Now what does this tale really mean, from our point of view, Theaetetus? How does it bear on what we were saying before? Do you see?
THEAETETUS: Not really, Socrates.
SOCRATES: Look here, then, let us see if we can somehow round it off. What it is trying to express, presumably, is this. All these things are in motion, just as we say; and their motion is distinguished by its swiftness or slowness. What is slow has its motion in one and the same place, and [d] in relation to the things in the immediate neighborhood; in this way it generates and the offspring are swifter, as they move through space, and their motion takes the form of spatial movement.
Thus the eye and some other thing—one of the things commensurate with the eye—which has come into its neighborhood, generate both whiteness and the perception which is by nature united with it (things which would never have come to be if it had been anything else that eye or object [e] approached). In this event, motions arise in the intervening space, sight from the side of the eye and whiteness from the side of that which cooperates in the production of the color. The eye is filled with sight; at that moment it sees, and becomes not indeed sight, but a seeing eye; while its partner in the process of producing color is filled with whiteness, and becomes not whiteness but white, a white stick or stone or whatever it is that happens to be colored this sort of color.
[157] We must understand this account as applying in the same way to hard and hot and everything else: nothing, as we were saying before, is in itself any of these. All of them, of all kinds whatsoever, are what things become through association with one another, as the result of motion. For even in the case of the active and passive motions it is impossible, as they say, for thought, taking them singly, to pin them down to being anything. There is no passive till it meets the active, no active except in conjunction with the passive; and what, in conjunction with one thing, is active, reveals itself as passive when it falls in with something else.
And so, wherever you turn, there is nothing, as we said at the outset, [b] which in itself is just one thing; all things become relatively to something. The verb ‘to be’ must be totally abolished—though indeed we have been led by habit and ignorance into using it ourselves more than once, even in what we have just been saying. That is wrong, these wise men tell us, nor should we allow the use of such words as ‘something’, ‘of something’, or ‘mine’, ‘this’ or ‘that’, or any other name that makes things stand still. We ought, rather, to speak according to nature and refer to things as ‘becoming’, ‘being produced’, ‘passing away’, ‘changing’; for if you speak in such a way as to make things stand still, you will easily be refuted. And this applies in speaking both of the individual case and of many aggregated together—such an aggregate, I mean, as people call ‘man’ or [c] ‘stone’, or to which they give the names of the different animals and sorts of thing.
—Well, Theaetetus, does this look to you a tempting meal and could you take a bite of the delicious stuff?
THEAETETUS: I really don’t know, Socrates. I can’t even quite see what you’re getting at—whether the things you are saying are what you think yourself, or whether you are just trying me out.
SOCRATES: You are forgetting, my friend. I don’t know anything about this kind of thing myself, and I don’t claim any of it as my own. I am barren of theories; my business is to attend you in your labor. So I chant incantations over you and offer you little tidbits from each of the wise till [d] I succeed in assisting you to bring your own belief forth into the light. When it has been born, I shall consider whether it is fertile or a wind-egg. But you must have courage and patience; answer like a man whatever appears to you about the things I ask you.
THEAETETUS: All right, go on with the questions.
SOCRATES: Tell me again, then, whether you like the suggestion that good and beautiful and all the things we were just speaking of cannot be said to ‘be’ anything, but are always ‘coming to be’.13
THEAETETUS: Well, as far as I’m concerned, while I’m listening to your exposition of it, it seems to me an extraordinarily reasonable view; and I feel that the way you have set out the matter has got to be accepted.
SOCRATES: In that case, we had better not pass over any point where our [e] theory is still incomplete. What we have not yet discussed is the question of dreams, and of insanity and other diseases; also what is called mishearing or misseeing or other cases of misperceiving. You realize, I suppose, that it would be generally agreed that all these cases appear to provide a refutation of the theory we have just expounded. For in these conditions, [158] we surely have false perceptions. Here it is far from being true that all things which appear to the individual also are. On the contrary, no one of the things which appear to him really is.
THEAETETUS: That is perfectly true, Socrates.
SOCRATES: Well then, my lad, what argument is left for the person who maintains that knowledge is perception and that what appears to any individual also is, for him to whom it appears to be?
THEAETETUS: Well, Socrates, I hardly like to tell you that I don’t know [b] what to say, seeing I’ve just got into trouble with you for that. But I really shouldn’t know how to dispute the suggestion that a madman believes what is false when he thinks he is a god; or a dreamer when he imagines he has wings and is flying in his sleep.
SOCRATES: But there’s a point here which is a matter of dispute, especially as regards dreams and real life—don’t you see?
THEAETETUS: What do you mean?
SOCRATES: There’s a question you must often have heard people ask—the question what evidence we could offer if we were asked whether in [c] the present instance, at this moment, we are asleep and dreaming all our thoughts, or awake and talking to each other in real life.
THEAETETUS: Yes, Socrates, it certainly is difficult to find the proof we want here. The two states seem to correspond in all their characteristics. There is nothing to prevent us from thinking when we are asleep that we are having the very same discussion that we have just had. And when we dream that we are telling the story of a dream, there is an extraordinary likeness between the two experiences.
SOCRATES: You see, then, it is not difficult to find matter for dispute, [d] when it is disputed even whether this is real life or a dream. Indeed we may say that, as our periods of sleeping and waking are of equal length, and as in each period the soul contends that the beliefs of the moment are preeminently true, the result is that for half our lives we assert the reality of the one set of objects, and for half that of the other set. And we make our assertions with equal conviction in both cases.
THEAETETUS: That certainly is so.
SOCRATES: And doesn’t the same argument apply in the cases of disease and madness, except that the periods of time are not equal?
THEAETETUS: Yes, that is so.
SOCRATES: Well now, are we going to fix the limits of truth by the clock?
[e] THEAETETUS: That would be a very funny thing to do.
SOCRATES: But can you produce some other clear indication to show which of these beliefs are true?
THEAETETUS: I don’t think I can.
SOCRATES: Then you listen to me and I’ll tell you the kind of thing that might be said by those people who propose it as a rule that whatever a man thinks at any time is the truth for him. I can imagine them putting their position by asking you this question: ‘Now, Theaetetus, suppose you have something which is an entirely different thing from something else. Can it have in any respect the same powers as the other thing?’ And observe, we are not to understand the question to refer to something which is the same in some respects while it is different in others, but to that which is wholly different.
THEAETETUS: In that case, then, it is impossible that it should have anything [159] the same, either as regards its powers or in any other respect, if it is a completely different thing.
SOCRATES: And aren’t we obliged to admit that such a thing is also unlike the other?
THEAETETUS: Yes, I t
hink so.
SOCRATES: Now supposing a thing is coming to be like or unlike to something, whether to itself or to something else; are we to say that when it is growing like it is coming to be the same, and when it is growing unlike it is coming to be a different thing?
THEAETETUS: Yes, that must be so.
SOCRATES: Now weren’t we saying, at an earlier stage, that there is a number—indeed an infinite number—of both active and passive factors?
THEAETETUS: Yes.
SOCRATES: Also this, that when a thing mixes now with one thing and now with another, it will not generate the same things each time but different things?
THEAETETUS: Yes, certainly. [b]
SOCRATES: Well, now let us apply this same statement to you and me and things in general. Take, for example, Socrates ill and Socrates well. Shall we say Socrates in health is like or unlike Socrates in sickness?
THEAETETUS: You mean the ill Socrates as a whole compared with the well Socrates as a whole?
SOCRATES: You get my point excellently; that is just what I mean.
THEAETETUS: Unlike, then, I suppose.
SOCRATES: And different also, in so far as he is unlike?
THEAETETUS: Yes, that follows.
SOCRATES: Similarly, you would say, when he is asleep or in any of the [c] conditions we enumerated just now?
THEAETETUS: Yes, I should.
SOCRATES: Then it must surely be true that, when any one of the naturally active factors finds Socrates well, it will be dealing with one me, and when it finds Socrates ill, with a different me?
THEAETETUS: Yes, surely.
SOCRATES: Then in these two events the combination of myself as passive and it as the active factor will generate different things?
THEAETETUS: Of course.
SOCRATES: Now if I drink wine when I am well, it appears to me pleasant and sweet?
THEAETETUS: Yes. [d]
SOCRATES: Going by what we earlier agreed, that is so because the active and passive factors, moving simultaneously, generate both sweetness and a perception; on the passive side, the perception makes the tongue percipient, while on the side of the wine, sweetness moving about it makes it both be and appear sweet to the healthy tongue.
THEAETETUS: That’s certainly the sense of what we agreed to before.
SOCRATES: But when the active factor finds Socrates ill, then, to begin with, it is not in strict truth the same man that it gets hold of, is it? Because here, as we saw, it has come upon an unlike.
THEAETETUS: Yes.
[e] SOCRATES: Then this pair, Socrates ill and the draft of wine, generates, presumably, different things again: a perception of bitterness in the region of the tongue, and bitterness coming to be and moving in the region of the wine. And then the wine becomes, not bitterness, but bitter; and I become, not perception, but percipient.
THEAETETUS: Yes, quite.
SOCRATES: And I shall never again become thus percipient of anything [160] else. A perception of something else is another perception, and makes another and a changed percipient. Nor again, in the case of that which acts on me, will it ever, in conjunction with something else, generate the same thing and itself become such as it now is. From something else it will generate something else, and itself become a changed thing.
THEAETETUS: That is so.
SOCRATES: Nor will I become such for myself or it such for itself.
THEAETETUS: No.
SOCRATES: But I must necessarily become percipient of something when [b] I become percipient; it is impossible to become percipient, yet percipient of nothing. And it again, when it becomes sweet or bitter or anything of that kind, must become so for somebody, because it is impossible to become sweet and yet sweet for no one.
THEAETETUS: Quite impossible.
SOCRATES: It remains, then, that I and it, whether we are or whether we become, are or become for each other. For our being is, by Necessity’s decree, tied to a partner; yet we are tied neither to any other thing in the world nor to our respective selves. It remains, then, that we are tied to each other. Hence, whether you apply the term ‘being’ to a thing or the term ‘becoming’, you must always use the words ‘for somebody’ or ‘of something’ or ‘relatively to something’. You must not speak of anything [c] as in itself either being or becoming nor let anyone else use such expressions. That is the meaning of the theory we have been expounding.
THEAETETUS: Yes, that’s certainly true, Socrates.
SOCRATES: Then since that which acts on me is for me, and not for anyone else, it is I who perceive it too, and nobody else?
THEAETETUS: Undoubtedly.
SOCRATES: Then my perception is true for me—because it is always a perception of that being which is peculiarly mine; and I am judge, as Protagoras said, of things that are, that they are, for me; and of things that are not, that they are not.
THEAETETUS: So it seems.
[d] SOCRATES: How then, if I am thus unerring and never stumble in my thought about what is—or what is coming to be—how can I fail to be a knower of the things of which I am a perceiver?
THEAETETUS: There is no way you could fail.
SOCRATES: Then that was a grand idea of yours when you told us that knowledge is nothing more or less than perception. So we find the various theories have converged to the same thing: that of Homer and Heraclitus and all their tribe, that all things flow like streams; of Protagoras, wisest of men, that man is the measure of all things; and of Theaetetus that, [e] these things being so, knowledge proves to be perception. What about it, Theaetetus? Shall we say we have here your first-born child, the result of my midwifery? Or what would you say?
THEAETETUS: Oh, there’s no denying it, Socrates.
SOCRATES: This, then, it appears, is what our efforts have at last brought forth—whatever it really is. And now that it has been born, we must perform the rite of running round the hearth with it; we must make it in good earnest go the round of discussion. For we must take care that we don’t overlook some defect in this thing that is entering into life; it may be something not worth bringing up, a wind-egg, a falsehood. What do [161] you say? Is it your opinion that your child ought in any case to be brought up and not exposed to die? Can you bear to see it found fault with, and not get into a rage if your first-born is stolen away from you?
THEODORUS: Theaetetus will put up with it, Socrates. He is not at all one to lose his temper. But tell me, in Heaven’s name, in what way is it not as it should be?
SOCRATES: You are the complete lover of discussion, Theodorus, and it is too good of you to think that I am a sort of bag of arguments, and can easily pick one out which will show you that this theory is wrong. [b] But you don’t realize what is happening. The arguments never come from me; they always come from the person I am talking to. All that I know, such as it is, is how to take an argument from someone else—someone who is wise—and give it a fair reception. So, now, I propose to try to get our answer out of Theaetetus, not to make any contribution of my own.
THEODORUS: That’s a better way of putting it, Socrates; do as you say.
SOCRATES: Well then, Theodorus, do you know what astonishes me about your friend Protagoras?
THEODORUS: No—what is it? [c]
SOCRATES: Well, I was delighted with his general statement of the theory that a thing is for any individual what it seems to him to be; but I was astonished at the way he began. I was astonished that he did not state at the beginning of the Truth that ‘Pig is the measure of all things’ or ‘Baboon’ or some yet more out-of-the-way creature with the power of perception. That would have made a most imposing and disdainful opening. It would have made it clear to us at once that, while we were standing astounded at his wisdom as though he were a god, he was in reality no better authority [d] than a tadpole—let alone any other man.
Or what are we to say, Theodorus? If whatever the individual judges by means of perception is true for him; if no man can assess another’s experience better than he, or can claim authority t
o examine another man’s judgment and see if it be right or wrong; if, as we have repeatedly said, only the individual himself can judge of his own world, and what he judges is always true and correct: how could it ever be, my friend, that [e] Protagoras was a wise man, so wise as to think himself fit to be the teacher of other men and worth large fees; while we, in comparison with him the ignorant ones, needed to go and sit at his feet—we who are ourselves each the measure of his own wisdom? Can we avoid the conclusion that Protagoras was just playing to the crowd when he said this? I say nothing about my own case and my art of midwifery and how silly we look. So too, I think, does the whole business of philosophical discussion. To examine and try to refute each other’s appearances and judgments, when each [162] person’s are correct—this is surely an extremely tiresome piece of nonsense, if the Truth of Protagoras is true, and not merely an oracle speaking in jest from the impenetrable sanctuary of the book.
THEODORUS: Protagoras was my friend, Socrates, as you have just remarked. I could not consent to have him refuted through my admissions; and yet I should not be prepared to resist you against my own judgment. So take on Theaetetus again. He seemed to be following you very sympathetically just now.
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