Theaetetus

THEAETETUS: Yes, indeed, it certainly seems so. SOCRATES: In which of the two classes, then, do you place being? For this, above all, accompanies everything. THEAETETUS: For my part, in the class of those things which the soul itself reaches out for by means of itself. SOCRATES: And do you include likeness and unlikeness, and sameness and difference? THEAETETUS: Yes. SOCRATES: And what about beautiful and ugly, and good and bad? THEAETETUS: These too seem to me to be among the things whose being the soul examines above all in their relation to one another, calculating in herself the past and the present in relation to the future. SOCRATES: Stay a moment. Is it not true that she will perceive the hardness of what is hard through touch, and the softness of what is soft in the same way? THEAETETUS: Yes. SOCRATES: But as for their being, and that they both are, and their opposition to each other, and again the being of this opposition, the soul itself attempts to judge for us by reverting to them and comparing them with each other. THEAETETUS: Most certainly. SOCRATES: Therefore, while humans and beasts alike are by nature able to perceive, from the moment of birth, all the impressions which reach the soul through the body, yet the calculations about these with respect to being and utility are acquired, by those who do acquire them, only with difficulty and over time, through many troubles and education? THEAETETUS: Quite so. SOCRATES: Is it possible, then, to attain truth for one who does not even attain being? THEAETETUS: Impossible. SOCRATES: And if one misses the truth of something, can one ever be knowledgeable of it? THEAETETUS: How could he, Socrates? SOCRATES: In the impressions, then, there is no knowledge, but in the reasoning about them; for in the latter, as it seems, it is possible to grasp being and truth, but in the former it is impossible. THEAETETUS: So it appears. SOCRATES: Do you, then, call that and this by the same name, when they have such great differences? THEAETETUS: Certainly not with any justice. SOCRATES: What name, then, do you give to that other—to seeing, hearing, smelling, feeling cold, and feeling warm? THEAETETUS: I call it perceiving; what else could it be? SOCRATES: You call the whole of it, then, perception? THEAETETUS: Necessarily. SOCRATES: And to this, we say, it is not granted to grasp truth, since it does not grasp being either. THEAETETUS: No, indeed. SOCRATES: Nor, then, of knowledge. THEAETETUS: No. SOCRATES: Then, Theaetetus, perception and knowledge could never be the same thing. THEAETETUS: It seems not, Socrates. And indeed, it has now become most completely clear that knowledge is something other than perception.

SOCRATES: But surely we did not begin our conversation for the sake of finding out what knowledge is not, but what it is. Still, we have progressed at least so far as not to look for it in perception at all, but in that name, whatever it is, which the soul has when it occupies itself, by itself, with the things that are. THEAETETUS: But that, Socrates, is called, I believe, opining. SOCRATES: You think rightly, my friend. Now look again from the beginning, wiping out everything that went before, and see if you can see any more clearly, now that you have advanced to this point. Tell me once more: what is knowledge? THEAETETUS: To say all opinion, Socrates, is impossible, since there is also false opinion; but it is likely that true opinion is knowledge, and let this be my answer. For if, as we proceed, it does not appear so as it does now, we shall try to say something else. SOCRATES: That is indeed how you ought to speak, Theaetetus, with more readiness than when you hesitated to answer at first. For if we do so, one of two things will happen: either we shall find what we are going after, or we shall be less likely to think we know what we do not know at all; and indeed, such a reward would not be to be despised. And so now, what do you say? Since there are two kinds of opinion, the one true and the other false, do you define true opinion as knowledge? THEAETETUS: I do; for that is what seems to me now once again. SOCRATES: Is it, then, worth our while to take up the subject of opinion again— THEAETETUS: What sort of thing do you mean? SOCRATES: It disturbs me in a way, both now and often at other times, so that I have been in great perplexity both with myself and with others, not being able to say what this experience of ours is and in what way it arises in us. THEAETETUS: What sort of thing indeed? SOCRATES: That a person should hold a false opinion. I am considering even now, still in doubt, whether we should let it go or examine it in a different way from how we did a little while ago. THEAETETUS: How could we not, Socrates, if it appears necessary in any way at all? For just now you and Theodorus spoke very well about leisure—how in such matters there is nothing to press us. SOCRATES: You have reminded me well. For perhaps it is not out of place to go back on our track, as it were. For surely it is better to accomplish a small thing well than a great deal insufficiently. THEAETETUS: Certainly. SOCRATES: How then? What indeed are we saying? Do we say that there is in every case a false opinion, and that one of us opines falsely, and another truly, as if this were so by nature? THEAETETUS: Yes, indeed we do.