nor exists not, or) both exists and exists not. And if it exists, how, by its attachment to an existing thing, does it make the whole non-existent and not, rather, existent? For an existing thing attached to an existing thing further strengthens its existence. 105. But if it is non-existent, for what reason when attached to what does not exist does it make it existent and not, rather, non-existent? For a non-existent attached to a non-existent produces, not existence but non-existence. Or how when it is non-existent does it transform the existent into non-existence, instead of making it partly existent and partly non-existent? For just as white and black, when put together, do not make black or white but what is partly white and partly black, so also the non-existent combined with the existent will make the whole partly existent and partly non-existent. 106. Besides, that which makes something non-existent makes something, and that which makes is and exists; the negative, therefore, as not existing, will not make anything non-existent. It remains, therefore, to say that it neither exists nor exists not. But if such is its nature, how, once more, when it neither exists nor exists not, does it cause non-existence when attached to what does not exist? 107. For just as that which is neither hot nor cold when attached to what is hot cannot make it cold, nor the cold hot, so it is contrary to reason that what is neither existent nor non-existent when attached to the existent should produce non-existence, and when attached to the non-existent, existence. And it will also be open to us to raise the same difficulties if they should declare that the negative is partly existent and partly non-existent.

108. And now that we have in some degree handled the legislation of the Dialecticians regarding simple propositions, let us proceed also to that which concerns the non-simple. Now non-simple propositions are those already mentioned above, being such as are composed of a duplicated proposition or of differing propositions, and are controlled by a conjunction or conjunctions. 109. Of these let us take for the present the hypothetical proposition so-called. This, then, is composed of a duplicated proposition or of differing propositions, by means of the conjunction “if” or “if in fact”; thus, for example, from a duplicated proposition and the conjunction “if” there is composed such a hypothetical proposition as this — “If it is day, it is day”; 110. and from differing propositions, and by means of the conjunction “if in fact,” one in this form — “If in fact it is day, it is light.” And of the propositions contained in the hypothetical proposition that which is placed after the conjunction “if” or “if in fact” is called both “antecedent” and “first,” and the other one both “consequent” and “second,” even if the whole proposition is reversed in order of expression, as thus — “It is light, if in fact it is day”; for in this, too, the proposition “it is light” is called “consequent” although it is uttered first, and “it is day” antecedent, although it is spoken second, owing to the fact that it is placed after the conjunction “if in fact.” 111. Such then — to put it briefly — is the construction of the hypothetical proposition, and a proposition of this kind seems to promise that its second logically follows its first, and that if the antecedent exists the consequent will exist. Hence, if this sort of promise is fulfilled and the consequent follows the antecedent, the hypothetical proposition is true; but if it is not fulfilled, it is false. 112. Accordingly, let us begin at once with this problem, and consider whether any hypothetical proposition can be found which is true and which fulfills the promise described.

Now all the Dialecticians agree in asserting that a hypothetical proposition is valid when its consequent follows (logically) its antecedent; but as to when and how it so follows they disagree with one another and propound conflicting criteria of this “following.” 113. Thus Philo “declared that” the hypothetical is true whenever it does not begin with what is true and end with what is false”; so that, according to him, the hypothetical is true in three ways and false in one way. For whenever it begins with truth and ends in truth it is true, as thus — “If it is day, it is light.” And whenever it begins with what is false and ends in what is false, once more it is true, as for instance “If the earth flies, the earth has wings.” 114. Likewise also that which begins with what is false and ends with what is true is true, as thus — “If the earth flies, the earth exists.” And it is false only in this one way, when it begins with truth and ends in what is false, as in a proposition of this kind — “If it is day, it is night”; for when it is day the clause “It is day” is true, and this was the antecedent, but the clause “It is night,” which was the consequent, is false. 115. — But Diodorus “ asserts that “the hypothetical proposition is true which neither admitted nor admits of beginning with truth and ending in falsehood.” And this is in conflict with the statement of Philo. For a hypothetical of this kind — “If it is day, I am conversing,” when at the present moment it is day and I am conversing, is true according to Philo since it begins with the true clause “It is day” and ends with the true “I am conversing”; but according to Diodorus it is false, for it admits of beginmng with a clause that is, at one time, true and ending in the false clause “I am conversing,” when I have ceased speaking; also it admitted of beginning with truth and ending with the falsehood “I am conversing,” 116. for before I began to converse it began wth the truth “It is day” and ended in the falsehood “I am conversing.” Again, a proposition in this form — “If it is night, I am conversing,” when it is day and I am silent, is likewise true according to Philo, for it begins with what is false and ends in what is false; but according to Diodorus it is false, for it admits of beginmng wth truth and ending in falsehood, after night has come on, and when I, again, am not conversing but keeping silence. 117. Moreover, the proposition “If it is night, it is day,” when it is day, is true according to Philo for the reason that it begins with the false “It is night” and ends in the true “It is day”; but according to Diodorus it is false for the reason that it admits of beginning, when night comes on, with the truth “It is night” and ending in the falsehood “It is day.”

118. Such, then, being the contradictory character (as these examples show) of the criteria of the hypothetical proposition, it is to be feared that the task of distinguishing the valid hypothetical is impracticable; for in order that we may perceive this, there must first of all be a decision of the controversy of the Dialecticians regarding its validity. And so long as this remains undecided, the valid proposition itself must also of necessity remain in suspense. 119. And naturally so. For we shall either give heed to all the criteria of the Dialecticians, or to some one of them. But it is not possible to give heed to them all; for — as I have pointed out in the case of the two mentioned above — they are conflicting, and things which conflict cannot be equally trustworthy. And if we give heed to some one of them, we shall give heed to it either at once and uncritically, or wth the support of reasoning which proves that a criterion of this kind is valid. 120. And if we shall assent to any one criterion uncritically and at once, why shall we assent to this one rather than to that one? And this is equivalent to giving one’s assent to none, because of the conflict. But if we assent with the support of reasoning which proves that the criterion of the hypothetical adopted by us is vahd, then this reasoning is either inconclusive and indecisive or conclusive and decisive. 121. But if it is inconclusive and indecisive it is untrustworthy and unsound when preferring a certain criterion of the hypothetical. And if it is conclusive, certainly it is conclusive for the reason that its conclusion follows its premises, so that it is approved because of a certain consistency. 122. But the consistency sought in the case of the hypothetical ought to have been approved by reasoning. So, then, a result of this kind is equivalent to falling into the fallacy of circular reasoning; for in order to perceive the hypothetical which requires to be approved by its consistency, we are obliged to have recourse to a form of reasoning, and in order that this reasoning may be valid, the consistency by which its validity is judged must be confirmed beforehand. 123. If then, judging by this impasse, we do not possess the valid hypothetical, neither shall we possess conclusive reasoning; and not possessing this, we shall not possess proof either; for proof is conclusive reasoning. And if proof is absent, the parade of Dogmatism is destroyed.

124. From these we may pass over both to the conjunctive and to the disjunctive, and generally to all the remaining forms of non-simple propositions. For the conjunctive must be composed either of simple or of non-simple or of mixed propositions, and all these are subject to doubt when the simple sort are already doubted. 125. Moreover, when they declare that the conjunctive which has all its parts true is valid — as, for instance, “It is day and it is light,” — and that that which has a false part is false, they are again laying down the law for themselves. For it should have followed at once that, if the compound with all its parts true is true, the compound with all its parts false is false, but that which has some parts false and at the same time some true is no more true than false. 126. For if it is open to them to lay down what laws they please and to make rules about these matters just as they choose, we must allow their assertion that the conjunctive which contains one false clause is false; but it will be open also to others to make a contrary rule and assert that the conjunctive with several true clauses and one false is true. 127. But if we ought to give heed to the real nature of these things, it is surely logical to say that the conjunctive which has one part true and one part false is no more true than false; for just as what is compounded of white and black is no more white than black (for the white was white and the black was black), so also the true is in fact only true and the false is only false, and the compound of the two must be described as no more true than false. 128. — But, they say, just as in ordinary speech “we do not say that the garment which as in most parts sound, but in a small part torn, is sound because of its more numerous and sound parts, but we call it torn because of its small part which is torn, so also with the conjunctive, — if it has only one part false and several true, the whole will be named after the one false part. But this is silly. 129. For we must allow ordinary speech to make use of inexact terms, as it does not seek after what is really true but what is supposed to be true. Thus we speak of digging a well and weaving a cloak and building a house, but not with exactness; for if there is a well, it is not being dug but it has been dug; and if there is a cloak, it is not being woven but it has been woven. So that in ordinary life and common conversation inexact speech is in place, but when we are inquiring into real facts, then we must stick to accuracy.

130. By all this it has been made sufficiently clear that the argument of those who make truth and falsehood to lie in incorporeal “expression” is hopeless and full of confusion; and it is easy also to see that the argument of those who place them in speech is not satisfactory. 131. For every speech, if it exists, is either coming to be or silenced; but neither does that which is coming to be exist, owing to its non-subsistence, nor that which is silenced, owing to its not as yet coming to be. Speech, therefore, does not exist. Now that which is coming to be does not exist, as is shown by parallel instances; for a house when coming to be is not a house, nor is a ship, nor anything else of the sort; nor, consequently, speech. And that silent speech has no existence either is admitted. If, then, speech is either becoming or silenced, and at neither of these periods exists, speech will not exist.

132. Another objection, — if the true resides in speech, it is either in a minimal or in a long speech; but it is not in a minimal, for the minimal object is indivisible and the true is not indivisible; nor is it in a long speech, for this is not really existent because, when the first part of it is being uttered, the second does not as yet exist, and when the second is being uttered the first no longer exists. So, then, the true does not reside in speech. 133. — Furthermore, if it resides in speech, it is either in significant or in non-significant speech. But it will not exist in that which has no significance, such as the words “Blituri” and “Skindapsos”; for how is it possible to accept as true a thing which is not significant? 134. It only remains, therefore, to say that it resides in significant speech. But this again is impossible; for no speech as speech is significant, for, were it so, all the Greeks and barbarians on perceiving speech ought also to have perceived what is signified by it. So that on this ground, too, the true must not be located in speech. 135. — Also, some forms of speech are simple, others composite — simple as, for instance, “Dion”; and composite, as “Dion walks.” If, then, the true exists in speech, it exists either in simple or in composite speech; but it does not exist in the simple and non-composite; for the true must be a proposition, and no proposition is non-composite. 136. And it will not exist in composite speech because no composite expression (such as “Dion exists”) subsists; for when we are saying “Dion” we are not as yet saying “exists,” and when we are uttering the latter we are no longer saying the former. So that the true is not in speech.

137. Nor yet is it in the motion of the intellect, as some have surmised. For if the true is in the motion of the intellect, none of the external things will be true; for the motion of the intellect is within us and not external. But it is absurd to say that none of the external things is true; therefore it is also absurd to locate the true in the motion of the intellect.

138. Also, as the motions of the intellect are peculiar to each individual, there will be nothing generally true, and when there is nothing that is true for all in common everything will be doubtful and discordant; for what this man holds as true (that is the motion of his intellect), that another man does not hold; and conversely, what that man holds, this man has not experienced. But it is absurd to say that there is nothing which by common consent is true; 139. hence also it is absurd and unsound to assert that the true resides in the motion of the intellect.

It follows, also, that those who locate the true in the motion of the intellect must agree that all such motions are true — the motion, for instance, of the intellects of Epicurus and of Zeno and of Democritus and of the rest; for it happens that all alike are motions of the intellect. But it is impossible that they should all be true, as likewise that they should all be false; neither, then, is the true the motion of the intellect.

140. And now that we have presented all these difficulties concerning the criterion and concerning the true, let us consider in the next place the methods, based on the criterion, which are devised for the apprehension of the true that is not immediately presented — that is to say. Sign and Proof. And first in order let us speak of Sign; for it is by participation in it that Proof becomes capable of revealing the conclusion.

Chapter II: Does a Sign Exist?

141. Since there is a certain twofold distinction of a most general kind in things by which some are pre-evident, others non-evident — those being pre-evident which are immediately and of themselves presented to the senses and the intellect, and those non-evident which are not apprehensible of themselves, — our discussion of the criterion has been given its due place, as serving to show the doubtfulness of things evident; 142. for if the criterion is proved to be precarious, it also becomes impossible to affirm, regarding things apparent, that they are in reality such as they appear. And as the distinct class of things non-evident is still left, we deem it well, for the purpose of refuting it also, to employ a concise method of attack which destroys both sign and proof; for when these in turn are abolished, the apprehension of the true by means of them likewise becomes precarious. But it is, perhaps, fitting, before going into particulars, to discuss briefly the nature of sign.

143. The term “sign,” then, has two senses, the general and the particular. In the general sense it is that which seems to make something evident —— in which sense we are accustomed to call that a sign which serves to effect the renewal of the object observed in conjunction with it, — and in the particular sense it means that which is indicative of a non-evident object; and it is this latter which we propose at present to investigate. 144. But if one is to understand its nature clearly, one must, again, grasp first the fact that, as we said above, those things are pre-evident which come to our knowledge of themselves — such as, at the present moment, the fact that “it is day” and that “I am conversing,” — and those things are non-evident which are not of this character.

Chapter III: How Many Are the Distinct Classes of Things Non-evident?

145. Of things non-evident some are absolutely non-evident, some naturally non-evident, and some temporarily non-evident. And of these, those are called “temporarily” non-evident which are in their nature manifest but are at certain times rendered non-evident to us owing to certain external circumstances — as for instance the city of Athens is to us at the present moment; for though it is naturally manifest and pre-evident, owing to the intervening distance it is rendered non-evident. 146. “Naturally” non-evident are the things which are everlastingly hidden away and are not capable of presenting themselves clearly to our perception, such as the intelligible pores “and the existence (maintained by certain physicists) of an infinite Void outside the universe. 147. And “absolutely” non-evident are said to be those things whose nature it is never to be presented to human apprehension, as is the fact that the stars are even in number or odd, and that the grains of sand in Libya are of a certain definite number. 148. Since, then, there are four distinct classes of objects — one being that of things manifest, the second of things absolutely non-evident, the third of things naturally non-evident, the fourth of things temporarily so, we assert that not every distinct class, but some of them, require a sign. 149. For obviously neither the absolutely non-evident nor the manifest things admit of a sign — the manifest because they strike on the senses of themselves and require no other thing to announce them, and the absolutely non-evident because they elude every kind of apprehension without exception and thus do not admit of apprehension by means of sign. 150. But things naturally non-evident, and things temporarily so, have need of the kind of observation effected by sign — the temporarily non-evident because, in certain circumstances, they are removed from our clear perception, and the naturally non-evident because they are for ever non-apparent. 151. As, then, there are two distinct classes of things which require sign. Sign also has revealed itself as twofold — the “commemorative,” which appears to be chiefly of use in the case of things temporarily non-evident, and the “indicative,” which is deemed proper for adoption in the case of things naturally non-evident. 152. — Thus the commemorative sign, when observed in conjunction with the thing signified in a clear perception, brings us, as soon as it is presented and when the thing signified has become non-evident, to a recollection of the thing observed along with it and now no longer clearly perceived — as in the case of smoke and fire; for as we have often observed these to be connected with each other, as soon as we see the one — that is to say, smoke — we recall the other — that is to say, the unseen five. 153. The same account applies to the scar which follows on the wound, and to the puncture of the heart which precedes death; for on seeing the scar we recall the wound which preceded it, and on viewing the puncture of the heart we foretell the imminence of death. — Such, then, is the special character of the “commemorative” sign; 154. but the “indicative” is of a different kind. For it does not, like the former, admit of being observed in conjunction with the thing signified (for the natm'ally non-evident object is, from the start, imperceptible and therefore cannot be observed along with any of the things apparent), but entirely of its oivn nature and constitution, all but uttering its voice aloud, it is said to signify that whereof it is indicative. 155. The soul, for instance, is one of the things naturally non-evident; for such is its nature that it never presents itself to our clear perception; and being such, it is announced “indicatively” by the bodily motions; for we argue that it is a certain power residing 'vvithin the body which inwardly excites in it such motions.

156. So then, as there are two signs — that which is “commemorative” and held to be mainly of use in the case of things temporarily non-evident, and the “indicative” which is employed in the case of things naturally non-evident — we propose to devote all our investigation and criticism not to the commemorative sign (for this is generally believed by all ordinary folk to be useful) but to the indicative; for this has been devised by the Dogmatic philosophers and by the Logical physicians, “as capable of affording them most necessary assistance. 157. Hence we are not attacking the common preconceptions of mankind, nor are we turning life upside down by asserting that no sign exists, as some slanderously affirm of us. For if we were abolishing every sign we might, perhaps, have been attacking ordinary life and all mankind; but as it is, we ourselves also are of the same mind and infer fire from smoke, and a previous wound from a scar, and death from a previous puncture of the heart, and oil from a previous fillet. 158. As it is, then, seeing that we affirm the commemorative sign which ordinary folk employ, but abolish the sign falsely imagined by the Dogmatists, one should rather say that not only do we not attack ordinary life but we even act as its advocates, inasmuch as we refute by means of natural science the Dogmatists who have risen up against the common judgment and declared that they discern by means of signs things naturally non-evident.

159. Let this, then, serve as a summary account of the sign now under investigation; and at this point it is right to keep in mind the practice of the Sceptics. This is to set out the arguments against the existence of the sign, but not with conviction or assent (for to do it with assent would be on a par with maintaining, like the Dogmatists, that a sign exists), but so as to bring the inquiry to a position of equipollence, and prove that the non-existence of a sign is equally credible vvith its existence, or, conversely, that the existence of a sign is equally incredible with its non-existence; for thereby there is produced in the intellect neutrality and suspension of judgment. 160. Moreover, on this account even the man who appears to contradict us, when we assert that no indicative sign exists, is actually supporting us, and by already adopting it himself he establishes the view that ought to be established sceptically; for if the arguments brought against the sign by the Doubters are exceedingly strong and almost incontrovertible, and those of the Dogmatists establishing its existence are not less weighty, we must at once suspend judgment regarding its existence and must not attach ourselves unjustly to either side. 161. And now that the practice of the Sceptics has been set forth, let us next proceed to develop the theme before us.

Of existing things, then, some, as the Sceptics assert, have an absolute, others a relative, existence. Absolutely existing are all such things as are perceived with a subsistence of their own and absolutely, as for instance white, black, sweet, bitter, and everything of a similar kind; for we apprehend these by themselves alone and separately and without the accompaniment of any other percept. 162. But those things are relative which are perceived as standing in some relation to another thing and no longer apprehended absolutely (that is, separately by themselves); as, for example, the whiter and blacker and sweeter and bitterer, and whatever else is of the same character. For the whiter or blacker is not perceived separately in the same way as the white or black; but in order to perceive the former, one must also apprehend along with it the object than which it is whiter, or than which it is blacker. And the same account applies to the sweeter and the bitterer. 163. Since, then, there are two distinct classes of things, one being that of things absolute, the second that of things relative, the indicative sign must belong either to the class of absolutes or to that of relatives; for there is no third class of things between these two. But it will not belong to the absolutes, as is at once agreed even by those of the other persuasion. 164. So, then, it will belong to the relative class. For just as the thing signified, because it is perceived as standing in relation to the sign, is a relative thing, (so too the sign is a relative thing,) for it is a sign of something, namely, of the thing signified. Certainly, if we take away, let us suppose, one of the two, the remaining one also will be taken away along with it, a thing which plainly happens also in the case of right and left; for if there is no right, neither will there be a left, owing to the fact that each of these is a relative; and if there is no left, the notion of right also is cancelled at the same time. 165. — Further, relatives are apprehended together; for, as I said, it is impossible to be aware of a whiter thing without a joint perception of that than which it is whiter, or of a blacker thing (without a joint apprehension of that than which it is blacker). So then, since the sign is, as we showed, a relative thing, that whereof it is a sign will be apprehended along with the sign. But the thing apprehended along with it will not be a sign of it. For to imagine that what is apprehended along with a thing can be a sign of that thing is perfectly absurd; for when both are pre-ceived at one and the same moment, neither does this serve to reveal that nor that serve to indicate this; and each, when it is presented by itself, hicks any such efficacy. 166. — Again, one might construct an argument of this sort; The sign, if it is apprehensible, is either apprehended before the thing signified, or apprehended along with it, or apjirehended after it; but, as we shall establish, it is not apprehended cither before, or along with, or after it; therefore the sign is not apprehensible. 167. Now to state that the sign is apprehended after the thing signified is seen at once to be absurd; for how can the sign still be capable of revealing when that which it serves to reveal — the thing signified — is apprehended before it? And, besides, if they make this statement, the Dogmatists will be accepting something which is in conflict with one of their usual dogmas. For they assert that the thing signified is non-evident and not apprehensible of itself; but if, after the apprehension of this, the sign is apprehended subsequently, this thing, which was detected before the presence of that which announces it, will not be non-evident. So that the sign is not apprehended after the thing signified. 168. — Nor yet, indeed, is it apprehended along with it, for the reason stated a little while ago; for things apprehended along with one another do not require announcement by one another but are presented of themselves simultaneously; and because of this, neither will the sign be said to be a sign, nor the thing signified to be any longer signified. 169. — It only remains, then, to declare that the sign is apprehended before the thing signified. And this, again, lies open to the same criticisms. For the Dogmatists ought first to prove that the sign is not a relative thing, or that relatives are not apprehended along with each other, and then in the next place get us to admit that the sign can be apprehended before the thing signified. 170. But as our primary assumptions remain unaltered, it is impossible to get evidence for the anterior apprehension of the sign, owing to the fact of its belonging to the class of relatives and having necessarily to be apprehended along with that whereof it is a sign. — But if it be so that the sign, in order to be apprehended, must either be apprehended before the thing signified, or apprehended along with this, or apprehended after it, and it has been proved that none of these alternatives is possible, one must declare that the sign is non-apprehensible.

171. Further, some confront the Dogmatists with another argument, to the same effect, in this form: If there exists an indicative sign, either it is an apparent sign of an apparent thing, or a non-apparent of a non-apparent, or an apparent of a non-apparent, or a non-apparent of an apparent; but it is neither an apparent sign of an apparent thing, nor a non-apparent of a non-apparent, nor an apparent of a non-apparent, nor the converse ; therefore no sign exists. 172. Such is the argument, and its demonstrative force is quite evident. And it will become yet more evident when we have indicated the objection brought against it by the Dogmatists. For they declare that they allow only two of these combinations, and as regards the remaining two they are at variance with us. 173. For, (say they,) whereas it is true that the apparent is a sign of the apparent and the apparent of the non-apparent, it is false that the non-apparent is indicative of the apparent or the non-apparent of the non-apparent. Thus, for example, an apparent thing is a sign of an apparent thing, as the shadow of the body; for it, being a sign, is an apparent one, and the body, being a thing signified, is an evident thing. And an apparent thing may really be indicative of a non-apparent, as blushing of shame; for the former is obvious and self-detected, but shame is invisible. 174. But those who speak thus are perfectly stupid. For if it be agreed that the sign is a relative thing and that relatives must necessarily be apprehended together, then, of the things thus simultaneously presented, it is not possible that one should be the sign, the other the thing signified; but always and in every case, because of the evident joint-presentation of the two together, neither one of them can be either sign or thing signified, as the one has nothing to reveal, and the other requires nothing to reveal it. 175. And the same may also be said about the remaining combination, in which they claim that the apparent is a sign of the non-apparent; for, if this is so, the sign must be apprehended before the thing signified and the thing signified apprehended after the sign, which is impossible because they belong to the class of relatives and must be apprehended along with each other.

176. Now, of the objects apprehended by man, some appear to be apprehended by means of sense, others by the intellect, — by means of sense, as white, black, sweet, bitter; and by intellect, fair, foul, lawful, lawless, pious, impious. So the sign also, if it is apprehensible, is one of the sensible or of the intelligible objects, so that if it does not belong to either of these classes it will have absolutely no existence at all. 177. And, what is more, we have here at once a direct evidence that it is non-apprehesible, — I mean in the fact that hitherto its nature has been rent in twain, some supposing it to be sensible, others intelligible. Thus Epicurus and the leaders of his School have stated that the sign is sensible, but the Stoics that it is intelligible. And this controversy remains, as one may say, eternally undecided, and while it remains undecided there is every necessity to keep the sign in suspense, since it is bound to be either sensible or intelligible. 178. Most serious of all is the fact that the promise it makes has become void, inasmuch as it promises that it will serve to reveal some other thing, but is itself now found, conversely, to require that other thing to reveal it; for if everything which is controverted is non-evident, and the non-evident is apprehensible through a sign, then certainly the sign too, being controverted, will require a sign to make it manifest, as it is non-evident. 179. — Moreover, they cannot assert that it is possible for them to establish it, when controverted, by proof and hold it trustworthy. For when they have first proved it, then let them accept it as trustworthy; but so long as they have only a mere promise and not proof, the case for suspension stands. 180 Further, proof also is a debatable thing, and being controverted it has need itself of something to lend it cogency; but to try to prove the thing in question by a thing in question is perfectly absurd. And, moreover, proof is, generically, a sign; for it serves to reveal its conclusion. 181. In order, then, that the sign may be established, the proof must be trustworthy; and in order that the proof may be trustworthy, the sign must be pre-established; so that each one of the two, as awaiting its confirmation from the other, is just as untrustworthy as the other. 182. Besides this, that which is taken as a proof for the establishment of sign is either sensible or intelligible. And if it is sensible, the original inquiry remains once more, by reason of the general disagreement about sensibles; while if it is intelligible, it is equally untrustworthy, for this latter cannot be apprehended apart from things sensible.

183. However, let it be agreed and granted, into the bargain, that the sign is either sensible or intelligible. Yet, even so, it is impossible that its real existence should be worthy of confidence. We must discuss in turn each of these alternatives, and, first and at once, the view that it is sensible. In order, then, that this may be admitted, the real existence of sensibles must first be unanimously allowed and be admitted by all the Physicists, so that the investigation of the sign may proceed from this as admitted. 184. This, however, is not unanimously allowed, but

Long as the waters flow and the tall trees cease not to burgeon,

the Physicists will never stop warring with one another about it; for Democritus asserts that none of the sensibles really exists, but our perceptions of them are certain empty affections of the senses, and in things external there exists nothing sweet or bitter or hot or cold or white or black or any other of the things apparent to all; for these are names for our affections. 185. But Epicurus declared that all sensibles really exist such as they appear and present themselves in sensation, as sense never lies, though we think that it lies. And the Stoics and Peripatetics, pursuing a middle course, have said that some sensibles really exist, as being true, and some do not exist, as sensation lies about them. 186. But now, to sum up: If we claim that the sign is sensible, it must first of all be agreed and firmly established that sensibles have substantial existence, in order that it may be granted that the sign also is definitely apprehensible; or else, if it is the case that their existence has been quarrelled over eternally, we shall have to admit that the sign also partakes of the same controversial character. 187. For just as white color cannot be apprehended securely if the substantial existence of sensibles be not admitted, because it is itself one of the sensibles, so neither can the sign — if it belongs to the class of sensibles — be said to have stable existence so long as the conflict regarding sensibles continues. Let us suppose now that there is unanimity about sensibles and that there exists no dispute whatsoever regarding them. How, I ask, can our opponents show us that the sign is in reality sensible? For every sensible thing ought naturally to present itself alike to all who are in a like condition and be similarly apprehended. Take white color, for instance; it is not apprehended in one way by Greeks, in another by barbarians; or in a special way by craftsmen and differently by ordinary folk; but in one and the same way by all those who have their senses unimpeded. 188. Bitter and sweet, again, are not tasted in this by this man and in a different way by that man, bnt similarly by each of those who are in a similar condition. Bnt the sign, as sign, does not seem to affect in the same way all those who are in a similar condition; but to some it is not a sign of anything at all, although it presents itself to them plainly, while to some it is a sign, yet not of the same thing but of something different; thus in medicine, for instance, the same appearances are signs of one thing to this man (such as Erasistratus), but of another to that man (say, Herophilus), and of another to a third (such as Asclepiades). We must not, then, say that the sign is sensible; for if the sensible affects all similarly, but the sign does not affect all smiilarly, the sign will not be sensible. 189. — Again, if the sign is sensible, it ought to follow that, just as fire, which is sensible, burns all those capable of being burnt, and snow, being sensible, chills all those capable of being chilled, so also the sign, if it belongs to the sensibles, leads all to the same signified thing. But, in fact, it does not so lead them; therefore it is not sensible. 190. — Furthermore, if the sign is sensible, the things non-evident are either apprehensible by us or non-apprehensible. If, then, they are non-apprehensible by us, the sign disappears; for things being of two kinds, some evident, others non-evident, if neither the evident thing possesses a sign owing to its being self-revealed, nor the non-evident things because they are non-apprehensible, there is no sign. 191. But if the non-evident things are apprehensible, it ought to follow again that, since the sign is sensible and the sensible affects all men ahke, the things non-evident are apprehended by all. But some — like the Empirical doctors and the Sceptic philosophers — assert that they are not apprehended, and others that they are apprehended but not equally. The sign, therefore, is not sensible.

192. “Yes,” they reply, “but just as fire, being sensible, exhibits different potencies owing to differences in the material subjected to it, and when applied to wax melts it, to clay hardens it, to wood burns it; so likewise it is probable that the sign also, being sensible, should serve to indicate different things according to the differences in those who apprehend it. 193. Nor is this paradoxical, since this is also seen to happen even in the case of commemorative signs; for the raising high of a torch signifies to some the approach of enemies, but to others indicates the arrival of friends; and the sound of a bell is to some a sign of the selling of meat, but to others of the need for watering the roads. Therefore the indicative sign also, having a sensible nature, will be capable of revealing things of different sorts.” 194. — But here, too, one might require those who make use of the inference from fire to prove that what happens to take place in the case of fire takes place also in the case of the sign. For the former possesses potencies, as stated above, which are undisputed, and there is nobody who differs about the fact that wax is melted by it, clay hardened, and wood burned. 195. But in the case of the indicative sign, if we allow that a similar result takes place we shall find ourselves in the most absurd position — that of asserting that each of the things indicated by it exists, so that, let us say, plethora and acrid humours and bodily constitution are all causes of disease. 196. But this is absurd; for it is not possible for causes, so conflicting and mutually destructive to co-exist. Let the dogmatizing philosophers, then, agree either to this, impossible though it be, or that the sign, being sensible, is indicalive of nothing, so far as its own power goes, 197. but that we with our differing dispositions are not all affected alike by it. But this they would not endure to agree to; and besides, these potencies of fire are not unanimously allowed but are matters of doubt. 198.For if fire was of a nature capable of burning, it ought to burn everything and not burn some things and not others; and if it had a power of melting, it ought to dissolve everything instead of dissolving some and not others. 199. But as it is, it seems to do these things not on account of its own nature but on account of the materials of the substances with which it is brought into contact; for instance, it burns wood, not because it is itself capable of burning, but because wood is in a fit state to be burnt when it receives the co-operation of fire; and it melts wax, not because it has a power of melting, bub because wax possesses a fitness for being melted when it receives the co-operation of fire. But this we shall explain more exactly when we come to consider the existence of such substances. 200. For the present, in reply to those who draw inferences from the commemorative sign and quote the case of the torch, and also of the sound of the bell, we must declare that it is not paradoxical for such signs to be capable of announcing more things than one. For they are determined, as they say, by the lawgivers and lie in our power, whether we wish them to indicate one thing or to be capable of announcing several things. 201. But as the indicative sign is supposed to be essentially suggestive of the thing signified, it must necessarily be indicative of one thing; and this must certainly be a thing of single form, since of course, if it is common to many things, it will not be a sign. For it is impossible for one object to be firmly apprehended by means of anything when the things indicated thereby are many. For example, a man’s fall from wealth to poverty is a sign alike of a life of dissipation, and of disaster by sea, and of contributions to friends; and being thus common to many things, it can no longer be indicative of any one of them in special; for if it is indicative of this one, why of this one rather than of that one? And if of that one, why of that one rather than of this one? 202. Nor, indeed, can it be indicative of all; for they are not all capable of co-existing. So, then, the indicative sign differs from the commemorative, and one must not draw inferences about the former from the latter, inasmuch as the one ought to serve to indicate one object alone, whereas the other can serve to manifest several objects, and to possess such significations as we ourselves may determine.

203. Further, every sensible thing, qua sensible, is incapable of being taught. For a man is not taught to see a white color, nor does he learn to taste sweetness, nor to feel heat, nor anything else of the kind; but it is from nature and without teaching that the knowledge of all these things comes to us. But the sign, qua sign, is taught, as they say, with much labor — that, for example, in navigation, which serve, to indicate winds and storms or fine weather. 204. So likewise the signs dealt with by those who treat of things in the heavens, like Aratus and Alexander the Aetolian; and similarly those of the Empiric physicians, such as blushing and swelling of the vessels and thirst and so on, which the uninstructed person does not apprehend as signs. 205. The sign, therefore, is not sensible; for if the sensible is incapable of being taught, but the sign, qua sign, is capable of being taught, the sign will not be sensible.

206. The sensible, too, qua sensible, is conceived as absolute — white, for instance, and black, sweet and bitter, and everything of that sort. But the sign, qua sign, is a relative thing; for it is viewed in regard to its relation to the thing signified. Therefore the sign does not belong to the class of sensibles.

207. Moreover, every sensible — as the term shows — is apprehensible by sense, but the sign, qua sign, is apprehended not by sense but by intellect. Thus we say that a sign is true or false, but the true and the false are not sensible; for each of them is a judgment, and the judgment belongs not to the sensibles but to the intelligibles. We must declare, therefore, that the sign does not belong to the class of sensibles.

208. We may also use this argument : If the indicative sign is sensible, the sensible ought, long before, to be indicative of something; but this is not the case. For if the sensible indicates anything, either the homogeneous nail be indicative of the homogeneous or the heterogeneous of the heterogeneous; but neither is the homogeneous indicative of the homogeneous nor the heterogeneous of the heterogeneous; therefore the sensible is not indicative of anything. 209. Suppose, for instance, that we had never experienced white color or black, and were to see white for the first time. Then, from our apprehension of the white we would not be able to apprehend black; 210. for though it is, perhaps, possible to form a notion that black is another color, and not of the same sort as white, yet to arrive at an apprehension of black color through the presence of white is a thing impossible. And the same account may be given of voice, and in general of all the other sensibles. So, then, the homogeneous sensible will not be indicative of the homogeneous — that is to say, the visible of the visible, or the audible of the audible, or the gustable of the gustable. 211. — Nor, again, is the heterogeneous indicative of the heterogeneous — as, for example, the visible of the audible, or the audible of the gustable or odorable; for one does not by smelhng a sweet scent arrive at an apprehension of white color, nor get a sweet taste by perceiving a voice.

212. However, it is far-fetched to inquire whether the homogeneous can be a sign of the homogeneous, or the heterogeneous of the heterogeneous, when any man of sense would despair of a thing much nearer to hand — I mean the fact that the sensible is not even able to be indicative of its own self. 213. For, as we have often pointed out, of those who have investigated the sensible, some assert that, as apprehended by sense, it is not the same as it is by nature; for it is not white or black, hot or cold, sweet or bitter, or possessed of any other such quality, but appears to be really such when our sense has empty affections and gives false reports; but others have thought that some sensibles are truly existent and some not; while others, again, have attributed existence to all equally. 214. Since, then, there exists an unsettled dispute of this magnitude regarding the real existence of sensibles, how is it possible to assert that the sensible is capable of manifesting itself, when it is not known as yet which of the discordant views is the true one? But this fact, at least, ought to stand fast — that if neither the homogeneous sensible is indicative of the homogeneous sensible, nor the heterogeneous of the heterogeneous, nor the sensible itself of itself, it is, consequently impossible to declare that the sign is sensible.

215. Aenesidemus, in the Fourth Book of his Pyrrhonean Discourses, propounds an argument on the same subject and to much the same effect in the following form: “If apparent things appear alike to all those in a similar condition, and signs are apparent things, signs appear alike to all those in a similar condition. But signs do not appear alike to all those in a similar condition; and apparent things appear alike to all those in a similar condition; therefore signs are not apparent things.” 216. Now Aenesidemus seems here to be terming sensibles “apparent things,” and he propounds an argument in which a second non-demonstrable is superadded to a third, the scheme of it being this: “If the first and the second, then the third; not the third, but the first; therefore not the second.” 217. That this is really so we shall show a little later on; at the moment we shall prove more simply that the premises of the argument are sound and that the conclusion follows from them. Thus, to start with, the major premise is true; for the consequent follows from the conjunctive clause — that is, from “Apparent things appear alike to all those in a similar condition, and signs are apparent things,” there follows “Signs appear alike to all those in a similar condition.” 218. For if all those who have unimpeded sight perceive white color similarly and not differently; and if all whose taste is in a natural state apprehend what is sweet as sweet; then all who are in a similar condition ought of necessity to apprehend the sign similarly, if it is a sensible thing like the white and the sweet. 219. So that the major premise is sound. And the second premise is also true, namely “But signs do not appear ahke to all those in a similar condition.” Thus, in the case of fever patients, flushing and prominence of the vessels and a moist skin and increased temperature and quickening of the pulses and all the other signs do not manifest themselves as signs of the same thing to those who are in a similar condition as regards their senses and the rest of their bodily constitution, nor do they appear alike to all; 220. but to Herophilus, for instance, they seem to be definite signs of good blood, and to Erasistratus of the transference of the blood from the veins to the arteries, and to Asclepiades of the lodgement of intelligible molecules in intelligible interstices. So, then, the second premise also is sound. 221. But so is the third as well, namely “Apparent things appear alike to all those in a similar condition.” Thus, for example, white color does not present itself in the same way to the man with jaundice, and to one who has blood-shot eyes, and to him who is in a natural condition (for their conditions are dissimilar, and because of this it appears yellow to the first, reddish to the second, and white to the third); yet to those who are in the same condition, that is to say in sound health, it appears white only. 222. So from these true premises there will be drawn the conclusion “Therefore the sign is not an apparent thing.”

This argument, then, has been shown by our examination of it to be true; 223. and that it is both non-demonstrable and syllogistic will appear when we have analyzed it. For — to go back to first principles — the term “non-demonstrable,” to start with, has two senses, being used both of arguments which are not demonstrated, and of those which have no need of demonstration owing to its being at once obvious in their case that they are conclusive. And we have often pointed out that the arguments set out by Chrysippus, at the beginning of his first Introduction to Syllogisms, are given this title in the second sense. 224. So now, this being assumed, one must understand that the first non-demonstrable argument is that composed of a hypothetical major premise and its antecedent, having as its conclusion the consequent in the major. That is to say, when an argument has two premises, of which the one is a hypothetical major and the other the antecedent in the major, and also has as its conclusion the consequent in the same major, then such an argument is called a “first non-demonstrable,” for example one in this form — “If it is day, it is light; but in fact it is day; therefore it is light.” For this has a hypothetical major as one of its premises, namely, “If it is day, it is light”; and as the second, the antecedent of the major, “But in fact it is day”; and thirdly, as its conclusion, the consequent of the major, “Therefore it is light.” — 225. The second non-demonstrable is that composed of a hypothetical major premise and the contradictory of the consequent in that major, and having as its conclusion the contradictory of the antecedent. That is to say, when an argument, composed once more of two premises, of which the one is a hypothetical major and the other the contradictory of the consequent in that major, has also as its conclusion the contradictory of the antecedent, then such an argument is a “second non-demonstrable” — as for example “If it is day, it is light; but it is not light; therefore it is not day.” For the one premise of the argument — namely, “If it is day, it is light” — is a hypothetical major; and “But it is not light,” which is the other premise of the argument, is the contradictory of the consequent in the major; and the conclusion, “Therefore it is not day,” is the contradictory of the antecedent. 226. — The third non-demonstrable argument is that composed of a negative conjunctive premise and one of the clauses of that conjunctive, and having as its conclusion the contradictory of the other clause in the conjunctive premise; for example, “It is not both day and night; but it is day; therefore it is not night.” For the premise “It is not both day and night” is the negative of the conjunctive, “It is both day and night,” and “It is day” is one of the clauses in the conjunctive, and “Therefore it is not night” is the contradictory of the other clause in the conjunctive.

227. Such, then, are these arguments; and the “moods” or “schemes,” so to say, in which the arguments of this kind are propounded are as follows: Of the first non-demonstrable — “If the first, then the second (is true); but the first (is true); therefore the second (is true).” Of the second — “If the first, then the second (is true); but the second is not (true); therefore the first is not (true).” Of the third — “The first and the second are not both (true); but the first is (true); therefore the second is not (true).”

228. Further, one should observe that some of the non-demonstrables are simple, others not simple. Simple ones are those which at once clearly declare that they draw a conclusion — that is to say, that the inference is introduced together with the premises themselves. The arguments stated above are of this land; for, in the case of the first, if we grant it to be true that “If it is day, it is light,” — true, I mean, that the existence of light follows on that of day, — and if we assume as true the first clause, that “it is day,” which is the antecedent in the major premise, it will necessarily follow that it is also light, which is the conclusion of the argument. 229. Not simple are those which are woven together out of simple ones, and which require to be broken up first into simple ones before it can be known that they, too, draw conclusions. And of these not simple arguments, some are composed of homogeneous parts, others of heterogeneous — of homogeneous, as in the case of those woven out of two first non-demonstrables, or of two second; 230. and of heterogeneous, as in the case of those compounded of a first non-demonstrable (and a third), or of a second and a third, and in general such as aie similar to these. Thus an argument such as the following is composed of homogeneous parts — “If it is day, it is light; but in fact it is day; therefore it is light.” For it is woven out of two first non-demonstrables, as we shall learn when we analyze it. 231. For one should observe that there is a dialectical rule handed down for the analysis of syllogisms, namely this — “When we know the premises which imply a certain conclusion, we know also potentially the conclusion involved in them, even though it be not explicitly stated.” Since, then, we have two premises. 232. — the major “If it is day, it is light,” which begins with the simple proposition “it is day” but ends with the not-simple major “if it is day, it is light,” and also its antecedent “it is day,” — from these we shall infer, by the first non-demonstrable, the consequent of that major, namely “Therefore if it is day, it is light.” 233. Potentially, then, we have this inference drawn in the argument, but as it is omitted in the explicit statement, when we have put it beside the minor premise of the expressed argument “it is day” we shall have the clause “it is light” deduced by the first non-demonstrable, which clause is the conclusion of the expressed argument. So that two first indemonstrables are formed, the one being of this sort — “If it is day, it is light,” and the other of this — “If it is day, it is light; but in fact it is day; therefore it is light.”

234. Such then is the type of the arguments which are woven out of homogeneous parts. Next come those with heterogeneous parts, sudi as that concerning the Sign propounded by Aenesidemus, which runs thus; “If the things apparent appear in like manner to all those in a similar condition, and the signs are things apparent, the signs appear in like manner to all those in a similar condition; and the things apparent appear in like manner to all those in a similar condition; but the signs do not appear in like manner to all those in a similar condition; therefore the signs are not things apparent.” 235. For an argument like this is compounded of the second non-demonstrable and the third, as one may learn from its analysis; and this will become clearer when we have given instruction as to its “scheme,” which goes thus: “If the first and the second, the third (is true); but the third is not (true), whereas the first is; therefore the second is not (true).” 236. For when we have a major premise in which the antecedent consists of the first and second conjoined, while the third is the consequent, and have also the clause “the third is not (true)” as the contradictory of the consequent, we shall also get for our conclusion the contradictory of the antecedent, namely “therefore the first and the second are not (true),” by the second non-demonstrable. But, in fact, this very conclusion is potentially contained in the argument, since we possess the premises which go to prove it, but in the explicit statement it is omitted. And when we have placed these alongside of the remaining premise, the first, we shall have deduced the conclusion, “therefore the second is not (true),” by the third non-demonstrable. So that there are two non-demonstrables, one in the form “If the first and the second, the third (is true); but the third is not (true); therefore the first and the second are not (true),” which is a second non-demonstrable; and the other, which is a third non-demonstrable, in the form “The first and the second are not (true); but in fact the first is (true); therefore the second is not (true).”

237. Such, then, is the analysis in the case of the “scheme,” and in the case of the argument it is analogous; for the third premise is missing, namely, “It is not (true) both that apparent things appear in like manner to all those in a similar condition, and that the signs are apparent,” which, taken in conjunction with the premise that “apparent things appear in like manner to all those in a similar condition,” proves the (conclusion) of the expressed (argument) by the third non-demonstrable. Hence there is brought about a second non-demonstrable in this form: “If apparent things appear in like manner to all those in a similar condition, and the signs are apparent, then the signs appear in like manner to all those in a similar condition; but the signs do not appear in like manner to all those in a similar condition; therefore the signs are not apparent”; 238. and a third in this form: “It is not (true both that) apparent things appear in like manner to all those in a similar condition and that the signs are apparent; but in fact apparent things appear in like manner to all those in a similar condition; therefore the signs are not apparent.”

239. The same method of deduction will be employed in propounding such an argument as this; “If apparent things appear equally to all, and things apparent are signs of things non-evident then things non-evident appear equally to all; but things non-evident do not appear equally to all, though things apparent do appear equally to all; therefore things apparent are not signs of things non-evident.” 240. Now the analysis of this argument is similar, [for in it a second non-demonstrable is superimposed on a third,] and the logical force of the premises is obvious. For it is plain at once that apparent things appear equally to all who have their senses unimpeded; for white does not appear differently to different people, nor black differently to different people, nor sweet in distinct ways, but they affect all similarly. 241. So if these things appear equally to all and possess the power of indicating things non-evident, then the non-evident things also must necessarily be perceived equally by all, as the causes are the same and the material substrate is similar. But this is not so; for all do not cognize non-evident things alike, although they experience seuse-objects equally; some, indeed, do not even arrive at a conception of them, while others do so arrive, but are swept off into a variety of complex and conflicting pronouncements. Therefore, in order that we may avoid this absurd consequence, it follows that the signs are not sensible.

242. It will also be possible by compressing the foregoing to propound concise arguments such as these: “If apparent things appear to all, but the signs do not appear to all, the apparent things are not signs. But in fact the first (is true); therefore the second (is true),” 243. And again: “If apparent things, in so far as they are apparent, do not require explanation, but the signs, in so far as they are signs, require explanation, the signs are not apparent. But in fact the first (is true), therefore the second (is true).”

In reply, then, to those who maintain that the sign is sensible let thus much be said by way of objection; 244. but let us also examine the view opposed to theirs —I mean that of those who conceive it to be intelligible. But perhaps it will be proper for us first to deal shortly with the view they accept, according to which the sign is, they maintain, a proposition, and on this account an intelligible. 245. Thus, in describing it, they say that “The Sign is an antecedent proposition in a valid hypothetical major premise, which serves to reveal the consequent.” And while there are, they say, many other tests of such a valid major, there is one above all — and even it not agreed upon — which shall be described. Every hypothetical major either begins with truth and ends in truth, or begins wth falsehood and ends in falsehood, or (proceeds) from truth to falsehood or from falsehood to truth. 246. The premise “If there are gods, the world is ordered by the gods’ providence” begins with truth and ends in truth; and “If the earth flies, the earth has wings” (proceeds) from falsehood to falsehood; and “If the earth flies, the earth exists” from falsehood to truth; and “If this man moves, this man walks” from truth to falsehood, when he is not walking but is moving. 247. As, then, there are four combinations of the major premise — when it begins with truth and ends in truth, or when (it proceeds) from falsehood to falsehood, or when (it proceeds) from falsehood to truth, or conversely from truth to falsehood, — in the first three modes the premise, they say, is true (for if it begins with truth and ends in truth it is true, and if it begins with falsehood and ends in falsehood it is again true, and so likewise when (it passes) from falsehood to truth); and in one mode only is it false, namely, when it begins with truth and ends in falsehood. 248. And this being so, one should not look, they say, for the sign in this unsound major premise but in the sound one; for it is called “a proposition which is the antecedent in a valid major premise.” But since there is not one valid major but three — namely, that which begins with truth and ends with truth, and that which (proceeds) from falsehood to falsehood, and that which (proceeds) from falsehood to truth — one has to inquire whether possibly the sign should be sought in all the valid premises, or in some, or in one. 249. So then, if the sign must be true and indicative of truth, it will not reside either in that which begins with falsehood and ends in falsehood or in that which (passes) from falsehood to truth. Thus it only remains for it to exist in that which both begins with truth and ends in truth, since it really exists itself and the thing signified also must co-exist with it. 250. So then, when the sign is said to be “a proposition which is the antecedent in a valid major premise,” one shall have to understand that it is an antecedent in that valid major only which begins with truth and ends in truth. Moreover, not every proposition which is an antecedent in a valid major beginning with truth and ending in truth is a sign. 251. Such a major premise as this, for instance — “If it is day, it is light,” — begins with the truth “it is day” and ends in the truth “it is light,” but it does not contain any antecedent proposition which is a sign of the consequent; for “it is day” does not serve to reveal that “it is light”; for just as the latter truth was perceived by means of itself, so also “it is light” was comprehended owing to its own obviousness. 252. The sign, therefore, must not only be the antecedent in a valid major premise — that is, in one that begins with truth and ends in truth — but must also possess a character which serves to reveal the consequent; as, for example, the antecedent in premises such as these — “If this woman has milk in her breasts, she has conceived”; and “If this man has had a viscid bronchial discharge, he has a wound in his lungs.” 253. For this premise is valid, as it begins with the truth “This man has had a viscid bronchial discharge,” and ends in the truth “he has a wound in his lungs”; and, besides, the first serves to reveal the second; for by observing the former we come to an apprehension of the latter.

254. Further, they say, the sign must be a present sign of a present thing. For some people erroneously claim that a present thing may also be a sign of a past thing, as in the case of “If this man has a scar, he has had a wound” (for if he has a scar it is present, for it is apparent, but his having had a wound is past, for there is no longer a wound), and that a present thing (may be the sign) of a future thing, as for instance that included in such a premise as this — “If this man is wounded in the heart, he will die,” for they say that the wound in the heart exists already, but death is in the future. 255. But those who make such statements are ignorant of the fact that though things past and things future are different, yet even in these cases the sign is a present (sign) of a present thing. For in the former (premise) — “If this man has a scar, he has had a wound” — the wound has existed already and is past, but the (statement) that this man has had a wound, which is a proposition, is present, being stated about a thing which has existed. And in the premise “If this man is wounded in the heart, he will die,” his death is in the future, but the proposition “he wll die” is present, though a statement about the future, inasmuch as it is true even now. 256. So that the sign is a proposition, and also it is the antecedent in a valid major premise which begins with truth and ends in truth, and it serves to reveal the consequent, and always it is a present sign of a present thing.

257. Now that these things have been explained according to their own rules of logic, it is proper to reply to them, first, in this wise; If the sign is sensible according to some, but intelligible according to others, and the dispute on this point is undecided up till now, we must declare that the sign is as yet non-evident. And being non-evident, it needs things to reveal it and ought not to be capable itself of revealing other things. 258. — Moreover, if the sign is, according to them, classed, as to its “substance,” under the head of “expression,” and if the existence of “expressions” is a matter of inquiry, it is absurd to take the particular as securely fixed before the genus is agreed upon. And we see that there are some who have denied the real existence of “expressions,” and these not only men of other Schools, such as the Epicureans, but even Stoics like Basileides who held that nothing incorporeal exists. So, then, we must preserve suspension of judgment regarding Sign. 259. But, say they, when we have first proved the real existence of “expressions” we shall have the reality of the sign also securely established. “Yes,” one will reply, “when you have proved it, then assume also that the existence of the sign is to he believed; but so long as you remain merely promising, we too must necessarily remain in an attitude of suspension.” 260. And further, how is it possible to prove the existence of “expressions”? For one will have to do this either by means of a sign or by proof. But neither by means of a sign nor by proof is it possible to do this; for these, being themselves “expressions,” are matters of inquiry like the other “expressions,” 261. and are so far from being capable of establishing anything firmly that, on the contrary, they themselves require something to establish them. The Stoics, too, have unwittingly fallen into the fallacy of circular reasoning. For in order that “expressions” may be agreed to, proof and sign must exist; and in order that proof and sign may really pre-exist, the reality of “expressions” must be previously confirmed. As these lean, then, on one another and await confirmation from one another, they are equally untrustworthy.

262. But let it be supposed and gratuitously conceded, for the sake of advancing our inquiry, that “expressions” are in existence, although the battle regarding them remains unending. If, then, they exist, the Stoics will declare that they are either corporeal or incorporeal. Now they will not say that they are corporeal; and if they are incorporeal, either — according to them — they effect something, or they effect nothing. Now they will not claim that they effect anything; for, according to them, 263. the incorporeal is not of a nature either to effect anything or to be affected. And since they effect nothing, they will not even indicate and make evident the thing of which they are signs; for to indicate anything and make it evident is to effect something. 264. But it is absurd that the sign should neither indicate nor make evident anything; therefore the sign is not an intelligible thing, nor yet a proposition.

Moreover, as we have frequently shown in many places, some things signify, others are signified. Vocal sounds signify, but “expressions” are signified, and they include also propositions. And as propositions are signified, but not signifying, the sign will not be a proposition.

265. Again, let it be conceded that “expressions” are of an incorporeal nature. Yet, since they assert that the sign is the antecedent in a valid major premise, the valid major will have to be tested and scrutinized beforehand, whether it be what is valid according to Philo, or according to Diodorus, or through congruence, or judged by some other criterion; for since on this point also there are many rival views it is impossible to have a firm grasp of the sign so long as the dispute remains unsettled.

266. Further, in addition to the foregoing arguments, even if we grant that the valid criterion is agreed upon and that it is incontestably of the kind the Stoics claim, none the less they must necessarily agree that the premise containing the sign is uncertain. For they hold that the thing signified is either pre-evident or non-evident. 267. And if it is pre-evident, it will not admit of being signified, nor will it be signified by anything but will be perceived of itself; while if it is non-evident, it certainly cannot be known whether it is true or false, since when it is known which of these it is it viull become pre-evident. 268. The premise, then, which contains the sign and the thing signified, as it ends in what is non-evident, is of necessity uncertain. For that it begins with truth is known, but it ends in the unknown. But in order to pass judgment upon it we must first of all learn wherein it ends, so that if it ends in truth we may pronounce it true because it begins with truth and ends in truth, but if it ends in falsehood, we may, contrariwise, declare it to be false because it begins with truth and ends in falsehood. So then, the sign should not be said to be a proposition, or an antecedent in a sound premise.

269. To these (objections) it should be added that those who champion this opinion are in conflict with evident facts. For if the sign is a judgment and an antecedent in a valid major premise, those who have no conception at all of a judgment, and have made no study of logical technicalities, ought to have been wholly incapable of interpreting by signs. 270. But this is not the case; for often illiterate pilots, and [often] farmers unskilled in logical theorems, interpret by signs excellently — the former on the sea (prognosticating) squalls and cahns, stormy weather and fair, and the latter on the farm (foretelling) good crops and bad crops, droughts and rainfalls. Yet why do we talk of men, when some of the Stoics have endowed even irrational animals with understanding of the sign? 271. For, in fact, the dog, when he tracks a beast by its footprints, is interpreting by signs; but he does not therefore derive an impression of the judgment “if this is a footprint, a beast is here.” The horse, too, at the prod of a goad or the crack of a whip leaps forward and starts to run, but he does not frame a judgment logically in a premise such as this — “If a whip has cracked, I must run.” Therefore the sign is not a judgment, which is the antecedent in a valid major premise.

272. Let these special arguments be stated against those who hold that the sign is intelligible; but it will be possible also to use against them the general arguments we have brought against those who assert that it is sensible. For if the sign is an antecedent proposition m a valid major premise, and in every major the consequent follows the antecedent, and these connections are between things present, then the sign and the thing signified, both being present at one and the same time, will necessarily co-exist and neither of them will serve to disclose the other, but both will be known of themselves.

273. Further, the sign serves to reveal the thing signified, and the thing signified is revealed by the sign. And these are not absolute things but relative; for the thing revealed is conceived in relation to that which reveals, and that which reveals is conceived in relation to that which is revealed. But if both, being relative things, are present at the same time, both co-exist; and if they co-exist, each of them is apprehensible of itself and neither of them through the other. 274. — This, too, may be said: Whatever be the character of the sign, either it is itself of such a nature as to indicate and disclose the mon-evident, or we are capable of remembering the things laid bare together with it. But it does not possess a nature capable of indicating non-evident things, since, (if so), it ought to indicate non-evident things to all men equally. Therefore it depends upon the state of our memory what view we take about the real nature of things.

275. But if the sign is neither sensible, as wc have shown, nor intelligible, as we have established, and besides these there is no third (possibility) , one must declare that no sign exists. But the Dogmatists remain muzzled as regards each of these objections, and by way of establishing the opposite they assert that Man does not differ in respect of uttered reason from the irrational animals (for crows and parrots and jays utter articulate sounds), but in respect of internal reason; 276. nor (does he differ) in respect of the merely simple impression (for the animals, too, receive impressions), but in respect of the transitive and constructive impression. Hence, since he has a conception of logical sequence, he immediately grasps also the notion of sign because of the sequence; for in fact the sign in itself is of this form — “If this, then this.” Therefore the existence of sign follows from the nature and structure of Man. — 277. Also, it is generally agreed that proof is of the genus sign. For it serves to make evident the conclusion, and the combination formed by its premises will be a sign of the existence of the conclusion. For example, in the case of this proof — “If motion exists, void exists; but motion exists; therefore void exists,” this combination “Motion exists, and if motion exists, void exists” is at once also a sign of the conclusion “void exists.” 278. The arguments, then, brought against the sign by the Doubters are, they say, either probative or non-probative. And if they are non-probative they are untrustworthy, seeing that they would hardly have been trusted, even had they been probative; while if they are probative it is plain that a sign exists, for proof is, as regards its genus, a form of sign. 279. — And if nothing is a sign of anything, the words uttered against the sign either signify something or signify nothing. And if nothing, neither will they destroy the existence of sign; for how can words that signify nothing possibly be trusted regarding the non-existence of a sign? And if they signify (something), the Sceptics are fools in that they verbally reject the sign while actually accepting it. 280. — Moreover, if there exists no special rule of art, art will not differ from lack of art. And if a special rule of art exists, it is either apparent or non-evident. But it will not be apparent, for things apparent appear to all similarly and without teaching. And if it is non-evident, it will be discerned by means of a sign. But if there exists anything discerned by means of a sign, there will also exist a sign.

281. Some also argue thus: “If a sign exists, a sign exists; if a sign does not exist, a sign exists. But a sign either exists not or exists; therefore it exists.” Such is the argument, and they declare that its first premise is valid; for it is duplicated, and “a sign exists” follows from “a sign exists” inasmuch as the second also will be (true) if the first is (true), since it differs in no respect from the first. And the premise “If a sign does not exist, a sign exists” is also valid in itself; for he who states that a sign does not exist is stating, consequently, that a sign does exist. For if no sign exists, there will be some sign that no sign exists. And reasonably so; for be who states that no sign exists affirms this either by mere assertion or by proof. And if he affirms it by assertion he will have (against him) the contrary assertion; 282. while if he tries to prove the truth of his statement, then by his argument proving the non-existence of a sign he will be signifying the non-existence of a sign, and in doing so he will be acknowledging the existence of a sign. So the first two premises are, they say, true. And the third also is true; for it is a disjunctive, composed of contradictories (the existence and non-existence of sign). Since, then, if every disjunctive is true when it has one clause true, and of contradictories one clause is regarded as true, one must declare that a premise thus constructed is indisputably true. So that the conclusion, “sign therefore exists,” is inferred along with the agreed premises.

283. It will also be possible, they say, to argue thus: In the argument there are two hypothetical premises and one disjunctive; and of these, the hypothetical promise that their consequents follow from their antecedents, while the disjunctive has one of its clauses true, since if both be true or both false the whole will be false. 284. Such then being the quality of the premises, let us assume that one of the clauses of the disjunctive is true and see how the conclusion is deduced. And let it be assumed first that “a sign exists” is true: then, since this is the antecedent in the first hypothetical premise, it will have as following from it the consequent in that premise. And that consequent was “a sign exists,” which is the same as the conclusion. The conclusion, therefore, will be deduced if it be assumed that the clause “a sign exists,” in the disjunctive, is true. Again, let it be assumed, conversely, that the other clause, “a sign does not exist,” is true. Then, since this is the antecedent in the second hypothetical premise, it will have as following from it the consequent in the second hypothetical. And what followed from it was “a sign exists,” which is also the conclusion. Therefore in this way also the conclusion is deduced.

285. Such are the contentions of the Dogmatists; and to the first of them, (taking them) in order, in which they inferred the existence of a sign from the structure of Man, one must straightway reply that they try to explain the less questionable by the more questionable. For the existence of a sign, even if it is controverted by some, such as the Sceptics, is nevertheless generally accepted by all the Dogmatists; 286. but that Man is providentially constructed is disputed by not a few of them. And it is extremely violent to try to explain by what is more generally controverted what is less so. Moreover, Heracleitus expressly affirms that “Man is not rational, and only the circumambient is intelligent.” But Empedocles, still more paradoxically, held that all things are rational, and not animals only but plants as well, as he writes expressly —

Wisdom and power of thought, know thou, are shared in by ail things.

287. Besides, there is a plausible argument to show that the irrational animals are not unwise. For if they possess “uttered reason,” they must necessarily possess also “internal reason”; for apart from this latter the uttered reason is non-existent. 288. And even if we grant that Man differs from the other animals in reason and transitive impression and conception of logical sequence, yet certainly we shall not agree that he is as described as regards things non-evident and matters of unsettled controversy, whereas in respect of things apparent he possesses a retentive sense of sequence, by which he remembers what things he has observed together with what, and what before what, and what after what, and from his experience of previous things revives the rest. 289. — But, they say, when it is agreed that proof is, in respect of its genus, a sign, if the arguments brought against the sign are not proofs they are untrustworthy, while if they are proofs a sign exists. But as we have previously stated that we do not object to the commemorative sign but to the indicative, we are able to admit that the arguments brought against the sign signify something, but not as yet in an indicative but in a commemorative way; for we are affected by them and we recall in memory the things that can be said against the indicative sign. 290. — And the same may be said regarding their next contention, in which they inquired whether the words uttered against the sign signify something or signify nothing. For if we abolished every sign it would necessarily result either that the words uttered by us against the sign signify nothing, or, if they are significant, that the existence of a sign is conceded. But as it is, since we make use of the distinction, and abolish one kind of sign but affirm the other, by (our allowing that) the words spoken against the indicative sign are significant it is not admitted that an indicative sign exists. 291. — Further, it was argued that if there is a special rule of art, this ought not to be pre-evident but non-evident and apprehensible by means of a sign. But this is to ignore the fact that (as we shall show later) while there is no rule of the art concerned with other cases, of the art which deals with things apparent there is a special rule; for (this art) effects the framing of its rules by means of things frequently observed or investigated; and the things frequently observed and investigated are peculiar to those who have made I he most frequent observations, and are not the common property of all.

292. Then, as to the final argument propounded by them in this form — “If the first, the first; if not the first, the first; either the first or not the first; therefore the first” — it is, perhaps, unsound also because of the redundancy in its premises, and it indisputably appears to cause worry even to them. 293. First one should speak of what comes first in order, that is to say, the redundancy. If the disjunctive premise in the argument is true, it is bound to have one clause true, just as they themselves previously stated. And having one clause true it convicts one of the hypothetical premises of redundancy. 294. For, on the one hand, if one of its clauses, namely “a sign exists,” be assumed as true, then for its deduction the duplicated hypothetical premise, “if a sign exists, a sign exists,” becomes necessary, but the remaining premise, “if a sign does not exist, a sign exists,” becomes redundant. And, on the other hand, if its clause “a sign does not exist” is assumed to be true, the duplicated premise is redundant for the purpose of establishing this, whereas the premise “if a sign does not exist, a sign exists” becomes necessary. The argument, therefore, is unsound because of redundancy. 295. — But, not to follow our adversaries into minute points, one may propound another argument of the following kind: If he who states that a sign does not exist is converted to stating that a sign exists, he also who states that a sign exists is converted to stating that a sign does not exist. But he who stated, sceptically, that a sign does not exist was converted, according to them, to stating that a sign exists; therefore he who states, dogmatically, that a sign exists will be converted to saying, as we shall show, that a sign does not exist. 296. For instance, it is necessary that he who states that a sign exists should confirm his assertion by a sign, but as it is not agreed that a sign exists, how can he use the sign for confirming the existence of a sign? And if he cannot prove by a sign that a sign exists he will be converted to agreeing that no sign exists. — But let it be granted and agreed, into the bargain, that only this particular sign exists which serves to inform us that a sign exists; of what advantage to them is this, when they are unable to mention any sign of their own special doctrines? 297. So that this does not profit them at all — the general agreement, I mean, that a sign exists; it is probably necessary for them to subjoin to the indefinite statement “a sign exists” the definitely expressed “this sign exists.” And this it is not possible for them to do. For every sign, equally with the thing signified, is a matter of opinion and of unsettled controversy. Thus, just as the clause “Someone is sailing through a rock” is false, since it is impossible to subjoin to it as a definite truth “This man is sailing through a rock,” so also, since we are unable to subjoin to the indefinite “a sign exists” a definite and true “this sign exists,” the clause “a sign exists” becomes false and its contradictory, “no sign exists,” true.

298. Let it be granted, however, both that the arguments brought forward by the Stoics are strong and that those of the Sceptics remain uncontroverted; what remains for us, with this equipollence of the two parties, except to suspend judgment and avoid definition regarding the matter in question, not affirming either that a sign exists or that it does not exist, but cautiously pronouncing that it is “no more existent than non-existent?

299. But since proof seems to come under the genus sign and to reveal the non-evident conclusion by means of the agreed premises, it is perhaps fitting to attach our inquiry about proof to our examination of sign.

Chapter IV: Concerning Proof

300. The reason why we are at present inquiring about proof has been shown before, when we were investigating the Sign and the Criterion; but in order that our treatment may not be unmethodical and that our suspension and our controversy with the Dogmatists may go forward, we must indicate tile meaning of proof. 301. Proof, then, in point of genus is an argument; for it is not, of course, a sensible thing, but a certain motion and assent of the mind, and these are rational. And an argument is, speaking in general terms, what is constructed of premises and a conclusion. 302. We give the name of “premises,” not to certain assumptions which we take by force, but to those which, because they are obvious, the interlocutor grants and concedes. A conclusion is that which is established from the premises. For example, this whole structure is an argument: “If it is day, it is light; but in fact it is day; therefore it is light”; and its premises are “If it is day, it is light,” and “but in fact it is day”; while its conclusion is “therefore it is light.” — And of arguments some are conclusive, some not; 303. and conclusive are those in which, when it is agreed that the premises are true, owing to this agreement the conclusion also appears to follow, as was the case with that set out a moment ago. For since it is composed of the hypothetical major premise “If it is day, it is light,” which promises that, if its first clause is true, the second also of its clauses will be true; 304. and also of the premise “it is day,” which is the antecedent in the major; I assert that if it is granted that the major premise is true, so that its consequent follows from its antecedent, and granted also that the first of its clauses, “it is day,” is a fact, — then, because of the actuality of these, the second also of its clauses, namely “it is light,” will be deduced, and this is the conclusion. 305. Such, then, in respect of their type, are the conclusive arguments, and those which are not of this kind are inconclusive. — Of the conclusive arguments some deduce something pre-evident, others something non-evident, — pre-evident, as in the case of the argument set forth in this form; “If it is day, it is hght; but in fact it is day; therefore it is light”; for “it is light” is just as apparent as “it is day.” And again one like this; “If Dion walks, Dion moves; but Dion walks; therefore Dion moves”; for “Dion moves,” which is the conclusion, is a thing patent of itself. 306. But an argument such as this deduces what is non-evident: “If sweat pours through the surface, intelligible pores of the flesh exist; but in fact the first (is true); therefore the second (is true)”; for the existence of intelligible pores of the flesh is a thing non-evident. And again: “That by the separation of which from the body men die is the soul; but it is by the separation of blood from the body that men die; therefore the blood is soul.” For it is not manifest that the substance of the soul consists in blood. 307. And of these arguments which deduce something non-evident some lead us on from the premises to the conclusion by way of progression only, others both by way of progression and by way of discovery as well. 308. And of these such as seem to depend on belief and memory lead us on by way of progression only, as, for example, “If a god has said to you that this man will be rich, this man will be rich; but this god (assume that I point to Zeus) has said to you that this man will be rich; therefore he will be rich.” For here we accept the conclusion, that this man will be rich, not as established by the power of the argument set forth, but owing to our belief in the statement of the god. 309. But an argument such as that propounded regarding the intelhgible pores leads us from the premises to the conclusion both by way of progression and by way of discovery. For the premises “If sweat flows through the surface, intelligible pores of the flesh exist,” and “Sweat flows through the surface,” teach us to conclude from their own nature that intelligible pores of the flesh exist, in virtue of a progression such as this — “Through a solid body of non-porous formation it is impossible for a hquid to flow; but sweat flows through the body; so the body will not be solid but of porous formation.”

310. This being so, proof must first of all be an argument; secondly, conclusive; thirdly, also true; fourthly, having also a non-evident conclusion; fifthly, having also this conclusion discovered through the power of the premises. 311. Thus an argument such as this, when it is day, — “If it is night, it is dark; but in fact it is night; therefore it is dark” — is conclusive in form (for its premises being granted its conclusion also is inferred to exist), but it certainly is not true (for it contains the false premise “it is night”); and on this account it is not probative. 312. Again, such an argument as this — “If it is day it is light; but it is day; therefore it is light,” — besides being conclusive is also true, since, its premises being granted, its conclusion also is granted, and by means of true premises it proves something true. But though it does so, still it is not a proof owing to its having as its conclusion what is pre-evident and not non-evident. 313. In the same way one like this — “If a god said to you that this man will be rich, this man will be rich; but this particular god said to you that this man will be rich; therefore he will be rich” — has a non-evident conclusion, that “this man will be rich,” but is not probative because it is not discovered by the power of tile premises but meets with acceptance through trust in the god. 314. When, then, all these things concur — that the argument is at once conclusive and true and making manifest a non-evident — then proof really exists. Hence also they describe it thus: “A proof is an argument which by means of agreed premises reveals by way of deduction a non-evident conclusion”; — for example, this: “If motion exists, void exists; but in fact motion exists; therefore void exists.” For the existence of void is non-evident, and also it appears to be revealed by way of deduction by means of the true premises “If motion exists, void exists” and “but motion exists.”

315. Such, then, are the points regarding the notion of the object of our inquiry which it was fitting to deal with first; and, next in order, we must explain its subject matter.

Chapter V: The Subject Matter of Proof

316. Some things — as we frequently said before are believed to be manifest, others non-evident; and manifest are those which are perceived involuntarily through presentation and through affection, such as, at the present moment, “It is day,” “This is a man,” and everything of the kind; but non-evident are those which are not of this sort. 317. And of things non-evident — according to the distinction which some people make — some are naturally non-evident, but others are given the same name, “non-evident,” as their genus. And naturally non-evident are the things which neither have been previously apprehended, nor are now being apprehended, nor will hereafter be apprehended, but are eternally unknowable, as for instance that the stars are even in number or odd. 318. Hence they are termed naturally non-evident, not because they possess in relation to themselves a non-evident nature, since this would be to state a contradiction (by saying, that is, that we do not know them and at the same time agreeing as to what nature they possess), but because they are non-evident to our nature. 319. Termed after their genus non-evident are the things which in their own proper nature are hidden but are made known, it is claimed by means of signs and proofs, as for instance that there exist indivisible elements which move in infinite void. 320. — If, however, such a difference in the things exists, we assert that proof is neither pre-evident (for it is not made known of itself and by a necessitated affection), nor naturally non-evident (for the apprehension of it is not despaired of), but belongs to the remaining species of things non-evident, which have their nature submerged and obscured for us, but are thought to be apprehended by philosophic argument. 321. This, however, we do not positively affirm, since it would be ridiculous to keep on inquiring about proof after conceding its real existence, but only that, in regard to its notion, it is of the kind described; for in this way, from this notion and preconception, the argument about its existence will emerge. 322. So, then, that proof is, in its notion, one of the non-evident things that cannot be made known through itself must be argued as follows.

What is pre-evident and manifest is in all ways pre-evident and manifest and is agreed by all and admits of no dispute; but the non-evident is disagreed about and naturally tends to fall into dispute. 323. And reasonably so; for every argument is judged to be either true or false according to its reference to the thing concerning which it is brought forward; for if it is found to be in accord with the thing concerning which it is brought forward, it is held to be true, but if at variance, false. For example, someone declares that it is day. Then by referring the statement to the fact and learning that the fact’s existence is confirmatory of the statement, we say that the statement is true. 324. Consequently, when the fact concerning which the argument is brought forward is manifest and pre-evident, it is easy to refer the statement to it and then, in this way, to declare either that the argument is true as confirmatory of the fact, or false if contradictory. But when the fact is non-evident and hidden from us, then, as there can no longer be any secure reference of the argument to it, it only remains for the mind to be persuaded and drawn into assent by probabilities. But when one man guesses and tries to persuade in one way, another in another, disputation springs up, since neither he who has missed the mark knows that he has missed it, nor he who has hit it knows that he has hit it. 325. — Accordingly, the Sceptics very neatly compare those who inquire about things non-evident to men shooting at a mark in the dark; for just as it is probable that one of these hits the mark and another misses, but which has hit or missed is unknowable, so, with the truth hidden almost in the depths of darkness, many arguments are shot at it, but which of them is in accord with it, and which at variance, it is impossible to learn, as the object of inquiry is removed from (the sphere of) the manifest. 326. And this was first stated by Xenophanes:

Yet, wlth respect to the gods and what I declare about all things,
No man has seen and no man will know the truth in its clearness.
Nay, for e’en should he chance to affirm what is really existent.
He himself knoweth it not; but opinion holds sway over all things.

327. So that if the pre-evident is, for the reason already stated, agreed, whereas the non-evident is in dispute, it must be that proof also, being in dispute, is non-evident. And that it really is a matter of dispute it does not need many arguments to show us but only a short reminder, which lies ready to hand, seeing that the dogmatic philosophers and the logical doctors affirm it, but the Empirics “deny it, and perhaps Democritus also (for he has spoken against it strongly in his Canons), 328. while the Sceptics have cautiously suspended judgment about it, making use of the formula “not more.” And among those who affirm it, again, there is no little dissension, as we shall explain as our discourse proceeds. So, then, proof is a thing non-evident.

329. Furthermore, if every proof which contains an opinion in the premises is indisputably an opinion, and every opinion is disputed, necessarily every proof is disputed and is one of the objects of inquiry. Epicurus, for instance, opines that he has put forward a very strong argument for the existence of void, namely this — “If motion exists, void exists; but in fact motion exists; therefore void exists.” 330. But if the premises of this proof had been agreed to by all, it would necessarily have had a conclusion also following from them and admitted by all. 331. But as it is, some have objected to it — I mean, to the deduction of the conclusion from the premises — not because it does not follow from them; but because they are false and not admitted. 332. For — not to run over a great number of judgments about it, but to state at once (the view) that a valid hypothetical premise is one that does not begin with truth and end in falsehood, — then, according to Epicurus, the premise “If motion exists, void exists,” as it begins with the truth “motion exists” and ends in truth, will be true; but according to the Peripatetics, as it begins with the truth “motion exists” and ends in the falsehood “void exists,” it will be false; 333. and according to Diodorus, as it begins with the falsehood “motion exists” and ends in the falsehood “void exists,” it will in itself be true, but the minor premise, “But motion in fact exists,” he criticizes as false; 334. according to the Sceptics, however, as it ends in a non-evident, it will be non-evident; for according to them “void exists” is one of the things unknowable. From this, then, it is plain that the premises of the proof are matters of dispute. And matters of dispute are also non-evident, so that proof based on them is also wholly non-evident.

335. Moreover, proof is a relative thing, for it does not appear by itself but is seen in relation to the thing proved. And the existence of relatives is a matter of inquiry, and there are many who say that they do not exist. And what is subject to dispute is non-evident. So in this way also proof is non-evident — Besides this, proof is composed either of sound, 336. as is said by the Epicureans, or of incorporeal expressions, as is said by the Stoics. But, whichever of these it is composed of, it is open to serious question. For it is a question whether “expressions” really exist, and there is much argument on the point; and whether sounds have any significance is also a matter of doubt. But if it is a question what subject matter is the basis of proof, and what is questioned is non-evident, certainly proof is non-evident.

Let this, then, be laid down as the basis of our counter-argument; and let us pass on to consider next the question of the existence of proof.

Chapter VI: Does Proof Exist?

337. Now that we have explained what is the matter of which proof consists, we shall in the next place attempt to deal with the arguments which render it precarious, and consider whether its real existence follows from its notion and preconception or not. Some people, to be sure, — and especially those of the Epicurean School — are wont to withstand us rather rudely and say — “Either you understand what proof is, or you do not understand; and if you understand and have a notion of it, proof exists; but if you do not understand, how do you inquire into a thing of which you have no understanding at all?” 331a. For in saying this they are pretty well overthrown by their own selves, since it is agreed that a preconception and notion must precede every object of inquiry. For how can anyone even begin to inquire if he has no notion of the object of inquiry? For neither if he has hit the mark will he know that he has hit it, nor if he has missed it, that he has missed it. 332a. Consequently we grant this point, and in fact so far are we from saying that we have not a notion of the whole object of inquiry that, on the contrary, we claim to have many notions and preconceptions of it, and that it is because of our inability to decide between them and to discover the most cogent among them that we revert to suspension and indecision. 333a. For if we had possessed but one preconception of the object of inquiry, then, by following this closely, we would have believed that the object was such as we felt it to be owing to that one notion; but now, since we have many notions of the one object, and these manifold and conflicting and equally trustworthy both because of their inherent probability and because of the trustworthiness of the men who champion them, — as we are unable either to believe them all because of the conflict; or to disbelieve all, as we do not possess any other notion more trustworthy than they; or to believe one and disbelieve another, owing to their equality,— we are necessarily reduced to suspending judgment. 334a. But we do, in fact, possess preconceptions in the way that has been indicated. And because of this, if preconception was apprehension, in granting that we have a preconception of the thing w’e should probably have been admitting also apprehension of it; but as it is, since the preconception and notion of the thing is not its existence, we say that we have a notion of it but do not apprehend it for the reasons already set forth; 335a. for, to be sure, if preconceptions are apprehensions, we too in our turn will ask them whether Epicurus has or has not a preconception and notion of the four elements; and if he has not, how will he apprehend the object of inquiry and inquire into a thing of which he has not even a notion? While if he has, how is it that he did not apprehend the fact that there are four elements? 336a. But they will, I suppose, say in defense that Epicurus has a notion of the four elements, but has not, certainly, apprehended them; for a notion is a bare movement of the mind, holding to which he demes that there are four elements. So then we, too, possess a notion of proof, and starting from it we shall inquire whether it exists or not; but though we possess the notion we shall not also admit the apprehension.

337a. To these people, however, a reply will be made at some later time; but since it behoves us to produce our counter-arguments in a methodical way, we must inquire which proof one should object to most. Now if we propose to object to the special proofs and those belonging to each art, we shall be making our objection in an unmethodical way, as such proofs are endless; 338. whereas, if we abolish generic proof, which is held to be inclusive of all the particular proofs, it is evident that thereby we shall have all included therein abolished. For just as if Animal exists not, neither does Man exist, and if Man subsists not, neither does Socrates subsist, — the particular’s being abolished along with the genera, — so if generic proof does not exist, particular proof wholly disappears as well. 339. For although the genus is not wholly abolished along with the particular, — Man with Socrates, for example, — yet, as I said, the particular is canceled along with the genus. It is necessary, then, for those who throw doubt on proof to impugn no other proof save only the generic, since actually all the rest follow it.

340. Since, then, proof is, as we have argued, a thing non-evident, it ought to have been proved; for every non-evident thing, if it is received without proof, is untrustworthy. Therefore the fact that proof is something will be established either by a generic or by a particular proof. 341. But certainly not by a particular proof; for as yet particular proof does not even exist, because generic proof is not admitted as yet. For just as, if it is not yet clear that Animal exists, neither is it known that Horse exists, so when it is not yet agreed that generic proof exists, none of the particular proofs ivill be trustworthy; 342. and, in addition, we shall be involved in circular reasoning; for in order to establish the generic proof we must have the particular trustworthy, and in order that the particular may be admitted we must have the generic established, so that we can neither have the former before the latter, nor the latter before the former. So, then, it is not possible for the generic proof to be proved by the particular proof. 343. — Nor yet by the generic proof; for this is the object of inquiry, and being non-evident and an object of inquiry it will not be capable of estabhshing itself, seeing that it itself needs things which reveal it. Unless, indeed, when accepted by assumption, it is said to be capable of establishing something. But if once things are accepted by assumption and are trustworthy, what further need is there to prove them, since we are able to accept them on the spot and consider them trustworthy without proof because of the assumption? 344. — Furthermore, if the generic proof is capable of establishing the generic proof, the same proof will be at once quite apparent and non-evident — quite apparent in so far as it proves, but non-evident in so far as it is proved. And it will be equally trustworthy and untrustworthy — trustworthy because it serves to reveal something, but untrustworthy because it is revealed. But it is extremely absurd to term the same thing at once both pre-evident and non-evident, both trustworthy and untrustworthy. Therefore also the claim that the generic proof is capable of establishing itself is absurd.

345. Moreover, there is also another way of showing that neither proof nor any other existing thing can be established by means of generic proof. For generic proof either possesses (or does not possess) these particular premises and this particular conclusion. If, then, it possesses these particular premises and this particular conclusion, it is a particular proof. But if it does not possess premises and a conclusion, since proof does not deduce without premises and a conclusion, generic proof will deduce nothing, and deducing nothing it ivill not even deduce its own existence. 346. — If, then, it is agreed that the first proof ought to be proved, and it cannot be proved either by generic or by particular proof, it is plain that, as nothing else beside these (proofs) is discovered, we ought to suspend judgment about the problem of proof. 347. Moreover, if the first proof is being proved,it is being proved either by a questioned proof or by an unquestioned proof. But not by an unquestioned, for when the firs thas come to be disputed, every proof is questioned; nor by a questioned proof, for, again, that proof, if questioned, must be established by another proof, and the third by a fourth, and the fourth by a fifth, and so on ad infinitum. So, then, it is not possible for proof to be firmly established.

348. But Demetrius the Laconian, one of the notables of the Epicurean School, used to declare that this sort of objection is easy to dispose of, “for,” says he, “when we have established one of the particular proofs (for example, that which deduces that indivisible elements exist, or that void exists) and shown that it is sure, we shall at once have secured, as included in this, the trustworthiness of generic proof; for where there exists the particular of a genus, there we certainly find also the genus of which it is the particular,” as we mentioned above. 349. But this, though it seems to be plausible, is in fact impossible. For, in the first place, no one will allow the Laconian to establish his particular proof when his generic proof does not pre-exist; and just as he himself claims that, if he possesses the particular proof, he at once possesses also the generic, so too the Sceptics will claim that, to gain credence for the particular, its genus must first be proved. 350. And, what is more, even if they allow him to do this (I mean, to establish a certain particular proof in order to confirm the generic), some of the kindred Schools will not stay quiet, but will overturn whatever proof he produces as trustworthy, and he will have a large host of men who refuse to allow its acceptance. For instance, if he takes the proof concerning atoms, a countless number will contradict him; if that concerning void, a vast crowd will object; and so likewise with the proof concerning images. 351. And even though the Sceptics may concur ever so much with his choice, he will be unable to establish a single one of his proofs owing to the conflict of the Dogmatists.

Besides, what sort of firm particular proof does he say that he will possess? It will he either that one of them all which pleases him of itself, or any one whatsoever, or the one which is being proved. But to take that one out of them all which pleases him is self-willed and choosing at random; 352. and if he takes any one whatsoever, he will be adopting all the proofs, on the one hand those of the Epicureans, and on the other those of the Stoics, and of the Peripatetics as well; which is absurd. And if he takes the one which is being proved, it is not a proof; for if it is being proved, it is in question, and being in question it will not be trustworthy but needing things to confirm it. Therefore it is not possible to hold as trustworthy one of the particular proofs. 353. — Moreover, the premises of the proof which the Laconian mentions are either controverted and untrustworthy or are uncontroverted and trustworthy. But if they are controverted and untrustworthy, the proof also which they compose will certainly be untrustworthy for establishing anything. And that they are trustworthy and uncontroverted is a vain hope rather than the truth. 354. For if all existing things are either sensible or intelligible, the premises also of the proof must be either sensible or intelligible. And whether they be sensible or intelligible, they are subjects of inquiry. For sensible things either really exist such as they appear; or they are empty affections and concoctions of the mind; or some of them not only appear but also exist, while others only appear and do not really exist as well. And one may see notable men, 355. the leaders of every School, (disagreeing,) since Democritus threw over all sensible reality, but Epicurus declared that every sensible thing has stable existence, while Zeno the Stoic employed a distinction ; so that if the premises are sensible, they are matters of dispute. — So likewise if they are intelligible; for concerning these also one may see a vast deal of conflict among ordinary folk on the one hand, and among philosophers on the other, as men’s tastes differ. 356. And further, in addition to what has been said, if every intelligible thing derives its origin and source of confirmation from sensation, and the things made known through sense are, as we have argued, disputable, the intelligibles also will necessarily be of the same sort; so that the premises, too, of the proof, to whichever class they belong, are untrustworthy and unsure. And because of this, proof also is not trustworthy.

357. To speak more generally, premises are things apparent, and it is a question whether things apparent really exist; and things questioned are not at once (accepted) premises but must be confirmed by something. By what means, then, can we establish that the apparent thing is really such as it appears? 358. Either, certainly, by means of a non-evident fact or by means of an apparent one. But to do so by means of a non-evident fact is absurd; for the non-evident is so far from being able to reveal anything that, on the contrary, it is itself in need of something to establish it. 359. And to do so by means of an apparent fact is much more absurd; for it is itself the thing in question, and nothing that is in question is capable of confirming itself. It is not feasible, therefore, to establish things apparent, in order, by this means, to have proof made trustworthy. 360. — “But,” say the Dogmatists, “one must certainly posit things apparent, because, firstly, we have nothing more trustworthy than they, and, next, because the argument which attacks them is overthrown by itself. For it destroys them by employing either assertion only, or things apparent, or things not apparent. But if it employs assertion, it is untrustworthy; for it is easy to put forward the opposite assertion. 361. And if it employs things not apparent, once again it is untrustworthy, since it attempts to overthrow apparent things by things not apparent. And if it attacks things apparent by things apparent, these must certainly be trustworthy, and in this way, too, the things apparent will at once be trustworthy. So that the argument goes against them.” 362. But as to ourselves — that the question whether things apparent are sensible or intelligible is one fraught with contention both among philosophers and among ordinary folk we have already argued. So, for the moment, in reply to the dilemma set forth, we must assert that we do not attack things apparent by employing either assertion or things not apparent, but by comparing them among themselves. For if sensibles had been found to be in accord with sensibles and intelligibles with intelligibles, and conversely, we might probably have conceded that they are such as they appear; 363. but now because on comparing them we find insoluble contradictions, through which some are expelled by others; and because we are unable either to posit all owing to this contradiction, or to posit some owing to the equipollence of the opposites, or to reject all owing to our having nothing more trustworthy than appearance; we have fallen back on suspension of judgment. 364. — But, (say they,) the argument which derives its credibility from things apparent, in the act of attacking these wrecks itself as well. But this is the plea of men who hastily assume the point at issue. For it is not the argument that is established by the things apparent, but the things apparent that are confirmed by the argument. 365. And naturally so; for if they are disputed (some saying that they really exist, some that they do not), they must be established by the argument. And those who bear witness to this are none other than those of the rival School who try to prove by argument that apparent things are true. And besides, on what grounds ought one to trust things apparent? 366. Instead, therefore, of apparent things being more certain than the argument, the argument is more certain than apparent things since it supports both itself and them.

Now if the premises of the proof are non-evident and the conclusion also non-evident, and again if that which is composed of non-evident things is non-evident, then proof is non-evident and requires something else to support it, which is not the character of proof.

367. But, say they, one ought not to ask for proof of everything, but accept some things by assumption, since the argument will not be able to go forward unless it be granted that there is something which is of itself trustworthy. But we shall reply, firstly, that there is no necessity for their dogmatic argumentations to go forward, fictitious as they are. 368. And, further, to what conclusion will they proceed? For as apparent things merely establish the fact that they appear, and are not capable also of showing that they subsist, let us assume also that the premises of the proof appear, and the conclusion likewise. But even so the matter in question ivill not be deduced, nor will the truth be introduced, so long as we abide by our bare assertion and our own affection. And the attempt to establish that apparent things not merely appear but also subsist is the act of men who are not satisfied with what is necessary for practical purposes but are eager also to assume hastily what is possible. 369. And in general — seeing that it is maintained by the Dogmatists that not only proof but practically the whole of philosophy proceeds from assumption — we shall endeavor so far as possible to make answer briefly to those who accept a thing by assumption. 370. If the things which they say they accept by assumption are trustworthy because accepted by assumption, their opposites also will appear trustworthy when accepted by assumption, and thus we shall be positing things that conflict; but if in the case of the latter — the opposites, I mean — the assumption is too weak to support them, it will be too weak also in the case of the former; so that, once again, we shall assume neither, 371. — Further, that which a man assumes is either true and such as he assumes it to be, or it is false. And if it is true, he that assumes it is wronging himself, seeing that, when it was possible for him not to postulate it but to take it as true of itself, he has recourse to a thing that is gravely suspected — to assumption, that is — when he postulates what is true of itself. But if it is false, the man who employs assumption is no longer wronging himself, but the real nature of the things, when he claims that the non-existent should of itself be conceded to him as existent, and compels one to accept what is false as true. 372. — Again, if a man maintains that everything which follows from the things accepted by assumption is certain, he confounds the whole of philosophic inquiry. For we shall assume, for instance, that 3 is 4, and deduce as a consequence that 6 is 8; and this — that 6 is 8 — will be true. 373. And if they should say to us that such a case is absurd (for the thing assumed must be certain, in order that its consequence also may be admitted), they shall hear us, in reply, maintaining that nothing should be accepted of itself and everything affirmed should be affirmed with precision. 374. — Furthermore, if the thing assumed, in that it is assumed, is certain and sure, let the dogmatic philosophers assume, not the things from which they deduce the non-evident, but the non-evident itself — that is to say, not the premises of the proof but the conclusion. But even were they to assume this ten thousand times, it is not trustworthy, owing to its being non-evident and the subject of inquiry. Thus it is, to be sure, apparent that if they postulate the premises of the proof without proof, they effect nothing in support of it since the premises themselves are matters of dispute.

375. Yes, by Zeus; but they are wont to interrupt with the reply that a guarantee of the strength of the assumption is the fact that what is concluded by the premises accepted by assumption is found to be true; for if what follows from the premises is sound, the premises from which they follow are true and indisputable. 376. But, someone will say, how can we show that what follows from the premise accepted by assumption is true? By means of itself or by means of the premises from which it follows? But it will not be by means of itself, for it is non-evident. Is it, then, by means of the premises? Not in this way either; for it is about these that the conflict exists, and it is they that must first be established. 377. Notwithstanding, let it be granted that what follows from the assumed premises is true; all the same, the assumed premises wll not on this account become true. For if, according to them, the true had followed the true only, the argument would have gone forward, so that the assumed premise would be true since the consequence of the premise is true; 378. but as it is, since they assert that both falsehood follows from falsehood and truth from falsehood, it is not necessary that if the consequent is true the antecedent also should be true, but it is possible for the antecedent to be false though the consequent is true.

Let thus much be said, then, — as “a bywork of our journey,” as they say, and an appendix — regarding the wrongfulness of founding proof on assumption. 379. Next one must point out that it also involves itself in circular reasoning, which is still more hopeless. For we have already established that proof is a non-evident thing, and every non-evident thing requires scrutiny, and what requires scrutiny needs a criterion to determine whether it is valid or not; for just as a thing which needs to be measured cannot be measured without a measure, and nothing that is being ruled is ruled without a rule, so also what is being scrutinized is not tested without a criterion. 380. Since, then, the existence of a criterion also is questioned, some declaring that none exists, others that it does exist, and others again suspending judgment about it, the fact that a criterion exists will, in turn, have to be proved by means of some proof. But in order to have the proof confirmed, we shall have to turn hack to the criterion, and thus, as we neither have the latter trustworthy before the former nor the former certain before the latter, we must agree to suspension of judgment about both.

381. In addition to what has been said, it will be possible also to attack proof on the ground of its conception. Though even were it conceived, it would not necessarily be existent; for, as I said, there are many things which are conceived but have no share in real existence. But as it is, when even the conception of proof is found to he impossible, the hope also of its existence is cut off beyond dispute. 382. As, then, there are two kinds of proof, the generic and the particular, we shall find the generic to be of itself inconceivable; for none of us knows generic proof nor has ever yet been able to establish anything by means of it. 383. Besides, one may well ask whether this kind of proof has, or has not, premises and a conclusion. And if it has not, how can it still be conceived as a proof, seeing that no conception of any proof is framed apart from its premises and conclusion? And if it has both — that is to say, the premises and the conclusion, — it is a particular proof; 384. for if everything that is proved and everything that proves belongs to the class of particulars, it is necessary that proof also should be one of the particulars. But our argument was not concerned with the particular but with the generic; therefore generic proof is not conceived. 385. — Nor, in fact, is particular proof. For proof was stated by the Dogmatists to be “an argument which reveals something non-evident through deduction by means of certain apparent things.” Either, then, the whole structure — that is, the thing, conceived as a compound of the premises and the conclusion — is proof, or the premises only are proof, and the conclusion is what is proved. But whichever of these they declare for, the conception of proof is upset. 386. For if, on the one hand, the compound of premises and conclusion is proof, proof must at once, of necessity, be non-evident as containing something non-evident; and being such, it must need a proof, which is absurd. So then the compound of premises and conclusion will not be proof, since we conceive of proof as neither non-evident nor needing proof. 387. — Again, proof is a relative thing; for it does not refer to itself, nor is it conceived as isolated, but it has something whereof it is a proof. If, then, its conclusion is included within it, whereas every relative thing is outside of the thing whereto it is said to be in relation, then proof is conceived as relative to nothing, since its conclusion is contained within it. 388. If, however, we assume another conclusion outside, in relation to which the proof will be conceived, there will then be two conclusions in the argument — first, the conclusion included in the proof, and secondly the outside one, as relative to which proof is conceived. But it is absurd to state two conclusions of one proof. Proof, therefore, is not the compound of premises and conclusion. 389. — It only remains, then, to declare that proof is composed of the premises only, which is silly. For then it is not even an argument at all, but a defective thing and mcaningless, since no sensible man asserts that a combination such as this — “If motion exists, void exists; but in fact motion exists” — when taken by itself either is an argument or contains any meaning. 390. If, therefore, proof is conceived neither as the compound of premises and conclusion, nor as that of the premises only, proof is inconceivable.

391. Again, the proof that it is proving is either a pre-evident proof of a pre-evident thing, or a non-evident of a non-evident, or a non-evident of a pre-evident, or a pre-evident of a non-evident; but it is none of these, as we shall establish; therefore, proof is not anything. 392. Now a proof cannot be a pre-evident one of a pre-evident thing, since the pre-evident has no need of proof, but is known of itself. Nor, again, will a proof be a non-evident one of a non-evident thing, inasmuch as, being non-evident, it will itself have need of something that establishes any other thing. 393. And in the same way it will not be a non-evident one of a pre-evident thing; for here both difficulties will meet in one; for the thing proved will need no proof, as it is pre-evident, while the proof, being non-evident, will have need of something to establish it. So that a proof could never be a non-evident one of a pre-evident thing. 394. All that is left is to say that it is a pre-evident one of a non-evident thing; and this, too, is doubtful. For if proof is not one of the things conceived as in isolation and absolute, but is one of the relatives, and relatives — as we showed in our inquiry regarding Sign — are apprehended together with one another, and things apprehended together are not revealed by one another but are of themselves pre-evident, — then proof will not be a pre-evident proof of a non-evident thing, owing to the fact that that thing, as apprehended together with the proof, is perceived by means of itself. 395. If, then, proof is neither such a thing as an apparent of an apparent, nor a non-evident of a non-evident, nor a non-evident of an apparent, nor an apparent of a non-evident, and besides these there is no other possibility, one must declare that proof is nothing.

396. As a sequel to what has been said, seeing that the Stoics seem to have elaborated most precisely the modes of proof, come and let us argue the matter briefly in reply to them, and show that, so far as depends on their assumptions, all things probably are non-apprehensible, and more particularly proof. 397. Now apprehension, as one may learn from them, is “assent to the apprehensive presentation”; and this seems to be a twofold thing, and to be partly involuntary, and partly voluntary and dependent on our judgment. For the experience of a presentation is involuntary, and it does not depend on the person affected, but on the cause of the presentation, that he is affected in this particular way — as, for instance, with a sense of whiteness when a white color presents itself, or with a sense of sweetness when something sweet is offered to his taste; but the act of assenting to this affection lies in the power of the person who receives the presentation. 398. So that apprehension has as its antecedent the apprehensive presentation, to which it is the assent. And the apprehensive presentation has as antecedent the presentation, of which it is a species. For if presentation does not exist, neither does apprehensive presentation exist, inasmuch as when the genus does not exist, the species does not exist either; and if apprehensive presentation does not exist, neither does assent thereto exist. And when assent to the apprehensive presentation is taken away, apprehension also is taken away. 399. Hence, if it be shown that, according to the Stoics, a presentation of proof cannot come into existence, it will be evident that no apprehensive presentation of proof will subsist, and, this being non-existent, assent to it will not exist either, and this is apprehension.

400. That a presentation of proof, according to the Stoics, does not exist is shown, firstly, by the general dissension among them as to what presentation is; for when they have agreed so far as to say that it is “an impression on the regent part,” they are at variance about “impression” itself, Cleanthes understanding it to mean literally “that conceived as involving depression and eminence,” but Chrysippus more loosely as a synonym for “alteration.” 401. If, then, even among themselves there is no agreement up till now about “impression,” presentation too, as being in dispute up till the present, must necessarily be treated with suspension, and also the proof which depends thereon. 402. Next, let it be granted that presentation exists, be it of whatsoever sort they wish, whether literal “impression” with depression and eminence or alteration; yet how this (impression) comes about is a most doubtful question. For evidently the presented object ought to be the active agent, and the regent part, as receiving the presentation, the passive subject, so that the former may impress and the latter be impressed; for it is not likely that presentation occurs in any other way. 403. Now, that the regent part can be passive someone, perhaps, ivill admit, although it is inadmissible; but how is proof likely to be the agent? For, according to them, it is either corporeal or incorporeal. 404. Now, it is not corporeal, for it is composed of incorporeal “expressions”; while if it is incorporeal, then, since incorporeals, according to them, can neither affect anything nor be affected, proof also, being incorporeal, will not be able to affect anything; and, as atfecting nothing, it will not impress the regent part; and, as not impressing this, neither will it produce therein a presentation of itself, nor, if this is so, an apprehensive presentation. 405. But if there exists no apprehensive presentation of it in the regent part, neither will there be an apprehension of it. 406. Therefore, according to the technical rules of the Stoics’ logic, proof is non-apprehensible.

Moreover, it is not allowable to say that incorporeals do not affect anything nor produce in us presentations, but it is we who form presentations from them. For if it is agreed that no effect is brought about without an agent and a passive subject, then the presentation of proof also, being an effect, should not be conceived without both agent and patient. 407. That the patient, then, is the regent part has been granted by the Stoics; but what the agent is which, according to them, makes the impression is worth considering. For either it is proof which impresses the regent part and excites its own presentation, or it is the regent part which impresses itself and causes presentation. But proof will not be capable of impressing the regent part; for it is incorporeal, and the incorporeal, according to them, neither effects nor suffers anything. 408. And if the regent part impresses itself, either what impresses is the same sort of thing as the impression, or else the impression is one sort of thing and what impresses something dissimilar. And if it is dissimilar, as the underlying objects are different, the presentations will be of different things; and this again forces the Stoic to admit the non-apprehensibility of all things. But if the impression is similar to what impresses, since the regent part impresses itself, it will receive a presentation not of the proof but of itself; which again is absurd.

409. But they endeavor also to render their view plausible by means of illustrations. For, say they, just as the trainer or sergeant sometimes takes hold of the boy’s hands when he is teaching him rhythm and how to make certain motions, and at other times stands at a distance and offers himself as a pattern for the boy’s imitation by making certain rhythmical motions, so also some of the objects presented produce the impression in the regent part as it were by touching and contact with it — such as white and black and body generally, — whereas others are not of this nature, since the regent part receives the presentation as a result of them but not by their agency, as is the case with incorporeal expressions. 410. But those who argue thus, though they use a plausible illustration, do not prove the matter in question. For the trainer or sergeant is corporeal, and because of this he was able to produce a presentation in the boy; but proof is incorporeal, and because of this it was questioned whether it is able to impress, as a presentation, the regent part. So that the original point in question has not been proved by them.

411. These arguments, therefore, having been indicated, let us pass on to consider whether the promise they ascribe to proof can be made good by their logical theory. Now they suppose that there are three forms of argument connected with one another — the conclusive and the true and the probative, 412. and of these the probative is always both true and conclusive, and the true is always conclusive but not necessarily probative as well, while the conclusive is not always true nor always probative. 413. Thus an argument such as this, when it is day — “If it is night, it is dark; but in fact it is night; therefore it is dark” — draws a conclusion because it is propounded in a valid form, but is not true as it has a false second premise, the minor “but in fact it is night.” 414. But one of this kind, when it is day — “If it is day, it is light; but in fact it is day; therefore it is light” — is at once both conclusive and true, as being not only propounded in a valid form but also drawing a true conclusion by means of true premises. 415. And they say that the conclusive argument is judged to be conclusive when the conclusion follows from the combination of the premises; for example, an argument such as this, when it is day — “If it is night, it is dark; but in fact it is night; therefore it is dark” — we declare to be conclusive, although it is not true because it leads us to a falsehood. 416. For when we have combined the premises thus, “It is night, and if it is night it is dark,” we frame a hypothetical syllogism which begins with this form of combination and ends in this form of conclusion “it is dark.” For this hypothetical syllogism is true, as it never begins with truth and ends in falsehood. For when it is day, it will begin with the falsehood “It is night, and if it is night, it is dark,” and will end in the falsehood “it is dark,” and thus will be true; and in the night, it will both begin with truth and end in truth, and for this very reason it will be true. 417. So, then, the conclusive argument is sound when, after we have combined the premises and framed a hypothetical syllogism which begins with the combination formed by the premises and ends in the conclusion, this syllogism itself is found to be true. 418. And the true argument is judged to be true not solely from the fact that the hypothetical syllogism which begins with the combination formed by the premises and ends with the conclusion is true, but also from the fact that the combination formed by the premises is valid; since, if either of these is found to be false, the argument also necessarily becomes false; just as the following, when it is night, “If it is day, it is light; but in fact it is day: therefore it is light,” is false because it contains the false premise “it is day.” 419. And the combination formed by the premises is false, as it has one of its premises — “it is day” — false; but the hypothetical syllogism, which begins with the combination formed by the premises and ends in the conclusion, will be true. For never when beginning with truth does it end in falsehood, but, in the night, it begins the combination with falsehood, and, in the day, as it begins with truth so also it ends in truth. 420. And again, an argument such as this is false — “If it is day, it is light; but it is light; therefore it is day,” as it can lead us by means of true premises to falsehood. 421. But in fact, if we examine it, the combination formed by the premises can be true when it is day — as for instance “It is light, and if it is day, it is light,” — but the hypothetical syllogism, which begins with the combination formed by the premises and ends in the conclusion, may be false, as for instance this — “If it is light and if it is day, it is light(; therefore it is day).” For this syllogism can, when it is night, begin with its combination which is true and end in the falsehood “it is day,” and on this account be false. So that the argument becomes true neither when the combination only, nor when the syllogism only, is true but when both are true. 422. — But the probative argument differs from the true because, while the true can have all its parts manifest (both the premises, I mean, and the conclusion), the probative purports to have something more — namely, the discovery of the conclusion, which is non-evident, by means of the premises. 423. Hence, an argument like this — “If it is day, it is light; but in fact it is day; therefore it is light,” which has both premises and conclusion manifest, is true and not probative; but one such as this — “If she has milk in her breasts, she has conceived; but in fact she has milk in her breasts; therefore she has conceived,” besides being true is also probative, for it has a non-evident conclusion, “therefore she has conceived,” and discovers this by means of its premises.

424. As there are, then, three kinds of argument, the conclusive and the true and the probative, if an argument is probative it must previously be true and conclusive; but one that is true is not necessarily probative, but it certainly is conclusive; and one that is conclusive is not always true, just as it is not always probative. 425. Since, then, the conclusive character must appertain to them all in common, if we shall establish that the conclusive argument is undiscoverable by the Stoics, we shall have established that the true and bhe probative cannot be discovered either. 426. And that there does not exist any conclusive argument is easy to perceive. For if they assert that a conclusive argument exists whenever there exists a true hypothetical syllogism, beginning with the combination formed by its premises and ending in its conclusion, the truth of the syllogism will have to be judged beforehand, and after that the conclusive argument which seems to depend on it must be accepted with certainty. 427. But the valid syllogism has not been determined up till now; neither, then, can the conclusive argument be ascertained. For just as, when a standard measure does not remain constant but varies from time to time, the thing measured also is not constant, so likewise, since the valid syllogism is, as it were, the standard for deducing the argument, when the former is undetermined it will follow that the latter too is not clear. 428. And that the valid syllogism is undetermined is taught us by the “Introductions” of the Stoics, in which they propose many determinations of it, which are contradictory and up till now undetermined. Hence, as the conclusive argument is of this sort, certainly the true also, and therefore also the probative, ought to be regarded with suspension.

But even if we leave this objection and proceed to the logical rules about “definite” and “indefinite” arguments, the construction of the probative argument will be found impossible. 429. Now concerning the definite arguments there is much close investigation, and there is no necessity to discuss them now, but we must give some account of the indefinite. They say, then, that the indefinite argument comes about in four ways — either through inconsistency, or through redundancy, or through being propounded in a bad form, or through deficiency. 430. Thus it is through inconsistency when the premises have no connection and consistency with each other and with the conclusion, as in an argument such as this — “If it is day, it is light; but in fact wheat is being sold in the market; therefore it is light.” For we see that in this instance neither the clause “if it is day” has any relevance and connection with the clause “wheat is being sold in the market,” nor either of these with the clause “therefore it is light,” but each of them is inconsistent with the others. 431. And the argument is indefinite through redundancy when something is included, extrmsically and superfluously, along with the premises, as is the case with one like this — “If it is day, it is light; but in fact it is day, and also virtue benefits; therefore it is light”; for the fact that virtue benefits is superfluously introduced along with the other premises, seeing that, when it is excluded, it is possible for the conclusion, “therefore it is light,” to be deduced by means of the remaining premises, “if it is day, it is light” and “but in fact it is day.” 432. And the argument becomes indefinite owing to being propounded in a bad form whenever it is propounded in any form that differs from the valid forms; for example, when a form such as this is valid — “If the first, the second; but in fact the first; therefore the second”; 433. and also this — “If the first, the second; but not the second; not, therefore, the first,” — we say that the argument propounded in this form — “If the first, the second; but not the first; not, therefore, the second,” is indefinite, not because it is impossible for an argument which deduces what is true by means of true premises to be propounded in this form (for this is possible, as for instance “If 3 is 4, 6 is 8; but 3 is not 4; therefore 6 is not 8”), but because it is possible for some bad arguments to be arranged in this form, such as this, for example — “If it is day it is light; but in fact it is not day; therefore it is not light.” 434. And the argument becomes indefinite through deficiency when one of its deductive premises is deficient. For example, “Either wealth is an evil or wealth is a good; but wealth is not an evil; therefore wealth is a good”; for in the disjunctive premise there is an omission of “Wealth is indifferent,” so that the valid statement ought rather to run thus — “Wealth is either a good or an evil or indifferent; but wealth is neither a good nor an evil; therefore it is indifferent.”

435. Such, then, being the logical theory laid down by the Stoics, one suspects that, if we go by it, an argument cannot be judged to be indefinite, — for example, that through inconsistency which takes the form — “If it is day it is light; but in fact wheat is being sold in the market; therefore it is light.” For the fact that the premises are inconsistent and possess no connection either with each other or with the conclusion is stated by them either by bare assertion or by establishing the fact by means of some technical and doctrinal method. 436. But if they are employing bare assertion, it is easy to reply with an opposite assertion, which asserts that every argument termed indefinite through inconsistency is definite; for if these men can be trusted on a bare assertion, those too who say the opposite will be able to be trusted; for they utter an equipollent assertion. And if they are expounding this by method, we shall inquire further what this method can possibly be. 437. And if they allege that the sign of the argument indefinite through inconsistency is the fact that the conclusion does not always follow from the combination of its premises, and that the syllogism which begins with the combination formed by the premises and ending in the conclusion is not valid, we shall assert that they are falling again into the original difficulty; for if, in order to discern the argument which is indefinite through inconsistency, we must have the valid syllogism determined, and up till now we have not got this determined, we certainly cannot ascertain the argument which is indefinite through inconsistency. 438. — But there exists also a second type of indefinite arguments — that through redundancy, — in which something from without is introduced into the premises which is redundant for establishing the conclusion. But, to judge by this, an argument propounded according to the first type will have to be indefinite through redundancy, since in it the hypothetical premise is redundant. This we shall learn when we have compared the arguments. 439. For they assert that an argument such as this is indefinite — “If it is day, it is light; but in fact it is day, and also virtue benefits; therefore it is light.” For in this case “virtue benefits” is redundant for the deduction of the conclusion, because when this clause is removed the conclusion can be deduced, with no deficiency from the two remaining premises. 440. The Sceptics, then, will say in reply that if that argument is indefinite through redundancy in which, when one premise is removed, the conclusion is deduced from the remaining premises, then we must declare that the argument propounded in the first mode is also indefinite, namely this — “If it is day, it is light; but in fact it is day; therefore it is light.” For in this the hypothetical premise “If it is day, (it is light)” is redundant for the establishing of the conclusion, and “therefore it is light” can be deduced from the clause “it is day” by itself. 441. And this is pre-evident even of itself, but it is also possible to argue it from its logical relation to the latter clause. For they will say that “it is light” either follows or does not follow from “it is day.” And if it follows, when the clause “it is day” is allowed of itself to be true, the clause “it is light” is also deduced, as necessarily following it: and this is the conclusion. 442. But if it does not follow, neither will it follow in the case of the hypothetical premise, and because of this the hypothetical premise will be false, as the consequent in it does not follow the antecedent. So that, to judge by the logical theory stated above, one of two things must result — either that the argument propounded in the first mode is found to be indefinite, as its hypothetical premise is redundant, or that it is wholly false because its hypothetical premise is false. 443. For to say that Chrysippus does not approve of arguments having but one premise — which some, perhaps, will say in reply to this objection — is utterly non-sensical. For it is neither necessary to believe in the utterances of Chrysippus as though they were pronouncements of the Delphic oracle, nor to pay attention to the witness of men (who are contradicted) by a witness (of their own) who says the opposite; for Antipater, one of the most eminent men in the Stoic school, asserted that arguments with a single premise can be constructed.

444. Again, in the third mode an argument is said to be indefinite owing to its being propounded in a bad form. So, once again, they will either state that an argument is propounded in a bad form by contenting themselves rvith assertion only or they will bring in also an argument to support it. But if they content themselves with assertion, we too will make the opposite assertion which declares that it has not been put in a bad form. 445. And if they bring in an argument, it must certainly be a true one. But how is it proved that this argument is true (I mean, that which proves that an argument has been propounded in a bad form)? Evidently by the fact that it is propounded in a valid form. So, then, in order that it may be knovm that the argument propounded in a bad form has been propounded in a bad form, a valid argument must be brought in; and in order that this may be valid, it must be propounded in a valid form. And for this reason, since neither the valid argument can be confirmed as being valid before the form, nor the form, as being a valid form, before the argument which determines it, the mode of circular reasoning, which allows no escape, is brought about.

446. The species of indefinite arguments which still remains — namely, that through deficiency — we have pretty well criticized already. For if the fully completed argument is undiscoverable, as we have shown above, the deficient also must be unknowable; but the fully completed is undiscoverable, as we have established; so then the deficient also will be unknowable.

447. But if there are, according to the Stoics, four modes in which an argument is indefinite, and we have proved that in each of them the indefinite arguments are not known, it will follow that the definite argument also is unknowable. And if this is not known, the probative argument also will be undiscoverable.

448. Furthermore, in the case of every true argument the premises must be approved (for when these are agreed, the conclusion is granted as following from them), but in the case of proof the premises are not approved, as we have established; therefore proof will not be able to be a true argument. 449. For, as we showed above, they maintain that the hypothetical premise is valid whenever it begins with truth (and ends in truth, or begins with falsehood) and ends in falsehood, or begins with falsehood and ends in truth; and is false in one mode — namely, when it begins with truth and ends in falsehood; and this being so, it null be found to be undetermined in the ease of proof. 450. For in all cases it begins with the minor premise and ends in the conclusion, as is the case with arguments such as this — “If motion exists, void exists; but in fact motion exists; therefore void exists.” For there the hypothetical major both begins with the minor premise “motion exists,” and ends in the conclusion “void exists.” 451. Either, then, the conclusion is a fact that is pre-evident and known by us, or it is non-evident and unknowable. “And if it is pre-evident and knowable, the argument is no longer probative, being composed of parts that are all pre-evident, the premises on the one side, and the conclusion on the other. But if it is non-evident, the major premise is necessarily undetermined. 452. For what it begins vnth is known to us (for it is pre-evident), but what it ends in is not known owing to its being non-evident. But when we do not understand whether this is true or false, we shall also be unable to pass judgment on the major premise. And when it is undetermined the argument, too, is bad.

453. Again, proof is a relative thing, and relatives are conceived only and do not really exist as well; so, then, proof too exists only in conception and not in reality. And that relative things are, in truth, only preserved by conception, and that they have no real existence, one may show by the admission of the Dogmatists. 454. For in describing the relative they say with one accord: “Relative is that which is conceived in relation to another;” whereas if it had participated in real existence they would not have given that account of it but rather this; “Relative is that which exists in relation to another.” Therefore the relative is not among the things that are really existent. — 455. Moreover, nothing which really exists can admit of any modification and alteration without being affected — just as white color cannot become black unless it has been converted and changed, and black cannot change to another color while it remains black, and in the same way what is sweet will not become bitter while it subsists unaffected and unaltered. 456. So that no real existent admits of change into something else without some affection. But the relative is modified without affection and when no alteration takes place in it. For example, when the stick of a cubit’s length is compared with one of a cubit’s length, it is said to be equal to it, but as compared with one of two cubits it is no longer equal but unequal, although no conversion or alteration has happened to it. And were we to conceive of a man pouring forth water out of a jug, if another jug is placed underneath this man will be said to pour in, but if there is no jug underneath, to pour out, although the man himself has undergone no conversion or alteration. 457. So that, if it is an attribute of the really existent not to submit to modification without being affected, and the relative has no such attribute, one must declare that the relative does not really exist. 458. — Besides this, the relative is relative to what is apart from it; for “above” is apart from “below.” 459. But if the relative has real existence and notmere conception, the one thing will be both opposites. But it is absurd to call the one the opposites; therefore the relative does not really exist but is only conceived. For, once again, the body of a cubit’s length is called greater in comparison with one of half a cubit, but smaller as compared to one of two cubits. But that the same thing at the same time should really be both greater and smaller — that is, two opposites — is a thing impossible. For it may possibly, perhaps, be conceived as such on account of the reference being to different objects, but it cannot be such in reality. Therefore relatives do not really exist.

460. Nevertheless, if the relative does exist, there exists an identical thing which is opposite to itself; but there is not such a thing; so neither in this way can we say that the relative really exists. — Again, if the relative really exists, there will be something opposite to itself; but it is not reasonable that there should be anything opposite to itself; neither, then, is it reasonable that the relative should really exist. 461. For “above” is opposite to “below,” and the same thing is “above” relatively to what lies beneath it, and “below” relatively to what lies above it. And if there are to be three things, “above” and “below” and “midway” between “above” and “below,” “midway” will be “above” relatively to what lies beneath it, and “below” relatively to what lies above it, and the same thing will be above and below; which is impossible. Therefore the relative does not really exist. — But if, after all, the relative does exist, the same thing will be above and below. And for this reason, even if it exists, the same thing is called “above” and “below” in respect of its relation to different things. The same thing, therefore, will come to be apart from itself, which is the greatest absurdity of all.

462. But if relatives are, in fact, non-existent, proof also, being a relative thing, will certainly be non-existent; but relatives have been proved to be non-existent; proof, therefore, will also be a non-existent thing.

463. Such, then, are the arguments for the non-existence of proof. Let us also examine the argument brought against them. The Dogmatic philosophers imagine that the argument which maintains the non-existence of proof is overthrown by itself, and that it affirms proof by the very means by which it abolishes it. Hence in withstanding the Sceptics they say: “He who states that proof is nothing states that proof is nothing either by using a bare and unproved assertion or by proving his statement by argument.” 464. And if it is by using bare assertion, none of those who are receiving the proof will trust him when using bare assertion, but he will be checked by the opposite assertion, when someone declares that proof exists. But if it is by proving the non-existence of proof (for this is what they say), he has thereby confessed that proof exists; for the argument which proves the non-existence of proof is a proof of the existence of proof. 465. And, in general, the argument against proof either is proof or is not proof; and if it is not proof, it is untrustworthy, but if it is proof, proof exists.” — And some, too, argue thus: 466. “If proof exists, proof exists; if proof exists not, proof exists; but proof either exists or exists not; therefore proof exists.” And indeed the convincing character of the premises of this argument is manifest. For the first hypothetical premise, “If proof exists, proof exists,” being duplicated, is true; for its second clause follows from its first as it does not differ from it. And the second hypothetical premise — “If proof exists not, proof exists” — is also valid; for the existence of proof follows from the non-existence of proof, which is its antecedent; 467. for the very argument which proves the non-existence of proof, being probative, certifies the existence of proof. And the disjunctive, “either proof exists or proof exists not,” being a disjunctive formed of the contradictories “proof exists” and “exists not,” must have one clause true and must therefore be true. So that, as the premises are true, the conclusion also is deduced therewith. 468. — And in another way,, also, one can show that the conclusion follows from the premises. For if the disjunctive premise is true when it has one of its clauses true, then whichever one of them we assume to be true the conclusion also will be deduced therewith. Let it be assumed that the first of its clauses — “proof exists” — is true. Then, since this is the antecedent in the first hypothetical premise, the consequent in that first premise will follow from it; but the consequent was “proof exists,” which is also the conclusion. Therefore, if it be granted that the clause “proof exists” is true in the disjunctive premise, the conclusion of the argument will follow. 469. And the same method of argumentation applies also to the remaining proposition — “proof exists not”; for this was the antecedent in the second hypothetical premise and, following from it, it had the conclusion of the argument.

470. Such being the objection of the Dogmatists, the Sceptics’ way of meeting it is short. For they will reply that if the Stoics are unable to answer the question in which they inquired whether the argument against proof is a proof or is not a proof, they ought to be indulgent toward the Sceptics if they are not prepared to answer so difficult a question. 471. But if what they demand of the Sceptics is easy for themselves, let them do what is easy and tell us in answer whether they assert that the argument against proof is proof or that it is not proof. For if it is not proof, it will not be possible to show by it that proof exists, nor to affirm that, because this argument is proof, proof must exist; for they have agreed that it is not proof. 472. But if it is proof, it certainly has its premises and its conclusion true; for proof is conceived as involving the truth of these. But its conclusion was “proof exists not”; therefore it is true that proof exists not, and the contradictory of this, that proof exists, is false. For by trying in this way to prove that the argument against proof is probative they no more affirm than deny proof. 473. Yet if the Sceptics are obliged to answer on their own behalf, they will give a safe answer. For they wll say that the argument against proof is merely probable and that at the moment it convinces them and draws them on to assent, but that they do not know whether it will still do so later on owing to the variableness of the human mind. For when our answer is framed thus, the Dogmatist will no longer be able to say anything. For either he will make it clear that the argument brought against proof is not true, or else he will establish the fact that he does not convince the Sceptic. 474. But if he proves the first, he is not in conflict with the Sceptic, since neither does the latter positively assert the truth of this argument, but merely says that it is probable. 475. And if he does the second he will show himself rash, by trying to upset another man’s mental impression by argument; for just as nobody can by argument convince the joyful man that he is not joyful, or the man in pain that he is not in pain, so nobody can convince the man who is convinced that he is not convinced. 476. — Furthermore, if the Sceptics had asseverated, together with assent, that proof in nothing, they might, perhaps, have been confuted by him who shows that proof exists; but as it is, seeing that they only make a bare statement of tire arguments against proof without assenting to them, so far from being injured by those who establish the opposite, they are benefited rather. 477. For if the arguments brought against proof have remained uncontradicted, and the arguments adopted in favor of proof’s existence are likewise strong, let us adhere neither to the former nor to the latter but agree to suspend judgment. 478. And if it be conceded that the argument against proof is probative, the Dogmatists will not gain any help thereby towards the existence of proof, as we have already shown; for it deduces the non-existence of proof, and if this is true the existence of truth becomes false. 479. — Yes, say they, but the argument which deduces that proof does not exist, being probative itself, banishes itself. To which it must be replied that it does not entirely banish itself. For many things are said which imply an exception; and just as we declare that Zeus is “the Father of both gods and men,” implying the exception of this god himself (for, to be sure, he is not his own father), so also when we say that no proof exists we imply in our statement the exception of the argument which proves that proof does not exist; for this alone is proof. 480. And even if it does banish itself, the existence of proof is not thereby confirmed. For there are many things which produce the same effect on themselves as they produce on other things. Just as, for example, fire after consuming the fuel destroys also itself, and like as purgatives after driving the fluids out of the bodies expel themselves as well, so too the argument against proof, after abolishing every proof, can cancel itself also. 481. And again, just as it is not impossible for the man who has ascended to a high place by a ladder to overturn the ladder with his foot after his ascent, so also it is not unlikely that the Sceptic after he has arrived at the demonstration of his thesis by means of the argument proving the non-existence of proof, as it were by a step-ladder, should then abolish this very argument.

Well, then, now that we have raised all these difficulties regarding the doctrines which belong to the division of Logic, we will proceed next to our criticism of the Physicists.


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