Aristotle · a new plain-English translation from the original language
1| There is a science that studies being as being, and the attributes that belong to it in its own right. This science is not the same as any of the sciences called particular sciences; for none of the others examines being as being universally, but each of them, marking off some part of it for itself, studies the accidental attribute of this part — as, for example, the mathematical sciences do. Since we are looking for the principles and the highest causes, it is clear that these must necessarily belong to some nature in its own right. If, then, those who sought the elements of the things that are were also seeking these same principles, the elements of being must likewise be elements not accidentally but qua being; therefore it is the first causes of being qua being that we too must grasp. Now being is spoken of in many ways, but always with reference to one thing and one single nature, and not homonymously, but just as everything called healthy is so called with reference to health — one thing because it preserves health, another because it produces it, another because it is a sign of health, another because it is receptive of it — [1003b] and as what is called medical is so called with reference to the medical art (one thing being called medical because it possesses the medical art, another because it is naturally well-suited to it, another because it is a function of the medical art), and we shall find other things spoken of in a similar way to these — so too being is spoken of in many ways, but always with reference to one starting point:
2| For some things are called beings because they are substances, others because they are affections of substance, others because they are a path toward substance, or destructions, or privations, or qualities, or things productive or generative of substance or of what is said in relation to substance, or negations of one of these or of substance. That is why we say that not-being is not-being. Just as there is a single science of all healthy things, so it is likewise with the others. For it is not only of things said in one sense that it belongs to a single science to study, but also of things said in relation to a single nature; for these too are said, in a way, in one sense. It is clear, then, that beings too are to be studied by a single science, insofar as they are beings. And everywhere the science, properly speaking, is of the primary thing, of that on which the others depend and through which they are named. If, then, this is substance, the philosopher would need to grasp the principles and causes of substances. Now for every genus there is a single perception of a single thing, and a single science, just as grammar, being one, studies all vocal sounds. That is why to study, as species of being qua being, however many there are, belongs generically to a single science — both the species themselves and the species of the species. If, then, being and the one are the same thing and a single nature, in that they follow upon each other as principle and cause do — though not as things made clear by a single account (and it makes no difference even if we take them in the same way, but rather this is even more to the purpose):
3| for 'one man' and 'man' are the same thing, and 'a man who is' and 'man' are the same, and the doubling in the phrase 'one man' and 'one man who is' does not signify anything different (and it is clear that they are not separated either in coming-to-be or in perishing), and likewise with 'one.' So it is clear that the addition, in these cases, signifies the same thing, and that the one is nothing other than being. Further, the substance of each thing is one, not accidentally, and likewise each is precisely a being, not accidentally; so that however many species there are of the one, there are just as many of being, and to study what each of these is belongs generically to the same science — I mean, for example, sameness and likeness and other such things. And nearly all the contraries are traced back to this principle:
4| [1004a] let these matters have been examined by us in our Selection of Contraries. And there are just as many parts of philosophy as there are substances, so that there must necessarily be some science that is first and one that comes next after it. For being and the one straightaway possess genera; that is why the sciences too will correspond to these. For the philosopher is spoken of in the way the mathematician is; for that discipline too has parts, and there is a first science and a second, and others in succession, among the mathematical sciences. Now since it belongs to a single science to study opposites, and to the one, plurality is opposed — and it belongs to a single science to study negation and privation, because in both cases what is studied is the one of which there is the negation or the privation (for we either say without qualification that that thing does not belong, or that it does not belong to some particular genus; for in privation a differentia is present in addition to what is stated in the negation — negation is simply the absence of that thing, whereas in privation some underlying nature also comes into play, of which the privation is asserted) — and plurality is opposed to the one — so that it belongs to the science we have mentioned to know also the things opposed to what has been said: the different, the unlike, the unequal, and whatever else is said either in accordance with these or in accordance with plurality and the one.
5| Among these is also contrariety; for contrariety is a kind of differentia, and differentia is otherness. So that, since the one is said in many ways, these things too will be said in many ways; nevertheless it belongs to a single science to know all of them. For it is not the case that, if something is said in many ways, it belongs to different sciences — rather that happens if the accounts refer neither to one thing said in one sense nor to one thing in relation to which the others are said. But since all things are referred back to what is primary — for example, whatever is called one is referred to the primary one — the same must be said to hold concerning sameness and otherness and the contraries. So that, having distinguished in how many ways each is said, one must then explain, within each category, how it is said in relation to the primary instance in that category; for some things will be said to be so by possessing that primary thing, others by producing it, and others in other such ways. It is clear, then — just what was said among the puzzles — that it belongs to a single science to give an account both of these things and of substance (this was one of the points among the puzzles), and that it belongs to the philosopher to be able to study all of them.
6| [1004b] For if it does not belong to the philosopher, who else will examine whether Socrates and Socrates-seated are the same thing, or whether one thing is contrary to one thing, or what the contrary is, or in how many ways it is said? And likewise concerning the other such matters. Since, then, these are affections belonging in their own right to the one qua one and to being qua being, and not to number, or lines, or fire as such, it is clear that it belongs to that science both to know what each is and to know their accidental attributes. And those who inquire into these things do not go wrong in this, as though they were not philosophizing, but rather because substance is prior, and about substance they understand nothing, since — just as number qua number has attributes proper to it, such as oddness, evenness, commensurability, equality, excess, deficiency, and these belong to numbers both in their own right and in relation to one another (and likewise the solid, and the unmoved, and the moving, and the weightless, and the thing having weight, each has other attributes proper to it) — so too being qua being has certain attributes proper to it, and it is about these that it belongs to the philosopher to investigate the truth. Here is a sign of this: the dialecticians and sophists put on the very same guise as the philosopher, for sophistry is wisdom only in appearance, and the dialecticians discuss all things, and being is common to all things, and they discuss these matters clearly because these belong properly to philosophy.
7| For sophistry and dialectic turn about the same genus as philosophy, but philosophy differs from the one in the manner of its capacity, and from the other in the choice it makes about its way of life; dialectic is a testing art concerning the very things of which philosophy has knowledge, while sophistry only appears to be such knowledge, without actually being it. Further, of the contraries, the one column is privation, and all things are traced back to being and not-being, and to the one and plurality — rest, for instance, belonging to the one, motion to plurality. And nearly everyone agrees that beings and substance are composed out of contraries; at any rate, everyone speaks of the principles as contraries: some say odd and even, others hot and cold, others limit and the unlimited, others love and strife. And all the other principles too are evidently traced back to the one and plurality (let this reduction stand as accepted by us),
8| [1005a] and the principles given by the others fall, quite completely, under these as under genera. It is clear, then, from these considerations too, that it belongs to a single science to study being qua being. For all things are either contraries or composed of contraries, and the principles of the contraries are the one and plurality. And these belong to a single science, whether they are said in one sense or not — which is perhaps in fact how the truth stands. But nevertheless, even if the one is said in many ways, the others will be said in relation to the primary sense, and the contraries likewise, and for this reason, even if being or the one is not a universal, the same in all cases, or separable — as indeed perhaps it is not, but rather some things are so in relation to one thing and others by succession — and it is for this reason that it does not belong to the geometer to study what the contrary is, or the complete, or the one, or being, or the same, or the different, except from a hypothesis. That it belongs, then, to a single science to study being qua being, and the attributes that belong to it qua being, is clear; and that this same science is theoretical not only of substances but also of their attributes — both those already mentioned, and those concerning prior and posterior, genus and species, whole and part, and the other such matters.
9| We must state whether it belongs to one science or to a different one to study both the things called axioms in mathematics and substance. It is clear that the inquiry into these belongs to one science, and to that of the philosopher; for they hold of all things that are, and not of some genus apart, peculiar to itself, separate from the rest. And everyone makes use of them, because they hold of being qua being, and each genus is a kind of being; but people use them only to the extent that is sufficient for their purposes, that is, to the extent that the genus about which they bring their demonstrations reaches. So since it is clear that these hold of all things insofar as they are beings (for this is what is common to them), the study of them belongs to the one who has knowledge of being qua being. That is why none of those who investigate some part attempts to say anything about them, whether they are true or not — neither the geometer nor the arithmetician — but only some of the natural philosophers do, and reasonably so, since they alone supposed that they were studying the whole of nature and being. But since there is one who stands still higher than the natural philosopher (for nature is one genus of being among others), the study of these axioms would belong to the one who studies universally and studies the primary substance:
10| [1005b] Natural science too is a kind of wisdom, but not the primary kind. As for those who attempt to say in what manner one ought to accept the truth, some do this out of a lack of training in analytics; for one ought to come to these questions already knowing them, not seeking to learn them while listening. That it belongs to the philosopher, and to the one who studies all substance according to its nature, to investigate the principles of syllogistic reasoning as well, is clear. And it is fitting that the one who knows most about each genus should be able to state the most secure principles of that subject matter, so that the one who studies beings qua being should state the most secure principles of all. This person is the philosopher. Now the most secure principle of all is one about which it is impossible to be mistaken; for such a principle must be the most familiar of all (for people are always deceived about the things they do not know) and it must not rest on any hypothesis. For whatever a person must possess in order to understand anything whatsoever of the things that are, this is not a hypothesis; and whatever a person must know in order to know anything at all, this too he must already possess on arrival. That such a principle is the most secure of all, then, is clear; but let us next state what it is. It is impossible for the same thing at the same time to belong and not to belong to the same thing in the same respect (let all the further qualifications we might add be understood as added, to meet the logical difficulties):
11| This, then, is the most secure of all principles; for it has the qualification just stated. For it is impossible for anyone to suppose that the same thing is and is not, as some think Heraclitus said; for it is not necessary that whatever a person says he also supposes. And if it is not possible for contraries to belong to the same thing at the same time (let the usual qualifications be understood as added to this premise as well), and the opinion contradicting a given opinion is its contrary, then it is clear that it is impossible for the same person at the same time to suppose that the same thing is and is not; for the one who was mistaken about this would hold contrary opinions at the same time. That is why all who offer demonstrations trace their argument back to this as the ultimate opinion; for by nature this is the starting point even of all the other axioms as well. But there are some who, as we said, themselves claim that it is possible for the same thing to be and not to be,
12| [1006a] and to suppose it in this way. And many even of those who study nature make use of this argument. But we have now taken it as impossible for the same thing at once to be and not to be, and through this we have shown that this is the most secure of all principles. Now some, out of lack of training, demand that this too be demonstrated; for it is a lack of training not to know for which things one ought to seek a demonstration and for which one ought not. For in general it is impossible for there to be a demonstration of everything (it would proceed to infinity, so that there would be no demonstration even so); and if there are some things for which one ought not to seek a demonstration, these people would not be able to say what principle they claim has a better right to be exempt than this one. Yet it is possible to prove even this by refutation, that it is impossible, provided only the disputant says something; but if he says nothing, it is absurd to look for an argument to address to one who has no argument on the point where he has none, since such a person, in that respect, is by now no better than a plant. I say that proving by refutation is different from demonstrating, because someone giving a demonstration might seem to be assuming what is at issue, whereas if someone else is responsible for such an assumption it would be a refutation and not a demonstration. The starting point for all such cases is not the demanding that the opponent say either that something is or that it is not (for one might suppose this to be assuming what is at issue), but that he signify something both to himself and to another;
13| for this is necessary, if he is to say anything at all. For if he does not, there would be no argument for such a person, neither to himself nor to anyone else. But if someone grants this, there will be a demonstration; for something will already have been fixed. But the one responsible is not the one giving the demonstration but the one who holds his ground; for in trying to do away with argument he still holds his ground on argument. Further, whoever grants this has granted that something is true apart from demonstration, so that not everything could be both so and not so. First, then, it is clear that this itself is true: that the name signifies the being or not-being of this particular thing, so that not everything could be both so and not so. Further, if 'man' signifies one thing, let this be 'two-footed animal.' By 'signifies one thing' I mean this: if this is what man is, then whatever is a man, this will be what being a man is for it (and it makes no difference even if someone should say that the name signifies more than one thing, so long as they are definite in number,
14| [1006b] for then a different name could be assigned to each definition. What I mean is this: if someone should say that 'man' does not signify one thing but many, of which one has as its single definition 'two-footed animal,' while there are also several others, definite in number, then a distinct name could be assigned to each definition. But if no such name were assigned, and instead he said it signifies infinitely many things, it is clear that there could be no argument at all; for not to signify one thing is to signify nothing, and if names do not signify, discourse with one another has been abolished, and, in truth, discourse with oneself as well; for it is not possible to think anything unless one thinks one thing, and if it is possible, a single name could be assigned to this thing). Let it be granted, then, as was said at the outset, that the name signifies something, and signifies one thing. It is not possible, then, for 'being a man' to signify exactly what 'not being a man' signifies, if 'man' signifies not only something predicated of one subject but also one thing (for we do not take 'signifying one thing' to mean 'being predicated of one subject,' since in that sense even 'musical' and 'white' and 'man' would signify one thing, so that all things would be one; for they would be synonymous). And the same thing will not be able both to be and not to be, except by homonymy, as when what we call a man, others might call not-a-man:
15| The point at issue is not whether the same thing can at once be called and not be called 'man,' but whether it can at once be, and not be, the thing itself. But if 'man' and 'not-man' do not signify something different, then clearly 'not being a man' does not differ from 'being a man' either, so that being a man will be the same as not being a man; for they will be one thing. For this is what being one signifies — as with 'cloak' and 'garment' — if the account is one; and if they will be one, then being a man and being not-a-man will signify one thing. But it has been shown that they signify something different. It is necessary, then, if it is true to say of something that it is a man, that it be a two-footed animal (for this is what 'man' signified); and if this is necessary, then it is not possible for the same thing at that time not to be a two-footed animal (for this is what 'being necessary' signifies: that it is impossible for it not to be so); it is not possible, then, for it to be true at the same time to say of the same thing that it is a man and that it is not a man. And the same argument holds also for its not being a man:
16| [1007a] For being a man and not being a man mean something different, if indeed being white and being a man also mean something different; for the former pair is far more opposed, so that it means something different. But if he will say that being white and this signify the same and one thing, again we will say the same thing we said before, that all things will be one, and not only the opposites. But if this is not possible, then what was said follows, if the person answers what is asked. And if, when someone asks a question simply, one adds the negations too, then he is not answering what is asked. For nothing prevents the same thing from being both a man and white and countless other things besides; but nevertheless, when asked whether it is true to say that this is a man or not, one must answer with what signifies one thing, and not add that it is also white and large. For it is indeed impossible to run through the accidents, since they are infinite in number; so let him either run through all of them or none. Likewise, then, even if the same thing is a thousand times over both man and not-man, one must not, in answering whether it is a man, add that it is at the same time also not a man, unless one is also going to add in answer all the other things that hold of it, all that it is and is not; and if one does this, one is not conversing.
17| And in general, those who say this do away with substance and the essence. For they are compelled to say that everything is accidental, and that being just what it is to be a man or to be an animal is not a thing. For if there is going to be some thing which is just what it is to be a man, this will not be the same as not being a man or as not being what it is to be a man (and yet these are the negations of it); for it was one thing that it signified, and this was the substance of something. And to signify substance is for its being to be nothing other than itself. But if being just what it is to be a man is going to be, for it, the same as being just what it is to be not-a-man, or the same as not being a man, then it will be something else, so that they are forced to say that for nothing will there be an account of this kind, but that everything is said accidentally; for it is by this that substance and accident are distinguished: for being white is accidental to man, because he is white but is not just what it is to be white. But if everything is said accidentally, there will be nothing that is primary, that of which the accident is said, if the accidental always signifies a predication holding of some underlying subject.
18| [1007b] It is therefore necessary to go on to infinity. But that is impossible; for not even more than two accidents are combined together: for an accident is not an accident of an accident, unless it is because both are accidents of the same thing—I mean, for example, that the white is musical and this is white because both are accidents of the man. But it is not the case that Socrates is musical in this way, namely because both are accidents of some other thing. Since, then, some things are called accidental in this way and others in that other way, those which are called accidental in the way white is of Socrates cannot go on to infinity upward—for instance, there is not some other accident belonging to white Socrates; for no one thing arises out of all of them together. Nor again will there be some other accident belonging to the white, such as the musical; for this is no more an accident of that than that is of this, and at the same time it has been distinguished that some things are accidental in this way and others as the musical is accidental to Socrates: and whichever are accidental in the latter way are not accidents of an accident, but only those in the former way are, so that not everything will be spoken of accidentally. There will therefore also be something that signifies substance. And if this is so, it has been shown that it is impossible for the contradictories to be predicated at the same time. Further, if all the contradictories are true of the same thing at the same time, it is clear that all things will be one. For the same thing will be both a trireme and a wall and a man, if it is possible either to affirm or to deny anything of anything, as is necessary for those who state the doctrine of Protagoras.
19| For if it seems to someone that a man is not a trireme, clearly he is not a trireme; so that he also is one, if indeed the contradiction is true. And so we get the doctrine of Anaxagoras, that all things are together, so that nothing truly exists. They seem, then, to be speaking of the indeterminate, and while thinking they are speaking of what is, they are speaking of what is not; for the indeterminate is what exists potentially and not in actuality. But surely they must say of everything either the affirmation or the negation with regard to everything; for it would be absurd if for each thing its own negation held, while the negation of something else which does not hold of it did not hold—I mean, for instance, if it is true to say of the man that he is not a man, clearly it is also true that he is either a trireme or not a trireme. If, then, the affirmation holds, the negation must hold necessarily too; but if the affirmation does not hold, then at least the negation will hold more than the negation of the thing itself does.
20| [1008a] If, then, that negation also holds, the negation of trireme will hold too; and if this holds, so will the affirmation. These things, then, follow for those who state this doctrine, and also that it is not necessary either to affirm or to deny. For if it is true that something is a man and not a man, clearly it will also be neither a man nor not a man; for to the two affirmations there correspond two negations, and if the former is one thing composed of both, this too would be one thing, opposed to it. Further, either this holds concerning all things—and a thing both is white and not white, and both is and is not—and likewise for the other affirmations and negations, or it does not, but holds concerning some things and not concerning others. And if it does not hold concerning all, then these exceptions would be agreed upon; but if it holds concerning all, then again either it holds for everything of which one can affirm and deny, and for everything of which one can deny and affirm, or it holds for those of which one can both affirm and deny, but not for everything of which one denies does one also affirm. And if the latter, there would be something fixed that is not, and this would be a firm belief; and if not-being is something firm and known, the opposed assertion would be more knowable still.
21| But if, alike, whatever can be denied can also be affirmed, then one must necessarily, in stating them separately, be speaking truly—saying, for instance, that it is white, and again that it is not white—or not. And if it is not true to state them separately, then he is not saying these things at all, and nothing exists (for how could things that do not exist speak or walk?); and all things would be one, as was said before, and man and god and trireme would be the same thing, and so would their contradictories (for if the same holds alike of each, nothing will differ from anything else; for if it will differ, this will be something true and particular). And likewise, if it is possible to speak truly by stating them separately, what was said follows, and in addition to this, that everyone would speak truly and everyone would speak falsely, and each person agrees that he himself is speaking falsely. At the same time it is also clear that there is nothing for the inquiry to be about with respect to this man; for he says nothing. For he says neither that it is so nor that it is not so, but that it is both so and not so; and again he denies both of these, saying that it is neither so nor not so; for if he did not, then something would already be determinate. Further, if when the affirmation is true the negation is false, and when this in turn is true the affirmation is false, then it would not be possible to affirm and deny the same thing truly at the same time.
22| [1008b] But perhaps they would say that this is just what was assumed from the start. Further, is it that the one who supposes that something either holds in a certain way or does not is mistaken, while the one who supposes both is right? For if the latter is right, what could be meant by saying that such is the nature of the things that are? And if he is not right, but is more right than the one who supposes in the other way, then things that are would already be in some determinate condition, and this would be true, and not at the same time also not true. But if everyone alike is both wrong and speaks the truth, then such a person will be able neither to utter a sound nor to say anything; for at the same time he is saying both this and not this. And if he supposes nothing, but thinks and does not think alike, in what way would he differ at all from the plants? Hence it is above all clear from this that no one is in this condition, neither anyone else nor those who state this doctrine. For why does a man walk to Megara instead of staying put, if he thinks he ought to walk? Nor, first thing in the morning, does he walk into a well or off a cliff if he happens upon one, but he plainly takes care to avoid it, as one who does not think alike that falling in is not good and is good. It is clear, then, that he supposes the one to be better and the other not better.
23| But if this is so, one must also hold that one thing is a man and another not a man, and that one thing is sweet and another not sweet. For people do not inquire and hold beliefs about everything on equal terms: when someone thinks it better to drink water and to see a man, he then seeks these things — and yet he ought to have sought them indifferently, if man and not-man were alike the same. But, as was said, there is no one who does not appear to be on guard about some things and not about others; so it seems that everyone holds, without qualification, that some things simply are so — if not about everything, at least about the better and the worse. And if people do this not from knowledge but from opinion, they ought to care about the truth all the more, just as a sick man ought to care about health more than a healthy one does; for the man who has opinion, compared with the man who has knowledge, is not in a healthy relation to the truth. Further, even if it is above all true that all things are both so and not so, still the more and the less are present in the nature of things; for we would not say that two and three are even in the same way, nor is the man who thinks four is five mistaken to the same degree as the man who thinks it is a thousand. If, then, they are not mistaken to the same degree, clearly one of them is less mistaken, so that he speaks the truth more. If, then, the more is nearer,
24| [1009a] there would then be something true, and the truer would be nearer to it. And even if there is no such thing, still there is already something more stable and truer, and we would be free from the unqualified account that prevents the intellect from determining anything. The argument of Protagoras, too, comes from the same opinion, and both of them must alike either hold or not hold: for if all things that seem to be so and appear to be so are true, then everything must be at once true and false (for many people hold beliefs contrary to one another, and think that those who do not hold the same opinions as themselves are mistaken; so that the same thing must both be and not be), and if this is so, then all the things that seem to be so must be true (for those who are mistaken and those who state the truth hold opposite opinions of one another; so if things stand this way, everyone will be stating the truth). That both arguments proceed from the same way of thinking, then, is clear; but the manner of dealing with the people who hold them is not the same in every case: some need persuasion, others force. Those who came to hold this belief because they were genuinely perplexed have an ignorance that is easily cured (for the response to them is directed not at their statement but at their thinking);
25| but those who say it merely for the sake of argument can be cured only by refuting the account as it stands in speech and in the words themselves. Now this opinion has come to those who are genuinely perplexed from the objects of perception: from seeing contradictories and contraries coming to be out of the same thing, they suppose that both hold at once. For if what is not cannot come to be, then the thing must have existed beforehand as both alike — just as Anaxagoras says that everything is mixed in everything, and Democritus too; for he too says that the void and the full are present alike in any and every part, although one of these is what is and the other what is not. Now to those who hold this belief on these grounds we shall say that in one way they speak correctly, and in another way they are ignorant: for being is spoken of in two ways, so that there is a way in which something can come to be out of what is not, and a way in which it cannot; and the same thing can be at once both being and not-being, but not in the same respect — for in potentiality it is possible for contraries to be the same thing at once, but in actuality it is not possible. Further, we shall require them to suppose that there is also some other substance among the things that are, in which there is neither motion nor destruction nor coming to be at all.
26| [1009b] — Likewise the belief about the truth of what appears has come to some people from the objects of perception. For they think that truth ought not to be judged by numbers, few or many, and yet the same thing appears sweet to some who taste it and bitter to others, so that if everyone were sick or everyone were out of their mind, and only two or three were healthy or in their right mind, these would seem to be the sick and the deranged ones, and the others not. Further, the same things appear contrary to many of the other animals and to us, and even to each person himself things do not always appear the same by way of perception. Which of these appearances, then, are true and which false, is unclear; for these are no more true than those, but alike. That is why Democritus says that either nothing is true or, to us at least, it is unclear. And in general, because they suppose that thought is perception, and that perception is a kind of alteration, they say that what appears according to perception must necessarily be true; for it is on these grounds that Empedocles and Democritus and, one might say, each of the others as well have become liable to opinions of this sort. Empedocles, for instance, says that when people's bodily state changes, their thought changes too: 'for according to what is present, cunning grows in men.'
27| (Empedocles, fr. 106) And elsewhere too he says: 'And insofar as men's nature changed, so their thinking too was always changing to match.' (Empedocles, fr. 108) Parmenides too declares the same thing in the same manner: 'For as each man at any time has the mixture of his much-bending limbs, so does thought stand present to men; for the very thing that thinks is the same as the nature of the limbs, in every man and in all — for what is fuller is thought.' (Parmenides, fr. 16) A saying of Anaxagoras to some of his companions is also remembered, that things would be for them such as they supposed them to be. They say Homer, too, appears to hold this same opinion, because he made Hector, when he was knocked senseless by the blow, lie there thinking other thoughts — as though even those out of their mind were thinking, only not the same thoughts. It is clear, then, that if both are forms of thought, the things that are must at once be so and not be so. And this is where the outcome becomes hardest to bear: for if those who have seen most clearly what truth is possible — and these are the very people who most seek it out and love it — hold opinions of this kind and make such statements about truth, how can those who are undertaking to philosophize not lose heart? For seeking the truth would then be like chasing things in flight.
28| [1010a] — The reason for this opinion among these thinkers is that, while investigating the truth about the things that are, they supposed that the things that are are only the objects of perception; and among these there is a great deal of the nature of the indeterminate present, and of being in the manner we described. That is why what they say is reasonable, though not true (for it is more fitting to put it this way than as Epicharmus put it against Xenophanes). Further, seeing this whole realm of nature in motion, and that nothing is truly said of what is changing, they supposed that it is not possible to state the truth about what is in every respect and in every way changing. For out of this supposition blossomed the most extreme of the opinions mentioned, that of those who claim to follow Heraclitus, and the sort of view Cratylus held, who in the end thought one should say nothing, and only moved his finger, and who reproached Heraclitus for saying that it is not possible to step into the same river twice — for Cratylus himself thought one could not do so even once. We, however, shall say in reply to this argument as well that what is changing, at the moment when it is changing, gives them some ground for thinking it does not exist — though this is in fact disputable; for what is losing something still has something of what it is losing, and of what is coming to be, something must already exist; and in general, if a thing is being destroyed, there will be something that is, and if a thing is coming to be, then that from which it comes to be and that by which it is generated must exist, and this cannot go on to infinity.
29| But let us set these points aside and say instead that changing in quantity is not the same as changing in quality: in respect of quantity a thing may well not remain the same, but it is by its form that we come to know everything. Further, it is worth reproaching those who hold this view, because, having seen that this is how things stand among the objects of perception themselves, and among a smaller number of them at that, they made the same pronouncement about the whole heaven; for the region of the perceptible world around us is the only part that continues in a state of destruction and coming to be, yet this is, so to speak, no part at all of the whole; so that it would have been more just for them to acquit this region for the sake of that other one than to condemn that one for the sake of this. Further, it is clear that against these thinkers too we shall say the same things we said earlier to the others: it must be shown to them, and they must be persuaded, that there is some unchanging nature. Indeed it turns out that for those who claim that the same thing at once is and is not, the consequence is rather that all things are at rest than that they are in motion; for there is nothing for a thing to change into, since everything already belongs to everything.
30| [1010b] —Now about truth: not everything that appears is true. First, even if perception is not false of its own proper object, still imagination is not the same thing as perception. Next, it is worth being surprised that they raise this puzzle at all: whether magnitudes and colors are as large and as such as they appear to those far off, or as they appear to those close up; whether they are as they appear to the healthy or as they appear to the sick; and whether things are heavier as they appear to the weak or as they appear to the strong; and whether things are true as they appear to those asleep or as they appear to those awake. For that they do not really believe this is plain: at any rate no one, if he supposes by night that he is in Athens when he is actually in Libya, sets off for the concert hall. Again, concerning the future — as Plato too says — surely the doctor's opinion and the ignorant person's opinion are not equally authoritative, for instance about whether someone is going to be healthy or not. Again, even among the perceptions themselves, the perception of what is foreign and not one's own is not equally authoritative as that of what is proper and one's own, nor the perception of what is near as that of what belongs to the sense itself; rather, sight is authoritative about color, not taste, and taste about flavor, not sight — and neither of these ever says, at the same time, about the same thing, that it is thus and not thus.
31| Nor, indeed, at a different time has there been dispute about the affection itself, but only about that to which the affection belongs. I mean, for example: the same wine might seem, either because it has changed or because the body has changed, at one time sweet and at another time not sweet; but the sweet itself, such as it is whenever it is present, has never yet changed — one is always right about it, and what is going to be sweet is of necessity such. Yet all these arguments do away with this, just as they do away with there being a substance of anything, so too with there being anything of necessity: for what is necessary cannot be now one way and now another, so that if something is of necessity, it will not be both thus and not thus. And in general, if only the perceptible exists, there would be nothing at all if living things did not exist; for there would be no perception. Now that neither the perceptible things nor the perceptions would exist is perhaps true (for this is an affection of the one perceiving), but that the underlying subjects which produce the perception should not exist even apart from perception is impossible. For perception surely is not of itself, but there is something else too besides the perception, which must of necessity be prior to the perception:
32| [1011a] for that which moves is by nature prior to that which is moved, and this holds no less even if these are said relative to each other. But there are some who raise this puzzle, both among those persuaded of these views and among those who merely state these arguments: they ask who is to judge the healthy person, and in general who is to judge correctly about each thing. But such puzzles are like puzzling over whether we are now asleep or awake, and all puzzles of this kind come to the same thing: for these people demand an account of everything; for they seek a starting point, and to get hold of this through demonstration, although it is plain from their actions that they are not really persuaded. But, as we said, this is their affliction: they seek an account of things of which there is no account; for the starting point of demonstration is not itself a demonstration. These people, then, could easily be persuaded of this (for it is not hard to grasp); but those who seek only compulsion in argument are seeking something impossible: for they demand to be told the opposite of what they say, while straightaway saying the opposite themselves. But if not all things are relative, but some things also exist just in themselves, then not everything that appears would be true; for what appears is an appearance to someone: so that the person who says all appearances are true makes all existing things relative.
33| Hence one must also be on guard, in dealing with those who seek compulsion in argument and at the same time demand that an account be given, that they are told: it is not the appearance that exists, but the appearance to the one to whom it appears, and when it appears, and in the respect and manner in which it appears. And if they demand an account, but do not demand it in this way, it will quickly turn out that they say contrary things themselves. For it is possible for the same thing to appear as honey to sight but not to taste, and, there being two eyes, for the same thing not to appear the same to each of the two, if they are unlike. Since, then, against those who, for the reasons stated long ago, assert that what appears is true, and that on account of this all things are alike false and true: the same things do not appear to everyone, nor do the same things always appear to the same person, but often contrary things appear at the same time (for touch says there are two, in the crossing of the fingers, while sight says one); but not, at any rate, to the same sense, in the same respect, in the same way, and at the same time — so that this, at least, would be true.
34| [1011b] But perhaps for this very reason it is necessary for those who speak this way not from puzzlement but for the sake of argument to say that this is not true, but is true for this person. And, as has been said before, they must of necessity make everything relative, both to opinion and to perception, so that nothing has come to be nor will come to be unless someone has first held an opinion about it. But if it has come to be or will come to be, it is clear that not everything can be relative to opinion. Again, if a thing is one, it is relative to one thing or to something determinate; and if the same thing is both half and equal, still the equal is not relative to the double. If, then, in relation to the one who forms the opinion, man and the object of opinion are the same, then the one forming the opinion will not be man but will be the object of opinion. And if each thing is going to be relative to the one forming the opinion, then the one forming the opinion will be relative to things infinite in kind. That the firmest opinion of all is that opposite statements are not true at the same time, then, and what follows for those who speak this way, and why they speak this way — let this much be said. But since it is impossible for the contradiction to be truly asserted at the same time of the same thing, it is clear that contraries too cannot belong to the same thing at the same time: for of contraries, one is no less a privation — a privation of substance —
35| and privation is a denial applying to some determinate genus. If, then, it is impossible to affirm and deny truly at the same time, it is also impossible for contraries to belong to a thing at the same time, but either both hold in a qualified way, or one holds in a qualified way and the other without qualification. But indeed there can be nothing in between a contradiction either; rather, of any one thing, it is necessary either to affirm or to deny any single predicate whatever. This is clear, first, once we have defined what the true and the false are. For to say of what is that it is not, or of what is not that it is, is false; while to say of what is that it is, and of what is not that it is not, is true; so that also the person who says that a thing is or is not will either speak truly or falsely — but it is not the case that what is is said not to be or to be, nor is this said of what is not. Again, either there will be something in between the contradiction, as gray is between black and white, or there will be nothing, as with what is neither man nor horse. If, then, it is like the latter, there could be no change (for a thing changes from not-good to good, or from this to not-good), but as things now stand, change is always apparent (for there is no change except into opposites and into what is intermediate); but if there is something in between, in this way too there would be a coming-to-be into white not out of not-white, but as things now stand this is not observed.
36| [1012a] Further, every object of thought and of intellect, thought either affirms or denies — this is clear from the definition — whenever it speaks truly or falsely: when it combines thus, affirming or denying, it speaks truly, but when it combines otherwise, it speaks falsely. Further, there must be something alongside every contradictory pair, unless one speaks merely for argument's sake; so that a person will neither speak truly nor fail to speak truly, and there will be something alongside being and not-being, so that there will also be some kind of change alongside coming-to-be and passing-away. Further, in all cases where the negation brings in the contrary with respect to coming-to-be, it will hold in these cases too — for example among numbers there will be a number that is neither odd nor not-odd; but that is impossible, as is clear from the definition. Further, it will proceed to infinity, and the things that are will not only be half again as many but more. For again it will be possible to deny this in relation to the affirmation and the negation, and this denial will be something in its own right; for its substance is some further thing. Further, when someone asks whether a thing is white and he says no, he has denied nothing other than its being; and the negation is its not being. This opinion has come to some people, as other paradoxes have too: for when they cannot refute eristic arguments, they give in to the argument and agree that what has been deduced is true.
37| Some, then, speak this way for such a reason, others because they demand an account of everything. The starting point against all of them is from a definition. A definition arises from its being necessary for them to signify something: for the account of which the name is a sign will be the definition. Heraclitus's account, which says that all things are and are not, seems to make everything true; Anaxagoras's, that there is something in between a contradictory pair, seems to make everything false: for whenever things are mixed, the mixture is neither good nor not-good, so that one can say nothing true. Once these points are distinguished, it is clear that it is impossible for what is said to hold in only one way and yet apply to everything, as some claim — some asserting that nothing is true (for they say nothing prevents all things from being that way, just as it is claimed the diagonal is commensurable), others that everything is true. These arguments are much the same as Heraclitus's: for the one who says that all things are true and all things false, and asserts each of these claims separately,
38| [1012b] so that if those claims are impossible, these must be impossible too. Further, there are plainly contradictory pairs that cannot both be true at once — nor can all pairs be false either, though from what has been said that would seem more possible. But against all such arguments one must demand, as was said in the arguments above as well, not that something is or is not, but that it signifies something, so that one must argue from a definition, having grasped what "false" or "true" signifies. If to state what is true is nothing other than to state the denial of what it is false to affirm, then it is impossible for all things to be false: for one part of the contradiction must necessarily be true. Further, if it is necessary either to affirm or to deny everything, it is impossible for both parts to be false: for one part of the contradiction is false. So there results the thing commonly said against all such arguments, that they destroy themselves. For the one who says all things are true makes the statement contrary to his own true as well, so that his own is not true (for the contrary speaker denies that his is true); and the one who says all things are false destroys himself in the same way. And if they make exceptions — one saying only that the contrary statement is not true, the other that his own is not false — it results none the less that they must posit infinitely many statements as true and false:
39| for the one who says that the true statement is true is himself speaking truly, and this will proceed to infinity. It is also clear that neither those who say all things are at rest speak truly, nor those who say all things are in motion. For if all things are at rest, the same things will always be true and false, but this plainly changes (for the one speaking once did not exist and again will not exist); and if all things are in motion, nothing will be true, so all things will be false — but it has been shown that this is impossible. Further, what is must necessarily change: for change is from one thing into another. But moreover it is not the case that all things are at rest, or in motion, at some time and at no time always at rest or in motion: for there is something that always moves the things that are in motion, and the first mover is itself unmoved.