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    "num": 17,
    "slug": "17-theaetetus",
    "title": "Theaetetus",
    "of": 24,
    "words": 31189,
    "text": "## Theaetetus\n\n\n#### 360 BC\n\n#### translated by Benjamin Jowett\n\n##### New York, C. Scribner's sons [1871]\n\nPERSONS OF THE DIALOGUE: SOCRATES; THEODORUS; THEAETETUS\nEuclid and Terpsion meet in front of Euclid's house in Megara; they\nenter the house, and the dialogue is read to them by a servant.\n\nEuclid. Have you only just arrived from the country, Terpsion?\n\nTerpsion. No, I came some time ago: and I have been in the Agora\nlooking for you, and wondering that I could not find you.\n\nEuc. But I was not in the city.\n\nTerp. Where then?\n\nEuc. As I was going down to the harbour, I met Theaetetus-he was\nbeing carried up to Athens from the army at Corinth.\n\nTerp. Was he alive or dead?\n\nEuc. He was scarcely alive, for he has been badly wounded; but he\nwas suffering even more from the sickness which has broken out in\nthe army.\n\nTerp. The dysentery, you mean?\n\nEuc. Yes.\n\nTerp. Alas! what a loss he will be!\n\nEuc. Yes, Terpsion, he is a noble fellow; only to-day I heard some\npeople highly praising his behaviour in this very battle.\n\nTerp. No wonder; I should rather be surprised at hearing anything\nelse of him. But why did he go on, instead of stopping at Megara?\n\nEuc. He wanted to get home: although I entreated and advised him\nto remain he would not listen to me; so I set him on his way, and\nturned back, and then I remembered what Socrates had said of him,\nand thought how remarkably this, like all his predictions, had been\nfulfilled. I believe that he had seen him a little before his own\ndeath, when Theaetetus was a youth, and he had a memorable\nconversation with him, which he repeated to me when I came to\nAthens; he was full of admiration of his genius, and said that he\nwould most certainly be a great man, if he lived.\n\nTerp. The prophecy has certainly been fulfilled; but what was the\nconversation? can you tell me?\n\nEuc. No, indeed, not offhand; but I took notes of it as soon as I\ngot home; these I filled up from memory, writing them out at\nleisure; and whenever I went to Athens, I asked Socrates about any\npoint which I had forgotten, and on my return I made corrections; thus\nI have nearly the whole conversation written down.\n\nTerp. I remember-you told me; and I have always been intending to\nask you to show me the writing, but have put off doing so; and now,\nwhy should we not read it through?-having just come from the\ncountry, I should greatly like to rest.\n\nEuc. I too shall be very glad of a rest, for I went with\nTheaetetus as far as Erineum. Let us go in, then, and, while we are\nreposing, the servant shall read to us.\n\nTerp. Very good.\n\nEuc. Here is the roll, Terpsion; I may observe that I have\nintroduced Socrates, not as narrating to me, but as actually\nconversing with the persons whom he mentioned-these were, Theodorus\nthe geometrician (of Cyrene), and Theaetetus. I have omitted, for\nthe sake of convenience, the interlocutory words \"I said,\" \"I\nremarked,\" which he used when he spoke of himself, and again, \"he\nagreed,\" or \"disagreed,\" in the answer, lest the repetition of them\nshould be troublesome.\n\nTerp. Quite right, Euclid.\n\nEuc. And now, boy, you may take the roll and read.\n\nEuclid's servant reads.\n\nSocrates. If I cared enough about the Cyrenians, Theodorus, I\nwould ask you whether there are any rising geometricians or\nphilosophers in that part of the world. But I am more interested in\nour own Athenian youth, and I would rather know who among them are\nlikely to do well. I observe them as far as I can myself, and I\nenquire of any one whom they follow, and I see that a great many of\nthem follow you, in which they are quite right, considering your\neminence in geometry and in other ways. Tell me then, if you have\nmet with any one who is good for anything.\n\nTheodorus. Yes, Socrates, I have become acquainted with one very\nremarkable Athenian youth, whom I commend to you as well worthy of\nyour attention. If he had been a beauty I should have been afraid to\npraise him, lest you should suppose that I was in love with him; but\nhe is no beauty, and you must not be offended if I say that he is very\nlike you; for he has a snub nose and projecting eyes, although these\nfeatures are less marked in him than in you. Seeing, then, that he has\nno personal attractions, I may freely say, that in all my\nacquaintance, which is very large, I never knew anyone who was his\nequal in natural gifts: for he has a quickness of apprehension which\nis almost unrivalled, and he is exceedingly gentle, and also the\nmost courageous of men; there is a union of qualities in him such as I\nhave never seen in any other, and should scarcely have thought\npossible; for those who, like him, have quick and ready and\nretentive wits, have generally also quick tempers; they are ships\nwithout ballast, and go darting about, and are mad rather than\ncourageous; and the steadier sort, when they have to face study, prove\nstupid and cannot remember. Whereas he moves surely and smoothly and\nsuccessfully in the path of knowledge and enquiry; and he is full of\ngentleness, flowing on silently like a river of oil; at his age, it is\nwonderful.\n\nSoc. That is good news; whose son is he?\n\nTheod. The name of his father I have forgotten, but the youth\nhimself is the middle one of those who are approaching us; he and\nhis companions have been anointing themselves in the outer court,\nand now they seem to have finished, and are towards us. Look and see\nwhether you know him.\n\nSoc. I know the youth, but I do not know his name; he is the son\nof Euphronius the Sunian, who was himself an eminent man, and such\nanother as his son is, according to your account of him; I believe\nthat he left a considerable fortune.\n\nTheod. Theaetetus, Socrates, is his name; but I rather think that\nthe property disappeared in the hands of trustees; notwithstanding\nwhich he is wonderfully liberal.\n\nSoc. He must be a fine fellow; tell him to come and sit by me.\n\nTheod. I will. Come hither, Theaetetus, and sit by Socrates.\n\nSoc. By all means, Theaetetus, in order that I may see the\nreflection of myself in your face, for Theodorus says that we are\nalike; and yet if each of us held in his hands a lyre, and he said\nthat they were, tuned alike, should we at once take his word, or\nshould we ask whether he who said so was or was not a musician?\n\nTheaetetus. We should ask.\n\nSoc. And if we found that he was, we should take his word; and if\nnot, not?\n\nTheaet. True.\n\nSoc. And if this supposed, likeness of our faces is a matter of\nany interest to us we should enquire whether he who says that we are\nalike is a painter or not?\n\nTheaet. Certainly we should.\n\nSoc. And is Theodorus a painter?\n\nTheaet. I never heard that he was.\n\nSoc. Is he a geometrician?\n\nTheaet. Of course he is, Socrates.\n\nSoc. And is he an astronomer and calculator and musician, and in\ngeneral an educated man?\n\nTheaet. I think so.\n\nSoc. If, then, he remarks on a similarity in our persons, either\nby way of praise or blame, there is no particular reason why we should\nattend to him.\n\nTheaet. I should say not.\n\nSoc. But if he praises the virtue or wisdom which are the mental\nendowments of either of us, then he who hears the praises will\nnaturally desire to examine him who is praised: and he again should be\nwilling to exhibit himself.\n\nTheaet. Very true, Socrates.\n\nSoc. Then now is the time, my dear Theaetetus, for me to examine,\nand for you to exhibit; since although Theodorus has praised many a\ncitizen and stranger in my hearing, never did I hear him praise any\none as he has been praising you.\n\nTheaet. I am glad to hear it, Socrates; but what if he was only in\njest?\n\nSoc. Nay, Theodorus is not given to jesting; and I cannot allow\nyou to retract your consent on any such pretence as that. If you do,\nhe will have to swear to his words; and we are perfectly sure that\nno one will be found to impugn him. Do not be shy then, but stand to\nyour word.\n\nTheaet. I suppose I must, if you wish it.\n\nSoc. In the first place, I should like to ask what you learn of\nTheodorus: something of geometry, perhaps?\n\nTheaet. Yes.\n\nSoc. And astronomy and harmony and calculation?\n\nTheaet. I do my best.\n\nSoc. Yes, my boy, and so do I: and my desire is to learn of him,\nor of anybody who seems to understand these things. And I get on\npretty well in general; but there is a little difficulty which I\nwant you and the company to aid me in investigating. Will you answer\nme a question: \"Is not learning growing wiser about that which you\nlearn?\"\n\nTheaet. Of course.\n\nSoc. And by wisdom the wise are wise?\n\nTheaet. Yes.\n\nSoc. And is that different in any way from knowledge?\n\nTheaet. What?\n\nSoc. Wisdom; are not men wise in that which they know?\n\nTheaet. Certainly they are.\n\nSoc. Then wisdom and knowledge are the same?\n\nTheaet. Yes.\n\nSoc. Herein lies the difficulty which I can never solve to my\nsatisfaction-What is knowledge? Can we answer that question? What\nsay you? which of us will speak first? whoever misses shall sit\ndown, as at a game of ball, and shall be donkey, as the boys say; he\nwho lasts out his competitors in the game without missing, shall be\nour king, and shall have the right of putting to us any questions\nwhich he pleases. .. Why is there no reply? I hope, Theodorus, that\nI am not betrayed into rudeness by my love of conversation? I only\nwant to make us talk and be friendly and sociable.\n\nTheod. The reverse of rudeness, Socrates: but I would rather that\nyou would ask one of the young fellows; for the truth is, that I am\nunused to your game of question and answer, and I am too old to learn;\nthe young will be more suitable, and they will improve more than I\nshall, for youth is always able to improve. And so having made a\nbeginning with Theaetetus, I would advise you to go on with him and\nnot let him off.\n\nSoc. Do you hear, Theaetetus, what Theodorus says? The\nphilosopher, whom you would not like to disobey, and whose word\nought to be a command to a young man, bids me interrogate you. Take\ncourage, then, and nobly say what you think that knowledge is.\n\nTheaet. Well, Socrates, I will answer as you and he bid me; and if\nmake a mistake, you will doubtless correct me.\n\nSoc. We will, if we can.\n\nTheaet. Then, I think that the sciences which I learn from\nTheodorus-geometry, and those which you just now mentioned-are\nknowledge; and I would include the art of the cobbler and other\ncraftsmen; these, each and all of, them, are knowledge.\n\nSoc. Too much, Theaetetus, too much; the nobility and liberality\nof your nature make you give many and diverse things, when I am asking\nfor one simple thing.\n\nTheaet. What do you mean, Socrates?\n\nSoc. Perhaps nothing. I will endeavour, however, to explain what I\nbelieve to be my meaning: When you speak of cobbling, you mean the art\nor science of making shoes?\n\nTheaet. Just so.\n\nSoc. And when you speak of carpentering, you mean the art of\nmaking wooden implements?\n\nTheaet. I do.\n\nSoc. In both cases you define the subject matter of each of the\ntwo arts?\n\nTheaet. True.\n\nSoc. But that, Theaetetus, was not the point of my question: we\nwanted to know not the subjects, nor yet the number of the arts or\nsciences, for we were not going to count them, but we wanted to know\nthe nature of knowledge in the abstract. Am I not right?\n\nTheaet. Perfectly right.\n\nSoc. Let me offer an illustration: Suppose that a person were to ask\nabout some very trivial and obvious thing-for example, What is clay?\nand we were to reply, that there is a clay of potters, there is a clay\nof oven-makers, there is a clay of brick-makers; would not the\nanswer be ridiculous?\n\nTheaet. Truly.\n\nSoc. In the first place, there would be an absurdity in assuming\nthat he who asked the question would understand from our answer the\nnature of \"clay,\" merely because we added \"of the image-makers,\" or of\nany other workers. How can a man understand the name of anything, when\nhe does not know the nature of it?\n\nTheaet. He cannot.\n\nSoc. Then he who does not know what science or knowledge is, has\nno knowledge of the art or science of making shoes?\n\nTheaet. None.\n\nSoc. Nor of any other science?\n\nTheaet. No.\n\nSoc. And when a man is asked what science or knowledge is, to give\nin answer the name of some art or science is ridiculous; for the\n-question is, \"What is knowledge?\" and he replies, \"A knowledge of\nthis or that.\"\n\nTheaet. True.\n\nSoc. Moreover, he might answer shortly and simply, but he makes an\nenormous circuit. For example, when asked about the day, he might have\nsaid simply, that clay is moistened earth-what sort of clay is not\nto the point.\n\nTheaet. Yes, Socrates, there is no difficulty as you put the\nquestion. You mean, if I am not mistaken, something like what occurred\nto me and to my friend here, your namesake Socrates, in a recent\ndiscussion.\n\nSoc. What was that, Theaetetus?\n\nTheaet. Theodorus was writing out for us something about roots, such\nas the roots of three or five, showing that they are incommensurable\nby the unit: he selected other examples up to seventeen-there he\nstopped. Now as there are innumerable roots, the notion occurred to us\nof attempting to include them all under one name or class.\n\nSoc. And did you find such a class?\n\nTheaet. I think that we did; but I should like to have your opinion.\n\nSoc. Let me hear.\n\nTheaet. We divided all numbers into two classes: those which are\nmade up of equal factors multiplying into one another, which we\ncompared to square figures and called square or equilateral\nnumbers;-that was one class.\n\nSoc. Very good.\n\nTheaet. The intermediate numbers, such as three and five, and\nevery other number which is made up of unequal factors, either of a\ngreater multiplied by a less, or of a less multiplied by a greater,\nand when regarded as a figure, is contained in unequal sides;-all\nthese we compared to oblong figures, and called them oblong numbers.\n\nSoc. Capital; and what followed?\n\nTheaet. The lines, or sides, which have for their squares the\nequilateral plane numbers, were called by us lengths or magnitudes;\nand the lines which are the roots of (or whose squares are equal to)\nthe oblong numbers, were called powers or roots; the reason of this\nlatter name being, that they are commensurable with the former\n[i.e., with the so-called lengths or magnitudes] not in linear\nmeasurement, but in the value of the superficial content of their\nsquares; and the same about solids.\n\nSoc. Excellent, my boys; I think that you fully justify the\npraises of Theodorus, and that he will not be found guilty of false\nwitness.\n\nTheaet. But I am unable, Socrates, to give you a similar answer\nabout knowledge, which is what you appear to want; and therefore\nTheodorus is a deceiver after all.\n\nSoc. Well, but if some one were to praise you for running, and to\nsay that he never met your equal among boys, and afterwards you were\nbeaten in a race by a grown-up man, who was a great runner-would the\npraise be any the less true?\n\nTheaet. Certainly not.\n\nSoc. And is the discovery of the nature of knowledge so small a\nmatter, as just now said? Is it not one which would task the powers of\nmen perfect in every way?\n\nTheaet. By heaven, they should be the top of all perfection!\n\nSoc. Well, then, be of good cheer; do not say that Theodorus was\nmistaken about you, but do your best to ascertain the true nature of\nknowledge, as well as of other things.\n\nTheaet. I am eager enough, Socrates, if that would bring to light\nthe truth.\n\nSoc. Come, you made a good beginning just now; let your own answer\nabout roots be your model, and as you comprehended them all in one\nclass, try and bring the many sorts of knowledge under one definition.\n\nTheaet. I can assure you, Socrates, that I have tried very often,\nwhen the report of questions asked by you was brought to me; but I can\nneither persuade myself that I have a satisfactory answer to give, nor\nhear of any one who answers as you would have him; and I cannot\nshake off a feeling of anxiety.\n\nSoc. These are the pangs of labour, my dear Theaetetus; you have\nsomething within you which you are bringing to the birth.\n\nTheaet. I do not know, Socrates; I only say what I feel.\n\nSoc. And have you never heard, simpleton, that I am the son of a\nmidwife, brave and burly, whose name was Phaenarete?\n\nTheaet. Yes, I have.\n\nSoc. And that I myself practise midwifery?\n\nTheaet. No, never.\n\nSoc. Let me tell you that I do though, my friend: but you must not\nreveal the secret, as the world in general have not found me out;\nand therefore they only say of me, that I am the strangest of\nmortals and drive men to their wits' end. Did you ever hear that too?\n\nTheaet. Yes.\n\nSoc. Shall I tell you the reason?\n\nTheaet. By all means.\n\nSoc. Bear in mind the whole business of the mid-wives, and then\nyou will see my meaning better:-No woman, as you are probably aware,\nwho is still able to conceive and bear, attends other women, but\nonly those who are past bearing.\n\nTheaet. Yes; I know.\n\nSoc. The reason of this is said to be that Artemis-the goddess of\nchildbirth-is not a mother, and she honours those who are like\nherself; but she could not allow the barren to be mid-wives, because\nhuman nature cannot know the mystery of an art without experience; and\ntherefore she assigned this office to those who are too old to bear.\n\nTheaet. I dare say.\n\nSoc. And I dare say too, or rather I am absolutely certain, that the\nmid-wives know better than others who is pregnant and who is not?\n\nTheaet. Very true.\n\nSoc. And by the use of potions and incantations they are able to\narouse the pangs and to soothe them at will; they can make those\nbear who have a difficulty in bearing, and if they think fit they\ncan smother the embryo in the womb.\n\nTheaet. They can.\n\nSoc. Did you ever remark that they are also most cunning\nmatchmakers, and have a thorough knowledge of what unions are likely\nto produce a brave brood?\n\nTheaet. No, never.\n\nSoc. Then let me tell you that this is their greatest pride, more\nthan cutting the umbilical cord. And if you reflect, you will see that\nthe same art which cultivates and gathers in the fruits of the\nearth, will be most likely to know in what soils the several plants or\nseeds should be deposited.\n\nTheaet. Yes, the same art.\n\nSoc. And do you suppose that with women the case is otherwise?\n\nTheaet. I should think not.\n\nSoc. Certainly not; but mid-wives are respectable women who have a\ncharacter to lose, and they avoid this department of their profession,\nbecause they are afraid of being called procuresses, which is a name\ngiven to those who join together man and woman in an unlawful and\nunscientific way; and yet the true midwife is also the true and only\nmatchmaker.\n\nTheaet. Clearly.\n\nSoc. Such are the mid-wives, whose task is a very important one\nbut not so important as mine; for women do not bring into the world at\none time real children, and at another time counterfeits which are\nwith difficulty distinguished from them; if they did, then the,\ndiscernment of the true and false birth would be the crowning\nachievement of the art of midwifery-you would think so?\n\nTheaet. Indeed I should.\n\nSoc. Well, my art of midwifery is in most respects like theirs;\nbut differs, in that I attend men and not women; and look after\ntheir souls when they are in labour, and not after their bodies: and\nthe triumph of my art is in thoroughly examining whether the thought\nwhich the mind of the young man brings forth is a false idol or a\nnoble and true birth. And like the mid-wives, I am barren, and the\nreproach which is often made against me, that I ask questions of\nothers and have not the wit to answer them myself, is very just-the\nreason is, that the god compels-me to be a midwife, but does not allow\nme to bring forth. And therefore I am not myself at all wise, nor have\nI anything to show which is the invention or birth of my own soul, but\nthose who converse with me profit. Some of them appear dull enough\nat first, but afterwards, as our acquaintance ripens, if the god is\ngracious to them, they all make astonishing progress; and this in\nthe opinion of others as well as in their own. It is quite dear that\nthey never learned anything from me; the many fine discoveries to\nwhich they cling are of their own making. But to me and the god they\nowe their delivery. And the proof of my words is, that many of them in\ntheir ignorance, either in their self-conceit despising me, or falling\nunder the influence of others, have gone away too soon; and have not\nonly lost the children of whom I had previously delivered them by an\nill bringing up, but have stifled whatever else they had in them by\nevil communications, being fonder of lies and shams than of the truth;\nand they have at last ended by seeing themselves, as others see\nthem, to be great fools. Aristeides, the son of Lysimachus, is one\nof them, and there are many others. The truants often return to me,\nand beg that I would consort with them again-they are ready to go to\nme on their knees and then, if my familiar allows, which is not always\nthe case, I receive them, and they begin to grow again. Dire are the\npangs which my art is able to arouse and to allay in those who consort\nwith me, just like the pangs of women in childbirth; night and day\nthey are full of perplexity and travail which is even worse than\nthat of the women. So much for them. And there are -others,\nTheaetetus, who come to me apparently having nothing in them; and as I\nknow that they have no need of my art, I coax them into marrying\nsome one, and by the grace of God I can generally tell who is likely\nto do them good. Many of them I have given away to Prodicus, and\nmany to other inspired sages. I tell you this long story, friend\nTheaetetus, because I suspect, as indeed you seem to think yourself,\nthat you are in labour-great with some conception. Come then to me,\nwho am a midwife's son and myself a midwife, and do your best to\nanswer the questions which I will ask you. And if I abstract and\nexpose your first-born, because I discover upon inspection that the\nconception which you have formed is a vain shadow, do not quarrel with\nme on that account, as the manner of women is when their first\nchildren are taken from them. For I have actually known some who\nwere ready to bite me when I deprived them of a darling folly; they\ndid not perceive that I acted from good will, not knowing that no\ngod is the enemy of man-that was not within the range of their\nideas; neither am I their enemy in all this, but it would be wrong for\nme to admit falsehood, or to stifle the truth. Once more, then,\nTheaetetus, I repeat my old question, \"What is knowledge?\"-and do\nnot say that you cannot tell; but quit yourself like a man, and by the\nhelp of God you will be able to tell.\n\nTheaet. At any rate, Socrates, after such an exhortation I should be\nashamed of not trying to do my best. Now he who knows perceives what\nhe knows, and, as far as I can see at present, knowledge is\nperception.\n\nSoc. Bravely said, boy; that is the way in which you should\nexpress your opinion. And now, let us examine together this conception\nof yours, and see whether it is a true birth or a mere,\nwind-egg:-You say that knowledge is perception?\n\nTheaet. Yes.\n\nSoc. Well, you have delivered yourself of a very important\ndoctrine about knowledge; it is indeed the opinion of Protagoras,\nwho has another way of expressing it, Man, he says, is the measure\nof all things, of the existence of things that are, and of the\nnon-existence of things that are not:-You have read him?\n\nTheaet. O yes, again and again.\n\nSoc. Does he not say that things are to you such as they appear to\nyou, and to me such as they appear to me, and that you and I are men?\n\nTheaet. Yes, he says so.\n\nSoc. A wise man is not likely to talk nonsense. Let us try to\nunderstand him: the same wind is blowing, and yet one of us may be\ncold and the other not, or one may be slightly and the other very\ncold?\n\nTheaet. Quite true.\n\nSoc. Now is the wind, regarded not in relation to us but absolutely,\ncold or not; or are we to say, with Protagoras, that the wind is\ncold to him who is cold, and not to him who is not?\n\nTheaet. I suppose the last.\n\nSoc. Then it must appear so to each of them?\n\nTheaet. Yes.\n\nSoc. And \"appears to him\" means the same as \"he perceives.\"\n\nTheaet. True.\n\nSoc. Then appearing and perceiving coincide in the case of hot and\ncold, and in similar instances; for things appear, or may be\nsupposed to be, to each one such as he perceives them?\n\nTheaet. Yes.\n\nSoc. Then perception is always of existence, and being the same as\nknowledge is unerring?\n\nTheaet. Clearly.\n\nSoc. In the name of the Graces, what an almighty wise man Protagoras\nmust have been! He spoke these things in a parable to the common herd,\nlike you and me, but told the truth, his Truth, in secret to his own\ndisciples.\n\nTheaet. What do you mean, Socrates?\n\nSoc. I am about to speak of a high argument, in which all things are\nsaid to be relative; you cannot rightly call anything by any name,\nsuch as great or small, heavy or light, for the great will be small\nand the heavy light-there is no single thing or quality, but out of\nmotion and change and admixture all things are becoming relatively\nto one another, which \"becoming\" is by us incorrectly called being,\nbut is really becoming, for nothing ever is, but all things are\nbecoming. Summon all philosophers-Protagoras, Heracleitus, Empedocles,\nand the rest of them, one after another, and with the exception of\nParmenides they will agree with you in this. Summon the great\nmasters of either kind of poetry-Epicharmus, the prince of Comedy, and\nHomer of Tragedy; when the latter sings of\n\nOcean whence sprang the gods, and mother Tethys,\n\ndoes he not mean that all things are the offspring, of flux and\nmotion?\n\nTheaet. I think so.\n\nSoc. And who could take up arms against such a great army having\nHomer for its general, and not appear ridiculous?\n\nTheaet. Who indeed, Socrates?\n\nSoc. Yes, Theaetetus; and there are plenty of other proofs which\nwill show that motion is the source of what is called being and\nbecoming, and inactivity of not-being and destruction; for fire and\nwarmth, which are supposed to be the parent and guardian of all\nother things, are born of movement and friction, which is a kind of\nmotion;-is not this the origin of fire?\n\nTheaet. It is.\n\nSoc. And the race of animals is generated in the same way?\n\nTheaet. Certainly.\n\nSoc. And is not the bodily habit spoiled by rest and idleness, but\npreserved for a long time by motion and exercise?\n\nTheaet. True.\n\nSoc. And what of the mental habit? Is not the soul informed, and\nimproved, and preserved by study and attention, which are motions; but\nwhen at rest, which in the soul only means want of attention and\nstudy, is uninformed, and speedily forgets whatever she has learned?\n\nTheaet. True.\n\nSoc. Then motion is a good, and rest an evil, to the soul as well as\nto the body?\n\nTheaet. Clearly.\n\nSoc. I may add, that breathless calm, stillness and the like waste\nand impair, while wind and storm preserve; and the palmary argument of\nall, which I strongly urge, is the golden chain in Homer, by which\nhe means the sun, thereby indicating that so long as the sun and the\nheavens go round in their orbits, all things human and divine are\nand are preserved, but if they were chained up and their motions\nceased, then all things would be destroyed, and, as the saying is,\nturned upside down.\n\nTheaet. I believe, Socrates, that you have truly explained his\nmeaning.\n\nSoc. Then now apply his doctrine to perception, my good friend,\nand first of all to vision; that which you call white colour is not in\nyour eyes, and is not a distinct thing which exists out of them. And\nyou must not assign any place to it: for if it had position it would\nbe, and be at rest, and there would be no process of becoming.\n\nTheaet. Then what is colour?\n\nSoc. Let us carry the principle which has just been affirmed, that\nnothing is self-existent, and then we shall see that white, black, and\nevery other colour, arises out of the eye meeting the appropriate\nmotion, and that what we call a colour is in each case neither the\nactive nor the passive element, but something which passes between\nthem, and is peculiar to each percipient; are you quite certain that\nthe several colours appear to a dog or to any animal whatever as\nthey appear to you?\n\nTheaet. Far from it.\n\nSoc. Or that anything appears the same to you as to another man? Are\nyou so profoundly convinced of this? Rather would it not be true\nthat it never appears exactly the same to you, because you are never\nexactly the same?\n\nTheaet. The latter.\n\nSoc. And if that with which I compare myself in size, or which I\napprehend by touch, were great or white or hot, it could not become\ndifferent by mere contact with another unless it actually changed; nor\nagain, if the comparing or apprehending subject were great or white or\nhot, could this, when unchanged from within become changed by any\napproximation or affection of any other thing. The fact is that in our\nordinary way of speaking we allow ourselves to be driven into most\nridiculous and wonderful contradictions, as Protagoras and all who\ntake his line of argument would remark.\n\nTheaet. How? and of what sort do you mean?\n\nSoc. A little instance will sufficiently explain my meaning: Here\nare six dice, which are more by a half when compared with four, and\nfewer by a half than twelve-they are more and also fewer. How can\nyou or any one maintain the contrary?\n\nTheaet. Very true.\n\nSoc. Well, then, suppose that Protagoras or some one asks whether\nanything can become greater or more if not by increasing, how would\nyou answer him, Theaetetus?\n\nTheaet. I should say \"No,\" Socrates, if I were to speak my mind in\nreference to this last question, and if I were not afraid of\ncontradicting my former answer.\n\nSoc. Capital excellent! spoken like an oracle, my boy! And if you\nreply \"Yes,\" there will be a case for Euripides; for our tongue will\nbe unconvinced, but not our mind.\n\nTheaet. Very true.\n\nSoc. The thoroughbred Sophists, who know all that can be known about\nthe mind, and argue only out of the superfluity of their wits, would\nhave had a regular sparring-match over this, and would -have knocked\ntheir arguments together finely. But you and I, who have no\nprofessional aims, only desire to see what is the mutual relation of\nthese principles-whether they are consistent with each or not.\n\nTheaet. Yes, that would be my desire.\n\nSoc. And mine too. But since this is our feeling, and there is\nplenty of time, why should we not calmly and patiently review our\nown thoughts, and thoroughly examine and see what these appearances in\nus really are? If I am not mistaken, they will be described by us as\nfollows:-first, that nothing can become greater or less, either in\nnumber or magnitude, while remaining equal to itself-you would agree?\n\nTheaet. Yes.\n\nSoc. Secondly, that without addition or subtraction there is no\nincrease or diminution of anything, but only equality.\n\nTheaet. Quite true.\n\nSoc. Thirdly, that what was not before cannot be afterwards, without\nbecoming and having become.\n\nTheaet. Yes, truly.\n\nSoc. These three axioms, if I am not mistaken, are fighting with one\nanother in our minds in the case of the dice, or, again, in such a\ncase as this-if I were to say that I, who am of a certain height and\ntaller than you, may within a year, without gaining or losing in\nheight, be not so tall-not that I should have lost, but that you would\nhave increased. In such a case, I am afterwards what I once was not,\nand yet I have not become; for I could not have become without\nbecoming, neither could I have become less without losing somewhat\nof my height; and I could give you ten thousand examples of similar\ncontradictions, if we admit them at all. I believe that you follow me,\nTheaetetus; for I suspect that you have thought of these questions\nbefore now.\n\nTheaet. Yes, Socrates, and I am amazed when I think of them; by\nthe Gods I am! and I want to know what on earth they mean; and there\nare times when my head quite swims with the contemplation of them.\n\nSoc. I see, my dear Theaetetus, that Theodorus had a true insight\ninto your nature when he said that you were a philosopher, for\nwonder is the feeling of a philosopher, and philosophy begins in\nwonder. He was not a bad genealogist who said that Iris (the messenger\nof heaven) is the child of Thaumas (wonder). But do you begin to see\nwhat is the explanation of this perplexity on the hypothesis which\nwe attribute to Protagoras?\n\nTheaet. Not as yet.\n\nSoc. Then you will be obliged to me if I help you to unearth the\nhidden \"truth\" of a famous man or school.\n\nTheaet. To be sure, I shall be very much obliged.\n\nSoc. Take a look round, then, and see that none of the uninitiated\nare listening. Now by the uninitiated I mean: the people who believe\nin nothing but what they can grasp in their hands, and who will not\nallow that action or generation or anything invisible can have real\nexistence.\n\nTheaet. Yes, indeed, Socrates, they are very hard and impenetrable\nmortals.\n\nSoc. Yes, my boy, outer barbarians. Far more ingenious are the\nbrethren whose mysteries I am about to reveal to you. Their first\nprinciple is, that all is motion, and upon this all the affections\nof which we were just now speaking, are supposed to depend: there is\nnothing but motion, which has two forms, one active and the other\npassive, both in endless number; and out of the union and friction\nof them there is generated a progeny endless in number, having two\nforms, sense and the object of sense, which are ever breaking forth\nand coming to the birth at the same moment. The senses are variously\nnamed hearing, seeing, smelling; there is the sense of heat, cold,\npleasure, pain, desire, fear, and many more which have names, as\nwell as innumerable others which are without them; each has its\nkindred object each variety of colour has a corresponding variety of\nsight, and so with sound and hearing, and with the rest of the\nsenses and the objects akin to them. Do you see, Theaetetus, the\nbearings of this tale on the preceding argument?\n\nTheaet. Indeed I do not.\n\nSoc. Then attend, and I will try to finish the story. The purport is\nthat all these things are in motion, as I was saying, and that this\nmotion is of two kinds, a slower and a quicker; and the slower\nelements have their motions in the same place and with reference to\nthings near them, and so they beget; but what is begotten is\nswifter, for it is carried to fro, and moves from place to place.\nApply this to sense:-When the eye and the appropriate object meet\ntogether and give birth to whiteness and the sensation connatural with\nit, which could not have been given by either of them going elsewhere,\nthen, while the sight: is flowing from the eye, whiteness proceeds\nfrom the object which combines in producing the colour; and so the eye\nis fulfilled with sight, and really sees, and becomes, not sight,\nbut a seeing eye; and the object which combined to form the colour\nis fulfilled with whiteness, and becomes not whiteness but a white\nthing, whether wood or stone or whatever the object may be which\nhappens to be colour,ed white. And this is true of all sensible\nobjects, hard, warm, and the like, which are similarly to be regarded,\nas I was saying before, not as having any absolute existence, but as\nbeing all of them of whatever kind. generated by motion in their\nintercourse with one another; for of the agent and patient, as\nexisting in separation, no trustworthy conception, as they say, can be\nformed, for the agent has no existence until united; with the patient,\nand the patient has no existence until united with the agent; and that\nwhich by uniting with something becomes an agent, by meeting with some\nother thing is converted into a patient. And from all these\nconsiderations, as I said at first, there arises a general reflection,\nthat there is no one self-existent thing, but everything is becoming\nand in relation; and being must be altogether abolished, although from\nhabit and ignorance we are compelled even in this discussion to retain\nthe use of the term. But great philosophers tell us that we are not to\nallow either the word \"something,\" or \"belonging to something,\" or \"to\nme,\" or \"this,\" or \"that,\" or any other detaining name to be used,\nin the language of nature all things are being created and\ndestroyed, coming into being and passing into new forms; nor can any\nname fix or detain them; he who attempts to fix them is easily\nrefuted. And this should be the way of speaking, not only of\nparticulars but of aggregates such aggregates as are expressed in\nthe word \"man,\" or \"stone,\" or any name of animal or of a class. O\nTheaetetus, are not these speculations sweet as honey? And do you\nnot like the taste of them in the mouth?\n\nTheaet. I do not know what to say, Socrates, for, indeed, I cannot\nmake out whether you are giving your own opinion or only wanting to\ndraw me out.\n\nSoc. You forget, my friend, that I neither know, nor profess to\nknow, anything of! these matters; you are the person who is in labour,\nI am the barren midwife; and this is why I soothe you, and offer you\none good thing after another, that you may taste them. And I hope that\nI may at last help to bring your own opinion into the light of day:\nwhen this has been accomplished, then we will determine whether what\nyou have brought forth is only a wind-egg or a real and genuine birth.\nTherefore, keep up your spirits, and answer like a man what you think.\n\nTheaet. Ask me.\n\nSoc. Then once more: Is it your opinion that nothing is but what\nbecomes? the good and the noble, as well; as all the other things\nwhich we were just now mentioning?\n\nTheaet. When I hear you discoursing in this style, I think that\nthere is a great deal in what you say, and I am very ready to\nassent. Soc. Let us not leave the argument unfinished, then; for there\nstill remains to be considered an objection which may be raised\nabout dreams and diseases, in particular about madness, and the\nvarious illusions of hearing and sight, or of other senses. For you\nknow that in all these cases the esse-percipi theory appears to be\nunmistakably refuted, since in dreams and illusions we certainly\nhave false perceptions; and far from saying that everything is which\nappears, we should rather say that nothing is which appears.\n\nTheaet. Very true, Socrates.\n\nSoc. But then, my boy, how can any one contend that knowledge is\nperception, or that to every man what appears is?\n\nTheaet. I am afraid to say, Socrates, that I have nothing to answer,\nbecause you rebuked me just now for making this excuse; but I\ncertainly cannot undertake to argue that madmen or dreamers think\ntruly, when they imagine, some of them that they are gods, and\nothers that they can fly, and are flying in their sleep.\n\nSoc. Do you see another question which can be raised about these\nphenomena, notably about dreaming and waking?\n\nTheaet. What question?\n\nSoc. A question which I think that you must often have heard persons\nask:-How can you determine whether at this moment we are sleeping, and\nall our thoughts are a dream; or whether we are awake, and talking\nto one another in the waking state?\n\nTheaet. Indeed, Socrates, I do not know how to prove the one any\nmore than the other, for in both cases the facts precisely\ncorrespond;-and there is no difficulty in supposing that during all\nthis discussion we have been talking to one another in a dream; and\nwhen in a dream we seem to be narrating dreams, the resemblance of the\ntwo states is quite astonishing.\n\nSoc. You see, then, that a doubt about the reality of sense is\neasily raised, since there may even be a doubt whether we are awake or\nin a dream. And as our time is equally divided between sleeping and\nwaking, in either sphere of existence the soul contends that the\nthoughts which are present to our minds at the time are true; and\nduring one half of our lives we affirm the truth of the one, and,\nduring the other half, of the other; and are equally confident of\nboth.\n\nTheaet. Most true.\n\nSoc. And may not the same be said of madness and other disorders?\nthe difference is only that the times are not equal.\n\nTheaet. Certainly.\n\nSoc. And is truth or falsehood to be determined by duration of time?\n\nTheaet. That would be in many ways ridiculous.\n\nSoc. But can you certainly determine: by any other means which of\nthese opinions is true?\n\nTheaet. I do not think that I can.\n\nSoc. Listen, then to a statement of the other side of the\nargument, which is made by the champions of appearance. They would\nsay, as I imagine-can that which is wholly other than something,\nhave the same quality as that from which it differs? and observe,\n-Theaetetus, that the word \"other\" means not \"partially,\" but\n\"wholly other.\"\n\nTheaet. Certainly, putting the question as you do, that which is\nwholly other cannot either potentially or in any other way be the\nsame.\n\nSoc. And must therefore be admitted to be unlike?\n\nTheaet. True.\n\nSoc. If, then, anything happens to become like or unlike itself or\nanother, when it becomes like we call it the same-when unlike, other?\n\nTheaet. Certainly.\n\nSoc. Were we not saying that there. are agents many and infinite,\nand patients many and infinite?\n\nTheaet. Yes.\n\nSoc. And also that different combinations will produce results which\nare not the same, but different?\n\nTheaet. Certainly.\n\nSoc. Let us take you and me, or anything as an example:-There is\nSocrates in health, and Socrates sick-Are they like or unlike?\n\nTheaet. You mean to, compare Socrates in health as a whole, and\nSocrates in sickness as a whole?\n\nSoc. Exactly; that is my meaning.\n\nTheaet. I answer, they are unlike.\n\nSoc. And if unlike, they are other?\n\nTheaet. Certainly.\n\nSoc. And would you not say the same of Socrates sleeping and waking,\nor in any of the states which we were mentioning?\n\nTheaet. I should.\n\nSoc. All agents have a different patient in Socrates, accordingly as\nhe is well or ill.\n\nTheaet. Of course.\n\nSoc. And I who am the patient, and that which is the agent, will\nproduce something different in each of the two cases?\n\nTheaet. Certainly.\n\nSoc. The wine which I drink when I am in health, appears sweet and\npleasant to me?\n\nTheaet. True.\n\nSoc. For, as has been already acknowledged, the patient and agent\nmeet together and produce sweetness and a perception of sweetness,\nwhich are in simultaneous motion, and the perception which comes\nfrom the patient makes the tongue percipient, and the quality of\nsweetness which arises out of and is moving about the wine, makes\nthe wine, both to be and to appear sweet to the healthy tongue.\n\nTheaet. Certainly; that has been already acknowledged.\n\nSoc. But when I am sick, the wine really acts upon another and a\ndifferent person?\n\nTheaet. Yes.\n\nSoc. The combination of the draught of wine, and the Socrates who is\nsick, produces quite another result; which is the sensation of\nbitterness in the tongue, and the, motion and creation of bitterness\nin and about the wine, which becomes not bitterness but something\nbitter; as I myself become not but percipient?\n\nTheaet. True.\n\nSoc. There is no, other object of which I shall ever have the same\nperception, for another object would give another perception, and\nwould make the perception other and different; nor can that object\nwhich affects me, meeting another, subject, produce, the same, or\nbecome similar, for that too would produce another result from another\nsubject, and become different.\n\nTheaet. True.\n\nSoc. Neither can by myself, have this sensation, nor the object by\nitself, this quality.\n\nTheaet. Certainly not.\n\nSoc. When I perceive I must become percipient of something-there can\nbe no such thing as perceiving and perceiving nothing; the object,\nwhether it become sweet, bitter, or of any other quality, must have\nrelation to a percipient; nothing can become sweet which is sweet to\nno one.\n\nTheaet. Certainly not.\n\nSoc. Then the inference is, that we [the agent and patient] are or\nbecome in relation to one another; there is a law which binds us one\nto the other, but not to any other existence, nor each of us to\nhimself; and therefore we can only be bound to one another; so that\nwhether a person says that a thing is or becomes, he must say that\nit is or becomes to or of or in relation to something else; but he\nmust not say or allow any one else to say that anything is or\nbecomes absolutely: -such is our conclusion.\n\nTheaet. Very true, Socrates.\n\nSoc. Then, if that which acts upon me has relation to me and to no\nother, I and no other am the percipient of it?\n\nTheaet. Of course.\n\nSoc. Then my perception is true to me, being inseparable from my own\nbeing; and, as Protagoras says, to myself I am judge of what is\nand-what is not to me.\n\nTheaet. I suppose so.\n\nSoc. How then, if I never err, and if my mind never trips in the\nconception of being or becoming, can I fail of knowing that which I\nperceive?\n\nTheaet. You cannot.\n\nSoc. Then you were quite right in affirming that knowledge is only\nperception; and the meaning turns out to be the same, whether with\nHomer and Heracleitus, and all that company, you say that all is\nmotion and flux, or with the great sage Protagoras, that man is the\nmeasure of all things; or with Theaetetus, that, given these premises,\nperception is knowledge. Am I not right, Theaetetus, and is not this\nyour newborn child, of which I have delivered you? What say you?\n\nTheaet. I cannot but agree, Socrates.\n\nSoc. Then this is the child, however he may turn out, which you\nand I have with difficulty brought into the world. And now that he\nis born, we must run round the hearth with him, and see whether he\nis worth rearing, or is only a wind-egg and a sham. Is he to be reared\nin any case, and not exposed? or will you bear to see him rejected,\nand not get into a passion if I take away your first-born?\n\nTheod. Theaetetus will not be angry, for he is very good-natured.\nBut tell me, Socrates, in heaven's name, is this, after all, not the\ntruth?\n\nSoc. You, Theodorus, are a lover of theories, and now you innocently\nfancy that I am a bag full of them, and can easily pull one out\nwhich will overthrow its predecessor. But you do not see that in\nreality none of these theories come from me; they all come from him\nwho talks with me. I only know just enough to extract them from the\nwisdom of another, and to receive them in a spirit of fairness. And\nnow I shall say nothing myself, but shall endeavour to elicit\nsomething from our young friend.\n\nTheod. Do as you say, Socrates; you are quite right.\n\nSoc. Shall I tell you, Theodorus, what amazes me in your\nacquaintance Protagoras?\n\nTheod. What is it?\n\nSoc. I am charmed with his doctrine, that what appears is to each\none, but I wonder that he did not begin his book on Truth with a\ndeclaration that a pig or a dog-faced baboon, or some other yet\nstranger monster which has sensation, is the measure of all things;\nthen he might have shown a magnificent contempt for our opinion of him\nby informing us at the outset that while we were reverencing him\nlike a God for his wisdom he was no better than a tadpole, not to\nspeak of his fellow-men-would not this have produced an\nover-powering effect? For if truth is only sensation, and no man can\ndiscern another's feelings better than he, or has any superior right\nto determine whether his opinion is true or false, but each, as we\nhave several times repeated, is to himself the sole judge, and\neverything that he judges is true and right, why, my friend, should\nProtagoras be preferred to the place of wisdom and instruction, and\ndeserve to be well paid, and we poor ignoramuses have to go to him, if\neach one is the measure of his own wisdom? Must he not be talking ad\ncaptandum in all this? I say nothing of the ridiculous predicament\nin which my own midwifery and the whole art of dialectic is placed;\nfor the attempt to supervise or refute the notions or opinions of\nothers would be a tedious and enormous piece of folly, if to each\nman his own are right; and this must be the case if Protagoras Truth\nis the real truth, and the philosopher is not merely amusing himself\nby giving oracles out of the shrine of his book.\n\nTheod. He was a friend of mine, Socrates, as you were saying, and\ntherefore I cannot have him refuted by my lips, nor can I oppose you\nwhen I agree with you; please, then, to take Theaetetus again; he\nseemed to answer very nicely.\n\nSoc. If you were to go into a Lacedaemonian palestra, Theodorus,\nwould you have a right to look on at the naked wrestlers, some of them\nmaking a poor figure, if you did not strip and give them an\nopportunity of judging of your own person?\n\nTheod. Why not, Socrates, if they would allow me, as I think you\nwill in consideration of my age and stiffness; let some more supple\nyouth try a fall with you, and do not drag me into the gymnasium.\n\nSoc. Your will is my will, Theodorus, as the proverbial philosophers\nsay, and therefore I will return to the sage Theaetetus: Tell me,\nTheaetetus, in reference to what I was saying, are you not lost in\nwonder, like myself, when you find that all of a sudden you are raised\nto the level of the wisest of men, or indeed of the gods?-for you\nwould assume the measure of Protagoras to apply to the gods as well as\nmen?\n\nTheaet. Certainly I should, and I confess to you that I am lost in\nwonder. At first hearing, I was quite satisfied with the doctrine,\nthat whatever appears is to each one, but now the face of things has\nchanged.\n\nSoc. Why, my dear boy, you are young, and therefore your ear is\nquickly caught and your mind influenced by popular arguments.\nProtagoras, or some one speaking on his behalf, will doubtless say\nin reply, good people, young and old, you meet and harangue, and bring\nin the gods, whose existence of non-existence I banish from writing\nand speech, or you talk about the reason of man being degraded to\nthe level of the brutes, which is a telling argument with the\nmultitude, but not one word of proof or demonstration do you offer.\nAll is probability with you, and yet surely you and Theodorus had\nbetter reflect whether you are disposed to admit of probability and\nfigures of speech in matters of such importance. He or any other\nmathematician who argued from probabilities and likelihoods in\ngeometry, would not be worth an ace.\n\nTheaet. But neither you nor we, Socrates, would be satisfied with\nsuch arguments.\n\nSoc. Then you and Theodorus mean to say that we must look at the\nmatter in some other way?\n\nTheaet. Yes, in quite another way.\n\nSoc. And the way will be to ask whether perception is or is not\nthe same as knowledge; for this was the real point of our argument,\nand with a view to this we raised (did we not?) those many strange\nquestions.\n\nTheaet. Certainly.\n\nSoc. Shall we say that we know every thing which we see and hear?\nfor example, shall we say that not having learned, we do not hear\nthe language of foreigners when they speak to us? or shall we say that\nwe not only hear, but know what they are saying? Or again, if we see\nletters which we do not understand, shall we say that we do not see\nthem? or shall we aver that, seeing them, we must know them?\n\nTheaet. We shall say, Socrates, that we know what we actually see\nand hear of them-that is to say, we see and know the figure and colour\nof the letters, and we hear and know the elevation or depression of\nthe sound of them; but we do not perceive by sight and hearing, or\nknow, that which grammarians and interpreters teach about them.\n\nSoc. Capital, Theaetetus; and about this there shall be no\ndispute, because I want you to grow; but there is another difficulty\ncoming, which you will also have to repulse.\n\nTheaet. What is it?\n\nSoc. Some one will say, Can a man who has ever known anything, and\nstill has and preserves a memory of that which he knows, not know that\nwhich he remembers at the time when he remembers? I have, I fear, a\ntedious way of putting a simple question, which is only, whether a man\nwho has learned, and remembers, can fail to know?\n\nTheaet. Impossible, Socrates; the supposition is monstrous.\n\nSoc. Am I talking nonsense, then? Think: is not seeing perceiving,\nand is not sight perception?\n\nTheaet. True.\n\nSoc. And if our recent definition holds, every man knows that\nwhich he has seen?\n\nTheaet. Yes.\n\nSoc. And you would admit that there is such a thing as memory?\n\nTheaet. Yes.\n\nSoc. And is memory of something or of nothing?\n\nTheaet. Of something, surely.\n\nSoc. Of things learned and perceived, that is?\n\nTheaet. Certainly.\n\nSoc. Often a man remembers that which he has seen?\n\nTheaet. True.\n\nSoc. And if he closed his eyes, would he forget?\n\nTheaet. Who, Socrates, would dare to say so?\n\nSoc. But we must say so, if the previous argument is to be\nmaintained.\n\nTheaet. What do you mean? I am not quite sure that I understand you,\nthough I have a strong suspicion that you are right.\n\nSoc. As thus: he who sees knows, as we say, that which he sees;\nfor perception and sight and knowledge are admitted to be the same.\n\nTheaet. Certainly.\n\nSoc. But he who saw, and has knowledge of that which he saw,\nremembers, when he closes his eyes, that which he no longer sees.\n\nTheaet. True.\n\nSoc. And seeing is knowing, and therefore not-seeing is not-knowing?\n\nTheaet. Very true.\n\nSoc. Then the inference is, that a man may have attained the\nknowledge, of something, which he may remember and yet not know,\nbecause he does not see; and this has been affirmed by us to be a\nmonstrous supposition.\n\nTheaet. Most true.\n\nSoc. Thus, then, the assertion that knowledge and perception are\none, involves a manifest impossibility?\n\nTheaet. Yes.\n\nSoc. Then they must be distinguished?\n\nTheaet. I suppose that they must.\n\nSoc. Once more we shall have to begin, and ask \"What is\nknowledge?\" and yet, Theaetetus, what are we going to do?\n\nTheaet. About what?\n\nSoc. Like a good-for-nothing cock, without having won the victory,\nwe walk away from the argument and crow.\n\nTheaet. How do you mean?\n\nSoc. After the manner of disputers, we were satisfied with mere\nverbal consistency, and were well pleased if in this way we could gain\nan advantage. Although professing not to be mere Eristics, but\nphilosophers, I suspect that we have unconsciously fallen into the\nerror of that ingenious class of persons.\n\nTheaet. I do not as yet understand you.\n\nSoc. Then I will try to explain myself: just now we asked the\nquestion, whether a man who had learned and remembered could fail to\nknow, and we showed that a person who had seen might remember when\nhe had his eyes shut and could not see, and then he would at the\nsame time remember and not know. But this was an impossibility. And so\nthe Protagorean fable came to nought, and yours also, who maintained\nthat knowledge is the same as perception.\n\nTheaet. True.\n\nSoc. And yet, my friend, I rather suspect that the result would have\nbeen different if Protagoras, who was the father of the first of the\ntwo-brats, had been alive; he would have had a great deal to say on\ntheir behalf. But he is dead, and we insult over his orphan child; and\neven the guardians whom he left, and of whom our friend Theodorus is\none, are unwilling to give any help, and therefore I suppose that must\ntake up his cause myself, and see justice done?\n\nTheod. Not I, Socrates, but rather Callias, the son of Hipponicus,\nis guardian of his orphans. I was too soon diverted from the\nabstractions of dialectic to geometry. Nevertheless, I shall be\ngrateful to you if you assist him.\n\nSoc. Very good, Theodorus; you shall see how I will come to the\nrescue. If a person does not attend to the meaning of terms as they\nare commonly used in argument, he may be involved even in greater\nparadoxes than these. Shall I explain this matter to you or to\nTheaetetus?\n\nTheod. To both of us, and let the younger answer; he will incur less\ndisgrace if he is discomfited.\n\nSoc. Then now let me ask the awful question, which is this:-Can a\nman know and also not know that which he knows?\n\nTheod. How shall we answer, Theaetetus?\n\nTheaet. He cannot, I should say.\n\nSoc. He can, if you maintain that seeing is knowing. When you are\nimprisoned in a well, as the saying is, and the self-assured adversary\ncloses one of your eyes with his hand, and asks whether you can see\nhis cloak with the eye which he has closed, how will you answer the\ninevitable man?\n\nTheaet. I should answer, \"Not with that eye but with the other.\"\n\nSoc. Then you see and do not see the same thing at the same time.\n\nTheaet. Yes, in a certain sense.\n\nSoc. None of that, he will reply; I do not ask or bid you answer\nin what sense you know, but only whether you know that which you do\nnot know. You have been proved to see that which you do not see; and\nyou have already admitted that seeing is knowing, and that\nnot-seeing is not-knowing: I leave you to draw the inference.\n\nTheaet. Yes, the inference is the contradictory of my assertion.\n\nSoc. Yes, my marvel, and there might have been yet worse things in\nstore for you, if an opponent had gone on to ask whether you can\nhave a sharp and also a dull knowledge, and whether you can know near,\nbut not at a distance, or know the same thing with more or less\nintensity, and so on without end. Such questions might have been put\nto you by a light-armed mercenary, who argued for pay. He would have\nlain in wait for you, and when you took up the position, that sense is\nknowledge, he would have made an assault upon hearing, smelling, and\nthe other senses;-he would have shown you no mercy; and while you were\nlost in envy and admiration of his wisdom, he would have got you\ninto his net, out of which you would not have escaped until you had\ncome to an understanding about the sum to be paid for your release.\nWell, you ask, and how will Protagoras reinforce his position? Shall I\nanswer for him?\n\nTheaet. By all means.\n\nSoc. He will repeat all those things which we have been urging on\nhis behalf, and then he will close with us in disdain, and say:-The\nworthy Socrates asked a little boy, whether the same man could\nremember and not know the same thing, and the boy said No, because\nhe was frightened, and could not see what was coming, and then\nSocrates made fun of poor me. The truth is, O slatternly Socrates,\nthat when you ask questions about any assertion of mine, and the\nperson asked is found tripping, if he has answered as I should have\nanswered, then I am refuted, but if he answers something else, then he\nis refuted and not I. For do you really suppose that any one would\nadmit the memory which a man has of an impression which has passed\naway to be the same with that which he experienced at the time?\nAssuredly not. Or would he hesitate to acknowledge that the same man\nmay know and not know the same thing? Or, if he is afraid of making\nthis admission, would he ever grant that one who has become unlike\nis the same as before he became unlike? Or would he admit that a man\nis one at all, and not rather many and infinite as the changes which\ntake place in him? I speak by the card in order to avoid entanglements\nof words. But, O my good sir, he would say, come to the argument in\na more generous spirit; and either show, if you can, that our\nsensations are not relative and individual, or, if you admit them to\nbe so, prove that this does not involve the consequence that the\nappearance becomes, or, if you will have the word, is, to the\nindividual only. As to your talk about pigs and baboons, you are\nyourself behaving like a pig, and you teach your hearers to make sport\nof my writings in the same ignorant manner; but this is not to your\ncredit. For I declare that the truth is as I have written, and that\neach of us is a measure of existence and of non-existence. Yet one man\nmay be a thousand times better than another in proportion as different\nthings are and appear to him.\n\nAnd I am far from saying that wisdom and the wise man have no\nexistence; but I say that the wise man is he who makes the evils which\nappear and are to a man, into goods which are and appear to him. And I\nwould beg you not to my words in the letter, but to take the meaning\nof them as I will explain them. Remember what has been already\nsaid,-that to the sick man his food appears to be and is bitter, and\nto the man in health the opposite of bitter. Now I cannot conceive\nthat one of these men can be or ought to be made wiser than the other:\nnor can you assert that the sick man because he has one impression\nis foolish, and the healthy man because he has another is wise; but\nthe one state requires to be changed into the other, the worse into\nthe better. As in education, a change of state has to be effected, and\nthe sophist accomplishes by words the change which the physician works\nby the aid of drugs. Not that any one ever made another think truly,\nwho previously thought falsely. For no one can think what is not, or\nthink anything different from that which he feels; and this is\nalways true. But as the inferior habit of mind has thoughts of kindred\nnature, so I conceive that a good mind causes men to have good\nthoughts; and these which the inexperienced call true, I maintain to\nbe only better, and not truer than others. And, O my dear Socrates,\nI do not call wise men tadpoles: far from it; I say that they are\nthe physicians of the human body, and the husbandmen of plants-for the\nhusbandmen also take away the evil and disordered sensations of\nplants, and infuse into them good and healthy sensations-aye and\ntrue ones; and the wise and good rhetoricians make the good instead of\nthe evil to seem just to states; for whatever appears to a state to be\njust and fair, so long as it is regarded as such, is just and fair\nto it; but the teacher of wisdom causes the good to take the place\nof the evil, both in appearance and in reality. And in like manner the\nSophist who is able to train his pupils in this spirit is a wise\nman, and deserves to be well paid by them. And so one man is wiser\nthan another; and no one thinks falsely, and you, whether you will\nor not, must endure to be a measure. On these foundations the argument\nstands firm, which you, Socrates, may, if you please, overthrow by\nan opposite argument, or if you like you may put questions to me-a\nmethod to which no intelligent person will object, quite the\nreverse. But I must beg you to put fair questions: for there is\ngreat inconsistency in saying that you have a zeal for virtue, and\nthen always behaving unfairly in argument. The unfairness of which I\ncomplain is that you do not distinguish between mere disputation and\ndialectic: the disputer may trip up his opponent as often as he likes,\nand make fun; but the dialectician will be in earnest, and only\ncorrect his adversary when necessary, telling him the errors into\nwhich he has fallen through his own fault, or that of the company\nwhich he has previously kept. If you do so, your adversary will lay\nthe blame of his own confusion and perplexity on himself, and not on\nyou; will follow and love you, and will hate himself, and escape\nfrom himself into philosophy, in order that he may become different\nfrom what he was. But the other mode of arguing, which is practised by\nthe many, will have just the opposite effect upon him; and as he grows\nolder, instead of turning philosopher, he will come to hate\nphilosophy. I would recommend you, therefore, as I said before, not to\nencourage yourself in this polemical and controversial temper, but\nto find out, in a friendly and congenial spirit, what we really mean\nwhen we say that all things are in motion, and that to every\nindividual and state what appears, is. In this manner you will\nconsider whether knowledge and sensation are the same or different,\nbut you will not argue, as you were just now doing, from the customary\nuse of names and words, which the vulgar pervert in all sorts of ways,\ncausing infinite perplexity to one another. Such, Theodorus, is the\nvery slight help which I am able to offer to your old friend; had he\nbeen living, he would have helped himself in a far more gloriose\nstyle.\n\nTheod. You are jesting, Socrates; indeed, your defence of him has\nbeen most valorous.\n\nSoc. Thank you, friend; and I hope that you observed Protagoras\nbidding us be serious, as the text, \"Man is the measure of all\nthings,\" was a solemn one; and he reproached us with making a boy\nthe medium of discourse, and said that the boy's timidity was made\nto tell against his argument; he also declared that we made a joke\nof him.\n\nTheod. How could I fail to observe all that, Socrates?\n\nSoc. Well, and shall we do as he says?\n\nTheod. By all means.\n\nSoc. But if his wishes are to be regarded, you and I must take up\nthe argument, and in all seriousness, and ask and answer one\nanother, for you see that the rest of us are nothing but boys. In no\nother way can we escape the imputation, that in our fresh analysis\nof his thesis we are making fun with boys.\n\nTheod. Well, but is not Theaetetus better able to follow a\nphilosophical enquiry than a great many men who have long beards?\n\nSoc. Yes, Theodorus, but not better than you; and therefore please\nnot to imagine that I am to defend by every means in my power your\ndeparted friend; and that you are to defend nothing and nobody. At any\nrate, my good man, do not sheer off until we know whether you are a\ntrue measure of diagrams, or whether all men are equally measures\nand sufficient for themselves in astronomy and geometry, and the other\nbranches of knowledge in which you are supposed to excel them.\n\nTheod. He who is sitting by you, Socrates, will not easily avoid\nbeing drawn into an argument; and when I said just now that you\nwould excuse me, and not, like the Lacedaemonians, compel me to\nstrip and fight, I was talking nonsense-I should rather compare you to\nScirrhon, who threw travellers from the rocks; for the Lacedaemonian\nrule is \"strip or depart,\" but you seem to go about your work more\nafter the fashion of Antaeus: you will not allow any one who\napproaches you to depart until you have stripped him, and he has\nbeen compelled to try a fall with you in argument.\n\nSoc. There, Theodorus, you have hit off precisely the nature of my\ncomplaint; but I am even more pugnacious than the giants of old, for I\nhave met with no end of heroes; many a Heracles, many a Theseus,\nmighty in words, has broken my head; nevertheless I am always at\nthis rough exercise, which inspires me like a passion. Please, then,\nto try a fall with me, whereby you will do yourself good as well as\nme.\n\nTheod. I consent; lead me whither you will, for I know that you\nare like destiny; no man can escape from any argument which you may\nweave for him. But I am not disposed to go further than you suggest.\n\nSoc. Once will be enough; and now take particular care that we do\nnot again unwittingly expose ourselves to the reproach of talking\nchildishly.\n\nTheod. I will do my best to avoid that error.\n\nSoc. In the first place, let us return to our old objection, and see\nwhether we were right in blaming and taking offence at Protagoras on\nthe ground that he assumed all to be equal and sufficient in wisdom;\nalthough he admitted that there was a better and worse, and that in\nrespect of this, some who as he said were the wise excelled others.\n\nTheod. Very true.\n\nSoc. Had Protagoras been living and answered for himself, instead of\nour answering for him, there would have been no need of our\nreviewing or reinforcing the argument. But as he is not here, and some\none may accuse us of speaking without authority on his behalf, had\nwe not better come to a clearer agreement about his meaning, for a\ngreat deal may be at stake?\n\nTheod. True.\n\nSoc. Then let us obtain, not through any third person, but from\nhis own statement and in the fewest words possible, the basis of\nagreement.\n\nTheod. In what way?\n\nSoc. In this way:-His words are, \"What seems to a man, is to him.\"\n\nTheod. Yes, so he says.\n\nSoc. And are not we, Protagoras, uttering the opinion of man, or\nrather of all mankind, when we say that every one thinks himself wiser\nthan other men in some things, and their inferior in others? In the\nhour of danger, when they are in perils of war, or of the sea, or of\nsickness, do they not look up to their commanders as if they were\ngods, and expect salvation from them, only because they excel them\nin knowledge? Is not the world full of men in their several\nemployments, who are looking for teachers and rulers of themselves and\nof the animals? and there are plenty who think that they are able to\nteach and able to rule. Now, in all this is implied that ignorance and\nwisdom exist among them, least in their own opinion.\n\nTheod. Certainly.\n\nSoc. And wisdom is assumed by them to be true thought, and ignorance\nto be false opinion.\n\nTheod. Exactly.\n\nSoc. How then, Protagoras, would you have us treat the argument?\nShall we say that the opinions of men are always true, or sometimes\ntrue and sometimes false? In either case, the result is the same,\nand their opinions are not always true, but sometimes true and\nsometimes false. For tell me, Theodorus, do you suppose that you\nyourself, or any other follower of Protagoras, would contend that no\none deems another ignorant or mistaken in his opinion?\n\nTheod. The thing is incredible, Socrates.\n\nSoc. And yet that absurdity is necessarily involved in the thesis\nwhich declares man to be the measure of all things.\n\nTheod. How so?\n\nSoc. Why, suppose that you determine in your own mind something to\nbe true, and declare your opinion to me; let us assume, as he\nargues, that this is true to you. Now, if so, you must either say that\nthe rest of us are not the judges of this opinion or judgment of\nyours, or that we judge you always to have a true opinion: But are\nthere not thousands upon thousands who, whenever you form a\njudgment, take up arms against you and are of an opposite judgment and\nopinion, deeming that you judge falsely?\n\nTheod. Yes, indeed, Socrates, thousands and tens of thousands, as\nHomer says, who give me a world of trouble.\n\nSoc. Well, but are we to assert that what you think is true to you\nand false to the ten thousand others?\n\nTheod. No other inference seems to be possible.\n\nSoc. And how about Protagoras himself? If neither he nor the\nmultitude thought, as indeed they do not think, that man is the\nmeasure of all things, must it not follow that the truth of which\nProtagoras wrote would be true to no one? But if you suppose that he\nhimself thought this, and that the multitude does not agree with\nhim, you must begin by allowing that in whatever proportion the many\nare more than one, in that proportion his truth is more untrue than\ntrue.\n\nTheod. That would follow if the truth is supposed to vary with\nindividual opinion.\n\nSoc. And the best of the joke is, that he acknowledges the truth\nof their opinion who believe his own opinion to be false; for he\nadmits that the opinions of all men are true.\n\nTheod. Certainly.\n\nSoc. And does he not allow that his own opinion is false, if he\nadmits that the opinion of those who think him false is true?\n\nTheod. Of course.\n\nSoc. Whereas the other side do not admit that they speak falsely?\n\nTheod. They do not.\n\nSoc. And he, as may be inferred from his writings, agrees that\nthis opinion is also true.\n\nTheod. Clearly.\n\nSoc. Then all mankind, beginning with Protagoras, will contend, or\nrather, I should say that he will allow, when he concedes that his\nadversary has a true opinion-Protagoras, I say, will himself allow\nthat neither a dog nor any ordinary man is the measure of anything\nwhich he has not learned-am I not right?\n\nTheod. Yes.\n\nSoc. And the truth of Protagoras being doubted by all, will be\ntrue neither to himself to any one else?\n\nTheod. I think, Socrates, that we are running my old friend too\nhard.\n\nSoc. But do not know that we are going beyond the truth.\nDoubtless, as he is older, he may be expected to be wiser than we are.\nAnd if he could only just get his head out of the world below, he\nwould have overthrown both of us again and again, me for talking\nnonsense and you for assenting to me, and have been off and\nunderground in a trice. But as he is not within call, we must make the\nbest use of our own faculties, such as they are, and speak out what\nappears to us to be true. And one thing which no one will deny is,\nthat there are great differences in the understandings of men.\n\nTheod. In that opinion I quite agree.\n\nSoc. And is there not most likely to be firm ground in the\ndistinction which we were indicating on behalf of Protagoras, viz.,\nthat most things, and all immediate sensations, such as hot, dry,\nsweet, are only such as they appear; if however difference of\nopinion is to be allowed at all, surely we must allow it in respect of\nhealth or disease? for every woman, child, or living creature has\nnot such a knowledge of what conduces to health as to enable them to\ncure themselves.\n\nTheod. I quite agree.\n\nSoc. Or again, in politics, while affirming that just and unjust,\nhonourable and disgraceful, holy and unholy, are in reality to each\nstate such as the state thinks and makes lawful, and that in\ndetermining these matters no individual or state is wiser than\nanother, still the followers of Protagoras will not deny that in\ndetermining what is or is not expedient for the community one state is\nwiser and one counsellor better that another-they will scarcely\nventure to maintain, that what a city enacts in the belief that it\nis expedient will always be really expedient. But in the other case, I\nmean when they speak of justice and injustice, piety and impiety, they\nare confident that in nature these have no existence or essence of\ntheir own-the truth is that which is agreed on at the time of the\nagreement, and as long as the agreement lasts; and this is the\nphilosophy of many who do not altogether go along with Protagoras.\nHere arises a new question, Theodorus, which threatens to be more\nserious than the last.\n\nTheod. Well, Socrates, we have plenty of leisure.\n\nSoc. That is true, and your remark recalls to my mind an observation\nwhich I have often made, that those who have passed their days in\nthe pursuit of philosophy are ridiculously at fault when they have\nto appear and speak in court. How natural is this!\n\nTheod. What do you mean?\n\nSoc. I mean to say, that those who have been trained in philosophy\nand liberal pursuits are as unlike those who from their youth\nupwards have been knocking about in the courts and such places, as a\nfreeman is in breeding unlike a slave.\n\nTheod. In what is the difference seen?\n\nSoc. In the leisure spoken of by you, which a freeman can always\ncommand: he has his talk, out in peace, and, like ourselves, he\nwanders at will from one subject to another, and from a second to a\nthird,-if the fancy takes him he begins again, as we are doing now,\ncaring not whether his words are many or few; his only aim is to\nattain the truth. But the lawyer is always in a hurry; there is the\nwater of the clepsydra driving him on, and not allowing him to\nexpatiate at will: and there is his adversary standing over him,\nenforcing his rights; the indictment, which in their phraseology is\ntermed the affidavit, is recited at the time: and from this he must\nnot deviate. He is a servant, and is continually disputing about a\nfellow servant before his master, who is seated, and has the cause\nin his hands; the trial is never about some indifferent matter, but\nalways concerns himself; and often the race is for his life. The\nconsequence has been, that he has become keen and shrewd; he has\nlearned how to flatter his master in word and indulge him in deed; but\nhis soul is small and unrighteous. His condition, which has been\nthat of a slave from his youth upwards, has deprived him of growth and\nuprightness and independence; dangers and fears, which were too much\nfor his truth and honesty, came upon him in early years, when the\ntenderness of youth was unequal to them, and he has been driven into\ncrooked ways; from the first he has practised deception and\nretaliation, and has become stunted and warped. And so he has passed\nout of youth into manhood, having no soundness in him; and is now,\nas he thinks, a master in wisdom. Such is the lawyer, Theodorus.\nWill you have the companion picture of the philosopher, who is of\nour brotherhood; or shall we return to the argument? Do not let us\nabuse the freedom of digression which we claim.\n\nTheod. Nay, Socrates, not until we have finished what we are\nabout; for you truly said that we belong to a brotherhood which is\nfree, and are not the servants of the argument; but the argument is\nour servant, and must wait our leisure. Who is our judge? Or where\nis the spectator having any right to censure or control us, as he\nmight the poets?\n\nSoc. Then, as this is your wish, I will describe the leaders; for\nthere is no use in talking about the inferior sort. In the first\nplace, the lords of philosophy have never, from their youth upwards,\nknown their way to the Agora, or the dicastery, or the council, or any\nother political assembly; they neither see nor hear the laws or\ndecrees, as they are called, of the state written or recited; the\neagerness of political societies in the attainment of office-clubs,\nand banquets, and revels, and singing-maidens,-do not enter even\ninto their dreams. Whether any event has turned out well or ill in the\ncity, what disgrace may have descended to any one from his\nancestors, male or female, are matters of which the philosopher no\nmore knows than he can tell, as they say, how many pints are contained\nin the ocean. Neither is he conscious of his ignorance. For he does\nnot hold aloof in order; that he may gain a reputation; but the\ntruth is, that the outer form of him only is in the city: his mind,\ndisdaining the littlenesses and nothingnesses of human things, is\n\"flying all abroad\" as Pindar says, measuring earth and heaven and the\nthings which are under and on the earth and above the heaven,\ninterrogating the whole nature of each and all in their entirety,\nbut not condescending to anything which is within reach.\n\nTheod. What do you mean, Socrates?\n\nSoc. I will illustrate my meaning, Theodorus, by the jest which\nthe clever witty Thracian handmaid is said to have made about\nThales, when he fell into a well as he was looking up at the stars.\nShe said, that he was so eager to know what was going on in heaven,\nthat he could not see what was before his feet. This is a jest which\nis equally applicable to all philosophers. For the philosopher is\nwholly unacquainted with his next-door neighbour; he is ignorant,\nnot only of what he is doing, but he hardly knows whether he is a\nman or an animal; he is searching into the essence of man, and busy in\nenquiring what belongs to such a nature to do or suffer different from\nany other;-I think that you understand me, Theodorus?\n\nTheod. I do, and what you say is true.\n\nSoc. And thus, my friend, on every occasion, private as well as\npublic, as I said at first, when he appears in a law-court, or in\nany place in which he has to speak of things which are at his feet and\nbefore his eyes, he is the jest, not only of Thracian handmaids but of\nthe general herd, tumbling into wells and every sort of disaster\nthrough his inexperience. His awkwardness is fearful, and gives the\nimpression of imbecility. When he is reviled, he has nothing\npersonal to say in answer to the civilities of his adversaries, for he\nknows no scandals of any one, and they do not interest him; and\ntherefore he is laughed at for his sheepishness; and when others are\nbeing praised and glorified, in the simplicity of his heart he\ncannot help going into fits of laughter, so that he seems to be a\ndownright idiot. When he hears a tyrant or king eulogized, he\nfancies that he is listening to the praises of some keeper of cattle-a\nswineherd, or shepherd, or perhaps a cowherd, who is congratulated\non the quantity of milk which he squeezes from them; and he remarks\nthat the creature whom they tend, and out of whom they squeeze the\nwealth, is of a less traitable and more insidious nature. Then, again,\nhe observes that the great man is of necessity as ill-mannered and\nuneducated as any shepherd-for he has no leisure, and he is surrounded\nby a wall, which is his mountain-pen. Hearing of enormous landed\nproprietors of ten thousand acres and more, our philosopher deems this\nto be a trifle, because he has been accustomed to think of the whole\nearth; and when they sing the, praises of family, and say that someone\nis a gentleman because he can show seven generations of wealthy\nancestors, he thinks that their sentiments only betray a dull and\nnarrow vision in those who utter them, and who are not educated enough\nto look at the whole, nor to consider that every man has had thousands\nand ten thousands of progenitors, and among them have been rich and\npoor, kings and slaves, Hellenes and barbarians, innumerable. And when\npeople pride themselves on having a pedigree of twenty-five ancestors,\nwhich goes back to Heracles, the son of Amphitryon, he cannot\nunderstand their poverty of ideas. Why are they unable to calculate\nthat Amphitryon had a twenty-fifth ancestor, who might have been\nanybody, and was such as fortune made him and he had a fiftieth, and\nso on? He amuses himself with the notion that they cannot count, and\nthinks that a little arithmetic would have got rid of their\nsenseless vanity. Now, in all these cases our philosopher is derided\nby the vulgar, partly because he is thought to despise them, and\nalso because he is ignorant of what is before him, and always at a\nloss.\n\nTheod. That is very true, Socrates.\n\nSoc. But, O my friend, when he draws the other into upper air, and\ngets him out of his pleas and rejoinders into the contemplation of\njustice and injustice in their own nature and in their difference from\none another and from all other things; or from the commonplaces\nabout the happiness of a king or of a rich man to the consideration of\ngovernment, and of human happiness and misery in general-what they\nare, and how a man is to attain the one and avoid the other-when\nthat narrow, keen, little legal mind is called to account about all\nthis, he gives the philosopher his revenge; for dizzied by the\nheight at which he is hanging, whence he looks down into space,\nwhich is a strange experience to him, he being dismayed, and lost, and\nstammering broken words, is laughed at, not by Thracian handmaidens or\nany other uneducated persons, for they have no eye for the\nsituation, but by every man who has not been brought up a slave.\nSuch are the two characters, Theodorus: the one of the freeman, who\nhas becomes trained in liberty and leisure, whom you call the\nphilosopher-him we cannot blame because he appears simple and of no\naccount when he has to perform some menial task, such as packing up\nbed-clothes, or flavouring a sauce or fawning speech; the other\ncharacter is that of the man who is able to do all this kind of\nservice smartly and neatly, but knows not how to wear his cloak like a\ngentleman; still less with the music of discourse can he hymn the true\nlife aright which is lived by immortals or men blessed of heaven.\n\nTheod. If you could only persuade everybody, Socrates, as you do me,\nof the truth of your words, there would be more peace and fewer\nevils among men.\n\nSoc. Evils, Theodorus, can never pass away; for there must always\nremain something which is antagonistic to good. Having no place\namong the gods in heaven, of necessity they hover around the mortal\nnature, and this earthly sphere. Wherefore we ought to fly away from\nearth to heaven as quickly as we can; and to fly away is to become\nlike God, as far as this is possible; and to become like him, is to\nbecome holy, just, and wise. But, O my friend, you cannot easily\nconvince mankind that they should pursue virtue or avoid vice, not\nmerely in order that a man may seem to be good, which is the reason\ngiven by the world, and in my judgment is only a repetition of an\nold wives fable. Whereas, the truth is that God is never in any way\nunrighteous-he is perfect righteousness; and he of us who is the\nmost righteous is most like him. Herein is seen the true cleverness of\na man, and also his nothingness and want of manhood. For to know\nthis is true wisdom and virtue, and ignorance of this is manifest\nfolly and vice. All other kinds of wisdom or cleverness, which seem\nonly, such as the wisdom of politicians, or the wisdom of the arts,\nare coarse and vulgar. The unrighteous man, or the sayer and doer of\nunholy things, had far better not be encouraged in the illusion that\nhis roguery is clever; for men glory in their shame -they fancy that\nthey hear others saying of them, \"These are not mere good-for\nnothing persons, mere burdens of the earth, but such as men should\nbe who mean to dwell safely in a state.\" Let us tell them that they\nare all the more truly what they do not think they are because they do\nnot know it; for they do not know the penalty of injustice, which\nabove all things they ought to know-not stripes and death, as they\nsuppose, which evil-doers often escape, but a penalty which cannot\nbe escaped.\n\nTheod. What is that?\n\nSoc. There are two patterns eternally set before them; the one\nblessed and divine, the other godless and wretched: but they do not\nsee them, or perceive that in their utter folly and infatuation they\nare growing like the one and unlike the other, by reason of their evil\ndeeds; and the penalty is, that they lead a life answering to the\npattern which they are growing like. And if we tell them, that\nunless they depart from their cunning, the place of innocence will not\nreceive them after death; and that here on earth, they will live\never in the likeness of their own evil selves, and with evil\nfriends-when they hear this they in their superior cunning will seem\nto be listening to the talk of idiots.\n\nTheod. Very true, Socrates.\n\nSoc. Too true, my friend, as I well know; there is, however, one\npeculiarity in their case: when they begin to reason in private\nabout their dislike of philosophy, if they have the courage to hear\nthe argument out and do not run away, they grow at last strangely\ndiscontented with themselves; their rhetoric fades away, and they\nbecome helpless as children. These however are digressions from\nwhich we must now desist, or they will overflow, and drown the\noriginal argument; to which, if you please, we will now return.\n\nTheod. For my part, Socrates, I would rather have the digressions,\nfor at my age I find them easier to follow; but if you wish, let us go\nback to the argument.\n\nSoc. Had we not reached the point at which the partisans of the\nperpetual flux, who say that things are as they seem to each one, were\nconfidently maintaining that the ordinances which the state\ncommanded 2nd thought just, were just to the state which imposed them,\nwhile they were in force; this was especially asserted of justice; but\nas to the good, no one had any longer the hardihood to contend of\nany ordinances which the state thought and enacted to be good that\nthese, while they were in force, were really good;-he who said so\nwould be playing with the name \"good,\" and would, not touch the real\nquestion-it would be a mockery, would it not?\n\nTheod. Certainly it would.\n\nSoc. He ought not to speak of the name, but of the thing which is\ncontemplated under the name.\n\nTheod. Right.\n\nSoc. Whatever be the term used, the good or expedient is the aim\nof legislation, and as far as she has an opinion, the state imposes\nall laws with a view to the greatest expediency; can legislation\nhave any other aim?\n\nTheod. Certainly not.\n\nSoc. But is the aim attained always? do not mistakes often happen?\n\nTheod. Yes, I think that there are mistakes.\n\nSoc. The possibility of error will be more distinctly recognized, if\nwe put the question in reference to the whole class under which the\ngood or expedient fall That whole class has to do with the future, and\nlaws are passed under the idea that they will be useful in after-time;\nwhich, in other words, is the future.\n\nTheod. Very true.\n\nSoc. Suppose now, that we ask Protagoras, or one of his disciples, a\nquestion:-O, Protagoras, we will say to him, Man is, as you declare,\nthe measure of all things-white, heavy, light: of all such things he\nis the judge; for he has the criterion of them in himself, and when he\nthinks that things are such as he experiences them to be, he thinks\nwhat is and is true to himself. Is it not so?\n\nTheod. Yes.\n\nSoc. And do you extend your doctrine, Protagoras (as we shall\nfurther say), to the future as well as to the present; and has he\nthe criterion not only of what in his opinion is but of what will\nbe, and do things always happen to him as he expected? For example,\ntake the case of heat:-When an ordinary man thinks that he is going to\nhave a fever, and that this kind of heat is coming on, and another\nperson, who is a physician, thinks the contrary, whose opinion is\nlikely to prove right? Or are they both right?-he will have a heat and\nfever in his own judgment, and not have a fever in the physician's\njudgment?\n\nTheod. How ludicrous!\n\nSoc. And the vinegrower, if I am not mistaken, is a better judge\nof the sweetness or dryness of the vintage which is not yet gathered\nthan the harp-player?\n\nTheod. Certainly.\n\nSoc. And in musical composition-the musician will know better than\nthe training master what the training master himself will hereafter\nthink harmonious or the reverse?\n\nTheod. Of course.\n\nSoc. And the cook will be a better judge than the guest, who is\nnot a cook, of the pleasure to be derived from the dinner which is\nin preparation; for of present or past pleasure we are not as yet\narguing; but can we say that every one will be to himself the best\njudge of the pleasure which will seem to be and will be to him in\nthe future?-nay, would not you, Protagoras, better guess which\narguments in a court would convince any one of us than the ordinary\nman?\n\nTheod. Certainly, Socrates, he used to profess in the strongest\nmanner that he was the superior of all men in this respect.\n\nSoc. To be sure, friend: who would have paid a large sum for the\nprivilege of talking to him, if he had really persuaded his visitors\nthat neither a prophet nor any other man was better able to judge what\nwill be and seem to be in the future than every one could for himself?\n\nTheod. Who indeed?\n\nSoc. And legislation and expediency are all concerned with the\nfuture; and every one will admit that states, in passing laws, must\noften fail of their highest interests?\n\nTheod. Quite true.\n\nSoc. Then we may fairly argue against your master, that he must\nadmit one man to be wiser than another, and that the wiser is a\nmeasure: but I, who know nothing, am not at all obliged to accept\nthe honour which the advocate of Protagoras was just now forcing\nupon me, whether I would or not, of being a measure of anything.\n\nTheod. That is the best refutation of him, Socrates; although he\nis also caught when he ascribes truth to the opinions of others, who\ngive the lie direct to his own opinion.\n\nSoc. There are many ways, Theodorus, in which the doctrine that\nevery opinion of: every man is true may be refuted; but there is\nmore difficulty, in proving that states of feeling, which are\npresent to a man, and out of which arise sensations and opinions in\naccordance with them, are also untrue. And very likely I have been\ntalking nonsense about them; for they may be unassailable, and those\nwho say that there is clear evidence of them, and that they are\nmatters of knowledge, may probably be right; in which case our\nfriend Theaetetus was not so far from the mark when he identified\nperception and knowledge. And therefore let us draw nearer, as the\nadvocate of Protagoras desires; and the truth of the universal flux\na ring: is the theory sound or not? at any rate, no small war is\nraging about it, and there are combination not a few.\n\nTheod. No small, war, indeed, for in most the sect makes rapid\nstrides, the disciples of Heracleitus are most energetic. upholders of\nthe doctrine.\n\nSoc. Then we are the more bound, my dear Theodorus, to examine the\nquestion from the foundation as it is set forth by themselves.\n\nTheod. Certainly we are. About these speculations of Heracleitus,\nwhich, as you say, are as old as Homer, or even older still, the\nEphesians themselves, who profess to know them, are downright mad, and\nyou cannot talk with them on the subject. For, in accordance with\ntheir text-books, they are always in motion; but as for dwelling\nupon an argument or a question, and quietly asking and answering in\nturn, they can no more do so than they can fly; or rather, the\ndetermination of these fellows not to have a particle of rest in\nthem is more than the utmost powers of negation can express. If you\nask any of them a question, he will produce, as from a quiver, sayings\nbrief and dark, and shoot them at you; and if you inquire the reason\nof what he has said, you will be hit by some other newfangled word,\nand will make no way with any of them, nor they with one another;\ntheir great care is, not to allow of any settled principle either in\ntheir arguments or in their minds, conceiving, as I imagine, that\nany such principle would be stationary; for they are at war with the\nstationary, and do what they can to drive it out everywhere.\n\nSoc. I suppose, Theodorus, that you have only seen them when they\nwere fighting, and have never stayed with them in time of peace, for\nthey are no friends of yours; and their peace doctrines are only\ncommunicated by them at leisure, as I imagine, to those disciples of\ntheirs whom they want to make like themselves.\n\nTheod. Disciples! my good sir, they have none; men of their sort are\nnot one another's disciples, but they grow up at their own sweet will,\nand get their inspiration anywhere, each of them saying of his\nneighbour that he knows nothing. Fro these men, then, as I was going\nto remark, you will never get a reason, whether with their will or\nwithout their will; we must take the question out of their hands,\nand make the analysis ourselves, as if we were doing geometrical\nproblem.\n\nSoc. Quite right too; but as touching the aforesaid problem, have we\nnot heard from the ancients, who concealed their wisdom from the\nmany in poetical figures, that Oceanus and Tethys, the origin of all\nthings, are streams, and that nothing is at rest? And now the moderns,\nin their superior wisdom, have declared the same openly, that the\ncobbler too may hear and learn of them, and no longer foolishly\nimagine that some things are at rest and others in motion-having\nlearned that all is motion, he will duly honour his teachers. I had\nalmost forgotten the opposite doctrine, Theodorus,\n\nAlone Being remains unmoved, which is the name for the all.\n\nThis is the language of Parmenides, Melissus, and their followers, who\nstoutly maintain that all being is one and self-contained, and has\nno place which to move. What shall we do, friend, with all these\npeople; for, advancing step by step, we have imperceptibly got between\nthe combatants, and, unless we can protect our retreat, we shall pay\nthe penalty of our rashness-like the players in the palaestra who\nare caught upon the line, and are dragged different ways by the two\nparties. Therefore I think that we had better begin by considering\nthose whom we first accosted, \"the river-gods,\" and, if we find any\ntruth in them, we will help them to pull us over, and try to get\naway from the others. But if the partisans of \"the whole\" appear to\nspeak more truly, we will fly off from the party which would move\nthe immovable, to them. And if I find that neither of them have\nanything reasonable to say, we shall be in a ridiculous position,\nhaving so great a conceit of our own poor opinion and rejecting that\nof ancient and famous men. O Theodorus, do you think that there is any\nuse in proceeding when the danger is so great?\n\nTheod. Nay, Socrates, not to examine thoroughly what the two parties\nhave to say would be quite intolerable.\n\nSoc. Then examine we must, since you, who were so reluctant. to\nbegin, are so eager to proceed. The nature of motion appears to be the\nquestion with which we begin. What do they mean when they say that all\nthings are in motion? Is there only one kind of motion, or, as I\nrather incline to think, two? should like to have your opinion upon\nthis point in addition to my own, that I may err, if I must err, in\nyour company; tell me, then, when a thing changes from one place to\nanother, or goes round in the same place, is not that what is called\nmotion?\n\nTheod. Yes.\n\nSoc. Here then we have one kind of motion. But when a thing,\nremaining on the same spot, grows old, or becomes black from being\nwhite, or hard from being soft, or undergoes any other change, may not\nthis be properly called motion of another kind?\n\nTheod. I think so.\n\nSoc. Say rather that it must be so. Of motion then there are these\ntwo kinds, \"change,\" and \"motion in place.\"\n\nTheod. You are right.\n\nSoc. And now, having made this distinction, let us address ourselves\nto those who say that all is motion, and ask them whether all things\naccording to them have the two kinds of motion, and are changed as\nwell as move in place, or is one thing moved in both ways, and another\nin one only?\n\nTheod. Indeed, I do not know what to answer; but I think they\nwould say that all things are moved in both ways.\n\nSoc. Yes, comrade; for, if not, they would have to say that the same\nthings are in motion and at rest, and there would be no more truth\nin saying that all things are in motion, than that all things are at\nrest.\n\nTheod. To be sure.\n\nSoc. And if they are to be in motion, and nothing is to be devoid of\nmotion, all things must always have every sort of motion?\n\nTheod. Most true.\n\nSoc. Consider a further point: did we not understand them to explain\nthe generation of heat, whiteness, or anything else, in some such\nmanner as the following:-were they not saying that each of them is\nmoving between the agent and the patient, together with a\nperception, and that the patient ceases to be a perceiving power and\nbecomes a percipient, and the agent a quale instead of a quality? I\nsuspect that quality may appear a strange and uncouth term to you, and\nthat you do not understand the abstract expression. Then I will take\nconcrete instances: I mean to say that the producing power or agent\nbecomes neither heat nor whiteness but hot and white, and the like\nof other things. For I must repeat what I said before, that neither\nthe agent nor patient have any absolute existence, but when they\ncome together and generate sensations and their objects, the one\nbecomes a thing a certain quality, and the other a percipient. You\nremember?\n\nTheod. Of course.\n\nSoc. We may leave the details of their theory unexamined, but we\nmust not forget to ask them the only question with which we are\nconcerned: Are all things in motion and flux?\n\nTheod. Yes, they will reply.\n\nSoc. And they are moved in both those ways which we distinguished,\nthat is to Way, they move in place and are also changed?\n\nTheod. Of course, if the motion is to be perfect.\n\nSoc. If they only moved in place and were not changed, we should\nbe able to say what is the nature of the things which are in motion\nand flux.\n\nTheod. Exactly.\n\nSoc. But now, since not even white continues to flow white, and\nwhiteness itself is a flux or change which is passing into another\ncolour, and is never to be caught standing still, can the name of\nany colour be rightly used at all?\n\nTheod. How is that possible, Socrates, either in the case of this or\nof any other quality-if while we are using the word the object is\nescaping in the flux?\n\nSoc. And what would you say of perceptions, such as sight and\nhearing, or any other kind of perception? Is there any stopping in the\nact of seeing and hearing?\n\nTheod. Certainly not, if all things are in motion.\n\nSoc. Then we must not speak of seeing any more than of not-seeing,\nnor of any other perception more than of any non-perception, if all\nthings partake of every kind of motion?\n\nTheod. Certainly not.\n\nSoc. Yet perception is knowledge: so at least Theaetetus and I\nwere saying.\n\nTheod. Very true.\n\nSoc. Then when we were asked what is knowledge, we no more\nanswered what is knowledge than what is not knowledge?\n\nTheod. I suppose not.\n\nSoc. Here, then, is a fine result: we corrected our first answer\nin our eagerness to prove that nothing is at rest. But if nothing is\nat rest, every answer upon whatever subject is equally right: you\nmay say that a thing is or is not thus; or, if you prefer, \"becomes\"\nthus; and if we say \"becomes,\" we shall not then hamper them with\nwords expressive of rest.\n\nTheod. Quite true.\n\nSoc. Yes, Theodorus, except in saying \"thus\" and \"not thus.\" But you\nought not to use the word \"thus,\" for there is no motion in \"thus\"\nor in \"not thus.\" The maintainers of the doctrine have as yet no words\nin which to express themselves, and must get a new language. I know of\nno word that will suit them, except perhaps \"no how,\" which is\nperfectly indefinite.\n\nTheod. Yes, that is a manner of speaking in which they will be quite\nat home.\n\nSoc. And so, Theodorus, we have got rid of your friend without\nassenting to his doctrine, that every man is the measure of all\nthings-a wise man only is a measure; neither can we allow that\nknowledge is perception, certainly not on the hypothesis of a\nperpetual flux, unless perchance our friend Theaetetus is able to\nconvince us that it is.\n\nTheod. Very good, Socrates; and now that the argument about the\ndoctrine of Protagoras has been completed, I am absolved from\nanswering; for this was the agreement.\n\nTheaet. Not, Theodorus, until you and Socrates have discussed the\ndoctrine of those who say that all things are at rest, as you were\nproposing.\n\nTheod. You, Theaetetus, who are a young rogue, must not instigate\nyour elders to a breach of faith, but should prepare to answer\nSocrates in the remainder of the argument.\n\nTheaet. Yes, if he wishes; but I would rather have heard about the\ndoctrine of rest.\n\nTheod. Invite Socrates to an argument-invite horsemen to the open\nplain; do but ask him, and he will answer.\n\nSoc. Nevertheless, Theodorus, I am afraid that I shall not be able\nto comply with the request of Theaetetus.\n\nTheod. Not comply! for what reason?\n\nSoc. My reason is that I have a kind of reverence; not so much for\nMelissus and the others, who say that \"All is one and at rest,\" as for\nthe great leader himself, Parmenides, venerable and awful, as in\nHomeric language he may be called;-him I should be ashamed to approach\nin a spirit unworthy of him. I met him when he was an old man, and I\nwas a mere youth, and he appeared to me to have a glorious depth of\nmind. And I am afraid that we may not understand his words, and may be\nstill further from understanding his meaning; above all I fear that\nthe nature of knowledge, which is the main subject of our\ndiscussion, may be thrust out of sight by the unbidden guests who will\ncome pouring in upon our feast of discourse, if we let them\nin-besides, the question which is now stirring is of immense extent,\nand will be treated unfairly if only considered by the way; or if\ntreated adequately and at length, will put into the shade the other\nquestion of knowledge. Neither the one nor the other can be allowed;\nbut I must try by my art of midwifery to deliver Theaetetus of his\nconceptions about knowledge.\n\nTheaet. Very well; do so if you will.\n\nSoc. Then now, Theaetetus, take another view of the subject: you\nanswered that knowledge is perception?\n\nTheaet. I did.\n\nSoc. And if any one were to ask you: With what does a man see\nblack and white colours? and with what does he hear high and low\nsounds?-you would say, if I am not mistaken, \"With the eyes and with\nthe ears.\"\n\nTheaet. I should.\n\nSoc. The free use of words and phrases, rather than minute\nprecision, is generally characteristic of a liberal education, and the\nopposite is pedantic; but sometimes precision. is necessary, and I\nbelieve that the answer which you have just given is open to the\ncharge of incorrectness; for which is more correct, to say that we see\nor hear with the eyes and with the ears, or through the eyes and\nthrough the ears.\n\nTheaet. I should say \"through,\" Socrates, rather than \"with.\"\n\nSoc. Yes, my boy, for no one can suppose that in each of us, as in a\nsort of Trojan horse, there are perched a number of unconnected\nsenses, which do not all meet in some one nature, the mind, or\nwhatever we please to call it, of which they are the instruments,\nand with which through them we perceive objects of sense.\n\nTheaet. I agree with you in that opinion.\n\nSoc. The reason why I am thus precise is, because I want to know\nwhether, when we perceive black and white through the eyes, and again,\nother qualities through other organs, we do not perceive them with one\nand the same part of ourselves, and, if you were asked, you might\nrefer all such perceptions to the body. Perhaps, however, I had better\nallow you to answer for yourself and not interfere; Tell me, then, are\nnot the organs through which you perceive warm and hard and light\nand sweet, organs of the body?\n\nTheaet. Of the body, certainly.\n\nSoc. And you would admit that what you perceive through one\nfaculty you cannot perceive through another; the objects of hearing,\nfor example, cannot be perceived through sight, or the objects of\nsight through hearing?\n\nTheaet. Of course not.\n\nSoc. If you have any thought about both of them, this common\nperception cannot come to you, either through the one or the other\norgan?\n\nTheaet. It cannot.\n\nSoc. How about sounds and colours: in the first place you would\nadmit that they both exist?\n\nTheaet. Yes.\n\nSoc. And that either of them is different from the other, and the\nsame with itself?\n\nTheaet. Certainly.\n\nSoc. And that both are two and each of them one?\n\nTheaet. Yes.\n\nSoc. You can further observe whether they are like or unlike one\nanother?\n\nTheaet. I dare say.\n\nSoc. But through what do you perceive all this about them? for\nneither through hearing nor yet through seeing can you apprehend\nthat which they have in common. Let me give you an illustration of the\npoint at issue:-If there were any meaning in asking whether sounds and\ncolours are saline or not, you would be able to tell me what faculty\nwould consider the question. It would not be sight or hearing, but\nsome other.\n\nTheaet. Certainly; the faculty of taste.\n\nSoc. Very good; and now tell me what is the power which discerns,\nnot only in sensible objects, but in all things, universal notions,\nsuch as those which are called being and not-being, and those others\nabout which we were just asking-what organs will you assign for the\nperception of these notions?\n\nTheaet. You are thinking of being and not being, likeness and\nunlikeness, sameness and difference, and also of unity and other\nnumbers which are applied to objects of sense; and you mean to ask,\nthrough what bodily organ the soul perceives odd and even numbers\nand other arithmetical conceptions.\n\nSoc. You follow me excellently, Theaetetus; that is precisely what I\nam asking.\n\nTheaet. Indeed, Socrates, I cannot answer; my only notion is, that\nthese, unlike objects of sense, have no separate organ, but that the\nmind, by a power of her own, contemplates the universals in all\nthings.\n\nSoc. You are a beauty, Theaetetus, and not ugly, as Theodorus was\nsaying; for he who utters the beautiful is himself beautiful and good.\nAnd besides being beautiful, you have done me a kindness in\nreleasing me from a very long discussion, if you are clear that the\nsoul views some things by herself and others through the bodily\norgans. For that was my own opinion, and I wanted you to agree with\nme.\n\nTheaet. I am quite clear.\n\nSoc. And to which class would you refer being or essence; for\nthis, of all our notions, is the most universal?\n\nTheaet. I should say, to that class which the soul aspires to know\nof herself.\n\nSoc. And would you say this also of like and unlike, same and other?\n\nTheaet. Yes.\n\nSoc. And would you say the same of the noble and base, and of good\nand evil?\n\nTheaet. These I conceive to be notions which are essentially\nrelative, and which the soul also perceives by comparing in herself\nthings past and present with the future.\n\nSoc. And does she not perceive the hardness of that which is hard by\nthe touch, and the softness of that which is soft equally by the\ntouch?\n\nTheaet. Yes.\n\nSoc. But their essence and what they are, and their opposition to\none another, and the essential nature of this opposition, the soul\nherself endeavours to decide for us by the review and comparison of\nthem?\n\nTheaet. Certainly.\n\nSoc. The simple sensations which reach the soul through the body are\ngiven at birth to men and animals by nature, but their reflections\non the being and use of them are slowly and hardly gained, if they are\never gained, by education and long experience.\n\nTheaet. Assuredly.\n\nSoc. And can a man attain truth who fails of attaining being?\n\nTheaet. Impossible.\n\nSoc. And can he who misses the truth of anything, have a knowledge\nof that thing?\n\nTheaet. He cannot.\n\nSoc. Then knowledge does not consist in impressions of sense, but in\nreasoning about them; in that only, and not in the mere impression,\ntruth and being can be attained?\n\nTheaet. Clearly.\n\nSoc. And would you call the two processes by the same name, when\nthere is so great difference between them?\n\nTheaet. That would certainly not be right.\n\nSoc. And what name would you give to seeing, hearing, smelling,\nbeing cold and being hot?\n\nTheaet. I should call all of them perceiving-what other name could\nbe given to them?\n\nSoc. Perception would be the collective name of them?\n\nTheaet. Certainly.\n\nSoc. Which, as we say, has no part in the attainment of truth any\nmore of being?\n\nTheaet. Certainly not.\n\nSoc. And therefore not in. science or knowledge?\n\nTheaet. No.\n\nSoc. Then perception, Theaetetus, can never be the same as knowledge\nor science?\n\nTheaet. Clearly not, Socrates; and knowledge has now been most\ndistinctly proved to be different from perception.\n\nSoc. But the original aim of our discussion was to find out rather\nwhat knowledge is than what it is not; at the same time we have made\nsome progress, for we no longer seek for knowledge, in perception at\nall, but in that other process, however called, in which the mind is\nalone and engaged with being.\n\nTheaet. You mean, Socrates, if I am not mistaken, what is called\nthinking or opining.\n\nSoc. You conceive truly. And now, my friend, Please to begin again\nat this point; and having wiped out of your memory all that has\npreceded, see if you have arrived at any clearer view, and once more\nsay what is knowledge.\n\nTheaet. I cannot say, Socrates, that all opinion is knowledge,\nbecause there may be a false opinion; but I will venture to assert,\nthat knowledge is true opinion: let this then be my reply; and if this\nis hereafter disproved, I must try to find another.\n\nSoc. That is the way in which you ought to answer, Theaetetus, and\nnot in your former hesitating strain, for if we are bold we shall gain\none of two advantages; either we shall find what we seek, or we\nshall be less likely to think that we know what we do not know-in\neither case we shall be richly rewarded. And now, what are you\nsaying?-Are there two sorts of opinion, one true and the other\nfalse; and do you define knowledge to be the true?\n\nTheaet. Yes, according to my present view.\n\nSoc. Is it still worth our while to resume the discussion touching\nopinion?\n\nTheaet. To what are you alluding?\n\nSoc. There is a point which often troubles me, and is a great\nperplexity to me, both in regard to myself and others. I cannot make\nout the nature or origin of the mental experience to which I refer.\n\nTheaet. Pray what is it?\n\nSoc. How there can be-false opinion-that difficulty still troubles\nthe eye of my mind; and I am uncertain whether I shall leave the\nquestion, or over again in a new way.\n\nTheaet. Begin again, Socrates,-at least if you think that there is\nthe slightest necessity for doing so. Were not you and Theodorus\njust now remarking very truly, that in discussions of this kind we may\ntake our own time?\n\nSoc. You are quite right, and perhaps there will be no harm in\nretracing our steps and beginning again. Better a little which is well\ndone, than a great deal imperfectly.\n\nTheaet. Certainly.\n\nSoc. Well, and what is the difficulty? Do we not speak of false\nopinion, and say that one man holds a false and another a true\nopinion, as though there were some natural distinction between them?\n\nTheaet. We certainly say so.\n\nSoc. All things and everything are either known or not known. I\nleave out of view the intermediate conceptions of learning and\nforgetting, because they have nothing to do with our present question.\n\nTheaet. There can be no doubt, Socrates, if you exclude these,\nthat there is no other alternative but knowing or not knowing a thing.\n\nSoc. That point being now determined, must we not say that he who\nhas an opinion, must have an opinion about something which he knows or\ndoes not know?\n\nTheaet. He must.\n\nSoc. He who knows, cannot but know; and he who does not know, cannot\nknow?\n\nTheaet. Of course.\n\nSoc. What shall we say then? When a man has a false opinion does\nhe think that which he knows to be some other thing which he knows,\nand knowing both, is he at the same time ignorant of both?\n\nTheaet. That, Socrates, is impossible.\n\nSoc. But perhaps he thinks of something which he does not know as\nsome other thing which he does not know; for example, he knows neither\nTheaetetus nor Socrates, and yet he fancies that Theaetetus is\nSocrates, or Socrates Theaetetus?\n\nTheaet. How can he?\n\nSoc. But surely he cannot suppose what he knows to be what he does\nnot know, or what he does not know to be what he knows?\n\nTheaet. That would be monstrous.\n\nSoc. Where, then, is false opinion? For if all things are either\nknown or unknown, there can be no opinion which is not comprehended\nunder this alternative, and so false opinion is excluded.\n\nTheaes. Most true.\n\nSoc. Suppose that we remove the question out of the sphere of\nknowing or not knowing, into that of being and not-being.\n\nTheaet. What do you mean?\n\nSoc. May we not suspect the simple truth to be that he who thinks\nabout anything, that which. is not, will necessarily think what is\nfalse, whatever in other respects may be the state of his mind?\n\nTheaet. That, again, is not unlikely, Socrates.\n\nSoc. Then suppose some one to say to us, Theaetetus:-Is it\npossible for any man to think that which is not, either as a\nself-existent substance or as a predicate of something else? And\nsuppose that we answer, \"Yes, he can, when he thinks what is not\ntrue.\"-That will be our answer?\n\nTheaet. Yes.\n\nSoc. But is there any parallel to this?\n\nTheaet. What do you mean?\n\nSoc. Can a man see something and yet see nothing?\n\nTheaet. Impossible.\n\nSoc. But if he sees any one thing, he sees something that exists. Do\nyou suppose that what is one is ever to be found among nonexisting\nthings?\n\nTheaet. I do not.\n\nSoc. He then who sees some one thing, sees something which is?\n\nTheaet. Clearly.\n\nSoc. And he who hears anything, hears some one thing, and hears that\nwhich is?\n\nTheaet. Yes.\n\nSoc. And he who touches anything, touches something which is one and\ntherefore is?\n\nTheaet. That again is true.\n\nSoc. And does not he who thinks, think some one thing?\n\nTheaet. Certainly.\n\nSoc. And does not he who thinks some one thing, think something\nwhich is?\n\nTheaet. I agree.\n\nSoc. Then he who thinks of that which is not, thinks of nothing?\n\nTheaet. Clearly.\n\nSoc. And he who thinks of nothing, does not think at all?\n\nTheaet. Obviously.\n\nSoc. Then no one can think that which is not, either as a\nself-existent substance or as a predicate of something else?\n\nTheaet. Clearly not.\n\nSoc. Then to think falsely is different from thinking that which\nis not?\n\nTheaet. It would seem so.\n\nSoc. Then false opinion has no existence in us, either in the sphere\nof being or of knowledge?\n\nTheaet. Certainly not.\n\nSoc. But may not the following be the description of what we express\nby this name?\n\nTheaet. What?\n\nSoc. May we not suppose that false opinion or thought is a sort of\nheterodoxy; a person may make an exchange in his mind, and say that\none real object is another real object. For thus he always thinks that\nwhich is, but he puts one thing in place of another; and missing the\naim of his thoughts, he may be truly said to have false opinion.\n\nTheaet. Now you appear to me to have spoken the exact truth: when\na man puts the base in the place of the noble, or the noble in the\nplace of the base, then he has truly false opinion.\n\nSoc. I see, Theaetetus, that your fear has disappeared, and that you\nare beginning to despise me.\n\nTheaet. What makes you say so?\n\nSoc. You think, if I am not mistaken, that your \"truly false\" is\nsafe from censure, and that I shall never ask whether there can be a\nswift which is slow, or a heavy which is light, or any other\nself-contradictory thing, which works, not according to its own\nnature, but according to that of its opposite. But I will not insist\nupon this, for I do not wish needlessly to discourage you. And so\nyou are satisfied that false opinion is heterodoxy, or the thought\nof something else?\n\nTheaet. I am.\n\nSoc. It is possible then upon your view for the mind to conceive\nof one thing as another?\n\nTheaet. True.\n\nSoc. But must not the mind, or thinking power, which misplaces them,\nhave a conception either of both objects or of one of them?\n\nTheaet. Certainly.\n\nSoc. Either together or in succession?\n\nTheaet. Very good.\n\nSoc. And do you mean by conceiving, the same which I mean?\n\nTheaet. What is that?\n\nSoc. I mean the conversation which the soul holds with herself in\nconsidering of anything. I speak of what I scarcely understand; but\nthe soul when thinking appears to me to be just talking-asking\nquestions of herself and answering them, affirming and denying. And\nwhen she has arrived at a decision, either gradually or by a sudden\nimpulse, and has at last agreed, and does not doubt, this is called\nher opinion. I say, then, that to form an opinion is to speak, and\nopinion is a word spoken,-I mean, to oneself and in silence, not aloud\nor to another: What think you?\n\nTheaet. I agree.\n\nSoc. Then when any one thinks of one thing as another, he is\nsaying to himself that one thing is another?\n\nTheaet. Yes.\n\nSoc. But do you ever remember saying to yourself that the noble is\ncertainly base, or the unjust just; or, best of all-have you ever\nattempted to convince yourself that one thing is another? Nay, not\neven in sleep, did you ever venture to say to yourself that odd is\neven, or anything of the kind?\n\nTheaet. Never.\n\nSoc. And do you suppose that any other man, either in his senses\nor out of them, ever seriously tried to persuade himself that an ox is\na horse, or that two are one?\n\nTheaet. Certainly not.\n\nSoc. But if thinking is talking to oneself, no one speaking and\nthinking of two objects, and apprehending them both in his soul,\nwill say and think that the one is the other of them, and I must\nadd, that even you, lover of dispute as you are, had better let the\nword \"other\" alone [i.e., not insist that \"one\" and \"other\" are the\nsame]. I mean to say, that no one thinks the noble to be base, or\nanything of the kind.\n\nTheaet. I will give up the word \"other,\" Socrates; and I agree to\nwhat you say.\n\nSoc. If a man has both of them in his thoughts, he cannot think that\nthe one of them is the other?\n\nTheat. True.\n\nSoc. Neither, if he has one of them only in his mind and not the\nother, can he think that one is the other?\n\nTheaet. True; for we should have to suppose that he apprehends\nthat which is not in his thoughts at all.\n\nSoc. Then no one who has either both or only one of the two\nobjects in his mind can think that the one is the other. And\ntherefore, he who maintains that false opinion is heterodoxy is\ntalking nonsense; for neither in this, any more than in the previous\nway, can false opinion exist in us.\n\nTheaet. No.\n\nSoc. But if, Theaetetus, this is not admitted, we shall be driven\ninto many absurdities.\n\nTheaet. What are they?\n\nSoc. I will not tell you until I have endeavoured to consider the\nmatter from every point of view. For I should be ashamed of us if we\nwere driven in our perplexity to admit the absurd consequences of\nwhich I speak. But if we find the solution, and get away from them, we\nmay regard them only as the difficulties of others, and the ridicule\nwill not attach to us. On the other hand, if we utterly fail, I\nsuppose that we must be humble, and allow the argument to trample us\nunder foot, as the sea-sick passenger is trampled upon by the\nsailor, and to do anything to us. Listen, then, while I tell you how I\nhope to find a way out of our difficulty.\n\nTheaet. Let me hear.\n\nSoc. I think that we were wrong in denying that a man could think\nwhat he knew to be what he did not know; and that there is a way in\nwhich such a deception is possible.\n\nTheaet. You mean to say, as I suspected at the time, that I may know\nSocrates, and at a distance see some one who is unknown to me, and\nwhom I mistake for him-them the deception will occur?\n\nSoc. But has not that position been relinquished by us, because\ninvolving the absurdity that we should know and not know the things\nwhich we know?\n\nTheaet. True.\n\nSoc. Let us make the assertion in another form, which may or may not\nhave a favourable issue; but as we are in a great strait, every\nargument should be turned over and tested. Tell me, then, whether I am\nright in saying that you may learn a thing which at one time you did\nnot know?\n\nTheaet. Certainly you may.\n\nSoc. And another and another?\n\nTheaet. Yes.\n\nSoc. I would have you imagine, then, that there exists in the mind\nof man a block of wax, which is of different sizes in different men;\nharder, moister, and having more or less of purity in one than\nanother, and in some of an intermediate quality.\n\nTheaet. I see.\n\nSoc. Let us say that this tablet is a gift of Memory, the mother\nof the Muses; and that when we wish to remember anything which we have\nseen, or heard, or thought in our own minds, we hold the wax to the\nperceptions and thoughts, and in that material receive the\nimpression of them as from the seal of a ring; and that we remember\nand know what is imprinted as long as the image lasts; but when the\nimage is effaced, or cannot be taken, then we forget and do not know.\n\nTheaet. Very good.\n\nSoc. Now, when a person has this knowledge, and is considering\nsomething which he sees or hears, may not false opinion arise in the\nfollowing manner?\n\nTheaet. In what manner?\n\nSoc. When he thinks what he knows, sometimes to be what he knows,\nand sometimes to be what he does not know. We were wrong before in\ndenying the possibility of this.\n\nTheaet. And how would you amend the former statement?\n\nSoc. I should begin by making a list of the impossible cases which\nmust be excluded. (1) No one can think one thing to be another when he\ndoes not perceive either of them, but has the memorial or seal of both\nof them in his mind; nor can any mistaking of one thing for another\noccur, when he only knows one, and does not know, and has no\nimpression of the other; nor can he think that one thing which he does\nnot know is another thing which he does not know, or that what he does\nnot know is what he knows; nor (2) that one thing which he perceives\nis another thing which he perceives, or that something which he\nperceives is something which he does not perceive; or that something\nwhich he does not perceive is something else which he does not\nperceive; or that something which he does not perceive is something\nwhich he perceives; nor again (3) can he think that something which he\nknows and perceives, and of which he has the impression coinciding\nwith sense, is something else which he knows and perceives, and of\nwhich he has the impression coinciding with sense;-this last case,\nif possible, is still more inconceivable than the others; nor (4)\ncan he think that something which he knows and perceives, and of which\nhe has the memorial coinciding with sense, is something else which\nhe knows; nor so long as these agree, can he think that a thing\nwhich he knows and perceives is another thing which he perceives; or\nthat a thing which he does not know and does not perceive, is the same\nas another thing which he does not know and does not perceive;-nor\nagain, can he suppose that a thing which he does not know and does not\nperceive is the same as another thing which he does not know; or\nthat a thing which he does not know and does not perceive is another\nthing which he does not perceive:-All these utterly and absolutely\nexclude the possibility of false opinion. The only cases, if any,\nwhich remain, are the following.\n\nTheaet. What are they? If you tell me, I may perhaps understand\nyou better; but at present I am unable to follow you.\n\nSoc. A person may think that some things which he knows, or which he\nperceives and does not know, are some other things which he knows\nand perceives; or that some things which he knows and perceives, are\nother things which he knows and perceives.\n\nTheaet. I understand you less than ever now.\n\nSoc. Hear me once more, then:-I, knowing Theodorus, and\nremembering in my own mind what sort of person he is, and also what\nsort of person Theaetetus is, at one time see them, and at another\ntime do not see them, and sometimes I touch them, and at another\ntime not, or at one time I may hear them or perceive them in some\nother way, and at another time not perceive them, but still I remember\nthem, and know them in my own mind.\n\nTheaet. Very true.\n\nSoc. Then, first of all, I want you to understand that a man may\nor may not perceive sensibly that which he knows.\n\nTheaet. True.\n\nSoc. And that which he does not know will sometimes not be perceived\nby him and sometimes will be perceived and only perceived?\n\nTheaet. That is also true.\n\nSoc. See whether you can follow me better now: Socrates can\nrecognize Theodorus and Theaetetus, but he sees neither of them, nor\ndoes he perceive them in any other way; he cannot then by any\npossibility imagine in his own mind that Theaetetus is Theodorus. Am I\nnot right?\n\nTheaet. You are quite right.\n\nSoc. Then that was the first case of which I spoke.\n\nTheaet. Yes.\n\nSoc. The second case was, that I, knowing one of you and not knowing\nthe other, and perceiving neither, can never think him whom I know\nto be him whom I do not know.\n\nTheaet. True.\n\nSoc. In the third case, not knowing and not perceiving either of\nyou, I cannot think that one of you whom I do not know is the other\nwhom I do not know. I need not again go over the catalogue of excluded\ncases, in which I cannot form a false opinion about you and Theodorus,\neither when I know both or when I am in ignorance of both, or when I\nknow one and not the other. And the same of perceiving: do you\nunderstand me?\n\nTheaet. I do.\n\nSoc. The only possibility of erroneous opinion is, when knowing\nyou and Theodorus, and having on the waxen block the impression of\nboth of you given as by a seal, but seeing you imperfectly and at a\ndistance, I try to assign the right impression of memory to the\nright visual impression, and to fit this into its own print: if I\nsucceed, recognition will take place; but if I fad and transpose them,\nputting the foot into the wrong shoe-that is to say, putting the\nvision of either of you on to the wrong impression, or if my mind,\nlike the sight in a mirror, which is transferred from right to left,\nerr by reason of some similar affection, then \"heterodoxy\" and false\nopinion ensues.\n\nTheaet. Yes, Socrates, you have described the nature of opinion with\nwonderful exactness.\n\nSoc. Or again, when I know both of you, and perceive as well as know\none of you, but not the other, and my knowledge of him does not accord\nwith perception-that was the case put by me just now which you did not\nunderstand\n\nTheaet. No, I did not.\n\nSoc. I meant to say, that when a person knows and perceives one of\nyou, his knowledge coincides with his perception, he will never\nthink him to be some other person, whom he knows and perceives, and\nthe knowledge of whom coincides with his perception-for that also\nwas a case supposed.\n\nTheaet. True.\n\nSoc. But there was an omission of the further case, in which, as\nwe now say, false opinion may arise, when knowing both, and seeing, or\nhaving some other sensible perception of both, I fail in holding the\nseal over against the corresponding sensation; like a bad archer, I\nmiss and fall wide of the mark-and this is called falsehood.\n\nTheaet. Yes; it is rightly so called.\n\nSoc. When, therefore, perception is present to one of the seals or\nimpressions but not to the other, and the mind fits the seal of the\nabsent perception on the one which is present, in any case of this\nsort the mind is deceived; in a word, if our view is sound, there\ncan be no error or deception about things which a man does not know\nand has never perceived, but only in things which are known and\nperceived; in these alone opinion turns and twists about, and\nbecomes alternately true and false;-true when the seals and\nimpressions of sense meet straight and opposite-false when they go\nawry and crooked.\n\nTheaet. And is not that, Socrates, nobly said?\n\nSoc. Nobly! yes; but wait a little and hear the explanation, and\nthen you will say so with more reason; for to think truly is noble and\nto be deceived is base.\n\nTheaet. Undoubtedly.\n\nSoc. And the origin of truth and error is as follows:-When the wax\nin the soul of any one is deep and abundant, and smooth and\nperfectly tempered, then the impressions which pass through the senses\nand sink into the heart of the soul, as Homer says in a parable,\nmeaning to indicate the likeness of the soul to wax (Kerh Kerhos);\nthese, I say, being pure and clear, and having a sufficient depth of\nwax, are also lasting, and minds, such as these, easily learn and\neasily retain, and are not liable to confusion, but have true\nthoughts, for they have plenty of room, and having clear impressions\nof things, as we term them, quickly distribute them into their\nproper places on the block. And such men are called wise. Do you\nagree?\n\nTheaet. Entirely.\n\nSoc. But when the heart of any one is shaggy-a quality which the\nall-wise poet commends, or muddy and of impure wax, or very soft, or\nvery hard, then there is a corresponding defect in the mind -the\nsoft are good at learning, but apt to forget; and the hard are the\nreverse; the shaggy and rugged and gritty, or those who have an\nadmixture of earth or dung in their composition, have the\nimpressions indistinct, as also the hard, for there is no depth in\nthem; and the soft too are indistinct, for their impressions are\neasily confused and effaced. Yet greater is the indistinctness when\nthey are all jostled together in a little soul, which has no room.\nThese are the natures which have false opinion; for when they see or\nhear or think of anything, they are slow in assigning the right\nobjects to the right impressions-in their stupidity they confuse them,\nand are apt to see and hear and think amiss-and such men are said to\nbe deceived in their knowledge of objects, and ignorant.\n\nTheaet. No man, Socrates, can say anything truer than that.\n\nSoc. Then now we may admit the existence of false opinion in us?\n\nTheaet. Certainly.\n\nSoc. And of true opinion also?\n\nTheaet. Yes.\n\nSoc. We have at length satisfactorily proven beyond a doubt there\nare these two sorts of opinion?\n\nTheaet. Undoubtedly.\n\nSoc. Alas, Theaetetus, what a tiresome creature is a man who is fond\nof talking!\n\nTheaet. What makes you say so?\n\nSoc. Because I am disheartened at my own stupidity and tiresome\ngarrulity; for what other term will describe the habit of a man who is\nalways arguing on all sides of a question; whose dulness cannot be\nconvinced, and who will never leave off?\n\nTheaet. But what puts you out of heart?\n\nSoc. I am not only out of heart, but in positive despair; for I do\nnot know what to answer if any one were to ask me:-O Socrates, have\nyou indeed discovered that false opinion arises neither in the\ncomparison of perceptions with one another nor yet in thought, but\nin union of thought and perception? Yes, I shall say, with the\ncomplacence of one who thinks that he has made a noble discovery.\n\nTheaet. I see no reason why we should be ashamed of our\ndemonstration, Socrates.\n\nSoc. He will say: You mean to argue that the man whom we only\nthink of and do not see, cannot be confused with the horse which we do\nnot see or touch, but only think of and do not perceive? That I\nbelieve to be my meaning, I shall reply.\n\nTheaet. Quite right.\n\nSoc. Well, then, he will say, according to that argument, the number\neleven, which is only thought, never be mistaken for twelve, which\nis only thought: How would you answer him?\n\nTheaet. I should say that a mistake may very likely arise between\nthe eleven or twelve which are seen or handled, but that no similar\nmistake can arise between the eleven and twelve which are in the mind.\n\nSoc. Well, but do you think that no one ever put before his own mind\nfive and seven, -I do not mean five or seven men or horses, but five\nor seven in the abstract, which, as we say, are recorded on the\nwaxen block, and in which false opinion is held to be impossible;\ndid no man ever ask himself how many these numbers make when added\ntogether, and answer that they are eleven, while another thinks that\nthey are twelve, or would all agree in thinking and saying that they\nare twelve?\n\nTheaet. Certainly not; many would think that they are eleven, and in\nthe higher numbers the chance of error is greater still; for I\nassume you to be speaking of numbers in general.\n\nSoc. Exactly; and I want you to consider whether this does not imply\nthat the twelve in the waxen block are supposed to be eleven?\n\nTheaet. Yes, that seems to be the case.\n\nSoc. Then do we not come back to the old difficulty? For he who\nmakes such a mistake does think one thing which he knows to be another\nthing which he knows; but this, as we said, was impossible, and\nafforded an irresistible proof of the non-existence of false\nopinion, because otherwise the same person would inevitably know and\nnot know the same thing at the same time.\n\nTheaet. Most true.\n\nSoc. Then false opinion cannot be explained as a confusion of\nthought and sense, for in that case we could not have been mistaken\nabout pure conceptions of thought; and thus we are obliged to say,\neither that false opinion does not exist, or that a man may not know\nthat which he knows;-which alternative do you prefer?\n\nTheaet. It is hard to determine, Socrates.\n\nSoc. And yet the argument will scarcely admit of both. But, as we\nare at our wits' end, suppose that we do a shameless thing?\n\nTheaet. What is it?\n\nSoc. Let us attempt to explain the verb \"to know.\"\n\nTheaet. And why should that be shameless?\n\nSoc. You seem not to be aware that the whole of our discussion\nfrom the very beginning has been a search after knowledge, of which we\nare assumed not to know the nature.\n\nTheaet. Nay, but I am well aware.\n\nSoc. And is it not shameless when we do not know what knowledge\nis, to be explaining the verb \"to know\"? The truth is, Theaetetus,\nthat we have long been infected with logical impurity. Thousands of\ntimes have we repeated the words \"we know,\" and \"do not know,\" and \"we\nhave or have not science or knowledge,\" as if we could understand what\nwe are saying to one another, so long as we remain ignorant about\nknowledge; and at this moment we are using the words \"we\nunderstand,\" \"we are ignorant,\" as though we could still employ them\nwhen deprived of knowledge or science.\n\nTheaet. But if you avoid these expressions, Socrates, how will you\never argue at all?\n\nSoc. I could not, being the man I am. The case would be different if\nI were a true hero of dialectic: and O that such an one were\npresent! for he would have told us to avoid the use of these terms; at\nthe same time he would not have spared in you and me the faults\nwhich I have noted. But, seeing that we are no great wits, shall I\nventure to say what knowing is? for I think that the attempt may be\nworth making.\n\nTheaet. Then by all means venture, and no one shall find fault\nwith you for using the forbidden terms.\n\nSoc. You have heard the common explanation of the verb \"to know\"?\n\nTheaet. I think so, but I do not remember it at the moment.\n\nSoc. They explain the word \"to know\" as meaning \"to have knowledge.\"\n\nTheaet. True.\n\nSoc. I should like to make a slight change, and say \"to possess\"\nknowledge.\n\nTheaet. How do the two expressions differ?\n\nSoc. Perhaps there may be no difference; but still I should like you\nto hear my view, that you may help me to test it.\n\nTheaet. I will, if I can.\n\nSoc. I should distinguish \"having\" from \"possessing\": for example, a\nman may buy and keep under his control a garment which he does not\nwear; and then we should say, not that he has, but that he possesses\nthe garment.\n\nTheaet. It would be the correct expression.\n\nSoc. Well, may not a man \"possess\" and yet not \"have\" knowledge in\nthe sense of which I am speaking? As you may suppose a man to have\ncaught wild birds -doves or any other birds-and to be keeping them\nin an aviary which he has constructed at home; we might say of him\nin one sense, that he always has them because he possesses them, might\nwe not?\n\nTheaet. Yes.\n\nSoc. And yet, in another sense, he has none of them; but they are in\nhis power, and he has got them under his hand in an enclosure of his\nown, and can take and have them whenever he likes;-he can catch any\nwhich he likes, and let the bird go again, and he may do so as often\nas he pleases.\n\nTheaet. True.\n\nSoc. Once more, then, as in what preceded we made a sort of waxen\nfigment in the mind, so let us now suppose that in the mind of each\nman there is an aviary of all sorts of birds-some flocking together\napart from the rest, others in small groups, others solitary, flying\nanywhere and everywhere.\n\nTheaet. Let us imagine such an aviary-and what is to follow?\n\nSoc. We may suppose that the birds are kinds of knowledge, and\nthat when we were children, this receptacle was empty; whenever a\nman has gotten and detained in the enclosure a kind of knowledge, he\nmay be said to have learned or discovered the thing which is the\nsubject of the knowledge: and this is to know.\n\nTheaet. Granted.\n\nSoc. And further, when any one wishes to catch any of these\nknowledges or sciences, and having taken, to hold it, and again to let\nthem go, how will he express himself?-will he describe the\n\"catching\" of them and the original \"possession\" in the same words?\nI will make my meaning clearer by an example:-You admit that there\nis an art of arithmetic?\n\nTheaet. To be sure.\n\nSoc. Conceive this under the form of a hunt after the science of odd\nand even in general.\n\nTheaet. I follow.\n\nSoc. Having the use of the art, the arithmetician, if I am not\nmistaken, has the conceptions of number under his hand, and can\ntransmit them to another.\n\nTheaet. Yes.\n\nSoc. And when transmitting them he may be said to teach them, and\nwhen receiving to learn them, and when receiving to learn them, and\nwhen having them in possession in the aforesaid aviary he may be\nsaid to know them.\n\nTheaet. Exactly.\n\nSoc. Attend to what follows: must not the perfect arithmetician know\nall numbers, for he has the science of all numbers in his mind?\n\nTheaet. True.\n\nSoc. And he can reckon abstract numbers in his head, or things about\nhim which are numerable?\n\nTheaet. Of course he can.\n\nSoc. And to reckon is simply to consider how much such and such a\nnumber amounts to?\n\nTheaet. Very true.\n\nSoc. And so he appears to be searching into something which he\nknows, as if he did not know it, for we have already admitted that\nhe knows all numbers;-you have heard these perplexing questions\nraised?\n\nTheaet. I have.\n\nSoc. May we not pursue the image of the doves, and say that the\nchase after knowledge is of two kinds? one kind is prior to possession\nand for the sake of possession, and the other for the sake of taking\nand holding in the hands that which is possessed already. And thus,\nwhen a man has learned and known something long ago, he may resume and\nget hold of the knowledge which he has long possessed, but has not\nat hand in his mind.\n\nTheaet. True.\n\nSoc. That was my reason for asking how we ought to speak when an\narithmetician sets about numbering, or a grammarian about reading?\nShall we say, that although he knows, he comes back to himself to\nlearn what he already knows?\n\nTheaet. It would be too absurd, Socrates.\n\nSoc. Shall we say then that he is going to read or number what he\ndoes not know, although we have admitted that he knows all letters and\nall numbers?\n\nTheaet. That, again, would be an absurdity.\n\nSoc. Then shall we say that about names we care nothing?-any one may\ntwist and turn the words \"knowing\" and \"learning\" in any way which\nhe likes, but since we have determined that the possession of\nknowledge is not the having or using it, we do assert that a man\ncannot not possess that which he possesses; and, therefore, in no case\ncan a man not know that which he knows, but he may get a false opinion\nabout it; for he may have the knowledge, not of this particular thing,\nbut of some other;-when the various numbers and forms of knowledge are\nflying about in the aviary, and wishing to capture a certain sort of\nknowledge out of the general store, he takes the wrong one by mistake,\nthat is to say, when he thought eleven to be twelve, he got hold of\nthe ringdove which he had in his mind, when he wanted the pigeon.\n\nTheaet. A very rational explanation.\n\nSoc. But when he catches the one which he wants, then he is not\ndeceived, and has an opinion of what is, and thus false and true\nopinion may exist, and the difficulties which were previously raised\ndisappear. I dare say that you agree with me, do you not?\n\nTheaet. Yes.\n\nSoc. And so we are rid of the difficulty of a man's not knowing what\nhe knows, for we are not driven to the inference that he does not\npossess what he possesses, whether he be or be not deceived. And yet I\nfear that a greater difficulty is looking in at the window.\n\nTheaet. What is it?\n\nSoc. How can the exchange of one knowledge for another ever become\nfalse opinion?\n\nTheaet. What do you mean?\n\nSoc. In the first place, how can a man who has the knowledge of\nanything be ignorant of that which he knows, not by reason of\nignorance, but by reason of his own knowledge? And, again, is it not\nan extreme absurdity that he should suppose another thing to be\nthis, and this to be another thing;-that, having knowledge present\nwith him in his mind, he should still know nothing and be ignorant\nof all things?-you might as well argue that ignorance may make a man\nknow, and blindness make him see, as that knowledge can make him\nignorant.\n\nTheaet. Perhaps, Socrates, we may have been wrong in making only\nforms of knowledge our birds: whereas there ought to have been forms\nof ignorance as well, flying about together in the mind, and then he\nwho sought to take one of them might sometimes catch a form of\nknowledge, and sometimes a form of ignorance; and thus he would have a\nfalse opinion from ignorance, but a true one from knowledge, about the\nsame thing.\n\nSoc. I cannot help praising you, Theaetetus, and yet I must beg\nyou to reconsider your words. Let us grant what you say-then,\naccording to you, he who takes ignorance will have a false\nopinion-am I right?\n\nTheaet. Yes.\n\nSoc. He will certainly not think that he has a false opinion?\n\nTheaet. Of course not.\n\nSoc. He will think that his opinion is true, and he will fancy\nthat he knows the things about which he has been deceived?\n\nTheaet. Certainly.\n\nSoc. Then he will think that he has captured knowledge and not\nignorance?\n\nTheaet. Clearly.\n\nSoc. And thus, after going a long way round, we are once more face\nto face with our original difficulty. The hero of dialectic will\nretort upon us:-\"O my excellent friends, he will say, laughing, if a\nman knows the form of ignorance and the form of knowledge, can he\nthink that one of them which he knows is the other which he knows? or,\nif he knows neither of them, can he think that the one which he\nknows not is another which he knows not? or, if he knows one and not\nthe other, can he think the one which he knows to be the one which\nhe does not know? or the one which he does not know to be the one\nwhich he knows? or will you tell me that there are other forms of\nknowledge which distinguish the right and wrong birds, and which the\nowner keeps in some other aviaries or graven on waxen blocks according\nto your foolish images, and which he may be said to know while he\npossesses them, even though he have them not at hand in his mind?\nAnd thus, in a perpetual circle, you will be compelled to go round and\nround, and you will make no progress.\" What are we to say in reply,\nTheaetetus?\n\nTheaet. Indeed, Socrates, I do not know what we are to say.\n\nSoc. Are not his reproaches just, and does not the argument truly\nshow that we are wrong in seeking for false opinion until we know what\nknowledge is; that must be first ascertained; then, the nature of\nfalse opinion?\n\nTheaet. I cannot but agree with you, Socrates, so far as we have yet\ngone.\n\nSoc. Then, once more, what shall we say that knowledge is?-for we\nare not going to lose heart as yet.\n\nTheaet. Certainly, I shall not lose heart, if you do not.\n\nSoc. What definition will be most consistent with our former views?\n\nTheaet. I cannot think of any but our old one, Socrates.\n\nSoc. What was it?\n\nTheaet. Knowledge was said by us to be true opinion; and true\nopinion is surely unerring, and the results which follow from it are\nall noble and good.\n\nSoc. He who led the way into the river, Theaetetus, said \"The\nexperiment will show\"; and perhaps if we go forward in the search,\nwe may stumble upon the thing which we are looking for; but if we stay\nwhere we are, nothing will come to light.\n\nTheaet. Very true; let us go forward and try.\n\nSoc. The trail soon comes to an end, for a whole profession is\nagainst us.\n\nTheaet. How is that, and what profession do you mean?\n\nSoc. The profession of the great wise ones who are called orators\nand lawyers; for these persuade men by their art and make them think\nwhatever they like, but they do not teach them. Do you imagine that\nthere are any teachers in the world so clever as to be able to\nconvince others of the truth about acts of robbery or violence, of\nwhich they were not eyewitnesses, while a little water is flowing in\nthe clepsydra?\n\nTheaet. Certainly not, they can only persuade them.\n\nSoc. And would you not say that persuading them is making them\nhave an opinion?\n\nTheaet. To be sure.\n\nSoc. When, therefore, judges are justly persuaded about matters\nwhich you can know only by seeing them, and not in any other way,\nand when thus judging of them from report they attain a true opinion\nabout them, they judge without knowledge and yet are rightly\npersuaded, if they have judged well.\n\nTheaet. Certainly.\n\nSoc. And yet, O my friend, if true opinion in law courts and\nknowledge are the same, the perfect judge could not have judged\nrightly without knowledge; and therefore I must infer that they are\nnot the same.\n\nTheaet. That is a distinction, Socrates, which I have heard made\nby some one else, but I had forgotten it. He said that true opinion,\ncombined with reason, was knowledge, but that the opinion which had no\nreason was out of the sphere of knowledge; and that things of which\nthere is no rational account are not knowable-such was the singular\nexpression which he used-and that things which have a reason or\nexplanation are knowable.\n\nSoc. Excellent; but then, how did he distinguish between things\nwhich are and are not \"knowable\"? I wish that you would repeat to me\nwhat he said, and then I shall know whether you and I have heard the\nsame tale.\n\nTheaet. I do not know whether I can recall it; but if another person\nwould tell me, I think that I could follow him.\n\nSoc. Let me give you, then, a dream in return for a dream:-Methought\nthat I too had a dream, and I heard in my dream that the primeval\nletters or elements out of which you and I and all other things are\ncompounded, have no reason or explanation; you can only name them, but\nno predicate can be either affirmed or denied of them, for in the\none case existence, in the other non-existence is already implied,\nneither of which must be added, if you mean to speak of this or that\nthing by itself alone. It should not be called itself, or that, or\neach, or alone, or this, or the like; for these go about everywhere\nand are applied to all things, but are distinct from them; whereas, if\nthe first elements could be described, and had a definition of their\nown, they would be spoken of apart from all else. But none of these\nprimeval elements can be defined; they can only be named, for they\nhave nothing but a name, and the things which are compounded of\nthem, as they are complex, are expressed by a combination of names,\nfor the combination of names is the essence of a definition. Thus,\nthen, the elements or letters are only objects of perception, and\ncannot be defined or known; but the syllables or combinations of\nthem are known and expressed, and are apprehended by true opinion.\nWhen, therefore, any one forms the true opinion of anything without\nrational explanation, you may say that his mind is truly exercised,\nbut has no knowledge; for he who cannot give and receive a reason\nfor a thing, has no knowledge of that thing; but when he adds rational\nexplanation, then, he is perfected in knowledge and may be all that\nI have been denying of him. Was that the form in which the dream\nappeared to you?\n\nTheaet. Precisely.\n\nSoc. And you allow and maintain that true opinion, combined with\ndefinition or rational explanation, is knowledge?\n\nTheaet. Exactly.\n\nSoc. Then may we assume, Theaetetus, that to-day, and in this casual\nmanner, we have found a truth which in former times many wise men have\ngrown old and have not found?\n\nTheaet. At any rate, Socrates, I am satisfied with the present\nstatement.\n\nSoc. Which is probably correct-for how can there be knowledge\napart from definition and true opinion? And yet there is one point\nin what has been said which does not quite satisfy me.\n\nTheaet. What was it?\n\nSoc. What might seem to be the most ingenious notion of all:-That\nthe elements or letters are unknown, but the combination or\nsyllables known.\n\nTheaet. And was that wrong?\n\nSoc. We shall soon know; for we have as hostages the instances which\nthe author of the argument himself used.\n\nTheaet. What hostages?\n\nSoc. The letters, which are the clements; and the syllables, which\nare the combinations;-he reasoned, did he not, from the letters of the\nalphabet?\n\nTheaet. Yes; he did.\n\nSoc. Let us take them and put them to the test, or rather, test\nourselves:-What was the way in which we learned letters? and, first of\nall, are we right in saying that syllables have a definition, but that\nletters have no definition?\n\nTheaet. I think so.\n\nSoc. I think so too; for, suppose that some one asks you to spell\nthe first syllable of my name:-Theaetetus, he says, what is SO?\n\nTheaet. I should reply S and O.\n\nSoc. That is the definition which you would give of the syllable?\n\nTheaet. I should.\n\nSoc. I wish that you would give me a similar definition of the S.\n\nTheaet. But how can any one, Socrates, tell the elements of an\nelement? I can only reply, that S is a consonant, a mere noise, as\nof the tongue hissing; B, and most other letters, again, are neither\nvowel-sounds nor noises. Thus letters may be most truly said to be\nundefined; for even the most distinct of them, which are the seven\nvowels, have a sound only, but no definition at all.\n\nSoc. Then, I suppose, my friend, that we have been so far right in\nour idea about knowledge?\n\nTheaet. Yes; I think that we have.\n\nSoc. Well, but have we been right in maintaining that the\nsyllables can be known, but not the letters?\n\nTheaet. I think so.\n\nSoc. And do we mean by a syllable two letters, or if there are more,\nall of them, or a single idea which arises out of the combination of\nthem?\n\nTheaet. I should say that we mean all the letters.\n\nSoc. Take the case of the two letters S and O, which form the\nfirst syllable of my own name; must not he who knows the syllable,\nknow both of them?\n\nTheaet. Certainly.\n\nSoc. He knows, that is, the S and O?\n\nTheaet. Yes.\n\nSoc. But can he be ignorant of either singly and yet know both\ntogether?\n\nTheaet. Such a supposition, Socrates, is monstrous and unmeaning.\n\nSoc. But if he cannot know both without knowing each, then if he\nis ever to know the syllable, he must know the letters first; and thus\nthe fine theory has again taken wings and departed.\n\nTheaet. Yes, with wonderful celerity.\n\nSoc. Yes, we did not keep watch properly. Perhaps we ought to have\nmaintained that a syllable is not the letters, but rather one single\nidea framed out of them, having a separate form distinct from them.\n\nTheaet. Very true; and a more likely notion than the other.\n\nSoc. Take care; let us not be cowards and betray a great and\nimposing theory.\n\nTheaet. No, indeed.\n\nSoc. Let us assume then, as we now say, that the syllable is a\nsimple form arising out of the several combinations of harmonious\nelements-of letters or of any other elements.\n\nTheaet. Very good.\n\nSoc. And it must have no parts.\n\nTheaet. Why?\n\nSoc. Because that which has parts must be a whole of all the\nparts. Or would you say that a whole, although formed out of the\nparts, is a single notion different from all the parts?\n\nTheaet. I should.\n\nSoc. And would you say that all and the whole are the same, or\ndifferent?\n\nTheaet. I am not certain; but, as you like me to answer at once, I\nshall hazard the reply, that they are different.\n\nSoc. I approve of your readiness, Theaetetus, but I must take time\nto think whether I equally approve of your answer.\n\nTheaet. Yes; the answer is the point.\n\nSoc. According to this new view, the whole is supposed to differ\nfrom all?\n\nTheaet. Yes.\n\nSoc. Well, but is there any difference between all [in the plural]\nand the all [in the singular]? Take the case of number:-When we say\none, two, three, four, five, six; or when we say twice three, or three\ntimes two, or four and two, or three and two and one, are we\nspeaking of the same or of different numbers?\n\nTheaet. Of the same.\n\nSoc. That is of six?\n\nTheaet. Yes.\n\nSoc. And in each form of expression we spoke of all the six?\n\nTheaet. True.\n\nSoc. Again, in speaking of all [in the plural] is there not one\nthing which we express?\n\nTheaet. Of course there is.\n\nSoc. And that is six?\n\nTheaet. Yes.\n\nSoc. Then in predicating the word \"all\" of things measured by\nnumber, we predicate at the same time a singular and a plural?\n\nTheaet. Clearly we do.\n\nSoc. Again, the number of the acre and the acre are the same; are\nthey not?\n\nTheaet. Yes.\n\nSoc. And the number of the stadium in like manner is the stadium?\n\nTheaet. Yes.\n\nSoc. And the army is the number of the army; and in all similar\ncases, the entire number of anything is the entire thing?\n\nTheaet. True.\n\nSoc. And the number of each is the parts of each?\n\nTheaet. Exactly.\n\nSoc. Then as many things as have parts are made up of parts?\n\nTheaet. Clearly.\n\nSoc. But all the parts are admitted to be the all, if the entire\nnumber is the all?\n\nTheaet. True.\n\nSoc. Then the whole is not made up of parts, for it would be the\nall, if consisting of all the parts?\n\nTheaet. That is the inference.\n\nSoc. But is a part a part of anything but the whole?\n\nTheaet. Yes, of the all.\n\nSoc. You make a valiant defence, Theaetetus. And yet is not the\nall that of which nothing is wanting?\n\nTheaet. Certainly.\n\nSoc. And is not a whole likewise that from which nothing is\nabsent? but that from which anything is absent is neither a whole\nnor all;-if wanting in anything, both equally lose their entirety of\nnature.\n\nTheaet. I now think that there is no difference between a whole\nand all.\n\nSoc. But were we not saying that when a thing has parts, all the\nparts will be a whole and all?\n\nTheaet. Certainly.\n\nSoc. Then, as I was saying before, must not the alternative be\nthat either the syllable is not the letters, and then the letters\nare not parts of the syllable, or that the syllable will be the same\nwith the letters, and will therefore be equally known with them?\n\nTheaet. You are right.\n\nSoc. And, in order to avoid this, we suppose it to be different from\nthem?\n\nTheaet. Yes.\n\nSoc. But if letters are not parts of syllables, can you tell me of\nany other parts of syllables, which are not letters?\n\nTheaet. No, indeed, Socrates; for if I admit the existence of\nparts in a syllable, it would be ridiculous in me to give up letters\nand seek for other parts.\n\nSoc. Quite true, Theaetetus, and therefore, according to our present\nview, a syllable must surely be some indivisible form?\n\nTheaet. True.\n\nSoc. But do you remember, my friend, that only a little while ago we\nadmitted and approved the statement, that of the first elements out of\nwhich all other things are compounded there could be no definition,\nbecause each of them when taken by itself is uncompounded; nor can one\nrightly attribute to them the words \"being\" or \"this,\" because they\nare alien and inappropriate words, and for this reason the letters\nor clements were indefinable and unknown?\n\nTheaet. I remember.\n\nSoc. And is not this also the reason why they are simple and\nindivisible? I can see no other.\n\nTheaet. No other reason can be given.\n\nSoc. Then is not the syllable in the same case as the elements or\nletters, if it has no parts and is one form?\n\nTheaet. To be sure.\n\nSoc. If, then, a syllable is a whole, and has many parts or letters,\nthe letters as well as the syllable must be intelligible and\nexpressible, since all the parts are acknowledged to be the same as\nthe whole?\n\nTheaet. True.\n\nSoc. But if it be one and indivisible, then the syllables and the\nletters are alike undefined and unknown, and for the same reason?\n\nTheaet. I cannot deny that.\n\nSoc. We cannot, therefore, agree in the opinion of him who says that\nthe syllable can be known and expressed, but not the letters.\n\nTheaet. Certainly not; if we may trust the argument.\n\nSoc. Well, but will you not be equally inclined to, disagree with\nhim, when you remember your own experience in learning to read?\n\nTheaet. What experience?\n\nSoc. Why, that in learning you were kept trying to distinguish the\nseparate letters both by the eye and by the car, in order that, when\nyou heard them spoken or saw them written, you might not be confused\nby their position.\n\nTheaet. Very true.\n\nSoc. And is the education of the harp-player complete unless he\ncan tell what string answers to a particular note; the notes, as every\none would allow, are the elements or letters of music?\n\nTheaet. Exactly.\n\nSoc. Then, if we argue from the letters and syllables which we\nknow to other simples and compounds, we shall say that the letters\nor simple clements as a class are much more certainly known than the\nsyllables, and much more indispensable to a perfect knowledge of any\nsubject; and if some one says that the syllable is known and the\nletter unknown, we shall consider that either intentionally or\nunintentionally he is talking nonsense?\n\nTheaet. Exactly.\n\nSoc. And there might be given other proofs of this belief, if I am\nnot mistaken. But do not let us in looking for them lose sight of\nthe question before us, which is the meaning of the statement, that\nright opinion with rational definition or explanation is the most\nperfect form of knowledge.\n\nTheaet. We must not.\n\nSoc. Well, and what is the meaning of the term \"explanation\"? I\nthink that we have a choice of three meanings.\n\nTheaet. What are they?\n\nSoc. In the first place, the meaning may be, manifesting one's\nthought by the voice with verbs and nouns, imaging an opinion in the\nstream which flows from the lips, as in a mirror or water. Does not\nexplanation appear to be of this nature?\n\nTheaet. Certainly; he who so manifests his thought, is said to\nexplain himself.\n\nSoc. And every one who is not born deaf or dumb is able sooner or\nlater to manifest what he thinks of anything; and if so, all those who\nhave a right opinion about anything will also have right\nexplanation; nor will right opinion be anywhere found to exist apart\nfrom knowledge.\n\nTheaet. True.\n\nSoc. Let us not, therefore, hastily charge him who gave this account\nof knowledge with uttering an unmeaning word; for perhaps he only\nintended to say, that when a person was asked what was the nature of\nanything, he should be able to answer his questioner by giving the\nclements of the thing.\n\nTheaet. As for example, Socrates...?\n\nSoc. As, for example, when Hesiod says that a waggon is made up of a\nhundred planks. Now, neither you nor I could describe all of them\nindividually; but if any one asked what is a waggon, we should be\ncontent to answer, that a waggon consists of wheels, axle, body, rims,\nyoke.\n\nTheaet. Certainly.\n\nSoc. And our opponent will probably laugh at us, just as he would if\nwe professed to be grammarians and to give a grammatical account of\nthe name of Theaetetus, and yet could only tell the syllables and\nnot the letters of your name-that would be true opinion, and not\nknowledge; for knowledge, as has been already remarked, is not\nattained until, combined with true opinion, there is an enumeration of\nthe elements out of which is composed.\n\nTheaet. Yes.\n\nSoc. In the same general way, we might also have true opinion\nabout a waggon; but he who can describe its essence by an\nenumeration of the hundred planks, adds rational explanation to true\nopinion, and instead of opinion has art and knowledge of the nature of\na waggon, in that he attains to the whole through the elements.\n\nTheaet. And do. you not agree in that view, Socrates?\n\nSoc. If you do, my friend; but I want to know first, whether you\nadmit the resolution of all things into their elements to be a\nrational explanation of them, and the consideration of them in\nsyllables or larger combinations of them to be irrational-is this your\nview?\n\nTheaet. Precisely.\n\nSoc. Well, and do you conceive that a man has knowledge of any\nelement who at one time affirms and at another time denies that\nclement of something, or thinks that. the same thing is composed of\ndifferent elements at different times?\n\nTheaet. Assuredly not.\n\nSoc. And do you not remember that in your case and in of others this\noften occurred in the process of learning to read?\n\nTheaet. You mean that I mistook the letters and misspelt the\nsyllables?\n\nSoc. Yes.\n\nTheaet. To be sure; I perfectly remember, and I am very far from\nsupposing that they who are in this condition, have knowledge.\n\nSoc. When a person, at the time of learning writes the name of\nTheaetetus, and thinks that he ought to write and does write Th and e;\nbut, again meaning to write the name of Theododorus, thinks that he\nought to write and does write T and e-can we suppose that he knows the\nfirst syllables of your two names?\n\nTheaet. We have already admitted that such a one has not yet\nattained knowledge.\n\nSoc. And in like manner be may enumerate without knowing them the\nsecond and third and fourth syllables of your name?\n\nTheaet. He may.\n\nSoc. And in that case, when he knows the order of the letters and\ncan write them out correctly, he has right opinion?\n\nTheaet. Clearly.\n\nSoc. But although we admit that he has right opinion, he will\nstill be without knowledge?\n\nTheaet. Yes.\n\nSoc. And yet he will have explanations, as well as right opinion,\nfor he knew the order of the letters when he wrote; and this we\nadmit be explanation.\n\nTheaet. True.\n\nSoc. Then, my friend, there is such a thing as right opinion\nunited with definition or explanation, which does not as yet attain to\nthe exactness of knowledge.\n\nTheaet. It would seem so.\n\nSoc. And what we fancied to be a perfect definition of knowledge\nis a dream only. But perhaps we had better not say so as yet, for were\nthere not three explanations of knowledge, one of which must, as we\nsaid, be adopted by him who maintains knowledge to be true opinion\ncombined with rational explanation? And very likely there may be found\nsome one who will not prefer this but the third.\n\nTheaet. You are quite right; there is still one remaining. The first\nwas the image or expression of the mind in speech; the second, which\nhas just been mentioned, is a way of reaching the whole by an\nenumeration of the elements. But what is; the third definition?\n\nSoc. There is, further, the popular notion of telling the mark or\nsign of difference which distinguishes the thing in question from\nall others.\n\nTheaet. Can you give me any example of such a definition?\n\nSoc. As, for example, in the case of the sun, I think that you would\nbe contented with the statement that the sun is, the brightest of\nthe heavenly bodies which revolve about the earth.\n\nTheaet. Certainly.\n\nSoc. Understand why:-the reason is, as I was just now saying, that\nif you get at the difference and distinguishing characteristic of each\nthing, then, as many persons affirm, you will get at the definition or\nexplanation of it; but while you lay hold only of the common and not\nof the characteristic notion, you will only have the definition of\nthose things to which this common quality belongs.\n\nTheaet. I understand you, and your account of definition is in my\njudgment correct.\n\nSoc. But he, who having right opinion about anything, can find out\nthe difference which distinguishes it from other things will know that\nof which before he had only an opinion.\n\nTheaet. Yes; that is what we are maintaining.\n\nSoc. Nevertheless, Theaetetus, on a nearer view, I find myself quite\ndisappointed; the picture, which at a distance was not so bad, has now\nbecome altogether unintelligible.\n\nTheaet. What do you mean?\n\nSoc. I will endeavour to explain: I will suppose myself to have true\nopinion of you, and if to this I add your definition, then I have\nknowledge, but if not, opinion only.\n\nTheaet. Yes.\n\nSoc. The definition was assumed to be the interpretation of your\ndifference.\n\nTheaet. True.\n\nSoc. But when I had only opinion, I had no conception of your\ndistinguishing characteristics.\n\nTheaet. I suppose not.\n\nSoc. Then I must have conceived of some general or common nature\nwhich no more belonged to you than to another.\n\nTheaet. True.\n\nSoc. Tell me, now-How in that case could I have formed a judgment of\nyou any more than of any one else? Suppose that I imagine Theaetetus\nto be a man who has nose, eyes, and mouth, and every other member\ncomplete; how would that enable me to distinguish Theaetetus from\nTheodorus, or from some outer barbarian?\n\nTheaet. How could it?\n\nSoc. Or if I had further conceived of you, not only as having nose\nand eyes, but as having a snub nose and prominent eyes, should I\nhave any more notion of you than of myself and others who resemble me?\n\nTheaet. Certainly not.\n\nSoc. Surely I can have no conception of Theaetetus until your\nsnub-nosedness has left an impression on my mind different from the\nsnub-nosedness of all others whom I have ever seen, and until your\nother peculiarities have a like distinctness; and so when I meet you\ntomorrow the right opinion will be re-called?\n\nTheaet. Most true.\n\nSoc. Then right opinion implies the perception of differences?\n\nTheaet. Clearly.\n\nSoc. What, then, shall we say of adding reason or explanation to\nright opinion? If the meaning is, that we should form an opinion of\nthe way in which something differs from another thing, the proposal is\nridiculous.\n\nTheaet. How so?\n\nSoc. We are supposed to acquire a right opinion of the differences\nwhich distinguish one thing from another when we have already a\nright opinion of them, and so we go round and round:-the revolution of\nthe scytal, or pestle, or any other rotatory machine, in the same\ncircles, is as nothing compared with such a requirement; and we may be\ntruly described as the blind directing the blind; for to add those\nthings which we already have, in order that we may learn what we\nalready think, is like a soul utterly benighted.\n\nTheaet. Tell me; what were you going to say just now, when you asked\nthe question?\n\nSoc. If, my boy, the argument, in speaking of adding the definition,\nhad used the word to \"know,\" and not merely \"have an opinion\" of the\ndifference, this which is the most promising of all the definitions of\nknowledge would have come to a pretty end, for to know is surely to\nacquire knowledge.\n\nTheaet. True.\n\nSoc. And so, when the question is asked, What is knowledge? this\nfair argument will answer \"Right opinion with knowledge,\"-knowledge,\nthat is, of difference, for this, as the said argument maintains, is\nadding the definition.\n\nTheaet. That seems to be true.\n\nSoc. But how utterly foolish, when we are asking what is\nknowledge, that the reply should only be, right opinion with knowledge\nof difference or of anything! And so, Theaetetus, knowledge is neither\nsensation nor true opinion, nor yet definition and explanation\naccompanying and added to true opinion?\n\nTheaet. I suppose not.\n\nSoc. And are you still in labour and travail, my dear friend, or\nhave you brought all that you have to say about knowledge to the\nbirth?\n\nTheaet. I am sure, Socrates, that you have elicited from me a good\ndeal more than ever was in me.\n\nSoc. And does not my art show that you have brought forth wind,\nand that the offspring of your brain are not worth bringing up?\n\nTheaet. Very true.\n\nSoc. But if, Theaetetus, you should ever conceive afresh, you will\nbe all the better for the present investigation, and if not, you\nwill be soberer and humbler and gentler to other men, and will be\ntoo modest to fancy that you know what you do not know. These are\nthe limits of my art; I can no further go, nor do I know aught of\nthe things which great and famous men know or have known in this or\nformer ages. The office of a midwife I, like my mother, have\nreceived from God; she delivered women, I deliver men; but they must\nbe young and noble and fair.\n\nAnd now I have to go to the porch of the King Archon, where I am\nto meet Meletus and his indictment. To-morrow morning, Theodorus, I\nshall hope to see you again at this place.\n\n-THE END-\n.",
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