Theaetetus (207-210)

SOC. Let us not, therefore, carelessly accuse him of talking nonsense who gave the definition of knowledge which we are now considering; for perhaps that is not what he meant. He may have meant that each person if asked about anything must be able in reply to give his questioner an account of it in terms of its elements.

THEAET. As for example, Socrates?

SOC. As, for example, Hesiod, speaking of a wagon, says,

a hundred pieces of wood in a wagon.

[*] Now I could not name the pieces, nor, I fancy, could you; but if we were asked what a wagon is, we should be satisfied if we could say wheels, axle, body, rims, yoke.

THEAET. Certainly.

SOC. But he, perhaps, would think we were ridiculous, just as he would if, on being asked about your name, we should reply by telling the syllables, holding a right opinion and expressing correctly what we have to say, but should think we were grammarians and as such both possessed and were expressing as grammarians would the rational explanation of the name Theaetetus. He would say that it is impossible for anyone to give a rational explanation of anything with knowledge, until he gives a complete enumeration of the elements, combined with true opinion. That, I believe, is what was said before.

THEAET. Yes, it was.

SOC. So, too, he would say that we have right opinion about a wagon, but that he who can give an account of its essential nature in terms of those one hundred parts has by this addition added rational explanation to true opinion and has acquired technical knowledge of the essential nature of a wagon, in place of mere opinion, by describing the whole in terms of its elements.

THEAET. Do you agree to that, Socrates?

SOC. If you, my friend, agree to it and accept the view that orderly description in terms of its elements is a rational account of anything, but that description in terms of syllables or still larger units is irrational, tell me so, that we may examine the question.

THEAET. Certainly I accept it.

SOC. Do you accept it in the belief that anyone has knowledge of anything when he thinks that the same element is a part sometimes of one thing and sometimes of another or when he is of opinion that the same thing has as a part of it sometimes one thing and sometimes another?

THEAET. Not at all, by Zeus.

SOC. Then do you forget that when you began to learn to read you and the others did just that?

THEAET. Do you mean when we thought that sometimes one letter and sometimes another belonged to the same syllable, and when we put the same letter sometimes into the proper syllable and sometimes into another?

SOC. That is what I mean.

THEAET. By Zeus, I do not forget, nor do I think that those have knowledge who are in that condition.

SOC. Take an example: When at such a stage in his progress a person in writing Theaetetus thinks he ought to write, and actually does write, TH and E, and again in trying to write Theodorus thinks he ought to write, and does write, T and E, shall we say that he knows the first syllable of your names?

THEAET. No, we just now agreed that a person in such a condition has not yet gained knowledge.

SOC. Then there is nothing to prevent the same person from being in that condition with respect to the second and third and fourth syllables?

THEAET. No, nothing.

SOC. Then, in that case, he has in mind the orderly description in terms of letters, and will write Theaetetus with right opinion, when he writes the letters in order?

THEAET. Evidently.

SOC. But he is still, as we say, without knowledge, though he has right opinion?

THEAET. Yes.

SOC. Yes, but with his opinion he has rational explanation; for he wrote with the method in terms of letters in his mind, and we agreed that that was rational explanation.

THEAET. True.

SOC. There is, then, my friend, a combination of right opinion with rational explanation, which cannot as yet properly be called knowledge?

THEAET. There is not much doubt about it.

SOC. So it seems that the perfectly true definition of knowledge, which we thought we had, was but a golden dream. Or shall we wait a bit before we condemn it? Perhaps the definition to be adopted is not this, but the remaining one of the three possibilities one of which we said must be affirmed by anyone who asserts that knowledge is right opinion combined with rational explanation.

THEAET. I am glad you called that to mind. For there is still one left. The first was a kind of vocal image of the thought, the second the orderly approach to the whole through the elements, which we have just been discussing, and what is the third?

SOC. It is just the definition which most people would give, that knowledge is the ability to tell some characteristic by which the object in question differs from all others.

THEAET. As an example of the method, what explanation can you give me, and of what thing?

SOC. As an example, if you like, take the sun: I think it is enough for you to be told that it is the brightest of the heavenly bodies that revolve about the earth.

THEAET. Certainly.

SOC. Understand why I say this. It is because, as we were just saying, if you get hold of the distinguishing characteristic by which a given thing differs from the rest, you will, as some say, get hold of the definition or explanation of it; but so long as you cling to some common quality, your explanation will pertain to all those objects to which the common quality belongs.

THEAET. I understand; and it seems to me that it is quite right to call that kind a rational explanation or definition.

SOC. Then he who possesses right opinion about anything and adds thereto a comprehension of the difference which distinguishes it from other things will have acquired knowledge of that thing of which he previously had only opinion.

THEAET. That is what we affirm.

SOC. Theaetetus, now that I have come closer to our statement, I do not understand it at all. It is like coming close to a scene-painting. [*] While I stood off at a distance, I thought there was something in it.

THEAET. What do you mean?

SOC. I will tell you if I can. Assume that I have right opinion about you; if I add the explanation or definition of you, then I have knowledge of you, otherwise I have merely opinion.

THEAET. Yes.

SOC. But explanation was, we agreed, the interpretation of your difference.

THEAET. It was.

SOC. Then so long as I had merely opinion, I did not grasp in my thought any of the points in which you differ from others?

THEAET. Apparently not.

SOC. Therefore I was thinking of some one of the common traits which you possess no more than other men.

THEAET. You must have been.

SOC. For heaven’s sake! How in the world could I in that case have any opinion about you more than about anyone else? Suppose that I thought That is Theaetetus which is a man and has nose and eyes and mouth and so forth, mentioning all the parts. Can this thought make me think of Theaetetus any more than of Theodorus or of the meanest of the Mysians, [*] as the saying is?

THEAET. Of course not.

SOC. But if I think not only of a man with nose and eyes, but of one with snub nose and protruding eyes, shall I then have an opinion of you any more than of myself and all others like me?

THEAET. Not at all.

SOC. No; I fancy Theaetetus will not be the object of opinion in me until this snubnosedness of yours has stamped and deposited in my mind a memorial different from those of the other examples of snubnosedness that I have seen, and the other traits that make up your personality have done the like. Then that memorial, if I meet you again tomorrow, will awaken my memory and make me have right opinion about you.

THEAET. Very true.

SOC. Then right opinion also would have to do with differences in any given instance?

THEAET. At any rate, it seems so.

SOC. Then what becomes of the addition of reason or explanation to right opinion? For if it is defined as the addition of an opinion of the way in which a given thing differs from the rest, it is an utterly absurd injunction.

THEAET. How so?

SOC. When we have a right opinion of the way in which certain things differ from other things, we are told to acquire a right opinion of the way in which those same things differ from other things! On this plan the twirling of a scytale [*] or a pestle or anything of the sort would be as nothing compared with this injunction. It might more justly be called a blind man’s giving directions; for to command us to acquire that which we already have, in order to learn that of which we already have opinion, is very like a man whose sight is mightily darkened.

THEAET. Tell me now, what did you intend to say when you asked the question a while ago?

SOC. If, my boy, the command to add reason or explanation means learning to know and not merely getting an opinion about the difference, our splendid definition of knowledge would be a fine affair! For learning to know is acquiring knowledge, is it not?

THEAET. Yes.

SOC. Then, it seems, if asked, What is knowledge? our leader will reply that it is right opinion with the addition of a knowledge of difference; for that would, according to him, be the addition of reason or explanation.

THEAET. So it seems.

SOC. And it is utterly silly, when we are looking for a definition of knowledge, to say that it is right opinion with knowledge, whether of difference or of anything else whatsoever. So neither perception, Theaetetus, nor true opinion, nor reason or explanation combined with true opinion could be knowledge.

THEAET. Apparently not.

SOC. Are we then, my friend, still pregnant and in travail with knowledge, or have we brought forth everything?

THEAET. Yes, we have, and, by Zeus, Socrates, with your help I have already said more than there was in me.

SOC. Then does our art of midwifery declare to us that all the offspring that have been born are mere wind-eggs and not worth rearing?

THEAET. It does, decidedly.

SOC. If after this you ever undertake to conceive other thoughts, Theaetetus, and do conceive, you will be pregnant with better thoughts than these by reason of the present search, and if you remain barren, you will be less harsh and gentler to your associates, for you will have the wisdom not to think you know that which you do not know. So much and no more my art can accomplish; nor do I know aught of the things that are known by others, the great and wonderful men who are today and have been in the past. This art, however, both my mother and I received from God, she for women and I for young and noble men and for all who are fair. And now I must go to the Porch of the King, to answer to the suit which Meletus [*] has brought against me. But in the morning, Theodorus, let us meet here again.