Theaetetus

EU. No, by Zeus, at least not offhand. But I made notes at the time as soon as I reached home, then afterwards at my leisure, as I recalled things, I wrote them down, and whenever I went to Athens I used to ask Socrates about what I could not remember, and then I came here and made corrections; so that I have pretty much the whole talk written down.

TERP. That is true. I heard you say so before; and really I have been waiting about here all along intending to ask you to show it to me. What hinders us from reading it now? Certainly I need to rest, since I have come from the country.

EU. And I myself went with Theaetetus as far as Erineum, so I also should not be sorry to take a rest. Come, let us go, and while we are resting, the boy shall read to us.

TERP. Very well.

EU. Here is the book, Terpsion. Now this is the way I wrote the conversation: I did not represent Socrates relating it to me, as he did, but conversing with those with whom he told me he conversed. And he told me they were the geometrician Theodorus and Theaetetus. Now in order that the explanatory words between the speeches might not be annoying in the written account, such as and I said or and I remarked, whenever Socrates spoke, or he agreed or he did not agree, in the case of the interlocutor, I omitted all that sort of thing and represented Socrates himself as talking with them.

TERP. That is quite fitting, Eucleides.

EU. Come, boy, take the book and read.

SOC. If I cared more for Cyrene and its affairs, Theodorus, I should ask you about things there and about the people, whether any of the young men there are devoting themselves to geometry or any other form of philosophy; but as it is, since I care less for those people than for the people here, I am more eager to know which of our own young men are likely to gain reputation. These are the things I myself investigate, so far as I can, and about which I question those others with whom I see that the young men like to associate. Now a great many of them come to you, and rightly, for you deserve it on account of your geometry, not to speak of other reasons. So if you have met with any young man who is worth mentioning, I should like to hear about him.

THEO. Truly, Socrates, it is well worth while for me to talk and for you to hear about a splendid young fellow, one of your fellow-citizens, whom I have met. Now if he were handsome, I should be very much afraid to speak, lest someone should think I was in love with him. But the fact is—now don’t be angry with me—he is not handsome, but is like you in his snub nose and protruding eyes, only those features are less marked in him than in you. You see I speak fearlessly. But I assure you that among all the young men I have ever met—and I have had to do with a great many—I never yet found one of such marvelously fine qualities. He is quick to learn, beyond almost anyone else, yet exceptionally gentle, and moreover brave beyond any other; I should not have supposed such a combination existed, and I do not see it elsewhere. On the contrary, those who, like him, have quick, sharp minds and good memories, have usually also quick tempers; they dart off and are swept away, like ships without ballast; they are excitable rather than courageous; those, on the other hand, who are steadier are somewhat dull when brought face to face with learning, and are very forgetful. But this boy advances toward learning and investigation smoothly and surely and successfully, with perfect gentleness, like a stream of oil that flows without a sound, so that one marvels how he accomplishes all this at his age.

SOC. That is good news; but which of our citizens is his father?

THEO. I have heard the name, but do not remember it. However, it does not matter, for the youth is the middle one of those who are now coming toward us. He and those friends of his were anointing themselves in the outer course, and now they seem to have finished and to be coming here. See if you recognize him.

SOC. Yes, I do. He is the son of Euphronius of Sunium, who is a man of just the sort you describe, and of good repute in other respects; moreover he left a very large property. But the youth’s name I do not know.

THEO. Theaetetus is his name, Socrates; but I believe the property was squandered by trustees. Nevertheless, Socrates, he is remarkably liberal with his money, too.

SOC. It is a noble man that you describe. Now please tell him to come here and sit by us.

THEO. I will. Theaetetus, come here to Socrates.

SOC. Yes, do so, Theaetetus, that I may look at myself and see what sort of a face I have; for Theodorus says it is like yours. Now if we each had a lyre, and he said we had tuned them to the same key, should we take his word for it without more ado, or should we inquire first whether he who said it was a musician?

THEAET. We should inquire.

SOC. Then if we found that he was a musician, we should believe him, but if not, we should refuse to take his word?

THEAET. Yes.

SOC. But now, if we are concerned about the likeness of our faces, we must consider whether he who speaks is a painter, or not.

THEAET. I think we must.

SOC. Well, is Theodorus a painter?

THEAET. Not so far as I know.

SOC. Nor a geometrician, either?

THEAET. Oh yes, decidedly, Socrates.

SOC. And an astronomer, and an arithmetician, and a musician, and in general an educated man?

THEAET. I think so.

SOC. Well then, if he says, either in praise or blame, that we have some physical resemblance, it is not especially worth while to pay attention to him.

THEAET. Perhaps not.

SOC. But what if he should praise the soul of one of us for virtue and wisdom? Is it not worth while for the one who hears to examine eagerly the one who is praised, and for that one to exhibit his qualities with eagerness?

THEAET. Certainly, Socrates.

SOC. Then, my dear Theaetetus, this is just the time for you to exhibit your qualities and for me to examine them; for I assure you that Theodorus, though he has praised many foreigners and citizens to me, never praised anyone as he praised you just now.

THEAET. A good idea, Socrates; but make sure that he was not speaking in jest.

SOC. That is not Theodorus’s way. But do not seek to draw back from your agreement on the pretext that he is jesting, or he will be forced to testify under oath; for certainly no one will accuse him of perjury. Come, be courageous and hold to the agreement.

THEAET. I suppose I must, if you say so.

SOC. Now tell me; I suppose you learn some geometry from Theodorus?

THEAET. Yes.

SOC. And astronomy and harmony and arithmetic?

THEAET. I try hard to do so.

SOC. And so do I, my boy, from him and from any others who I think know anything about these things. But nevertheless, although in other respects I get on fairly well in them, yet I am in doubt about one little matter, which should be investigated with your help and that of these others. Tell me, is not learning growing wiser about that which one learns?

THEAET. Of course.

SOC. And the wise, I suppose, are wise by wisdom.

THEAET. Yes.

SOC. And does this differ at all from knowledge?

THEAET. Does what differ?

SOC. Wisdom. Or are not people wise in that of which they have knowledge?

THEAET. Of course.

SOC. Then knowledge and wisdom are the same thing?

THEAET. Yes.

SOC. Well, it is just this that I am in doubt about and cannot fully grasp by my own efforts—what knowledge really is. Can we tell that? What do you say? Who of us will speak first? And he who fails, and whoever fails in turn, shall go and sit down and be donkey, as the children say when they play ball; and whoever gets through without failing shall be our king and shall order us to answer any questions he pleases. Why are you silent? I hope, Theodorus, I am not rude, through my love of discussion and my eagerness to make us converse and show ourselves friends and ready to talk to one another.

THEO. That sort of thing would not be at all rude, Socrates; but tell one of the youths to answer your questions; for I am unused to such conversation and, moreover, I am not of an age to accustom myself to it. But that would be fitting for these young men, and they would improve much more than I; for the fact is, youth admits of improvement in every way. Come, question Theaetetus as you began to do, and do not let him off.

SOC. Well, Theaetetus, you hear what Theodorus says, and I think you will not wish to disobey him, nor is it right for a young person to disobey a wise man when he gives instructions about such matters. Come, speak up well and nobly. What do you think knowledge is?

THEAET. Well, Socrates, I must, since you bid me. For, if I make a mistake, you are sure to set me right.

SOC. Certainly, if we can.

THEAET. Well then, I think the things one might learn from Theodorus are knowledge—geometry and all the things you spoke of just now—and also cobblery and the other craftsmen’s arts; each and all of these are nothing else but knowledge.

SOC. You are noble and generous, my friend, for when you are asked for one thing you give many, and a variety of things instead of a simple answer.

THEAET. What do you mean by that, Socrates?

SOC. Nothing, perhaps; but I will tell you what I think I mean. When you say cobblery you speak of nothing else than the art of making shoes, do you?

THEAET. Nothing else.

SOC. And when you say carpentry? Do you mean anything else than the art of making wooden furnishings?

THEAET. Nothing else by that, either.

SOC. Then in both cases you define that to which each form of knowledge belongs?

THEAET. Yes.

SOC. But the question, Theaetetus, was not to what knowledge belongs, nor how many the forms of knowledge are; for we did not wish to number them, but to find out what knowledge itself really is. Or is there nothing in what I say?

THEAET. Nay, you are quite right.

SOC. Take this example. If anyone should ask us about some common everyday thing, for instance, what clay is, and we should reply that it is the potters’ clay and the oven makers’ clay and the brickmakers’ clay, should we not be ridiculous?

THEAET. Perhaps.

SOC. Yes in the first place for assuming that the questioner can understand from our answer what clay is, when we say clay, no matter whether we add the image-makers’ or any other craftsmen’s. Or does anyone, do you think, understand the name of anything when he does not know what the thing is?

THEAET. By no means.

SOC. Then he does not understand knowledge of shoes if he does not know knowledge.

THEAET. No.

SOC. Then he who is ignorant of knowledge does not understand cobblery or any other art.

THEAET. That is true.

SOC. Then it is a ridiculous answer to the question what is knowledge? when we give the name of some art; for we give in our answer something that knowledge belongs to, when that was not what we were asked.

THEAET. So it seems.

SOC. Secondly, when we might have given a short, everyday answer, we go an interminable distance round; for instance, in the question about clay, the everyday, simple thing would be to say clay is earth mixed with moisture without regard to whose clay it is.

THEAET. It seems easy just now, Socrates, as you put it; but you are probably asking the kind of thing that came up among us lately when your namesake, Socrates here, and I were talking together.

SOC. What kind of thing was that, Theaetetus?

THEAET. Theodorus here was drawing some figures for us in illustration of roots, showing that squares containing three square feet and five square feet are not commensurable in length with the unit of the foot, and so, selecting each one in its turn up to the square containing seventeen square feet and at that he stopped. Now it occurred to us, since the number of roots appeared to be infinite, to try to collect them under one name, by which we could henceforth call all the roots.

SOC. And did you find such a name?

THEAET. I think we did. But see if you agree.

SOC. Speak on.

THEAET. We divided all number into two classes. The one, the numbers which can be formed by multiplying equal factors, we represented by the shape of the square and called square or equilateral numbers.

SOC. Well done!

THEAET. The numbers between these, such as three and five and all numbers which cannot be formed by multiplying equal factors, but only by multiplying a greater by a less or a less by a greater, and are therefore always contained in unequal sides, we represented by the shape of the oblong rectangle and called oblong numbers.

SOC. Very good; and what next?

THEAET. All the lines which form the four sides of the equilateral or square numbers we called lengths, and those which form the oblong numbers we called surds, because they are not commensurable with the others in length, but only in the areas of the planes which they have the power to form. And similarly in the case of solids.

SOC. Most excellent, my boys! I think Theodorus will not be found liable to an action for false witness.

THEAET. But really, Socrates, I cannot answer that question of yours about knowledge, as we answered the question about length and square roots. And yet you seem to me to want something of that kind. So Theodorus appears to be a false witness after all.

SOC. Nonsense! If he were praising your running and said he had never met any young man who was so good a runner, and then you were beaten in a race by a full grown man who held the record, do you think his praise would be any less truthful?

THEAET. Why, no.

SOC. And do you think that the discovery of knowledge, as I was just now saying, is a small matter and not a task for the very ablest men?

THEAET. By Zeus, I think it is a task for the very ablest.

SOC. Then you must have confidence in yourself, and believe that Theodorus is right, and try earnestly in every way to gain an understanding of the nature of knowledge as well as of other things.

THEAET. If it is a question of earnestness, Socrates, the truth will come to light.

SOC. Well then—for you pointed out the way admirably just now—take your answer about the roots as a model, and just as you embraced them all in one class, though they were many, try to designate the many forms of knowledge by one definition.

THEAET. But I assure you, Socrates, I have often tried to work that out, when I heard reports of the questions that you asked, but I can neither persuade myself that I have any satisfactory answer, nor can I find anyone else who gives the kind of answer you insist upon; and yet, on the other hand, I cannot get rid of a feeling of concern about the matter.

SOC. Yes, you are suffering the pangs of labor, Theaetetus, because you are not empty, but pregnant.

THEAET. I do not know, Socrates; I merely tell you what I feel.

SOC. Have you then not heard, you absurd boy, that I am the son of a noble and burly midwife, Phaenarete?

THEAET. Yes, I have heard that.

SOC. And have you also heard that I practise the same art?

THEAET. No, never.

SOC. But I assure you it is true; only do not tell on me to the others; for it is not known that I possess this art. But other people, since they do not know it, do not say this of me, but say that I am a most eccentric person and drive men to distraction. Have you heard that also?

THEAET. Yes, I have.

SOC. Shall I tell you the reason then?

THEAET. Oh yes, do.

SOC. Just take into consideration the whole business of the midwives, and you will understand more easily what I mean. For you know, I suppose, that no one of them attends other women while she is still capable of conceiving and bearing but only those do so who have become too old to bear.

THEAET. Yes, certainly.

SOC. They say the cause of this is Artemis, because she, a childless goddess, has had childbirth allotted to her as her special province. Now it would seem she did not allow barren women to be midwives, because human nature is too weak to acquire an art which deals with matters of which it has no experience, but she gave the office to those who on account of age were not bearing children, honoring them for their likeness to herself.

THEAET. Very likely.

SOC. Is it not, then, also likely and even necessary, that midwives should know better than anyone else who are pregnant and who are not?

THEAET. Certainly.

SOC. And furthermore, the midwives, by means of drugs and incantations, are able to arouse the pangs of labor and, if they wish, to make them milder, and to cause those to bear who have difficulty in bearing; and they cause miscarriages if they think them desirable.

THEAET. That is true.

SOC. Well, have you noticed this also about them, that they are the most skillful of matchmakers, since they are very wise in knowing what union of man and woman will produce the best possible children?

THEAET. I do not know that at all.

SOC. But be assured that they are prouder of this than of their skill in cutting the umbilical cord. Just consider. Do you think the knowledge of what soil is best for each plant or seed belongs to the same art as the tending and harvesting of the fruits of the earth, or to another?

THEAET. To the same art.

SOC. And in the case of a woman, do you think, my friend, that there is one art for the sowing and another for the harvesting?

THEAET. It is not likely.

SOC. No; but because there is a wrongful and unscientific way of bringing men and women together, which is called pandering, the midwives, since they are women of dignity and worth, avoid matchmaking, through fear of falling under the charge of pandering. And yet the true midwife is the only proper match-maker.

THEAET. It seems so.

SOC. So great, then, is the importance of midwives; but their function is less important than mine. For women do not, like my patients, bring forth at one time real children and at another mere images which it is difficult to distinguish from the real. For if they did, the greatest and noblest part of the work of the midwives would be in distinguishing between the real and the false. Do you not think so?

THEAET. Yes, I do.

SOC. All that is true of their art of midwifery is true also of mine, but mine differs from theirs in being practised upon men, not women, and in tending their souls in labor, not their bodies. But the greatest thing about my art is this, that it can test in every way whether the mind of the young man is bringing forth a mere image, an imposture, or a real and genuine offspring. For I have this in common with the midwives: I am sterile in point of wisdom, and the reproach which has often been brought against me, that I question others but make no reply myself about anything, because I have no wisdom in me, is a true reproach; and the reason of it is this: the god compels me to act as midwife, but has never allowed me to bring forth. I am, then, not at all a wise person myself, nor have I any wise invention, the offspring born of my own soul; but those who associate with me, although at first some of them seem very ignorant, yet, as our acquaintance advances, all of them to whom the god is gracious make wonderful progress, not only in their own opinion, but in that of others as well. And it is clear that they do this, not because they have ever learned anything from me, but because they have found in themselves many fair things and have brought them forth. But the delivery is due to the god and me. And the proof of it is this: many before now, being ignorant of this fact and thinking that they were themselves the cause of their success, but despising me, have gone away from me sooner than they ought, whether of their own accord or because others persuaded them to do so. Then, after they have gone away, they have miscarried thenceforth on account of evil companionship, and the offspring which they had brought forth through my assistance they have reared so badly that they have lost it; they have considered impostures and images of more importance than the truth, and at last it was evident to themselves, as well as to others, that they were ignorant.

SOC. One of these was Aristeides, the son of Lysimachus, and there are very many more. When such men come back and beg me, as they do, with wonderful eagerness to let them join me again, the spiritual monitor that comes to me forbids me to associate with some of them, but allows me to converse with others, and these again make progress. Now those who associate with me are in this matter also like women in childbirth; they are in pain and are full of trouble night and day, much more than are the women; and my art can arouse this pain and cause it to cease. Well, that is what happens to them. But in some cases, Theaetetus, when they do not seem to me to be exactly pregnant, since I see that they have no need of me, I act with perfect goodwill as match-maker and, under God, I guess very successfully with whom they can associate profitably, and I have handed over many of them to Prodicus, and many to other wise and inspired men. Now I have said all this to you at such length, my dear boy, because I suspect that you, as you yourself believe, are in pain because you are pregnant with something within you. Apply, then, to me, remembering that I am the son of a midwife and have myself a midwife’s gifts, and do your best to answer the questions I ask as I ask them. And if, when I have examined any of the things you say, it should prove that I think it is a mere image and not real, and therefore quietly take it from you and throw it away, do not be angry as women are when they are deprived of their first offspring. For many, my dear friend, before this have got into such a state of mind towards me that they are actually ready to bite me, if I take some foolish notion away from them, and they do not believe that I do this in kindness, since they are far from knowing that no god is unkind to mortals, and that I do nothing of this sort from unkindness, either, and that it is quite out of the question for me to allow an imposture or to destroy the true. And so, Theaetetus, begin again and try to tell us what knowledge is. And never say that you are unable to do so; for if God wills it and gives you courage, you will be able.

THEAET. Well then, Socrates, since you are so urgent it would be disgraceful for anyone not to exert himself in every way to say what he can. I think, then, that he who knows anything perceives that which he knows, and, as it appears at present, knowledge is nothing else than perception.

SOC. Good! Excellent, my boy! That is the way one ought to speak out. But come now, let us examine your utterance together, and see whether it is a real offspring or a mere wind-egg. Perception, you say, is knowledge?

THEAET. Yes.

SOC. And, indeed, if I may venture to say so, it is not a bad description of knowledge that you have given, but one which Protagoras also used to give. Only, he has said the same thing in a different way. For he says somewhere that man is the measure of all things, of the existence of the things that are and the non-existence of the things that are not. You have read that, I suppose?

THEAET. Yes, I have read it often.

SOC. Well, is not this about what he means, that individual things are for me such as they appear to me, and for you in turn such as they appear to you —you and I being man?

THEAET. Yes, that is what he says.

SOC. It is likely that a wise man is not talking nonsense; so let us follow after him. Is it not true that sometimes, when the same wind blows, one of us feels cold, and the other does not? or one feels slightly and the other exceedingly cold?

THEAET. Certainly.

SOC. Then in that case, shall we say that the wind is in itself cold or not cold or shall we accept Protagoras’s saying that it is cold for him who feels cold and not for him who does not?

THEAET. Apparently we shall accept that.

SOC. Then it also seems cold, or not, to each of the two?

THEAET. Yes.

SOC. But seems denotes perceiving?

THEAET. It does.

SOC. Then seeming and perception are the same thing in matters of warmth and everything of that sort. For as each person perceives things, such they are to each person.

THEAET. Apparently.

SOC. Perception, then, is always of that which exists and, since it is knowledge, cannot be false.

THEAET. So it seems.

SOC. By the Graces! I wonder if Protagoras, who was a very wise man, did not utter this dark saying to the common herd like ourselves, and tell the truth in secret to his pupils.

THEAET. Why, Socrates, what do you mean by that?

SOC. I will tell you and it is not a bad description, either, that nothing is one and invariable, and you could not rightly ascribe any quality whatsoever to anything, but if you call it large it will also appear to be small, and light if you call it heavy, and everything else in the same way, since nothing whatever is one, either a particular thing or of a particular quality; but it is out of movement and motion and mixture with one another that all those things become which we wrongly say are—wrongly, because nothing ever is, but is always becoming. And on this subject all the philosophers, except Parmenides, may be marshalled in one line—Protagoras and Heracleitus and Empedocles—and the chief poets in the two kinds of poetry, Epicharmus, in comedy, and in tragedy, Homer, who, in the line0ceanus the origin of the gods, and Tethys their mother,Hom. Il. 14.201, 302has said that all things are the offspring of flow and motion; or don’t you think he means that?

THEAET. I think he does.

SOC. Then who could still contend with such a great host, led by Homer as general, and not make himself ridiculous?

THEAET. It is not easy, Socrates.

SOC. No, Theaetetus, it is not. For the doctrine is amply proved by this, namely, that motion is the cause of that which passes for existence, that is, of becoming, whereas rest is the cause of non-existence and destruction; for warmth or fire, which, you know, is the parent and preserver of all other things, is itself the offspring of movement and friction, and these two are forms of motion. Or are not these the source of fire?

THEAET. Yes, they are.

SOC. And furthermore, the animal kingdom is sprung from these same sources.

THEAET. Of course.

SOC. Well, then, is not the bodily habit destroyed by rest and idleness, and preserved, generally speaking, by gymnastic exercises and motions?

THEAET. Yes.

SOC. And what of the habit of the soul? Does not the soul acquire information and is it not preserved and made better through learning and practice, which are motions, whereas through rest, which is want of practice and of study, it learns nothing and forgets what it has learned?

THEAET. Certainly.

SOC. Then the good, both for the soul and for the body, is motion, and rest is the opposite?

THEAET. Apparently.

SOC. Now shall I go on and mention to you also windless air, calm sea, and all that sort of thing, and say that stillness causes decay and destruction and that the opposite brings preservation? And shall I add to this the all-compelling and crowning argument that Homer by the golden chain refers to nothing else than the sun, and means that so long as the heavens and the sun go round everything exists and is preserved, among both gods and men, but if the motion should stop, as if bound fast, everything would be destroyed and would, as the saying is, be turned upside down?

THEAET. Yes, Socrates, I think he means what you say he does.

SOC. Then, my friend, you must apply the doctrine in this way: first as concerns vision, the color that you call white is not to be taken as something separate outside of your eyes, nor yet as something inside of them; and you must not assign any place to it, for then it would at once be in a definite position and stationary and would have no part in the process of becoming.

THEAET. But what do you mean?