Theaetetus

SOC. Because I have a reverential fear of examining in a flippant manner Melissus and the others who teach that the universe is one and motionless, and because I reverence still more one man, Parmenides. Parmenides seems to me to be, in Homer’s words,

one to be venerated

awful.

THEO. Yes, if that is your opinion, we ought to do so.

SOC. Consider, then, Theaetetus, this further point about what has been said. Now you answered that perception is knowledge, did you not?

THEAET. Yes.

SOC. If, then, anyone should ask you, By what does a man see white and black colors and by what does he hear high and low tones? you would, I fancy, say, By his eyes and ears.

THEAET. Yes, I should.

SOC. The easy use of words and phrases and the avoidance of strict precision is in general a sign of good breeding; indeed, the opposite is hardly worthy of a gentleman, but sometimes it is necessary, as now it is necessary to object to your answer, in so far as it is incorrect. Just consider; which answer is more correct, that our eyes are that by which we see or that through which we see, and our ears that by which or that through which we hear?

THEAET. I think, Socrates, we perceive through, rather than by them, in each case.

SOC. Yes, for it would be strange indeed, my boy, if there are many senses ensconced within us, as if we were so many wooden horses of Troy, and they do not all unite in one power, whether we should call it soul or something else, by which we perceive through these as instruments the objects of perception.

THEAET. I think what you suggest is more likely than the other way.

SOC. Now the reason why I am so precise about the matter is this: I want to know whether there is some one and the same power within ourselves by which we perceive black and white through the eyes, and again other qualities through the other organs, and whether you will be able, if asked, to refer all such activities to the body. But perhaps it is better that you make the statement in answer to a question than that I should take all the trouble for you. So tell me: do you not think that all the organs through which you perceive hot and hard and light and sweet are parts of the body? Or are they parts of something else?

THEAET. Of nothing else.

SOC. And will you also be ready to agree that it is impossible to perceive through one sense what you perceive through another; for instance, to perceive through sight what you perceive through hearing, or through hearing what you perceive through sight?

THEAET. Of course I shall.

SOC. Then if you have any thought about both of these together, you would not have perception about both together either through one organ or through the other.

THEAET. No.

SOC. Now in regard to sound and color, you have, in the first place, this thought about both of them, that they both exist?

THEAET. Certainly.

SOC. And that each is different from the other and the same as itself?

THEAET. Of course.

SOC. And that both together are two and each separately is one?

THEAET. Yes, that also.

SOC. And are you able also to observe whether they are like or unlike each other?

THEAET. May be.

SOC. Now through what organ do you think all this about them? For it is impossible to grasp that which is common to them both either through hearing or through sight. Here is further evidence for the point I am trying to make: if it were possible to investigate the question whether the two, sound and color, are bitter or not, you know that you will be able to tell by what faculty you will investigate it, and that is clearly neither hearing nor sight, but something else.

THEAET. Of course it is,—the faculty exerted through the tongue.

SOC. Very good. But through what organ is the faculty exerted which makes known to you that which is common to all things, as well as to these of which we are speaking—that which you call being and not-being, and the other attributes of things, about which we were asking just now? What organs will you assign for all these, through which that part of us which perceives gains perception of each and all of them?

THEAET. You mean being and not-being, and likeness and unlikeness, and identity and difference, and also unity and plurality as applied to them. And you are evidently asking also through what bodily organs we perceive by our soul the odd and the even and everything else that is in the same category.

SOC. Bravo, Theaetetus! you follow me exactly; that is just what I mean by my question.

THEAET. By Zeus, Socrates, I cannot answer, except that I think there is no special organ at all for these notions, as there are for those others; but it appears to me that the soul views by itself directly what all things have in common.

SOC. Why, you are beautiful, Theaetetus, and not, as Theodorus said, ugly; for he who speaks beautifully is beautiful and good. But besides being beautiful, you have done me a favor by relieving me from a long discussion, if you think that the soul views some things by itself directly and others through the bodily faculties; for that was my own opinion, and I wanted you to agree.

THEAET. Well, I do think so.

SOC. To which class, then, do you assign being; for this, more than anything else, belongs to all things?

THEAET. I assign them to the class of notions which the soul grasps by itself directly.

SOC. And also likeness and unlikeness and identity and difference?

THEAET. Yes.

SOC. And how about beautiful and ugly, and good and bad?

THEAET. I think that these also are among the things the essence of which the soul most certainly views in their relations to one another, reflecting within itself upon the past and present in relation to the future.

SOC. Stop there. Does it not perceive the hardness of the hard through touch, and likewise the softness of the soft?

THEAET. Yes.

SOC. But their essential nature and the fact that they exist, and their opposition to one another, and, in turn, the essential nature of this opposition, the soul itself tries to determine for us by reverting to them and comparing them with one another.

THEAET. Certainly.

SOC. Is it not true, then, that all sensations which reach the soul through the body, can be perceived by human beings, and also by animals, from the moment of birth; whereas reflections about these, with reference to their being and usefulness, are acquired, if at all, with difficulty and slowly, through many troubles, in other words, through education?

THEAET. Assuredly.

SOC. Is it, then, possible for one to attain truth who cannot even get as far as being?

THEAET. No.

SOC. And will a man ever have knowledge of anything the truth of which he fails to attain?

THEAET. How can he, Socrates?

SOC. Then knowledge is not in the sensations, but in the process of reasoning about them; for it is possible, apparently, to apprehend being and truth by reasoning, but not by sensation.

THEAET. So it seems.

SOC. Then will you call the two by the same name, when there are so great differences between them?

THEAET. No, that would certainly not be right.

SOC. What name will you give, then, to the one which includes seeing, hearing, smelling, being cold, and being hot?

THEAET. Perceiving. What other name can I give it?

SOC. Collectively you call it, then, perception?

THEAET. Of course.

SOC. By which, we say, we are quite unable to apprehend truth, since we cannot apprehend being, either.

THEAET. No; certainly not.

SOC. Nor knowledge either, then.

THEAET. No.

SOC. Then, Theaetetus, perception and knowledge could never be the same.

THEAET. Evidently not, Socrates; and indeed now at last it has been made perfectly clear that knowledge is something different from perception.