{"collection":"philosophy-ethics","full_text_available":true,"graph_url":"https://unchartedknowledge.5gfusion.net/v2/api/page/gutenberg_1726/graph","html_url":"https://unchartedknowledge.5gfusion.net/v2/page/gutenberg_1726","id":"gutenberg_1726","license":"Public Domain (US)","rights_basis":"gutenberg_metadata_copyright_false","source":"gutenberg","source_url":"https://www.gutenberg.org/ebooks/1726","summary":null,"tags":["Category: Classics of Literature","Category: Philosophy & Ethics","Classical literature","Knowledge, Theory of -- Early works to 1800","Philosophy"],"text":"Produced by Sue Asscher\n\n\n\n\n\nTHEAETETUS\n\nBy Plato\n\n\nTranslated by Benjamin Jowett\n\n\n\n\nINTRODUCTION AND ANALYSIS.\n\nSome dialogues of Plato are of so various a character that their\nrelation to the other dialogues cannot be determined with any degree of\ncertainty. The Theaetetus, like the Parmenides, has points of similarity\nboth with his earlier and his later writings. The perfection of style,\nthe humour, the dramatic interest, the complexity of structure, the\nfertility of illustration, the shifting of the points of view, are\ncharacteristic of his best period of authorship. The vain search, the\nnegative conclusion, the figure of the midwives, the constant profession\nof ignorance on the part of Socrates, also bear the stamp of the early\ndialogues, in which the original Socrates is not yet Platonized. Had we\nno other indications, we should be disposed to range the Theaetetus with\nthe Apology and the Phaedrus, and perhaps even with the Protagoras and\nthe Laches.\n\nBut when we pass from the style to an examination of the subject,\nwe trace a connection with the later rather than with the earlier\ndialogues. In the first place there is the connexion, indicated by Plato\nhimself at the end of the dialogue, with the Sophist, to which in\nmany respects the Theaetetus is so little akin. (1) The same persons\nreappear, including the younger Socrates, whose name is just mentioned\nin the Theaetetus; (2) the theory of rest, which Socrates has declined\nto consider, is resumed by the Eleatic Stranger; (3) there is a similar\nallusion in both dialogues to the meeting of Parmenides and Socrates\n(Theaet., Soph.); and (4) the inquiry into not-being in the Sophist\nsupplements the question of false opinion which is raised in the\nTheaetetus. (Compare also Theaet. and Soph. for parallel turns of\nthought.) Secondly, the later date of the dialogue is confirmed by the\nabsence of the doctrine of recollection and of any doctrine of ideas\nexcept that which derives them from generalization and from reflection\nof the mind upon itself. The general character of the Theaetetus is\ndialectical, and there are traces of the same Megarian influences which\nappear in the Parmenides, and which later writers, in their matter of\nfact way, have explained by the residence of Plato at Megara. Socrates\ndisclaims the character of a professional eristic, and also, with a sort\nof ironical admiration, expresses his inability to attain the Megarian\nprecision in the use of terms. Yet he too employs a similar sophistical\nskill in overturning every conceivable theory of knowledge.\n\nThe direct indications of a date amount to no more than this: the\nconversation is said to have taken place when Theaetetus was a youth,\nand shortly before the death of Socrates. At the time of his own death\nhe is supposed to be a full-grown man. Allowing nine or ten years for\nthe interval between youth and manhood, the dialogue could not have been\nwritten earlier than 390, when Plato was about thirty-nine years of age.\nNo more definite date is indicated by the engagement in which Theaetetus\nis said to have fallen or to have been wounded, and which may have taken\nplace any time during the Corinthian war, between the years 390-387.\nThe later date which has been suggested, 369, when the Athenians and\nLacedaemonians disputed the Isthmus with Epaminondas, would make the\nage of Theaetetus at his death forty-five or forty-six. This a little\nimpairs the beauty of Socrates' remark, that 'he would be a great man if\nhe lived.'\n\nIn this uncertainty about the place of the Theaetetus, it seemed better,\nas in the case of the Republic, Timaeus, Critias, to retain the order in\nwhich Plato himself has arranged this and the two companion dialogues.\nWe cannot exclude the possibility which has been already noticed in\nreference to other works of Plato, that the Theaetetus may not have\nbeen all written continuously; or the probability that the Sophist and\nPoliticus, which differ greatly in style, were only appended after a\nlong interval of time. The allusion to Parmenides compared with the\nSophist, would probably imply that the dialogue which is called by his\nname was already in existence; unless, indeed, we suppose the passage in\nwhich the allusion occurs to have been inserted afterwards. Again,\nthe Theaetetus may be connected with the Gorgias, either dialogue from\ndifferent points of view containing an analysis of the real and apparent\n(Schleiermacher); and both may be brought into relation with the Apology\nas illustrating the personal life of Socrates. The Philebus, too, may\nwith equal reason be placed either after or before what, in the language\nof Thrasyllus, may be called the Second Platonic Trilogy. Both the\nParmenides and the Sophist, and still more the Theaetetus, have points\nof affinity with the Cratylus, in which the principles of rest and\nmotion are again contrasted, and the Sophistical or Protagorean theory\nof language is opposed to that which is attributed to the disciple\nof Heracleitus, not to speak of lesser resemblances in thought and\nlanguage. The Parmenides, again, has been thought by some to hold an\nintermediate position between the Theaetetus and the Sophist; upon this\nview, the Sophist may be regarded as the answer to the problems about\nOne and Being which have been raised in the Parmenides. Any of these\narrangements may suggest new views to the student of Plato; none of them\ncan lay claim to an exclusive probability in its favour.\n\nThe Theaetetus is one of the narrated dialogues of Plato, and is\nthe only one which is supposed to have been written down. In a short\nintroductory scene, Euclides and Terpsion are described as meeting\nbefore the door of Euclides' house in Megara. This may have been a\nspot familiar to Plato (for Megara was within a walk of Athens), but no\nimportance can be attached to the accidental introduction of the founder\nof the Megarian philosophy. The real intention of the preface is to\ncreate an interest about the person of Theaetetus, who has just been\ncarried up from the army at Corinth in a dying state. The expectation\nof his death recalls the promise of his youth, and especially the famous\nconversation which Socrates had with him when he was quite young, a few\ndays before his own trial and death, as we are once more reminded at the\nend of the dialogue. Yet we may observe that Plato has himself forgotten\nthis, when he represents Euclides as from time to time coming to Athens\nand correcting the copy from Socrates' own mouth. The narrative, having\nintroduced Theaetetus, and having guaranteed the authenticity of the\ndialogue (compare Symposium, Phaedo, Parmenides), is then dropped. No\nfurther use is made of the device. As Plato himself remarks, who in this\nas in some other minute points is imitated by Cicero (De Amicitia), the\ninterlocutory words are omitted.\n\nTheaetetus, the hero of the battle of Corinth and of the dialogue, is\na disciple of Theodorus, the great geometrician, whose science is thus\nindicated to be the propaedeutic to philosophy. An interest has been\nalready excited about him by his approaching death, and now he is\nintroduced to us anew by the praises of his master Theodorus. He is a\nyouthful Socrates, and exhibits the same contrast of the fair soul and\nthe ungainly face and frame, the Silenus mask and the god within, which\nare described in the Symposium. The picture which Theodorus gives of\nhis courage and patience and intelligence and modesty is verified in\nthe course of the dialogue. His courage is shown by his behaviour in the\nbattle, and his other qualities shine forth as the argument proceeds.\nSocrates takes an evident delight in 'the wise Theaetetus,' who has more\nin him than 'many bearded men'; he is quite inspired by his answers. At\nfirst the youth is lost in wonder, and is almost too modest to speak,\nbut, encouraged by Socrates, he rises to the occasion, and grows full of\ninterest and enthusiasm about the great question. Like a youth, he has\nnot finally made up his mind, and is very ready to follow the lead of\nSocrates, and to enter into each successive phase of the discussion\nwhich turns up. His great dialectical talent is shown in his power of\ndrawing distinctions, and of foreseeing the consequences of his own\nanswers. The enquiry about the nature of knowledge is not new to him;\nlong ago he has felt the 'pang of philosophy,' and has experienced the\nyouthful intoxication which is depicted in the Philebus. But he\nhas hitherto been unable to make the transition from mathematics to\nmetaphysics. He can form a general conception of square and oblong\nnumbers, but he is unable to attain a similar expression of knowledge\nin the abstract. Yet at length he begins to recognize that there are\nuniversal conceptions of being, likeness, sameness, number, which the\nmind contemplates in herself, and with the help of Socrates is conducted\nfrom a theory of sense to a theory of ideas.\n\nThere is no reason to doubt that Theaetetus was a real person, whose\nname survived in the next generation. But neither can any importance be\nattached to the notices of him in Suidas and Proclus, which are probably\nbased on the mention of him in Plato. According to a confused statement\nin Suidas, who mentions him twice over, first, as a pupil of Socrates,\nand then of Plato, he is said to have written the first work on the Five\nSolids. But no early authority cites the work, the invention of which\nmay have been easily suggested by the division of roots, which Plato\nattributes to him, and the allusion to the backward state of solid\ngeometry in the Republic. At any rate, there is no occasion to recall\nhim to life again after the battle of Corinth, in order that we may\nallow time for the completion of such a work (Muller). We may also\nremark that such a supposition entirely destroys the pathetic interest\nof the introduction.\n\nTheodorus, the geometrician, had once been the friend and disciple of\nProtagoras, but he is very reluctant to leave his retirement and defend\nhis old master. He is too old to learn Socrates' game of question and\nanswer, and prefers the digressions to the main argument, because he\nfinds them easier to follow. The mathematician, as Socrates says in the\nRepublic, is not capable of giving a reason in the same manner as the\ndialectician, and Theodorus could not therefore have been appropriately\nintroduced as the chief respondent. But he may be fairly appealed to,\nwhen the honour of his master is at stake. He is the 'guardian of his\norphans,' although this is a responsibility which he wishes to throw\nupon Callias, the friend and patron of all Sophists, declaring that\nhe himself had early 'run away' from philosophy, and was absorbed in\nmathematics. His extreme dislike to the Heraclitean fanatics, which may\nbe compared with the dislike of Theaetetus to the materialists, and his\nready acceptance of the noble words of Socrates, are noticeable traits\nof character.\n\nThe Socrates of the Theaetetus is the same as the Socrates of the\nearlier dialogues. He is the invincible disputant, now advanced in\nyears, of the Protagoras and Symposium; he is still pursuing his divine\nmission, his 'Herculean labours,' of which he has described the origin\nin the Apology; and he still hears the voice of his oracle, bidding him\nreceive or not receive the truant souls. There he is supposed to have\na mission to convict men of self-conceit; in the Theaetetus he has\nassigned to him by God the functions of a man-midwife, who delivers men\nof their thoughts, and under this character he is present throughout the\ndialogue. He is the true prophet who has an insight into the natures\nof men, and can divine their future; and he knows that sympathy is the\nsecret power which unlocks their thoughts. The hit at Aristides, the son\nof Lysimachus, who was specially committed to his charge in the Laches,\nmay be remarked by the way. The attempt to discover the definition\nof knowledge is in accordance with the character of Socrates as he\nis described in the Memorabilia, asking What is justice? what is\ntemperance? and the like. But there is no reason to suppose that he\nwould have analyzed the nature of perception, or traced the connexion\nof Protagoras and Heracleitus, or have raised the difficulty respecting\nfalse opinion. The humorous illustrations, as well as the serious\nthoughts, run through the dialogue. The snubnosedness of Theaetetus, a\ncharacteristic which he shares with Socrates, and the man-midwifery\nof Socrates, are not forgotten in the closing words. At the end of the\ndialogue, as in the Euthyphro, he is expecting to meet Meletus at the\nporch of the king Archon; but with the same indifference to the result\nwhich is everywhere displayed by him, he proposes that they shall\nreassemble on the following day at the same spot. The day comes, and\nin the Sophist the three friends again meet, but no further allusion is\nmade to the trial, and the principal share in the argument is assigned,\nnot to Socrates, but to an Eleatic stranger; the youthful Theaetetus\nalso plays a different and less independent part. And there is no\nallusion in the Introduction to the second and third dialogues, which\nare afterwards appended. There seems, therefore, reason to think that\nthere is a real change, both in the characters and in the design.\n\nThe dialogue is an enquiry into the nature of knowledge, which is\ninterrupted by two digressions. The first is the digression about the\nmidwives, which is also a leading thought or continuous image, like the\nwave in the Republic, appearing and reappearing at intervals. Again and\nagain we are reminded that the successive conceptions of knowledge are\nextracted from Theaetetus, who in his turn truly declares that Socrates\nhas got a great deal more out of him than ever was in him. Socrates is\nnever weary of working out the image in humorous details,--discerning\nthe symptoms of labour, carrying the child round the hearth, fearing\nthat Theaetetus will bite him, comparing his conceptions to wind-eggs,\nasserting an hereditary right to the occupation. There is also a serious\nside to the image, which is an apt similitude of the Socratic theory\nof education (compare Republic, Sophist), and accords with the ironical\nspirit in which the wisest of men delights to speak of himself.\n\nThe other digression is the famous contrast of the lawyer and\nphilosopher. This is a sort of landing-place or break in the middle of\nthe dialogue. At the commencement of a great discussion, the reflection\nnaturally arises, How happy are they who, like the philosopher, have\ntime for such discussions (compare Republic)! There is no reason for the\nintroduction of such a digression; nor is a reason always needed, any\nmore than for the introduction of an episode in a poem, or of a topic in\nconversation. That which is given by Socrates is quite sufficient, viz.\nthat the philosopher may talk and write as he pleases. But though not\nvery closely connected, neither is the digression out of keeping with\nthe rest of the dialogue. The philosopher naturally desires to pour\nforth the thoughts which are always present to him, and to discourse of\nthe higher life. The idea of knowledge, although hard to be defined, is\nrealised in the life of philosophy. And the contrast is the favourite\nantithesis between the world, in the various characters of sophist,\nlawyer, statesman, speaker, and the philosopher,--between opinion and\nknowledge,--between the conventional and the true.\n\nThe greater part of the dialogue is devoted to setting up and throwing\ndown definitions of science and knowledge. Proceeding from the lower to\nthe higher by three stages, in which perception, opinion, reasoning are\nsuccessively examined, we first get rid of the confusion of the idea of\nknowledge and specific kinds of knowledge,--a confusion which has been\nalready noticed in the Lysis, Laches, Meno, and other dialogues. In\nthe infancy of logic, a form of thought has to be invented before the\ncontent can be filled up. We cannot define knowledge until the nature of\ndefinition has been ascertained. Having succeeded in making his meaning\nplain, Socrates proceeds to analyze (1) the first definition which\nTheaetetus proposes: 'Knowledge is sensible perception.' This is\nspeedily identified with the Protagorean saying, 'Man is the measure\nof all things;' and of this again the foundation is discovered in the\nperpetual flux of Heracleitus. The relativeness of sensation is then\ndeveloped at length, and for a moment the definition appears to be\naccepted. But soon the Protagorean thesis is pronounced to be suicidal;\nfor the adversaries of Protagoras are as good a measure as he is, and\nthey deny his doctrine. He is then supposed to reply that the perception\nmay be true at any given instant. But the reply is in the end shown to\nbe inconsistent with the Heraclitean foundation, on which the doctrine\nhas been affirmed to rest. For if the Heraclitean flux is extended to\nevery sort of change in every instant of time, how can any thought\nor word be detained even for an instant? Sensible perception, like\neverything else, is tumbling to pieces. Nor can Protagoras himself\nmaintain that one man is as good as another in his knowledge of the\nfuture; and 'the expedient,' if not 'the just and true,' belongs to the\nsphere of the future.\n\nAnd so we must ask again, What is knowledge? The comparison of\nsensations with one another implies a principle which is above\nsensation, and which resides in the mind itself. We are thus led to look\nfor knowledge in a higher sphere, and accordingly Theaetetus, when again\ninterrogated, replies (2) that 'knowledge is true opinion.' But how is\nfalse opinion possible? The Megarian or Eristic spirit within us revives\nthe question, which has been already asked and indirectly answered in\nthe Meno: 'How can a man be ignorant of that which he knows?' No answer\nis given to this not unanswerable question. The comparison of the mind\nto a block of wax, or to a decoy of birds, is found wanting.\n\nBut are we not inverting the natural order in looking for opinion before\nwe have found knowledge? And knowledge is not true opinion; for the\nAthenian dicasts have true opinion but not knowledge. What then\nis knowledge? We answer (3), 'True opinion, with definition or\nexplanation.' But all the different ways in which this statement may be\nunderstood are set aside, like the definitions of courage in the Laches,\nor of friendship in the Lysis, or of temperance in the Charmides. At\nlength we arrive at the conclusion, in which nothing is concluded.\n\nThere are two special difficulties which beset the student of the\nTheaetetus: (1) he is uncertain how far he can trust Plato's account of\nthe theory of Protagoras; and he is also uncertain (2) how far, and in\nwhat parts of the dialogue, Plato is expressing his own opinion.\nThe dramatic character of the work renders the answer to both these\nquestions difficult.\n\n1. In reply to the first, we have only probabilities to offer. Three\nmain points have to be decided: (a) Would Protagoras have identified\nhis own thesis, 'Man is the measure of all things,' with the other,\n'All knowledge is sensible perception'? (b) Would he have based the\nrelativity of knowledge on the Heraclitean flux? (c) Would he have\nasserted the absoluteness of sensation at each instant? Of the work of\nProtagoras on 'Truth' we know nothing, with the exception of the two\nfamous fragments, which are cited in this dialogue, 'Man is the measure\nof all things,' and, 'Whether there are gods or not, I cannot tell.' Nor\nhave we any other trustworthy evidence of the tenets of Protagoras, or\nof the sense in which his words are used. For later writers, including\nAristotle in his Metaphysics, have mixed up the Protagoras of Plato, as\nthey have the Socrates of Plato, with the real person.\n\nReturning then to the Theaetetus, as the only possible source from which\nan answer to these questions can be obtained, we may remark, that Plato\nhad 'The Truth' of Protagoras before him, and frequently refers to the\nbook. He seems to say expressly, that in this work the doctrine of the\nHeraclitean flux was not to be found; 'he told the real truth' (not\nin the book, which is so entitled, but) 'privately to his\ndisciples,'--words which imply that the connexion between the doctrines\nof Protagoras and Heracleitus was not generally recognized in Greece,\nbut was really discovered or invented by Plato. On the other hand,\nthe doctrine that 'Man is the measure of all things,' is expressly\nidentified by Socrates with the other statement, that 'What appears to\neach man is to him;' and a reference is made to the books in which the\nstatement occurs;--this Theaetetus, who has 'often read the books,' is\nsupposed to acknowledge (so Cratylus). And Protagoras, in the speech\nattributed to him, never says that he has been misunderstood: he rather\nseems to imply that the absoluteness of sensation at each instant was\nto be found in his words. He is only indignant at the 'reductio ad\nabsurdum' devised by Socrates for his 'homo mensura,' which Theodorus\nalso considers to be 'really too bad.'\n\nThe question may be raised, how far Plato in the Theaetetus could\nhave misrepresented Protagoras without violating the laws of dramatic\nprobability. Could he have pretended to cite from a well-known writing\nwhat was not to be found there? But such a shadowy enquiry is not worth\npursuing further. We need only remember that in the criticism which\nfollows of the thesis of Protagoras, we are criticizing the Protagoras\nof Plato, and not attempting to draw a precise line between his real\nsentiments and those which Plato has attributed to him.\n\n2. The other difficulty is a more subtle, and also a more important one,\nbecause bearing on the general character of the Platonic dialogues. On\na first reading of them, we are apt to imagine that the truth is only\nspoken by Socrates, who is never guilty of a fallacy himself, and is the\ngreat detector of the errors and fallacies of others. But this natural\npresumption is disturbed by the discovery that the Sophists are\nsometimes in the right and Socrates in the wrong. Like the hero of a\nnovel, he is not to be supposed always to represent the sentiments\nof the author. There are few modern readers who do not side with\nProtagoras, rather than with Socrates, in the dialogue which is\ncalled by his name. The Cratylus presents a similar difficulty: in\nhis etymologies, as in the number of the State, we cannot tell how\nfar Socrates is serious; for the Socratic irony will not allow him\nto distinguish between his real and his assumed wisdom. No one is the\nsuperior of the invincible Socrates in argument (except in the first\npart of the Parmenides, where he is introduced as a youth); but he is by\nno means supposed to be in possession of the whole truth. Arguments are\noften put into his mouth (compare Introduction to the Gorgias) which\nmust have seemed quite as untenable to Plato as to a modern writer.\nIn this dialogue a great part of the answer of Protagoras is just\nand sound; remarks are made by him on verbal criticism, and on the\nimportance of understanding an opponent's meaning, which are conceived\nin the true spirit of philosophy. And the distinction which he is\nsupposed to draw between Eristic and Dialectic, is really a criticism of\nPlato on himself and his own criticism of Protagoras.\n\nThe difficulty seems to arise from not attending to the dramatic\ncharacter of the writings of Plato. There are two, or more, sides to\nquestions; and these are parted among the different speakers. Sometimes\none view or aspect of a question is made to predominate over the rest,\nas in the Gorgias or Sophist; but in other dialogues truth is divided,\nas in the Laches and Protagoras, and the interest of the piece consists\nin the contrast of opinions. The confusion caused by the irony of\nSocrates, who, if he is true to his character, cannot say anything\nof his own knowledge, is increased by the circumstance that in the\nTheaetetus and some other dialogues he is occasionally playing both\nparts himself, and even charging his own arguments with unfairness. In\nthe Theaetetus he is designedly held back from arriving at a conclusion.\nFor we cannot suppose that Plato conceived a definition of knowledge to\nbe impossible. But this is his manner of approaching and surrounding a\nquestion. The lights which he throws on his subject are indirect, but\nthey are not the less real for that. He has no intention of proving a\nthesis by a cut-and-dried argument; nor does he imagine that a great\nphilosophical problem can be tied up within the limits of a definition.\nIf he has analyzed a proposition or notion, even with the severity of\nan impossible logic, if half-truths have been compared by him with\nother half-truths, if he has cleared up or advanced popular ideas, or\nillustrated a new method, his aim has been sufficiently accomplished.\n\nThe writings of Plato belong to an age in which the power of analysis\nhad outrun the means of knowledge; and through a spurious use of\ndialectic, the distinctions which had been already 'won from the void\nand formless infinite,' seemed to be rapidly returning to their original\nchaos. The two great speculative philosophies, which a century earlier\nhad so deeply impressed the mind of Hellas, were now degenerating into\nEristic. The contemporaries of Plato and Socrates were vainly trying to\nfind new combinations of them, or to transfer them from the object to\nthe subject. The Megarians, in their first attempts to attain a severer\nlogic, were making knowledge impossible (compare Theaet.). They were\nasserting 'the one good under many names,' and, like the Cynics, seem\nto have denied predication, while the Cynics themselves were depriving\nvirtue of all which made virtue desirable in the eyes of Socrates and\nPlato. And besides these, we find mention in the later writings of\nPlato, especially in the Theaetetus, Sophist, and Laws, of certain\nimpenetrable godless persons, who will not believe what they 'cannot\nhold in their hands'; and cannot be approached in argument, because they\ncannot argue (Theat; Soph.). No school of Greek philosophers exactly\nanswers to these persons, in whom Plato may perhaps have blended some\nfeatures of the Atomists with the vulgar materialistic tendencies of\nmankind in general (compare Introduction to the Sophist).\n\nAnd not only was there a conflict of opinions, but the stage which the\nmind had reached presented other difficulties hardly intelligible to\nus, who live in a different cycle of human thought. All times of mental\nprogress are times of confusion; we only see, or rather seem to see\nthings clearly, when they have been long fixed and defined. In the\nage of Plato, the limits of the world of imagination and of pure\nabstraction, of the old world and the new, were not yet fixed. The\nGreeks, in the fourth century before Christ, had no words for 'subject'\nand 'object,' and no distinct conception of them; yet they were always\nhovering about the question involved in them. The analysis of sense, and\nthe analysis of thought, were equally difficult to them; and hopelessly\nconfused by the attempt to solve them, not through an appeal to facts,\nbut by the help of general theories respecting the nature of the\nuniverse.\n\nPlato, in his Theaetetus, gathers up the sceptical tendencies of his\nage, and compares them. But he does not seek to reconstruct out of them\na theory of knowledge. The time at which such a theory could be framed\nhad not yet arrived. For there was no measure of experience with which\nthe ideas swarming in men's minds could be compared; the meaning of\nthe word 'science' could scarcely be explained to them, except from the\nmathematical sciences, which alone offered the type of universality and\ncertainty. Philosophy was becoming more and more vacant and abstract,\nand not only the Platonic Ideas and the Eleatic Being, but all\nabstractions seemed to be at variance with sense and at war with one\nanother.\n\nThe want of the Greek mind in the fourth century before Christ was\nnot another theory of rest or motion, or Being or atoms, but rather a\nphilosophy which could free the mind from the power of abstractions\nand alternatives, and show how far rest and how far motion, how far the\nuniversal principle of Being and the multitudinous principle of atoms,\nentered into the composition of the world; which could distinguish\nbetween the true and false analogy, and allow the negative as well as\nthe positive a place in human thought. To such a philosophy Plato, in\nthe Theaetetus, offers many contributions. He has followed philosophy\ninto the region of mythology, and pointed out the similarities of\nopposing phases of thought. He has also shown that extreme abstractions\nare self-destructive, and, indeed, hardly distinguishable from one\nanother. But his intention is not to unravel the whole subject of\nknowledge, if this had been possible; and several times in the course\nof the dialogue he rejects explanations of knowledge which have germs of\ntruth in them; as, for example, 'the resolution of the compound into the\nsimple;' or 'right opinion with a mark of difference.'\n\n...\n\nTerpsion, who has come to Megara from the country, is described as\nhaving looked in vain for Euclides in the Agora; the latter explains\nthat he has been down to the harbour, and on his way thither had met\nTheaetetus, who was being carried up from the army to Athens. He was\nscarcely alive, for he had been badly wounded at the battle of Corinth,\nand had taken the dysentery which prevailed in the camp. The mention of\nhis condition suggests the reflection, 'What a loss he will be!' 'Yes,\nindeed,' replies Euclid; 'only just now I was hearing of his noble\nconduct in the battle.' 'That I should expect; but why did he not remain\nat Megara?' 'I wanted him to remain, but he would not; so I went with\nhim as far as Erineum; and as I parted from him, I remembered that\nSocrates had seen him when he was a youth, and had a remarkable\nconversation with him, not long before his own death; and he then\nprophesied of him that he would be a great man if he lived.' 'How true\nthat has been; how like all that Socrates said! And could you repeat the\nconversation?' 'Not from memory; but I took notes when I returned home,\nwhich I afterwards filled up at leisure, and got Socrates to correct\nthem from time to time, when I came to Athens'...Terpsion had long\nintended to ask for a sight of this writing, of which he had already\nheard. They are both tired, and agree to rest and have the conversation\nread to them by a servant...'Here is the roll, Terpsion; I need\nonly observe that I have omitted, for the sake of convenience, the\ninterlocutory words, \"said I,\" \"said he\"; and that Theaetetus, and\nTheodorus, the geometrician of Cyrene, are the persons with whom\nSocrates is conversing.'\n\nSocrates begins by asking Theodorus whether, in his visit to Athens, he\nhas found any Athenian youth likely to attain distinction in science.\n'Yes, Socrates, there is one very remarkable youth, with whom I have\nbecome acquainted. He is no beauty, and therefore you need not imagine\nthat I am in love with him; and, to say the truth, he is very like you,\nfor he has a snub nose, and projecting eyes, although these features are\nnot so marked in him as in you. He combines the most various qualities,\nquickness, patience, courage; and he is gentle as well as wise, always\nsilently flowing on, like a river of oil. Look! he is the middle one of\nthose who are entering the palaestra.'\n\nSocrates, who does not know his name, recognizes him as the son of\nEuphronius, who was himself a good man and a rich. He is informed by\nTheodorus that the youth is named Theaetetus, but the property of his\nfather has disappeared in the hands of trustees; this does not, however,\nprevent him from adding liberality to his other virtues. At the desire\nof Socrates he invites Theaetetus to sit by them.\n\n'Yes,' says Socrates, 'that I may see in you, Theaetetus, the image\nof my ugly self, as Theodorus declares. Not that his remark is of any\nimportance; for though he is a philosopher, he is not a painter, and\ntherefore he is no judge of our faces; but, as he is a man of science,\nhe may be a judge of our intellects. And if he were to praise the mental\nendowments of either of us, in that case the hearer of the eulogy ought\nto examine into what he says, and the subject should not refuse to be\nexamined.' Theaetetus consents, and is caught in a trap (compare the\nsimilar trap which is laid for Theodorus). 'Then, Theaetetus, you will\nhave to be examined, for Theodorus has been praising you in a style of\nwhich I never heard the like.' 'He was only jesting.' 'Nay, that is not\nhis way; and I cannot allow you, on that pretence, to retract the assent\nwhich you have already given, or I shall make Theodorus repeat your\npraises, and swear to them.' Theaetetus, in reply, professes that he is\nwilling to be examined, and Socrates begins by asking him what he learns\nof Theodorus. He is himself anxious to learn anything of anybody; and\nnow he has a little question to which he wants Theaetetus or Theodorus\n(or whichever of the company would not be 'donkey' to the rest) to find\nan answer. Without further preface, but at the same time apologizing\nfor his eagerness, he asks, 'What is knowledge?' Theodorus is too old\nto answer questions, and begs him to interrogate Theaetetus, who has the\nadvantage of youth.\n\nTheaetetus replies, that knowledge is what he learns of Theodorus,\ni.e. geometry and arithmetic; and that there are other kinds of\nknowledge--shoemaking, carpentering, and the like. But Socrates rejoins,\nthat this answer contains too much and also too little. For although\nTheaetetus has enumerated several kinds of knowledge, he has not\nexplained the common nature of them; as if he had been asked, 'What is\nclay?' and instead of saying 'Clay is moistened earth,' he had answered,\n'There is one clay of image-makers, another of potters, another of\noven-makers.' Theaetetus at once divines that Socrates means him to\nextend to all kinds of knowledge the same process of generalization\nwhich he has already learned to apply to arithmetic. For he has\ndiscovered a division of numbers into square numbers, 4, 9, 16, etc.,\nwhich are composed of equal factors, and represent figures which have\nequal sides, and oblong numbers, 3, 5, 6, 7, etc., which are composed of\nunequal factors, and represent figures which have unequal sides. But\nhe has never succeeded in attaining a similar conception of knowledge,\nthough he has often tried; and, when this and similar questions were\nbrought to him from Socrates, has been sorely distressed by them.\nSocrates explains to him that he is in labour. For men as well as\nwomen have pangs of labour; and both at times require the assistance of\nmidwives. And he, Socrates, is a midwife, although this is a secret; he\nhas inherited the art from his mother bold and bluff, and he ushers into\nlight, not children, but the thoughts of men. Like the midwives, who are\n'past bearing children,' he too can have no offspring--the God will not\nallow him to bring anything into the world of his own. He also reminds\nTheaetetus that the midwives are or ought to be the only matchmakers\n(this is the preparation for a biting jest); for those who reap the\nfruit are most likely to know on what soil the plants will grow. But\nrespectable midwives avoid this department of practice--they do not want\nto be called procuresses. There are some other differences between the\ntwo sorts of pregnancy. For women do not bring into the world at one\ntime real children and at another time idols which are with difficulty\ndistinguished from them. 'At first,' says Socrates in his character of\nthe man-midwife, 'my patients are barren and stolid, but after a while\nthey \"round apace,\" if the gods are propitious to them; and this is due\nnot to me but to themselves; I and the god only assist in bringing their\nideas to the birth. Many of them have left me too soon, and the result\nhas been that they have produced abortions; or when I have delivered\nthem of children they have lost them by an ill bringing up, and have\nended by seeing themselves, as others see them, to be great fools.\nAristides, the son of Lysimachus, is one of these, and there have been\nothers. The truants often return to me and beg to be taken back; and\nthen, if my familiar allows me, which is not always the case, I receive\nthem, and they begin to grow again. There come to me also those who have\nnothing in them, and have no need of my art; and I am their matchmaker\n(see above), and marry them to Prodicus or some other inspired sage who\nis likely to suit them. I tell you this long story because I suspect\nthat you are in labour. Come then to me, who am a midwife, and the son\nof a midwife, and I will deliver you. And do not bite me, as the women\ndo, if I abstract your first-born; for I am acting out of good-will\ntowards you; the God who is within me is the friend of man, though he\nwill not allow me to dissemble the truth. Once more then, Theaetetus,\nI repeat my old question--\"What is knowledge?\" Take courage, and by the\nhelp of God you will discover an answer.' 'My answer is, that knowledge\nis perception.' 'That is the theory of Protagoras, who has another way\nof expressing the same thing when he says, \"Man is the measure of all\nthings.\" He was a very wise man, and we should try to understand him.\nIn order to illustrate his meaning let me suppose that there is the same\nwind blowing in our faces, and one of us may be hot and the other cold.\nHow is this? Protagoras will reply that the wind is hot to him who is\ncold, cold to him who is hot. And \"is\" means \"appears,\" and when you\nsay \"appears to him,\" that means \"he feels.\" Thus feeling, appearance,\nperception, coincide with being. I suspect, however, that this was only\na \"facon de parler,\" by which he imposed on the common herd like you and\nme; he told \"the truth\" (in allusion to the title of his book, which\nwas called \"The Truth\") in secret to his disciples. For he was really\na votary of that famous philosophy in which all things are said to be\nrelative; nothing is great or small, or heavy or light, or one, but all\nis in motion and mixture and transition and flux and generation, not\n\"being,\" as we ignorantly affirm, but \"becoming.\" This has been the\ndoctrine, not of Protagoras only, but of all philosophers, with the\nsingle exception of Parmenides; Empedocles, Heracleitus, and others, and\nall the poets, with Epicharmus, the king of Comedy, and Homer, the king\nof Tragedy, at their head, have said the same; the latter has these\nwords--\n\n\"Ocean, whence the gods sprang, and mother Tethys.\"\n\nAnd many arguments are used to show, that motion is the source of life,\nand rest of death: fire and warmth are produced by friction, and living\ncreatures owe their origin to a similar cause; the bodily frame is\npreserved by exercise and destroyed by indolence; and if the sun ceased\nto move, \"chaos would come again.\" Now apply this doctrine of \"All\nis motion\" to the senses, and first of all to the sense of sight. The\ncolour of white, or any other colour, is neither in the eyes nor out of\nthem, but ever in motion between the object and the eye, and varying in\nthe case of every percipient. All is relative, and, as the followers of\nProtagoras remark, endless contradictions arise when we deny this; e.g.\nhere are six dice; they are more than four and less than twelve; \"more\nand also less,\" would you not say?' 'Yes.' 'But Protagoras will retort:\n\"Can anything be more or less without addition or subtraction?\"'\n\n'I should say \"No\" if I were not afraid of contradicting my former\nanswer.'\n\n'And if you say \"Yes,\" the tongue will escape conviction but not the\nmind, as Euripides would say?' 'True.' 'The thoroughbred Sophists, who\nknow all that can be known, would have a sparring match over this, but\nyou and I, who have no professional pride, want only to discover whether\nour ideas are clear and consistent. And we cannot be wrong in saying,\nfirst, that nothing can be greater or less while remaining equal;\nsecondly, that there can be no becoming greater or less without addition\nor subtraction; thirdly, that what is and was not, cannot be without\nhaving become. But then how is this reconcilable with the case of the\ndice, and with similar examples?--that is the question.' 'I am often\nperplexed and amazed, Socrates, by these difficulties.' 'That is because\nyou are a philosopher, for philosophy begins in wonder, and Iris is\nthe child of Thaumas. Do you know the original principle on which the\ndoctrine of Protagoras is based?' 'No.' 'Then I will tell you; but we\nmust not let the uninitiated hear, and by the uninitiated I mean the\nobstinate people who believe in nothing which they cannot hold in their\nhands. The brethren whose mysteries I am about to unfold to you are far\nmore ingenious. They maintain that all is motion; and that motion\nhas two forms, action and passion, out of which endless phenomena are\ncreated, also in two forms--sense and the object of sense--which come to\nthe birth together. There are two kinds of motions, a slow and a fast;\nthe motions of the agent and the patient are slower, because they move\nand create in and about themselves, but the things which are born of\nthem have a swifter motion, and pass rapidly from place to place.\nThe eye and the appropriate object come together, and give birth to\nwhiteness and the sensation of whiteness; the eye is filled with seeing,\nand becomes not sight but a seeing eye, and the object is filled with\nwhiteness, and becomes not whiteness but white; and no other compound of\neither with another would have produced the same effect. All sensation\nis to be resolved into a similar combination of an agent and patient.\nOf either, taken separately, no idea can be formed; and the agent may\nbecome a patient, and the patient an agent. Hence there arises a general\nreflection that nothing is, but all things become; no name can detain or\nfix them. Are not these speculations charming, Theaetetus, and very good\nfor a person in your interesting situation? I am offering you specimens\nof other men's wisdom, because I have no wisdom of my own, and I want\nto deliver you of something; and presently we will see whether you\nhave brought forth wind or not. Tell me, then, what do you think of the\nnotion that \"All things are becoming\"?'\n\n'When I hear your arguments, I am marvellously ready to assent.'\n\n'But I ought not to conceal from you that there is a serious objection\nwhich may be urged against this doctrine of Protagoras. For there are\nstates, such as madness and dreaming, in which perception is false; and\nhalf our life is spent in dreaming; and who can say that at this instant\nwe are not dreaming? Even the fancies of madmen are real at the time.\nBut if knowledge is perception, how can we distinguish between the true\nand the false in such cases? Having stated the objection, I will now\nstate the answer. Protagoras would deny the continuity of phenomena;\nhe would say that what is different is entirely different, and whether\nactive or passive has a different power. There are infinite agents and\npatients in the world, and these produce in every combination of them a\ndifferent perception. Take myself as an instance:--Socrates may be ill\nor he may be well,--and remember that Socrates, with all his accidents,\nis spoken of. The wine which I drink when I am well is pleasant to\nme, but the same wine is unpleasant to me when I am ill. And there\nis nothing else from which I can receive the same impression, nor can\nanother receive the same impression from the wine. Neither can I and the\nobject of sense become separately what we become together. For the one\nin becoming is relative to the other, but they have no other relation;\nand the combination of them is absolute at each moment. (In modern\nlanguage, the act of sensation is really indivisible, though capable of\na mental analysis into subject and object.) My sensation alone is true,\nand true to me only. And therefore, as Protagoras says, \"To myself I\nam the judge of what is and what is not.\" Thus the flux of Homer and\nHeracleitus, the great Protagorean saying that \"Man is the measure of\nall things,\" the doctrine of Theaetetus that \"Knowledge is perception,\"\nhave all the same meaning. And this is thy new-born child, which by my\nart I have brought to light; and you must not be angry if instead of\nrearing your infant we expose him.'\n\n'Theaetetus will not be angry,' says Theodorus; 'he is very\ngood-natured. But I should like to know, Socrates, whether you mean to\nsay that all this is untrue?'\n\n'First reminding you that I am not the bag which contains the arguments,\nbut that I extract them from Theaetetus, shall I tell you what amazes me\nin your friend Protagoras?'\n\n'What may that be?'\n\n'I like his doctrine that what appears is; but I wonder that he did\nnot begin his great work on Truth with a declaration that a pig, or a\ndog-faced baboon, or any other monster which has sensation, is a measure\nof all things; then, while we were reverencing him as a god, he might\nhave produced a magnificent effect by expounding to us that he was no\nwiser than a tadpole. For if sensations are always true, and one man's\ndiscernment is as good as another's, and every man is his own judge,\nand everything that he judges is right and true, then what need of\nProtagoras to be our instructor at a high figure; and why should we\nbe less knowing than he is, or have to go to him, if every man is the\nmeasure of all things? My own art of midwifery, and all dialectic, is\nan enormous folly, if Protagoras' \"Truth\" be indeed truth, and the\nphilosopher is not merely amusing himself by giving oracles out of his\nbook.'\n\nTheodorus thinks that Socrates is unjust to his master, Protagoras; but\nhe is too old and stiff to try a fall with him, and therefore refers him\nto Theaetetus, who is already driven out of his former opinion by the\narguments of Socrates.\n\nSocrates then takes up the defence of Protagoras, who is supposed to\nreply in his own person--'Good people, you sit and declaim about the\ngods, of whose existence or non-existence I have nothing to say, or you\ndiscourse about man being reduced to the level of the brutes; but what\nproof have you of your statements? And yet surely you and Theodorus had\nbetter reflect whether probability is a safe guide. Theodorus would be\na bad geometrician if he had nothing better to offer.'...Theaetetus is\naffected by the appeal to geometry, and Socrates is induced by him to\nput the question in a new form. He proceeds as follows:--'Should we say\nthat we know what we see and hear,--e.g. the sound of words or the sight\nof letters in a foreign tongue?'\n\n'We should say that the figures of the letters, and the pitch of the\nvoice in uttering them, were known to us, but not the meaning of them.'\n\n'Excellent; I want you to grow, and therefore I will leave that answer\nand ask another question: Is not seeing perceiving?' 'Very true.' 'And\nhe who sees knows?' 'Yes.' 'And he who remembers, remembers that which\nhe sees and knows?' 'Very true.' 'But if he closes his eyes, does he not\nremember?' 'He does.' 'Then he may remember and not see; and if seeing\nis knowing, he may remember and not know. Is not this a \"reductio ad\nabsurdum\" of the hypothesis that knowledge is sensible perception? Yet\nperhaps we are crowing too soon; and if Protagoras, \"the father of the\nmyth,\" had been alive, the result might have been very different. But he\nis dead, and Theodorus, whom he left guardian of his \"orphan,\" has not\nbeen very zealous in defending him.'\n\nTheodorus objects that Callias is the true guardian, but he hopes that\nSocrates will come to the rescue. Socrates prefaces his defence by\nresuming the attack. He asks whether a man can know and not know at the\nsame time? 'Impossible.' Quite possible, if you maintain that seeing is\nknowing. The confident adversary, suiting the action to the word, shuts\none of your eyes; and now, says he, you see and do not see, but do\nyou know and not know? And a fresh opponent darts from his ambush, and\ntransfers to knowledge the terms which are commonly applied to sight.\nHe asks whether you can know near and not at a distance; whether you can\nhave a sharp and also a dull knowledge. While you are wondering at his\nincomparable wisdom, he gets you into his power, and you will not escape\nuntil you have come to an understanding with him about the money which\nis to be paid for your release.\n\nBut Protagoras has not yet made his defence; and already he may be heard\ncontemptuously replying that he is not responsible for the admissions\nwhich were made by a boy, who could not foresee the coming move, and\ntherefore had answered in a manner which enabled Socrates to raise a\nlaugh against himself. 'But I cannot be fairly charged,' he will say,\n'with an answer which I should not have given; for I never maintained\nthat the memory of a feeling is the same as a feeling, or denied that a\nman might know and not know the same thing at the same time. Or, if you\nwill have extreme precision, I say that man in different relations is\nmany or rather infinite in number. And I challenge you, either to show\nthat his perceptions are not individual, or that if they are, what\nappears to him is not what is. As to your pigs and baboons, you are\nyourself a pig, and you make my writings a sport of other swine. But\nI still affirm that man is the measure of all things, although I admit\nthat one man may be a thousand times better than another, in proportion\nas he has better impressions. Neither do I deny the existence of wisdom\nor of the wise man. But I maintain that wisdom is a practical remedial\npower of turning evil into good, the bitterness of disease into the\nsweetness of health, and does not consist in any greater truth or\nsuperior knowledge. For the impressions of the sick are as true as the\nimpressions of the healthy; and the sick are as wise as the healthy. Nor\ncan any man be cured of a false opinion, for there is no such thing;\nbut he may be cured of the evil habit which generates in him an evil\nopinion. This is effected in the body by the drugs of the physician, and\nin the soul by the words of the Sophist; and the new state or opinion\nis not truer, but only better than the old. And philosophers are not\ntadpoles, but physicians and husbandmen, who till the soil and infuse\nhealth into animals and plants, and make the good take the place of the\nevil, both in individuals and states. Wise and good rhetoricians make\nthe good to appear just in states (for that is just which appears just\nto a state), and in return, they deserve to be well paid. And you,\nSocrates, whether you please or not, must continue to be a measure.\nThis is my defence, and I must request you to meet me fairly. We are\nprofessing to reason, and not merely to dispute; and there is a great\ndifference between reasoning and disputation. For the disputer is always\nseeking to trip up his opponent; and this is a mode of argument which\ndisgusts men with philosophy as they grow older. But the reasoner is\ntrying to understand him and to point out his errors to him, whether\narising from his own or from his companion's fault; he does not argue\nfrom the customary use of names, which the vulgar pervert in all manner\nof ways. If you are gentle to an adversary he will follow and love you;\nand if defeated he will lay the blame on himself, and seek to escape\nfrom his own prejudices into philosophy. I would recommend you,\nSocrates, to adopt this humaner method, and to avoid captious and verbal\ncriticisms.'\n\nSuch, Theodorus, is the very slight help which I am able to afford to\nyour friend; had he been alive, he would have helped himself in far\nbetter style.\n\n'You have made a most valorous defence.'\n\nYes; but did you observe that Protagoras bade me be serious, and\ncomplained of our getting up a laugh against him with the aid of a boy?\nHe meant to intimate that you must take the place of Theaetetus, who may\nbe wiser than many bearded men, but not wiser than you, Theodorus.\n\n'The rule of the Spartan Palaestra is, Strip or depart; but you are like\nthe giant Antaeus, and will not let me depart unless I try a fall with\nyou.'\n\nYes, that is the nature of my complaint. And many a Hercules, many a\nTheseus mighty in deeds and words has broken my head; but I am always at\nthis rough game. Please, then, to favour me.\n\n'On the condition of not exceeding a single fall, I consent.'\n\nSocrates now resumes the argument. As he is very desirous of doing\njustice to Protagoras, he insists on citing his own words,--'What\nappears to each man is to him.' And how, asks Socrates, are these words\nreconcileable with the fact that all mankind are agreed in thinking\nthemselves wiser than others in some respects, and inferior to them in\nothers? In the hour of danger they are ready to fall down and worship\nany one who is their superior in wisdom as if he were a god. And the\nworld is full of men who are asking to be taught and willing to be\nruled, and of other men who are willing to rule and teach them. All\nwhich implies that men do judge of one another's impressions, and think\nsome wise and others foolish. How will Protagoras answer this argument?\nFor he cannot say that no one deems another ignorant or mistaken. If you\nform a judgment, thousands and tens of thousands are ready to maintain\nthe opposite. The multitude may not and do not agree in Protagoras'\nown thesis that 'Man is the measure of all things;' and then who is to\ndecide? Upon his own showing must not his 'truth' depend on the number\nof suffrages, and be more or less true in proportion as he has more or\nfewer of them? And he must acknowledge further, that they speak truly\nwho deny him to speak truly, which is a famous jest. And if he admits\nthat they speak truly who deny him to speak truly, he must admit that\nhe himself does not speak truly. But his opponents will refuse to admit\nthis of themselves, and he must allow that they are right in their\nrefusal. The conclusion is, that all mankind, including Protagoras\nhimself, will deny that he speaks truly; and his truth will be true\nneither to himself nor to anybody else.\n\nTheodorus is inclined to think that this is going too far. Socrates\nironically replies, that he is not going beyond the truth. But if the\nold Protagoras could only pop his head out of the world below, he would\ndoubtless give them both a sound castigation and be off to the shades\nin an instant. Seeing that he is not within call, we must examine the\nquestion for ourselves. It is clear that there are great differences in\nthe understandings of men. Admitting, with Protagoras, that immediate\nsensations of hot, cold, and the like, are to each one such as they\nappear, yet this hypothesis cannot be extended to judgments or opinions.\nAnd even if we were to admit further,--and this is the view of some who\nare not thorough-going followers of Protagoras,--that right and wrong,\nholy and unholy, are to each state or individual such as they appear,\nstill Protagoras will not venture to maintain that every man is equally\nthe measure of expediency, or that the thing which seems is expedient\nto every one. But this begins a new question. 'Well, Socrates, we have\nplenty of leisure. Yes, we have, and, after the manner of philosophers,\nwe are digressing; I have often observed how ridiculous this habit of\ntheirs makes them when they appear in court. 'What do you mean?' I mean\nto say that a philosopher is a gentleman, but a lawyer is a servant.\nThe one can have his talk out, and wander at will from one subject\nto another, as the fancy takes him; like ourselves, he may be long or\nshort, as he pleases. But the lawyer is always in a hurry; there is the\nclepsydra limiting his time, and the brief limiting his topics, and his\nadversary is standing over him and exacting his rights. He is a servant\ndisputing about a fellow-servant before his master, who holds the cause\nin his hands; the path never diverges, and often the race is for his\nlife. Such experiences render him keen and shrewd; he learns the arts of\nflattery, and is perfect in the practice of crooked ways; dangers have\ncome upon him too soon, when the tenderness of youth was unable to meet\nthem with truth and honesty, and he has resorted to counter-acts of\ndishonesty and falsehood, and become warped and distorted; without any\nhealth or freedom or sincerity in him he has grown up to manhood, and is\nor esteems himself to be a master of cunning. Such are the lawyers; will\nyou have the companion picture of philosophers? or will this be too much\nof a digression?\n\n'Nay, Socrates, the argument is our servant, and not our master. Who is\nthe judge or where is the spectator, having a right to control us?'\n\nI will describe the leaders, then: for the inferior sort are not worth\nthe trouble. The lords of philosophy have not learned the way to the\ndicastery or ecclesia; they neither see nor hear the laws and votes of\nthe state, written or recited; societies, whether political or festive,\nclubs, and singing maidens do not enter even into their dreams. And the\nscandals of persons or their ancestors, male and female, they know no\nmore than they can tell the number of pints in the ocean. Neither\nare they conscious of their own ignorance; for they do not practise\nsingularity in order to gain reputation, but the truth is, that the\nouter form of them only is residing in the city; the inner man, as\nPindar says, is going on a voyage of discovery, measuring as with line\nand rule the things which are under and in the earth, interrogating the\nwhole of nature, only not condescending to notice what is near them.\n\n'What do you mean, Socrates?'\n\nI will illustrate my meaning by the jest of the witty maid-servant, who\nsaw Thales tumbling into a well, and said of him, that he was so eager\nto know what was going on in heaven, that he could not see what was\nbefore his feet. This is applicable to all philosophers. The philosopher\nis unacquainted with the world; he hardly knows whether his neighbour is\na man or an animal. For he is always searching into the essence of man,\nand enquiring what such a nature ought to do or suffer different from\nany other. Hence, on every occasion in private life and public, as I was\nsaying, when he appears in a law-court or anywhere, he is the joke, not\nonly of maid-servants, but of the general herd, falling into wells\nand every sort of disaster; he looks such an awkward, inexperienced\ncreature, unable to say anything personal, when he is abused, in answer\nto his adversaries (for he knows no evil of any one); and when he hears\nthe praises of others, he cannot help laughing from the bottom of\nhis soul at their pretensions; and this also gives him a ridiculous\nappearance. A king or tyrant appears to him to be a kind of swine-herd\nor cow-herd, milking away at an animal who is much more troublesome and\ndangerous than cows or sheep; like the cow-herd, he has no time to be\neducated, and the pen in which he keeps his flock in the mountains is\nsurrounded by a wall. When he hears of large landed properties of ten\nthousand acres or more, he thinks of the whole earth; or if he is\ntold of the antiquity of a family, he remembers that every one has had\nmyriads of progenitors, rich and poor, Greeks and barbarians, kings\nand slaves. And he who boasts of his descent from Amphitryon in the\ntwenty-fifth generation, may, if he pleases, add as many more, and\ndouble that again, and our philosopher only laughs at his inability to\ndo a larger sum. Such is the man at whom the vulgar scoff; he seems to\nthem as if he could not mind his feet. 'That is very true, Socrates.'\nBut when he tries to draw the quick-witted lawyer out of his pleas and\nrejoinders to the contemplation of absolute justice or injustice in\ntheir own nature, or from the popular praises of wealthy kings to the\nview of happiness and misery in themselves, or to the reasons why a man\nshould seek after the one and avoid the other, then the situation is\nreversed; the little wretch turns giddy, and is ready to fall over the\nprecipice; his utterance becomes thick, and he makes himself ridiculous,\nnot to servant-maids, but to every man of liberal education. Such are\nthe two pictures: the one of the philosopher and gentleman, who may be\nexcused for not having learned how to make a bed, or cook up flatteries;\nthe other, a serviceable knave, who hardly knows how to wear his\ncloak,--still less can he awaken harmonious thoughts or hymn virtue's\npraises.\n\n'If the world, Socrates, were as ready to receive your words as I am,\nthere would be greater peace and less evil among mankind.'\n\nEvil, Theodorus, must ever remain in this world to be the antagonist of\ngood, out of the way of the gods in heaven. Wherefore also we should fly\naway from ourselves to them; and to fly to them is to become like them;\nand to become like them is to become holy, just and true. But many\nlive in the old wives' fable of appearances; they think that you should\nfollow virtue in order that you may seem to be good. And yet the truth\nis, that God is righteous; and of men, he is most like him who is most\nrighteous. To know this is wisdom; and in comparison of this the wisdom\nof the arts or the seeming wisdom of politicians is mean and common. The\nunrighteous man is apt to pride himself on his cunning; when others\ncall him rogue, he says to himself: 'They only mean that I am one who\ndeserves to live, and not a mere burden of the earth.' But he should\nreflect that his ignorance makes his condition worse than if he knew.\nFor the penalty of injustice is not death or stripes, but the fatal\nnecessity of becoming more and more unjust. Two patterns of life are set\nbefore him; the one blessed and divine, the other godless and wretched;\nand he is growing more and more like the one and unlike the other. He\ndoes not see that if he continues in his cunning, the place of innocence\nwill not receive him after death. And yet if such a man has the courage\nto hear the argument out, he often becomes dissatisfied with himself,\nand has no more strength in him than a child.--But we have digressed\nenough.\n\n'For my part, Socrates, I like the digressions better than the argument,\nbecause I understand them better.'\n\nTo return. When we left off, the Protagoreans and Heracliteans were\nmaintaining that the ordinances of the State were just, while they\nlasted. But no one would maintain that the laws of the State were always\ngood or expedient, although this may be the intention of them. For\nthe expedient has to do with the future, about which we are liable to\nmistake. Now, would Protagoras maintain that man is the measure not\nonly of the present and past, but of the future; and that there is no\ndifference in the judgments of men about the future? Would an untrained\nman, for example, be as likely to know when he is going to have a fever,\nas the physician who attended him? And if they differ in opinion,\nwhich of them is likely to be right; or are they both right? Is not a\nvine-grower a better judge of a vintage which is not yet gathered, or a\ncook of a dinner which is in preparation, or Protagoras of the probable\neffect of a speech than an ordinary person? The last example speaks 'ad\nhominen.' For Protagoras would never have amassed a fortune if every man\ncould judge of the future for himself. He is, therefore, compelled to\nadmit that he is a measure; but I, who know nothing, am not equally\nconvinced that I am. This is one way of refuting him; and he is refuted\nalso by the authority which he attributes to the opinions of others, who\ndeny his opinions. I am not equally sure that we can disprove the truth\nof immediate states of feeling. But this leads us to the doctrine of\nthe universal flux, about which a battle-royal is always going on in the\ncities of Ionia. 'Yes; the Ephesians are downright mad about the\nflux; they cannot stop to argue with you, but are in perpetual motion,\nobedient to their text-books. Their restlessness is beyond expression,\nand if you ask any of them a question, they will not answer, but dart at\nyou some unintelligible saying, and another and another, making no way\neither with themselves or with others; for nothing is fixed in them\nor their ideas,--they are at war with fixed principles.' I suppose,\nTheodorus, that you have never seen them in time of peace, when they\ndiscourse at leisure to their disciples? 'Disciples! they have none;\nthey are a set of uneducated fanatics, and each of them says of the\nother that they have no knowledge. We must trust to ourselves, and not\nto them for the solution of the problem.' Well, the doctrine is old,\nbeing derived from the poets, who speak in a figure of Oceanus and\nTethys; the truth was once concealed, but is now revealed by the\nsuperior wisdom of a later generation, and made intelligible to the\ncobbler, who, on hearing that all is in motion, and not some things\nonly, as he ignorantly fancied, may be expected to fall down and worship\nhis teachers. And the opposite doctrine must not be forgotten:--\n\n     'Alone being remains unmoved which is the name for all,'\n\nas Parmenides affirms. Thus we are in the midst of the fray; both\nparties are dragging us to their side; and we are not certain which of\nthem are in the right; and if neither, then we shall be in a ridiculous\nposition, having to set up our own opinion against ancient and famous\nmen.\n\nLet us first approach the river-gods, or patrons of the flux.\n\nWhen they speak of motion, must they not include two kinds of motion,\nchange of place and change of nature?--And all things must be supposed\nto have both kinds of motion; for if not, the same things would be at\nrest and in motion, which is contrary to their theory. And did we not\nsay, that all sensations arise thus: they move about between the agent\nand patient together with a perception, and the patient ceases to be a\nperceiving power and becomes a percipient, and the agent a quale instead\nof a quality; but neither has any absolute existence? But now we make\nthe further discovery, that neither white or whiteness, nor any sense\nor sensation, can be predicated of anything, for they are in a perpetual\nflux. And therefore we must modify the doctrine of Theaetetus and\nProtagoras, by asserting further that knowledge is and is not sensation;\nand of everything we must say equally, that this is and is not, or\nbecomes or becomes not. And still the word 'this' is not quite correct,\nfor language fails in the attempt to express their meaning.\n\nAt the close of the discussion, Theodorus claims to be released from the\nargument, according to his agreement. But Theaetetus insists that they\nshall proceed to consider the doctrine of rest. This is declined by\nSocrates, who has too much reverence for the great Parmenides lightly\nto attack him. (We shall find that he returns to the doctrine of rest\nin the Sophist; but at present he does not wish to be diverted from\nhis main purpose, which is, to deliver Theaetetus of his conception of\nknowledge.) He proceeds to interrogate him further. When he says that\n'knowledge is in perception,' with what does he perceive? The first\nanswer is, that he perceives sights with the eye, and sounds with the\near. This leads Socrates to make the reflection that nice distinctions\nof words are sometimes pedantic, but sometimes necessary; and he\nproposes in this case to substitute the word 'through' for 'with.' For\nthe senses are not like the Trojan warriors in the horse, but have\na common centre of perception, in which they all meet. This common\nprinciple is able to compare them with one another, and must therefore\nbe distinct from them (compare Republic). And as there are facts of\nsense which are perceived through the organs of the body, there are also\nmathematical and other abstractions, such as sameness and difference,\nlikeness and unlikeness, which the soul perceives by herself. Being is\nthe most universal of these abstractions. The good and the beautiful are\nabstractions of another kind, which exist in relation and which above\nall others the mind perceives in herself, comparing within her past,\npresent, and future. For example; we know a thing to be hard or soft by\nthe touch, of which the perception is given at birth to men and animals.\nBut the essence of hardness or softness, or the fact that this hardness\nis, and is the opposite of softness, is slowly learned by reflection and\nexperience. Mere perception does not reach being, and therefore fails of\ntruth; and therefore has no share in knowledge. But if so, knowledge\nis not perception. What then is knowledge? The mind, when occupied\nby herself with being, is said to have opinion--shall we say that\n'Knowledge is true opinion'? But still an old difficulty recurs; we\nask ourselves, 'How is false opinion possible?' This difficulty may be\nstated as follows:--\n\nEither we know or do not know a thing (for the intermediate processes\nof learning and forgetting need not at present be considered); and in\nthinking or having an opinion, we must either know or not know that\nwhich we think, and we cannot know and be ignorant at the same time; we\ncannot confuse one thing which we do not know, with another thing which\nwe do not know; nor can we think that which we do not know to be that\nwhich we know, or that which we know to be that which we do not know.\nAnd what other case is conceivable, upon the supposition that we either\nknow or do not know all things? Let us try another answer in the sphere\nof being: 'When a man thinks, and thinks that which is not.' But would\nthis hold in any parallel case? Can a man see and see nothing? or hear\nand hear nothing? or touch and touch nothing? Must he not see, hear, or\ntouch some one existing thing? For if he thinks about nothing he does\nnot think, and not thinking he cannot think falsely. And so the path of\nbeing is closed against us, as well as the path of knowledge. But may\nthere not be 'heterodoxy,' or transference of opinion;--I mean, may not\none thing be supposed to be another? Theaetetus is confident that this\nmust be 'the true falsehood,' when a man puts good for evil or evil\nfor good. Socrates will not discourage him by attacking the paradoxical\nexpression 'true falsehood,' but passes on. The new notion involves a\nprocess of thinking about two things, either together or alternately.\nAnd thinking is the conversing of the mind with herself, which is\ncarried on in question and answer, until she no longer doubts, but\ndetermines and forms an opinion. And false opinion consists in saying to\nyourself, that one thing is another. But did you ever say to yourself,\nthat good is evil, or evil good? Even in sleep, did you ever imagine\nthat odd was even? Or did any man in his senses ever fancy that an ox\nwas a horse, or that two are one? So that we can never think one thing\nto be another; for you must not meet me with the verbal quibble that\none--eteron--is other--eteron (both 'one' and 'other' in Greek are\ncalled 'other'--eteron). He who has both the two things in his mind,\ncannot misplace them; and he who has only one of them in his mind,\ncannot misplace them--on either supposition transplacement is\ninconceivable.\n\nBut perhaps there may still be a sense in which we can think that\nwhich we do not know to be that which we know: e.g. Theaetetus may know\nSocrates, but at a distance he may mistake another person for him. This\nprocess may be conceived by the help of an image. Let us suppose that\nevery man has in his mind a block of wax of various qualities, the gift\nof Memory, the mother of the Muses; and on this he receives the seal or\nstamp of those sensations and perceptions which he wishes to remember.\nThat which he succeeds in stamping is remembered and known by him as\nlong as the impression lasts; but that, of which the impression is\nrubbed out or imperfectly made, is forgotten, and not known. No one can\nthink one thing to be another, when he has the memorial or seal of both\nof these in his soul, and a sensible impression of neither; or when he\nknows one and does not know the other, and has no memorial or seal of\nthe other; or when he knows neither; or when he perceives both, or one\nand not the other, or neither; or when he perceives and knows both,\nand identifies what he perceives with what he knows (this is still more\nimpossible); or when he does not know one, and does not know and does\nnot perceive the other; or does not perceive one, and does not know\nand does not perceive the other; or has no perception or knowledge\nof either--all these cases must be excluded. But he may err when he\nconfuses what he knows or perceives, or what he perceives and does not\nknow, with what he knows, or what he knows and perceives with what he\nknows and perceives.\n\nTheaetetus is unable to follow these distinctions; which Socrates\nproceeds to illustrate by examples, first of all remarking, that\nknowledge may exist without perception, and perception without\nknowledge. I may know Theodorus and Theaetetus and not see them; I\nmay see them, and not know them. 'That I understand.' But I could not\nmistake one for the other if I knew you both, and had no perception of\neither; or if I knew one only, and perceived neither; or if I knew\nand perceived neither, or in any other of the excluded cases. The only\npossibility of error is: 1st, when knowing you and Theodorus, and having\nthe impression of both of you on the waxen block, I, seeing you both\nimperfectly and at a distance, put the foot in the wrong shoe--that\nis to say, put the seal or stamp on the wrong object: or 2ndly, when\nknowing both of you I only see one; or when, seeing and knowing you\nboth, I fail to identify the impression and the object. But there could\nbe no error when perception and knowledge correspond.\n\nThe waxen block in the heart of a man's soul, as I may say in the words\nof Homer, who played upon the words ker and keros, may be smooth and\ndeep, and large enough, and then the signs are clearly marked and\nlasting, and do not get confused. But in the 'hairy heart,' as the\nall-wise poet sings, when the wax is muddy or hard or moist, there is\na corresponding confusion and want of retentiveness; in the muddy and\nimpure there is indistinctness, and still more in the hard, for there\nthe impressions have no depth of wax, and in the moist they are too\nsoon effaced. Yet greater is the indistinctness when they are all jolted\ntogether in a little soul, which is narrow and has no room. These are\nthe sort of natures which have false opinion; from stupidity they see\nand hear and think amiss; and this is falsehood and ignorance. Error,\nthen, is a confusion of thought and sense.\n\nTheaetetus is delighted with this explanation. But Socrates has no\nsooner found the new solution than he sinks into a fit of despondency.\nFor an objection occurs to him:--May there not be errors where there is\nno confusion of mind and sense? e.g. in numbers. No one can confuse\nthe man whom he has in his thoughts with the horse which he has in his\nthoughts, but he may err in the addition of five and seven. And observe\nthat these are purely mental conceptions. Thus we are involved once more\nin the dilemma of saying, either that there is no such thing as false\nopinion, or that a man knows what he does not know.\n\nWe are at our wit's end, and may therefore be excused for making a\nbold diversion. All this time we have been repeating the words 'know,'\n'understand,' yet we do not know what knowledge is. 'Why, Socrates,\nhow can you argue at all without using them?' Nay, but the true hero\nof dialectic would have forbidden me to use them until I had explained\nthem. And I must explain them now. The verb 'to know' has two senses,\nto have and to possess knowledge, and I distinguish 'having' from\n'possessing.' A man may possess a garment which he does not wear; or he\nmay have wild birds in an aviary; these in one sense he possesses, and\nin another he has none of them. Let this aviary be an image of the mind,\nas the waxen block was; when we are young, the aviary is empty; after\na time the birds are put in; for under this figure we may describe\ndifferent forms of knowledge;--there are some of them in groups, and\nsome single, which are flying about everywhere; and let us suppose\na hunt after the science of odd and even, or some other science. The\npossession of the birds is clearly not the same as the having them in\nthe hand. And the original chase of them is not the same as taking them\nin the hand when they are already caged.\n\nThis distinction between use and possession saves us from the absurdity\nof supposing that we do not know what we know, because we may know in\none sense, i.e. possess, what we do not know in another, i.e. use. But\nhave we not escaped one difficulty only to encounter a greater? For how\ncan the exchange of two kinds of knowledge ever become false opinion?\nAs well might we suppose that ignorance could make a man know, or that\nblindness could make him see. Theaetetus suggests that in the aviary\nthere may be flying about mock birds, or forms of ignorance, and we\nput forth our hands and grasp ignorance, when we are intending to grasp\nknowledge. But how can he who knows the forms of knowledge and the forms\nof ignorance imagine one to be the other? Is there some other form of\nknowledge which distinguishes them? and another, and another? Thus we go\nround and round in a circle and make no progress.\n\nAll this confusion arises out of our attempt to explain false opinion\nwithout having explained knowledge. What then is knowledge? Theaetetus\nrepeats that knowledge is true opinion. But this seems to be refuted by\nthe instance of orators and judges. For surely the orator cannot convey\na true knowledge of crimes at which the judges were not present; he\ncan only persuade them, and the judge may form a true opinion and truly\njudge. But if true opinion were knowledge they could not have judged\nwithout knowledge.\n\nOnce more. Theaetetus offers a definition which he has heard: Knowledge\nis true opinion accompanied by definition or explanation. Socrates has\nhad a similar dream, and has further heard that the first elements are\nnames only, and that definition or explanation begins when they are\ncombined; the letters are unknown, the syllables or combinations\nare known. But this new hypothesis when tested by the letters of the\nalphabet is found to break down. The first syllable of Socrates' name\nis SO. But what is SO? Two letters, S and O, a sibilant and a vowel,\nof which no further explanation can be given. And how can any one\nbe ignorant of either of them, and yet know both of them? There is,\nhowever, another alternative:--We may suppose that the syllable has a\nseparate form or idea distinct from the letters or parts. The all of the\nparts may not be the whole. Theaetetus is very much inclined to adopt\nthis suggestion, but when interrogated by Socrates he is unable to\ndraw any distinction between the whole and all the parts. And if the\nsyllables have no parts, then they are those original elements of which\nthere is no explanation. But how can the syllable be known if the letter\nremains unknown? In learning to read as children, we are first taught\nthe letters and then the syllables. And in music, the notes, which\nare the letters, have a much more distinct meaning to us than the\ncombination of them.\n\nOnce more, then, we must ask the meaning of the statement, that\n'Knowledge is right opinion, accompanied by explanation or definition.'\nExplanation may mean, (1) the reflection or expression of a man's\nthoughts--but every man who is not deaf and dumb is able to express his\nthoughts--or (2) the enumeration of the elements of which anything is\ncomposed. A man may have a true opinion about a waggon, but then, and\nthen only, has he knowledge of a waggon when he is able to enumerate\nthe hundred planks of Hesiod. Or he may know the syllables of the name\nTheaetetus, but not the letters; yet not until he knows both can he be\nsaid to have knowledge as well as opinion. But on the other hand he may\nknow the syllable 'The' in the name Theaetetus, yet he may be mistaken\nabout the same syllable in the name Theodorus, and in learning to read\nwe often make such mistakes. And even if he could write out all the\nletters and syllables of your name in order, still he would only have\nright opinion. Yet there may be a third meaning of the definition,\nbesides the image or expression of the mind, and the enumeration of the\nelements, viz. (3) perception of difference.\n\nFor example, I may see a man who has eyes, nose, and mouth;--that will\nnot distinguish him from any other man. Or he may have a snub-nose and\nprominent eyes;--that will not distinguish him from myself and you and\nothers who are like me. But when I see a certain kind of snub-nosedness,\nthen I recognize Theaetetus. And having this sign of difference, I have\nknowledge. But have I knowledge or opinion of this difference; if I\nhave only opinion I have not knowledge; if I have knowledge we assume\na disputed term; for knowledge will have to be defined as right opinion\nwith knowledge of difference.\n\nAnd so, Theaetetus, knowledge is neither perception nor true opinion,\nnor yet definition accompanying true opinion. And I have shown that the\nchildren of your brain are not worth rearing. Are you still in labour,\nor have you brought all you have to say about knowledge to the birth? If\nyou have any more thoughts, you will be the better for having got rid of\nthese; or if you have none, you will be the better for not fancying that\nyou know what you do not know. Observe the limits of my art, which, like\nmy mother's, is an art of midwifery; I do not pretend to compare with\nthe good and wise of this and other ages.\n\nAnd now I go to meet Meletus at the porch of the King Archon; but\nto-morrow I shall hope to see you again, Theodorus, at this place.\n\n...\n\nI. The saying of Theaetetus, that 'Knowledge is sensible perception,'\nmay be assumed to be a current philosophical opinion of the age. 'The\nancients,' as Aristotle (De Anim.) says, citing a verse of Empedocles,\n'affirmed knowledge to be the same as perception.' We may now examine\nthese words, first, with reference to their place in the history of\nphilosophy, and secondly, in relation to modern speculations.\n\n(a) In the age of Socrates the mind was passing from the object to the\nsubject. The same impulse which a century before had led men to form\nconceptions of the world, now led them to frame general notions of the\nhuman faculties and feelings, such as memory, opinion, and the like. The\nsimplest of these is sensation, or sensible perception, by which Plato\nseems to mean the generalized notion of feelings and impressions of\nsense, without determining whether they are conscious or not.\n\nThe theory that 'Knowledge is sensible perception' is the antithesis of\nthat which derives knowledge from the mind (Theaet.), or which assumes\nthe existence of ideas independent of the mind (Parm.). Yet from their\nextreme abstraction these theories do not represent the opposite poles\nof thought in the same way that the corresponding differences would\nin modern philosophy. The most ideal and the most sensational have a\ntendency to pass into one another; Heracleitus, like his great successor\nHegel, has both aspects. The Eleatic isolation of Being and the Megarian\nor Cynic isolation of individuals are placed in the same class by Plato\n(Soph.); and the same principle which is the symbol of motion to one\nmind is the symbol of rest to another. The Atomists, who are sometimes\nregarded as the Materialists of Plato, denied the reality of sensation.\nAnd in the ancient as well as the modern world there were reactions from\ntheory to experience, from ideas to sense. This is a point of view from\nwhich the philosophy of sensation presented great attraction to the\nancient thinker. Amid the conflict of ideas and the variety of opinions,\nthe impression of sense remained certain and uniform. Hardness,\nsoftness, cold, heat, etc. are not absolutely the same to different\npersons, but the art of measuring could at any rate reduce them all\nto definite natures (Republic). Thus the doctrine that knowledge is\nperception supplies or seems to supply a firm standing ground. Like the\nother notions of the earlier Greek philosophy, it was held in a very\nsimple way, without much basis of reasoning, and without suggesting the\nquestions which naturally arise in our own minds on the same subject.\n\n(b) The fixedness of impressions of sense furnishes a link of connexion\nbetween ancient and modern philosophy. The modern thinker often repeats\nthe parallel axiom, 'All knowledge is experience.' He means to say that\nthe outward and not the inward is both the original source and the final\ncriterion of truth, because the outward can be observed and analyzed;\nthe inward is only known by external results, and is dimly perceived\nby each man for himself. In what does this differ from the saying of\nTheaetetus? Chiefly in this--that the modern term 'experience,' while\nimplying a point of departure in sense and a return to sense, also\nincludes all the processes of reasoning and imagination which have\nintervened. The necessary connexion between them by no means affords a\nmeasure of the relative degree of importance which is to be ascribed to\neither element. For the inductive portion of any science may be small,\nas in mathematics or ethics, compared with that which the mind has\nattained by reasoning and reflection on a very few facts.\n\nII. The saying that 'All knowledge is sensation' is identified by Plato\nwith the Protagorean thesis that 'Man is the measure of all things.'\nThe interpretation which Protagoras himself is supposed to give of these\nlatter words is: 'Things are to me as they appear to me, and to you as\nthey appear to you.' But there remains still an ambiguity both in the\ntext and in the explanation, which has to be cleared up. Did Protagoras\nmerely mean to assert the relativity of knowledge to the human mind? Or\ndid he mean to deny that there is an objective standard of truth?\n\nThese two questions have not been always clearly distinguished; the\nrelativity of knowledge has been sometimes confounded with uncertainty.\nThe untutored mind is apt to suppose that objects exist independently\nof the human faculties, because they really exist independently of the\nfaculties of any individual. In the same way, knowledge appears to be\na body of truths stored up in books, which when once ascertained are\nindependent of the discoverer. Further consideration shows us that these\ntruths are not really independent of the mind; there is an adaptation of\none to the other, of the eye to the object of sense, of the mind to the\nconception. There would be no world, if there neither were nor ever\nhad been any one to perceive the world. A slight effort of reflection\nenables us to understand this; but no effort of reflection will enable\nus to pass beyond the limits of our own faculties, or to imagine the\nrelation or adaptation of objects to the mind to be different from that\nof which we have experience. There are certain laws of language and\nlogic to which we are compelled to conform, and to which our ideas\nnaturally adapt themselves; and we can no more get rid of them than we\ncan cease to be ourselves. The absolute and infinite, whether explained\nas self-existence, or as the totality of human thought, or as the\nDivine nature, if known to us at all, cannot escape from the category of\nrelation.\n\nBut because knowledge is subjective or relative to the mind, we are\nnot to suppose that we are therefore deprived of any of the tests or\ncriteria of truth. One man still remains wiser than another, a\nmore accurate observer and relater of facts, a truer measure of the\nproportions of knowledge. The nature of testimony is not altered, nor\nthe verification of causes by prescribed methods less certain. Again,\nthe truth must often come to a man through others, according to the\nmeasure of his capacity and education. But neither does this affect the\ntestimony, whether written or oral, which he knows by experience to\nbe trustworthy. He cannot escape from the laws of his own mind; and\nhe cannot escape from the further accident of being dependent for his\nknowledge on others. But still this is no reason why he should always be\nin doubt; of many personal, of many historical and scientific facts he\nmay be absolutely assured. And having such a mass of acknowledged truth\nin the mathematical and physical, not to speak of the moral sciences,\nthe moderns have certainly no reason to acquiesce in the statement\nthat truth is appearance only, or that there is no difference between\nappearance and truth.\n\nThe relativity of knowledge is a truism to us, but was a great\npsychological discovery in the fifth century before Christ. Of this\ndiscovery, the first distinct assertion is contained in the thesis of\nProtagoras. Probably he had no intention either of denying or affirming\nan objective standard of truth. He did not consider whether man in the\nhigher or man in the lower sense was a 'measure of all things.' Like\nother great thinkers, he was absorbed with one idea, and that idea was\nthe absoluteness of perception. Like Socrates, he seemed to see that\nphilosophy must be brought back from 'nature' to 'truth,' from the world\nto man. But he did not stop to analyze whether he meant 'man' in the\nconcrete or man in the abstract, any man or some men, 'quod semper quod\nubique' or individual private judgment. Such an analysis lay beyond\nhis sphere of thought; the age before Socrates had not arrived at these\ndistinctions. Like the Cynics, again, he discarded knowledge in any\nhigher sense than perception. For 'truer' or 'wiser' he substituted\nthe word 'better,' and is not unwilling to admit that both states and\nindividuals are capable of practical improvement. But this improvement\ndoes not arise from intellectual enlightenment, nor yet from\nthe exertion of the will, but from a change of circumstances and\nimpressions; and he who can effect this change in himself or others may\nbe deemed a philosopher. In the mode of effecting it, while agreeing\nwith Socrates and the Cynics in the importance which he attaches to\npractical life, he is at variance with both of them. To suppose that\npractice can be divorced from speculation, or that we may do good\nwithout caring about truth, is by no means singular, either in\nphilosophy or life. The singularity of this, as of some other\n(so-called) sophistical doctrines, is the frankness with which they are\navowed, instead of being veiled, as in modern times, under ambiguous and\nconvenient phrases.\n\nPlato appears to treat Protagoras much as he himself is treated by\nAristotle; that is to say, he does not attempt to understand him from\nhis own point of view. But he entangles him in the meshes of a more\nadvanced logic. To which Protagoras is supposed to reply by Megarian\nquibbles, which destroy logic, 'Not only man, but each man, and each\nman at each moment.' In the arguments about sight and memory there is a\npalpable unfairness which is worthy of the great 'brainless brothers,'\nEuthydemus and Dionysodorus, and may be compared with the egkekalummenos\n('obvelatus') of Eubulides. For he who sees with one eye only cannot be\ntruly said both to see and not to see; nor is memory, which is liable\nto forget, the immediate knowledge to which Protagoras applies the\nterm. Theodorus justly charges Socrates with going beyond the truth;\nand Protagoras has equally right on his side when he protests against\nSocrates arguing from the common use of words, which 'the vulgar pervert\nin all manner of ways.'\n\nIII. The theory of Protagoras is connected by Aristotle as well as Plato\nwith the flux of Heracleitus. But Aristotle is only following Plato,\nand Plato, as we have already seen, did not mean to imply that such a\nconnexion was admitted by Protagoras himself. His metaphysical genius\nsaw or seemed to see a common tendency in them, just as the modern\nhistorian of ancient philosophy might perceive a parallelism between\ntwo thinkers of which they were probably unconscious themselves. We must\nremember throughout that Plato is not speaking of Heracleitus, but of\nthe Heracliteans, who succeeded him; nor of the great original ideas of\nthe master, but of the Eristic into which they had degenerated a hundred\nyears later. There is nothing in the fragments of Heracleitus which at\nall justifies Plato's account of him. His philosophy may be resolved\ninto two elements--first, change, secondly, law or measure pervading\nthe change: these he saw everywhere, and often expressed in strange\nmythological symbols. But he has no analysis of sensible perception such\nas Plato attributes to him; nor is there any reason to suppose that\nhe pushed his philosophy into that absolute negation in which\nHeracliteanism was sunk in the age of Plato. He never said that 'change\nmeans every sort of change;' and he expressly distinguished between\n'the general and particular understanding.' Like a poet, he surveyed\nthe elements of mythology, nature, thought, which lay before him, and\nsometimes by the light of genius he saw or seemed to see a mysterious\nprinciple working behind them. But as has been the case with other great\nphilosophers, and with Plato and Aristotle themselves, what was really\npermanent and original could not be understood by the next generation,\nwhile a perverted logic carried out his chance expressions with an\nillogical consistency. His simple and noble thoughts, like those of the\ngreat Eleatic, soon degenerated into a mere strife of words. And when\nthus reduced to mere words, they seem to have exercised a far wider\ninfluence in the cities of Ionia (where the people 'were mad about\nthem') than in the life-time of Heracleitus--a phenomenon which, though\nat first sight singular, is not without a parallel in the history of\nphilosophy and theology.\n\nIt is this perverted form of the Heraclitean philosophy which is\nsupposed to effect the final overthrow of Protagorean sensationalism.\nFor if all things are changing at every moment, in all sorts of ways,\nthen there is nothing fixed or defined at all, and therefore no sensible\nperception, nor any true word by which that or anything else can be\ndescribed. Of course Protagoras would not have admitted the justice\nof this argument any more than Heracleitus would have acknowledged the\n'uneducated fanatics' who appealed to his writings. He might have said,\n'The excellent Socrates has first confused me with Heracleitus, and\nHeracleitus with his Ephesian successors, and has then disproved the\nexistence both of knowledge and sensation. But I am not responsible\nfor what I never said, nor will I admit that my common-sense account of\nknowledge can be overthrown by unintelligible Heraclitean paradoxes.'\n\nIV. Still at the bottom of the arguments there remains a truth, that\nknowledge is something more than sensible perception;--this alone would\nnot distinguish man from a tadpole. The absoluteness of sensations\nat each moment destroys the very consciousness of sensations (compare\nPhileb.), or the power of comparing them. The senses are not mere holes\nin a 'Trojan horse,' but the organs of a presiding nature, in which they\nmeet. A great advance has been made in psychology when the senses\nare recognized as organs of sense, and we are admitted to see or feel\n'through them' and not 'by them,' a distinction of words which, as\nSocrates observes, is by no means pedantic. A still further step has\nbeen made when the most abstract notions, such as Being and Not-being,\nsameness and difference, unity and plurality, are acknowledged to be the\ncreations of the mind herself, working upon the feelings or impressions\nof sense. In this manner Plato describes the process of acquiring them,\nin the words 'Knowledge consists not in the feelings or affections\n(pathemasi), but in the process of reasoning about them (sullogismo).'\nHere, is in the Parmenides, he means something not really different\nfrom generalization. As in the Sophist, he is laying the foundation of a\nrational psychology, which is to supersede the Platonic reminiscence of\nIdeas as well as the Eleatic Being and the individualism of Megarians\nand Cynics.\n\nV. Having rejected the doctrine that 'Knowledge is perception,' we now\nproceed to look for a definition of knowledge in the sphere of opinion.\nBut here we are met by a singular difficulty: How is false opinion\npossible? For we must either know or not know that which is presented\nto the mind or to sense. We of course should answer at once: 'No; the\nalternative is not necessary, for there may be degrees of knowledge; and\nwe may know and have forgotten, or we may be learning, or we may have a\ngeneral but not a particular knowledge, or we may know but not be able\nto explain;' and many other ways may be imagined in which we know and do\nnot know at the same time. But these answers belong to a later stage of\nmetaphysical discussion; whereas the difficulty in question naturally\narises owing to the childhood of the human mind, like the parallel\ndifficulty respecting Not-being. Men had only recently arrived at the\nnotion of opinion; they could not at once define the true and pass\nbeyond into the false. The very word doxa was full of ambiguity, being\nsometimes, as in the Eleatic philosophy, applied to the sensible world,\nand again used in the more ordinary sense of opinion. There is no\nconnexion between sensible appearance and probability, and yet both\nof them met in the word doxa, and could hardly be disengaged from one\nanother in the mind of the Greek living in the fifth or fourth century\nB.C. To this was often added, as at the end of the fifth book of the\nRepublic, the idea of relation, which is equally distinct from either of\nthem; also a fourth notion, the conclusion of the dialectical process,\nthe making up of the mind after she has been 'talking to herself'\n(Theat.).\n\nWe are not then surprised that the sphere of opinion and of Not-being\nshould be a dusky, half-lighted place (Republic), belonging neither\nto the old world of sense and imagination, nor to the new world of\nreflection and reason. Plato attempts to clear up this darkness. In\nhis accustomed manner he passes from the lower to the higher, without\nomitting the intermediate stages. This appears to be the reason why he\nseeks for the definition of knowledge first in the sphere of opinion.\nHereafter we shall find that something more than opinion is required.\n\nFalse opinion is explained by Plato at first as a confusion of mind and\nsense, which arises when the impression on the mind does not correspond\nto the impression made on the senses. It is obvious that this\nexplanation (supposing the distinction between impressions on the mind\nand impressions on the senses to be admitted) does not account for all\nforms of error; and Plato has excluded himself from the consideration of\nthe greater number, by designedly omitting the intermediate processes\nof learning and forgetting; nor does he include fallacies in the use of\nlanguage or erroneous inferences. But he is struck by one possibility\nof error, which is not covered by his theory, viz. errors in arithmetic.\nFor in numbers and calculation there is no combination of thought and\nsense, and yet errors may often happen. Hence he is led to discard the\nexplanation which might nevertheless have been supposed to hold good\n(for anything which he says to the contrary) as a rationale of error, in\nthe case of facts derived from sense.\n\nAnother attempt is made to explain false opinion by assigning to error\na sort of positive existence. But error or ignorance is essentially\nnegative--a not-knowing; if we knew an error, we should be no longer in\nerror. We may veil our difficulty under figures of speech, but these,\nalthough telling arguments with the multitude, can never be the real\nfoundation of a system of psychology. Only they lead us to dwell upon\nmental phenomena which if expressed in an abstract form would not be\nrealized by us at all. The figure of the mind receiving impressions is\none of those images which have rooted themselves for ever in language.\nIt may or may not be a 'gracious aid' to thought; but it cannot be\ngot rid of. The other figure of the enclosure is also remarkable as\naffording the first hint of universal all-pervading ideas,--a notion\nfurther carried out in the Sophist. This is implied in the birds, some\nin flocks, some solitary, which fly about anywhere and everywhere. Plato\ndiscards both figures, as not really solving the question which to us\nappears so simple: 'How do we make mistakes?' The failure of the enquiry\nseems to show that we should return to knowledge, and begin with that;\nand we may afterwards proceed, with a better hope of success, to the\nexamination of opinion.\n\nBut is true opinion really distinct from knowledge? The difference\nbetween these he seeks to establish by an argument, which to us appears\nsingular and unsatisfactory. The existence of true opinion is proved\nby the rhetoric of the law courts, which cannot give knowledge, but\nmay give true opinion. The rhetorician cannot put the judge or juror in\npossession of all the facts which prove an act of violence, but he may\ntruly persuade them of the commission of such an act. Here the idea of\ntrue opinion seems to be a right conclusion from imperfect knowledge.\nBut the correctness of such an opinion will be purely accidental; and is\nreally the effect of one man, who has the means of knowing, persuading\nanother who has not. Plato would have done better if he had said that\ntrue opinion was a contradiction in terms.\n\nAssuming the distinction between knowledge and opinion, Theaetetus, in\nanswer to Socrates, proceeds to define knowledge as true opinion, with\ndefinite or rational explanation. This Socrates identifies with another\nand different theory, of those who assert that knowledge first begins\nwith a proposition.\n\nThe elements may be perceived by sense, but they are names, and cannot\nbe defined. When we assign to them some predicate, they first begin to\nhave a meaning (onomaton sumploke logou ousia). This seems equivalent\nto saying, that the individuals of sense become the subject of knowledge\nwhen they are regarded as they are in nature in relation to other\nindividuals.\n\nYet we feel a difficulty in following this new hypothesis. For must not\nopinion be equally expressed in a proposition? The difference between\ntrue and false opinion is not the difference between the particular and\nthe universal, but between the true universal and the false. Thought may\nbe as much at fault as sight. When we place individuals under a\nclass, or assign to them attributes, this is not knowledge, but a very\nrudimentary process of thought; the first generalization of all, without\nwhich language would be impossible. And has Plato kept altogether clear\nof a confusion, which the analogous word logos tends to create, of a\nproposition and a definition? And is not the confusion increased by the\nuse of the analogous term 'elements,' or 'letters'? For there is no real\nresemblance between the relation of letters to a syllable, and of the\nterms to a proposition.\n\nPlato, in the spirit of the Megarian philosophy, soon discovers a flaw\nin the explanation. For how can we know a compound of which the simple\nelements are unknown to us? Can two unknowns make a known? Can a whole\nbe something different from the parts? The answer of experience is that\nthey can; for we may know a compound, which we are unable to analyze\ninto its elements; and all the parts, when united, may be more than all\nthe parts separated: e.g. the number four, or any other number, is more\nthan the units which are contained in it; any chemical compound is more\nthan and different from the simple elements. But ancient philosophy\nin this, as in many other instances, proceeding by the path of mental\nanalysis, was perplexed by doubts which warred against the plainest\nfacts.\n\nThree attempts to explain the new definition of knowledge still remain\nto be considered. They all of them turn on the explanation of logos. The\nfirst account of the meaning of the word is the reflection of thought in\nspeech--a sort of nominalism 'La science est une langue bien faite.' But\nanybody who is not dumb can say what he thinks; therefore mere speech\ncannot be knowledge. And yet we may observe, that there is in this\nexplanation an element of truth which is not recognized by Plato; viz.\nthat truth and thought are inseparable from language, although mere\nexpression in words is not truth. The second explanation of logos is the\nenumeration of the elementary parts of the complex whole. But this is\nonly definition accompanied with right opinion, and does not yet attain\nto the certainty of knowledge. Plato does not mention the greater\nobjection, which is, that the enumeration of particulars is endless;\nsuch a definition would be based on no principle, and would not help us\nat all in gaining a common idea. The third is the best explanation,--the\npossession of a characteristic mark, which seems to answer to the\nlogical definition by genus and difference. But this, again, is equally\nnecessary for right opinion; and we have already determined, although\nnot on very satisfactory grounds, that knowledge must be distinguished\nfrom opinion. A better distinction is drawn between them in the Timaeus.\nThey might be opposed as philosophy and rhetoric, and as conversant\nrespectively with necessary and contingent matter. But no true idea of\nthe nature of either of them, or of their relation to one another, could\nbe framed until science obtained a content. The ancient philosophers\nin the age of Plato thought of science only as pure abstraction, and to\nthis opinion stood in no relation.\n\nLike Theaetetus, we have attained to no definite result. But an\ninteresting phase of ancient philosophy has passed before us. And the\nnegative result is not to be despised. For on certain subjects, and in\ncertain states of knowledge, the work of negation or clearing the ground\nmust go on, perhaps for a generation, before the new structure can begin\nto rise. Plato saw the necessity of combating the illogical logic of\nthe Megarians and Eristics. For the completion of the edifice, he makes\npreparation in the Theaetetus, and crowns the work in the Sophist.\n\nMany (1) fine expressions, and (2) remarks full of wisdom, (3) also\ngerms of a metaphysic of the future, are scattered up and down in\nthe dialogue. Such, for example, as (1) the comparison of Theaetetus'\nprogress in learning to the 'noiseless flow of a river of oil';\nthe satirical touch, 'flavouring a sauce or fawning speech'; or the\nremarkable expression, 'full of impure dialectic'; or the lively images\nunder which the argument is described,--'the flood of arguments pouring\nin,' the fresh discussions 'bursting in like a band of revellers.'\n(2) As illustrations of the second head, may be cited the remark of\nSocrates, that 'distinctions of words, although sometimes pedantic, are\nalso necessary'; or the fine touch in the character of the lawyer,\nthat 'dangers came upon him when the tenderness of youth was unequal to\nthem'; or the description of the manner in which the spirit is broken\nin a wicked man who listens to reproof until he becomes like a child; or\nthe punishment of the wicked, which is not physical suffering, but the\nperpetual companionship of evil (compare Gorgias); or the saying, often\nrepeated by Aristotle and others, that 'philosophy begins in wonder,\nfor Iris is the child of Thaumas'; or the superb contempt with which\nthe philosopher takes down the pride of wealthy landed proprietors by\ncomparison of the whole earth. (3) Important metaphysical ideas are: a.\nthe conception of thought, as the mind talking to herself; b. the notion\nof a common sense, developed further by Aristotle, and the explicit\ndeclaration, that the mind gains her conceptions of Being, sameness,\nnumber, and the like, from reflection on herself; c. the excellent\ndistinction of Theaetetus (which Socrates, speaking with emphasis,\n'leaves to grow') between seeing the forms or hearing the sounds of\nwords in a foreign language, and understanding the meaning of them; and\nd. the distinction of Socrates himself between 'having' and 'possessing'\nknowledge, in which the answer to the whole discussion appears to be\ncontained.\n\n...\n\nThere is a difference between ancient and modern psychology, and we\nhave a difficulty in explaining one in the terms of the other. To us the\ninward and outward sense and the inward and outward worlds of which they\nare the organs are parted by a wall, and appear as if they could never\nbe confounded. The mind is endued with faculties, habits, instincts, and\na personality or consciousness in which they are bound together. Over\nagainst these are placed forms, colours, external bodies coming into\ncontact with our own body. We speak of a subject which is ourselves,\nof an object which is all the rest. These are separable in thought, but\nunited in any act of sensation, reflection, or volition. As there are\nvarious degrees in which the mind may enter into or be abstracted from\nthe operations of sense, so there are various points at which this\nseparation or union may be supposed to occur. And within the sphere\nof mind the analogy of sense reappears; and we distinguish not only\nexternal objects, but objects of will and of knowledge which we contrast\nwith them. These again are comprehended in a higher object, which\nreunites with the subject. A multitude of abstractions are created by\nthe efforts of successive thinkers which become logical determinations;\nand they have to be arranged in order, before the scheme of thought is\ncomplete. The framework of the human intellect is not the peculium of\nan individual, but the joint work of many who are of all ages and\ncountries. What we are in mind is due, not merely to our physical, but\nto our mental antecedents which we trace in history, and more especially\nin the history of philosophy. Nor can mental phenomena be truly\nexplained either by physiology or by the observation of consciousness\napart from their history. They have a growth of their own, like the\ngrowth of a flower, a tree, a human being. They may be conceived as of\nthemselves constituting a common mind, and having a sort of personal\nidentity in which they coexist.\n\nSo comprehensive is modern psychology, seeming to aim at constructing\nanew the entire world of thought. And prior to or simultaneously with\nthis construction a negative process has to be carried on, a clearing\naway of useless abstractions which we have inherited from the past. Many\nerroneous conceptions of the mind derived from former philosophies\nhave found their way into language, and we with difficulty disengage\nourselves from them. Mere figures of speech have unconsciously\ninfluenced the minds of great thinkers. Also there are some\ndistinctions, as, for example, that of the will and of the reason, and\nof the moral and intellectual faculties, which are carried further than\nis justified by experience. Any separation of things which we cannot see\nor exactly define, though it may be necessary, is a fertile source of\nerror. The division of the mind into faculties or powers or virtues is\ntoo deeply rooted in language to be got rid of, but it gives a false\nimpression. For if we reflect on ourselves we see that all our faculties\neasily pass into one another, and are bound together in a single mind or\nconsciousness; but this mental unity is apt to be concealed from us by\nthe distinctions of language.\n\nA profusion of words and ideas has obscured rather than enlightened\nmental science. It is hard to say how many fallacies have arisen from\nthe representation of the mind as a box, as a 'tabula rasa,' a book,\na mirror, and the like. It is remarkable how Plato in the Theaetetus,\nafter having indulged in the figure of the waxen tablet and the decoy,\nafterwards discards them. The mind is also represented by another class\nof images, as the spring of a watch, a motive power, a breath, a stream,\na succession of points or moments. As Plato remarks in the Cratylus,\nwords expressive of motion as well as of rest are employed to describe\nthe faculties and operations of the mind; and in these there is\ncontained another store of fallacies. Some shadow or reflection of the\nbody seems always to adhere to our thoughts about ourselves, and mental\nprocesses are hardly distinguished in language from bodily ones. To see\nor perceive are used indifferently of both; the words intuition, moral\nsense, common sense, the mind's eye, are figures of speech transferred\nfrom one to the other. And many other words used in early poetry or in\nsacred writings to express the works of mind have a materialistic sound;\nfor old mythology was allied to sense, and the distinction of matter and\nmind had not as yet arisen. Thus materialism receives an illusive aid\nfrom language; and both in philosophy and religion the imaginary figure\nor association easily takes the place of real knowledge.\n\nAgain, there is the illusion of looking into our own minds as if our\nthoughts or feelings were written down in a book. This is another figure\nof speech, which might be appropriately termed 'the fallacy of the\nlooking-glass.' We cannot look at the mind unless we have the eye\nwhich sees, and we can only look, not into, but out of the mind at\nthe thoughts, words, actions of ourselves and others. What we dimly\nrecognize within us is not experience, but rather the suggestion of an\nexperience, which we may gather, if we will, from the observation of the\nworld. The memory has but a feeble recollection of what we were saying\nor doing a few weeks or a few months ago, and still less of what we\nwere thinking or feeling. This is one among many reasons why there is\nso little self-knowledge among mankind; they do not carry with them\nthe thought of what they are or have been. The so-called 'facts of\nconsciousness' are equally evanescent; they are facts which nobody ever\nsaw, and which can neither be defined nor described. Of the three laws\nof thought the first (All A = A) is an identical proposition--that is to\nsay, a mere word or symbol claiming to be a proposition: the two others\n(Nothing can be A and not A, and Everything is either A or not A) are\nuntrue, because they exclude degrees and also the mixed modes and double\naspects under which truth is so often presented to us. To assert that\nman is man is unmeaning; to say that he is free or necessary and cannot\nbe both is a half truth only. These are a few of the entanglements which\nimpede the natural course of human thought. Lastly, there is the fallacy\nwhich lies still deeper, of regarding the individual mind apart from\nthe universal, or either, as a self-existent entity apart from the ideas\nwhich are contained in them.\n\nIn ancient philosophies the analysis of the mind is still rudimentary\nand imperfect. It naturally began with an effort to disengage the\nuniversal from sense--this was the first lifting up of the mist. It\nwavered between object and subject, passing imperceptibly from one or\nBeing to mind and thought. Appearance in the outward object was for a\ntime indistinguishable from opinion in the subject. At length mankind\nspoke of knowing as well as of opining or perceiving. But when the word\n'knowledge' was found how was it to be explained or defined? It was not\nan error, it was a step in the right direction, when Protagoras said\nthat 'Man is the measure of all things,' and that 'All knowledge is\nperception.' This was the subjective which corresponded to the objective\n'All is flux.' But the thoughts of men deepened, and soon they began\nto be aware that knowledge was neither sense, nor yet opinion--with or\nwithout explanation; nor the expression of thought, nor the enumeration\nof parts, nor the addition of characteristic marks. Motion and rest were\nequally ill adapted to express its nature, although both must in some\nsense be attributed to it; it might be described more truly as the mind\nconversing with herself; the discourse of reason; the hymn of dialectic,\nthe science of relations, of ideas, of the so-called arts and sciences,\nof the one, of the good, of the all:--this is the way along which Plato\nis leading us in his later dialogues. In its higher signification it was\nthe knowledge, not of men, but of gods, perfect and all sufficing:--like\nother ideals always passing out of sight, and nevertheless present to\nthe mind of Aristotle as well as Plato, and the reality to which they\nwere both tending. For Aristotle as well as Plato would in modern\nphraseology have been termed a mystic; and like him would have defined\nthe higher philosophy to be 'Knowledge of being or essence,'--words to\nwhich in our own day we have a difficulty in attaching a meaning.\n\nYet, in spite of Plato and his followers, mankind have again and again\nreturned to a sensational philosophy. As to some of the early thinkers,\namid the fleetings of sensible objects, ideas alone seemed to be fixed,\nso to a later generation amid the fluctuation of philosophical opinions\nthe only fixed points appeared to be outward objects. Any pretence\nof knowledge which went beyond them implied logical processes, of the\ncorrectness of which they had no assurance and which at best were only\nprobable. The mind, tired of wandering, sought to rest on firm ground;\nwhen the idols of philosophy and language were stripped off, the\nperception of outward objects alone remained. The ancient Epicureans\nnever asked whether the comparison of these with one another did not\ninvolve principles of another kind which were above and beyond them. In\nlike manner the modern inductive philosophy forgot to enquire into\nthe meaning of experience, and did not attempt to form a conception of\noutward objects apart from the mind, or of the mind apart from them.\nSoon objects of sense were merged in sensations and feelings, but\nfeelings and sensations were still unanalyzed. At last we return to\nthe doctrine attributed by Plato to Protagoras, that the mind is only a\nsuccession of momentary perceptions. At this point the modern philosophy\nof experience forms an alliance with ancient scepticism.\n\nThe higher truths of philosophy and religion are very far removed from\nsense. Admitting that, like all other knowledge, they are derived from\nexperience, and that experience is ultimately resolvable into facts\nwhich come to us through the eye and ear, still their origin is a\nmere accident which has nothing to do with their true nature. They\nare universal and unseen; they belong to all times--past, present, and\nfuture. Any worthy notion of mind or reason includes them. The proof of\nthem is, 1st, their comprehensiveness and consistency with one another;\n2ndly, their agreement with history and experience. But sensation is of\nthe present only, is isolated, is and is not in successive moments. It\ntakes the passing hour as it comes, following the lead of the eye or\near instead of the command of reason. It is a faculty which man has in\ncommon with the animals, and in which he is inferior to many of them.\nThe importance of the senses in us is that they are the apertures of the\nmind, doors and windows through which we take in and make our own the\nmaterials of knowledge. Regarded in any other point of view sensation\nis of all mental acts the most trivial and superficial. Hence the term\n'sensational' is rightly used to express what is shallow in thought and\nfeeling.\n\nWe propose in what follows, first of all, like Plato in the Theaetetus,\nto analyse sensation, and secondly to trace the connexion between\ntheories of sensation and a sensational or Epicurean philosophy.\n\nParagraph I. We, as well as the ancients, speak of the five senses, and\nof a sense, or common sense, which is the abstraction of them. The\nterm 'sense' is also used metaphorically, both in ancient and modern\nphilosophy, to express the operations of the mind which are immediate or\nintuitive. Of the five senses, two--the sight and the hearing--are of\na more subtle and complex nature, while two others--the smell and the\ntaste--seem to be only more refined varieties of touch. All of them\nare passive, and by this are distinguished from the active faculty of\nspeech: they receive impressions, but do not produce them, except in so\nfar as they are objects of sense themselves.\n\nPhysiology speaks to us of the wonderful apparatus of nerves, muscles,\ntissues, by which the senses are enabled to fulfil their functions. It\ntraces the connexion, though imperfectly, of the bodily organs with the\noperations of the mind. Of these latter, it seems rather to know the\nconditions than the causes. It can prove to us that without the brain we\ncannot think, and that without the eye we cannot see: and yet there is\nfar more in thinking and seeing than is given by the brain and the eye.\nIt observes the 'concomitant variations' of body and mind. Psychology,\non the other hand, treats of the same subject regarded from another\npoint of view. It speaks of the relation of the senses to one another;\nit shows how they meet the mind; it analyzes the transition from sense\nto thought. The one describes their nature as apparent to the outward\neye; by the other they are regarded only as the instruments of the mind.\nIt is in this latter point of view that we propose to consider them.\n\nThe simplest sensation involves an unconscious or nascent operation\nof the mind; it implies objects of sense, and objects of sense have\ndifferences of form, number, colour. But the conception of an object\nwithout us, or the power of discriminating numbers, forms, colours,\nis not given by the sense, but by the mind. A mere sensation does not\nattain to distinctness: it is a confused impression, sugkechumenon ti,\nas Plato says (Republic), until number introduces light and order\ninto the confusion. At what point confusion becomes distinctness is a\nquestion of degree which cannot be precisely determined. The distant\nobject, the undefined notion, come out into relief as we approach\nthem or attend to them. Or we may assist the analysis by attempting\nto imagine the world first dawning upon the eye of the infant or of a\nperson newly restored to sight. Yet even with them the mind as well\nas the eye opens or enlarges. For all three are inseparably bound\ntogether--the object would be nowhere and nothing, if not perceived by\nthe sense, and the sense would have no power of distinguishing without\nthe mind.\n\nBut prior to objects of sense there is a third nature in which they\nare contained--that is to say, space, which may be explained in various\nways. It is the element which surrounds them; it is the vacuum or void\nwhich they leave or occupy when passing from one portion of space to\nanother. It might be described in the language of ancient philosophy, as\n'the Not-being' of objects. It is a negative idea which in the course\nof ages has become positive. It is originally derived from the\ncontemplation of the world without us--the boundless earth or sea, the\nvacant heaven, and is therefore acquired chiefly through the sense of\nsight: to the blind the conception of space is feeble and inadequate,\nderived for the most part from touch or from the descriptions of others.\nAt first it appears to be continuous; afterwards we perceive it to be\ncapable of division by lines or points, real or imaginary. By the\nhelp of mathematics we form another idea of space, which is altogether\nindependent of experience. Geometry teaches us that the innumerable\nlines and figures by which space is or may be intersected are absolutely\ntrue in all their combinations and consequences. New and unchangeable\nproperties of space are thus developed, which are proved to us in a\nthousand ways by mathematical reasoning as well as by common experience.\nThrough quantity and measure we are conducted to our simplest and purest\nnotion of matter, which is to the cube or solid what space is to\nthe square or surface. And all our applications of mathematics are\napplications of our ideas of space to matter. No wonder then that they\nseem to have a necessary existence to us. Being the simplest of our\nideas, space is also the one of which we have the most difficulty in\nridding ourselves. Neither can we set a limit to it, for wherever we\nfix a limit, space is springing up beyond. Neither can we conceive a\nsmallest or indivisible portion of it; for within the smallest there\nis a smaller still; and even these inconceivable qualities of space,\nwhether the infinite or the infinitesimal, may be made the subject of\nreasoning and have a certain truth to us.\n\nWhether space exists in the mind or out of it, is a question which has\nno meaning. We should rather say that without it the mind is incapable\nof conceiving the body, and therefore of conceiving itself. The mind may\nbe indeed imagined to contain the body, in the same way that Aristotle\n(partly following Plato) supposes God to be the outer heaven or circle\nof the universe. But how can the individual mind carry about the\nuniverse of space packed up within, or how can separate minds have\neither a universe of their own or a common universe? In such conceptions\nthere seems to be a confusion of the individual and the universal. To\nsay that we can only have a true idea of ourselves when we deny the\nreality of that by which we have any idea of ourselves is an absurdity.\nThe earth which is our habitation and 'the starry heaven above' and\nwe ourselves are equally an illusion, if space is only a quality or\ncondition of our minds.\n\nAgain, we may compare the truths of space with other truths derived from\nexperience, which seem to have a necessity to us in proportion to the\nfrequency of their recurrence or the truth of the consequences which may\nbe inferred from them. We are thus led to remark that the necessity\nin our ideas of space on which much stress has been laid, differs in a\nslight degree only from the necessity which appears to belong to other\nof our ideas, e.g. weight, motion, and the like. And there is another\nway in which this necessity may be explained. We have been taught it,\nand the truth which we were taught or which we inherited has never been\ncontradicted in all our experience and is therefore confirmed by it. Who\ncan resist an idea which is presented to him in a general form in every\nmoment of his life and of which he finds no instance to the contrary?\nThe greater part of what is sometimes regarded as the a priori intuition\nof space is really the conception of the various geometrical figures of\nwhich the properties have been revealed by mathematical analysis. And\nthe certainty of these properties is immeasurably increased to us by our\nfinding that they hold good not only in every instance, but in all the\nconsequences which are supposed to flow from them.\n\nNeither must we forget that our idea of space, like our other ideas,\nhas a history. The Homeric poems contain no word for it; even the later\nGreek philosophy has not the Kantian notion of space, but only the\ndefinite 'place' or 'the infinite.' To Plato, in the Timaeus, it is\nknown only as the 'nurse of generation.' When therefore we speak of\nthe necessity of our ideas of space we must remember that this is a\nnecessity which has grown up with the growth of the human mind, and\nhas been made by ourselves. We can free ourselves from the perplexities\nwhich are involved in it by ascending to a time in which they did not\nas yet exist. And when space or time are described as 'a priori forms or\nintuitions added to the matter given in sensation,' we should consider\nthat such expressions belong really to the 'pre-historic study' of\nphilosophy, i.e. to the eighteenth century, when men sought to explain\nthe human mind without regard to history or language or the social\nnature of man.\n\nIn every act of sense there is a latent perception of space, of which\nwe only become conscious when objects are withdrawn from it. There are\nvarious ways in which we may trace the connexion between them. We may\nthink of space as unresisting matter, and of matter as divided into\nobjects; or of objects again as formed by abstraction into a collective\nnotion of matter, and of matter as rarefied into space. And motion may\nbe conceived as the union of there and not there in space, and force\nas the materializing or solidification of motion. Space again is the\nindividual and universal in one; or, in other words, a perception and\nalso a conception. So easily do what are sometimes called our simple\nideas pass into one another, and differences of kind resolve themselves\ninto differences of degree.\n\nWithin or behind space there is another abstraction in many respects\nsimilar to it--time, the form of the inward, as space is the form of the\noutward. As we cannot think of outward objects of sense or of outward\nsensations without space, so neither can we think of a succession of\nsensations without time. It is the vacancy of thoughts or sensations,\nas space is the void of outward objects, and we can no more imagine\nthe mind without the one than the world without the other. It is to\narithmetic what space is to geometry; or, more strictly, arithmetic may\nbe said to be equally applicable to both. It is defined in our minds,\npartly by the analogy of space and partly by the recollection of events\nwhich have happened to us, or the consciousness of feelings which we are\nexperiencing. Like space, it is without limit, for whatever beginning or\nend of time we fix, there is a beginning and end before them, and so\non without end. We speak of a past, present, and future, and again the\nanalogy of space assists us in conceiving of them as coexistent. When\nthe limit of time is removed there arises in our minds the idea of\neternity, which at first, like time itself, is only negative, but\ngradually, when connected with the world and the divine nature, like\nthe other negative infinity of space, becomes positive. Whether time is\nprior to the mind and to experience, or coeval with them, is (like\nthe parallel question about space) unmeaning. Like space it has been\nrealized gradually: in the Homeric poems, or even in the Hesiodic\ncosmogony, there is no more notion of time than of space. The conception\nof being is more general than either, and might therefore with greater\nplausibility be affirmed to be a condition or quality of the mind. The a\npriori intuitions of Kant would have been as unintelligible to Plato as\nhis a priori synthetical propositions to Aristotle. The philosopher of\nKonigsberg supposed himself to be analyzing a necessary mode of thought:\nhe was not aware that he was dealing with a mere abstraction. But now\nthat we are able to trace the gradual developement of ideas through\nreligion, through language, through abstractions, why should we\ninterpose the fiction of time between ourselves and realities? Why\nshould we single out one of these abstractions to be the a priori\ncondition of all the others? It comes last and not first in the order of\nour thoughts, and is not the condition precedent of them, but the last\ngeneralization of them. Nor can any principle be imagined more suicidal\nto philosophy than to assume that all the truth which we are capable of\nattaining is seen only through an unreal medium. If all that exists\nin time is illusion, we may well ask with Plato, 'What becomes of the\nmind?'\n\nLeaving the a priori conditions of sensation we may proceed to consider\nacts of sense. These admit of various degrees of duration or intensity;\nthey admit also of a greater or less extension from one object, which is\nperceived directly, to many which are perceived indirectly or in a less\ndegree, and to the various associations of the object which are latent\nin the mind. In general the greater the intension the less the extension\nof them. The simplest sensation implies some relation of objects to\none another, some position in space, some relation to a previous or\nsubsequent sensation. The acts of seeing and hearing may be almost\nunconscious and may pass away unnoted; they may also leave an impression\nbehind them or power of recalling them. If, after seeing an object we\nshut our eyes, the object remains dimly seen in the same or about the\nsame place, but with form and lineaments half filled up. This is the\nsimplest act of memory. And as we cannot see one thing without at\nthe same time seeing another, different objects hang together in\nrecollection, and when we call for one the other quickly follows. To\nthink of the place in which we have last seen a thing is often the\nbest way of recalling it to the mind. Hence memory is dependent on\nassociation. The act of recollection may be compared to the sight of an\nobject at a great distance which we have previously seen near and seek\nto bring near to us in thought. Memory is to sense as dreaming is to\nwaking; and like dreaming has a wayward and uncertain power of recalling\nimpressions from the past.\n\nThus begins the passage from the outward to the inward sense. But as\nyet there is no conception of a universal--the mind only remembers\nthe individual object or objects, and is always attaching to them some\ncolour or association of sense. The power of recollection seems to\ndepend on the intensity or largeness of the perception, or on the\nstrength of some emotion with which it is inseparably connected. This is\nthe natural memory which is allied to sense, such as children appear to\nhave and barbarians and animals. It is necessarily limited in range, and\nits limitation is its strength. In later life, when the mind has become\ncrowded with names, acts, feelings, images innumerable, we acquire\nby education another memory of system and arrangement which is both\nstronger and weaker than the first--weaker in the recollection\nof sensible impressions as they are represented to us by eye or\near--stronger by the natural connexion of ideas with objects or with one\nanother. And many of the notions which form a part of the train of our\nthoughts are hardly realized by us at the time, but, like numbers or\nalgebraical symbols, are used as signs only, thus lightening the labour\nof recollection.\n\nAnd now we may suppose that numerous images present themselves to the\nmind, which begins to act upon them and to arrange them in various\nways. Besides the impression of external objects present with us or just\nabsent from us, we have a dimmer conception of other objects which have\ndisappeared from our immediate recollection and yet continue to exist in\nus. The mind is full of fancies which are passing to and fro before it.\nSome feeling or association calls them up, and they are uttered by the\nlips. This is the first rudimentary imagination, which may be truly\ndescribed in the language of Hobbes, as 'decaying sense,' an expression\nwhich may be applied with equal truth to memory as well. For memory and\nimagination, though we sometimes oppose them, are nearly allied; the\ndifference between them seems chiefly to lie in the activity of the one\ncompared with the passivity of the other. The sense decaying in memory\nreceives a flash of light or life from imagination. Dreaming is a link\nof connexion between them; for in dreaming we feebly recollect and also\nfeebly imagine at one and the same time. When reason is asleep the\nlower part of the mind wanders at will amid the images which have been\nreceived from without, the intelligent element retires, and the sensual\nor sensuous takes its place. And so in the first efforts of imagination\nreason is latent or set aside; and images, in part disorderly, but also\nhaving a unity (however imperfect) of their own, pour like a flood over\nthe mind. And if we could penetrate into the heads of animals we should\nprobably find that their intelligence, or the state of what in them is\nanalogous to our intelligence, is of this nature.\n\nThus far we have been speaking of men, rather in the points in which\nthey resemble animals than in the points in which they differ from\nthem. The animal too has memory in various degrees, and the elements\nof imagination, if, as appears to be the case, he dreams. How far their\npowers or instincts are educated by the circumstances of their lives\nor by intercourse with one another or with mankind, we cannot precisely\ntell. They, like ourselves, have the physical inheritance of form,\nscent, hearing, sight, and other qualities or instincts. But they\nhave not the mental inheritance of thoughts and ideas handed down by\ntradition, 'the slow additions that build up the mind' of the human\nrace. And language, which is the great educator of mankind, is wanting\nin them; whereas in us language is ever present--even in the infant the\nlatent power of naming is almost immediately observable. And therefore\nthe description which has been already given of the nascent power of\nthe faculties is in reality an anticipation. For simultaneous with their\ngrowth in man a growth of language must be supposed. The child of two\nyears old sees the fire once and again, and the feeble observation of\nthe same recurring object is associated with the feeble utterance of the\nname by which he is taught to call it. Soon he learns to utter the name\nwhen the object is no longer there, but the desire or imagination of it\nis present to him. At first in every use of the word there is a colour\nof sense, an indistinct picture of the object which accompanies it. But\nin later years he sees in the name only the universal or class word, and\nthe more abstract the notion becomes, the more vacant is the image\nwhich is presented to him. Henceforward all the operations of his mind,\nincluding the perceptions of sense, are a synthesis of sensations,\nwords, conceptions. In seeing or hearing or looking or listening the\nsensible impression prevails over the conception and the word. In\nreflection the process is reversed--the outward object fades away into\nnothingness, the name or the conception or both together are everything.\nLanguage, like number, is intermediate between the two, partaking of the\ndefiniteness of the outer and of the universality of the inner world.\nFor logic teaches us that every word is really a universal, and only\ncondescends by the help of position or circumlocution to become the\nexpression of individuals or particulars. And sometimes by using words\nas symbols we are able to give a 'local habitation and a name' to the\ninfinite and inconceivable.\n\nThus we see that no line can be drawn between the powers of sense and\nof reflection--they pass imperceptibly into one another. We may indeed\ndistinguish between the seeing and the closed eye--between the sensation\nand the recollection of it. But this distinction carries us a very\nlittle way, for recollection is present in sight as well as sight\nin recollection. There is no impression of sense which does not\nsimultaneously recall differences of form, number, colour, and the like.\nNeither is such a distinction applicable at all to our internal bodily\nsensations, which give no sign of themselves when unaccompanied with\npain, and even when we are most conscious of them, have often no\nassignable place in the human frame. Who can divide the nerves or great\nnervous centres from the mind which uses them? Who can separate the\npains and pleasures of the mind from the pains and pleasures of the\nbody? The words 'inward and outward,' 'active and passive,' 'mind and\nbody,' are best conceived by us as differences of degree passing into\ndifferences of kind, and at one time and under one aspect acting in\nharmony and then again opposed. They introduce a system and order into\nthe knowledge of our being; and yet, like many other general terms, are\noften in advance of our actual analysis or observation.\n\nAccording to some writers the inward sense is only the fading away or\nimperfect realization of the outward. But this leaves out of sight one\nhalf of the phenomenon. For the mind is not only withdrawn from\nthe world of sense but introduced to a higher world of thought and\nreflection, in which, like the outward sense, she is trained and\neducated. By use the outward sense becomes keener and more intense,\nespecially when confined within narrow limits. The savage with little\nor no thought has a quicker discernment of the track than the civilised\nman; in like manner the dog, having the help of scent as well as of\nsight, is superior to the savage. By use again the inward thought\nbecomes more defined and distinct; what was at first an effort is made\neasy by the natural instrumentality of language, and the mind learns to\ngrasp universals with no more exertion than is required for the sight of\nan outward object. There is a natural connexion and arrangement of them,\nlike the association of objects in a landscape. Just as a note or two of\nmusic suffices to recall a whole piece to the musician's or composer's\nmind, so a great principle or leading thought suggests and arranges a\nworld of particulars. The power of reflection is not feebler than the\nfaculty of sense, but of a higher and more comprehensive nature. It not\nonly receives the universals of sense, but gives them a new content by\ncomparing and combining them with one another. It withdraws from the\nseen that it may dwell in the unseen. The sense only presents us with\na flat and impenetrable surface: the mind takes the world to pieces and\nputs it together on a new pattern. The universals which are detached\nfrom sense are reconstructed in science. They and not the mere\nimpressions of sense are the truth of the world in which we live; and\n(as an argument to those who will only believe 'what they can hold in\ntheir hands') we may further observe that they are the source of our\npower over it. To say that the outward sense is stronger than the\ninward is like saying that the arm of the workman is stronger than the\nconstructing or directing mind.\n\nReturning to the senses we may briefly consider two questions--first\ntheir relation to the mind, secondly, their relation to outward\nobjects:--\n\n1. The senses are not merely 'holes set in a wooden horse' (Theaet.),\nbut instruments of the mind with which they are organically connected.\nThere is no use of them without some use of words--some natural or\nlatent logic--some previous experience or observation. Sensation, like\nall other mental processes, is complex and relative, though apparently\nsimple. The senses mutually confirm and support one another; it is hard\nto say how much our impressions of hearing may be affected by those\nof sight, or how far our impressions of sight may be corrected by the\ntouch, especially in infancy. The confirmation of them by one another\ncannot of course be given by any one of them. Many intuitions which are\ninseparable from the act of sense are really the result of complicated\nreasonings. The most cursory glance at objects enables the experienced\neye to judge approximately of their relations and distance, although\nnothing is impressed upon the retina except colour, including gradations\nof light and shade. From these delicate and almost imperceptible\ndifferences we seem chiefly to derive our ideas of distance and\nposition. By comparison of what is near with what is distant we learn\nthat the tree, house, river, etc. which are a long way off are objects\nof a like nature with those which are seen by us in our immediate\nneighbourhood, although the actual impression made on the eye is very\ndifferent in one case and in the other. This is a language of 'large and\nsmall letters' (Republic), slightly differing in form and exquisitely\ngraduated by distance, which we are learning all our life long, and\nwhich we attain in various degrees according to our powers of sight or\nobservation. There is nor the consideration. The greater or less strain\nupon the nerves of the eye or ear is communicated to the mind and\nsilently informs the judgment. We have also the use not of one eye only,\nbut of two, which give us a wider range, and help us to discern, by the\ngreater or less acuteness of the angle which the rays of sight form,\nthe distance of an object and its relation to other objects. But we are\nalready passing beyond the limits of our actual knowledge on a subject\nwhich has given rise to many conjectures. More important than the\naddition of another conjecture is the observation, whether in the case\nof sight or of any other sense, of the great complexity of the causes\nand the great simplicity of the effect.\n\nThe sympathy of the mind and the ear is no less striking than\nthe sympathy of the mind and the eye. Do we not seem to perceive\ninstinctively and as an act of sense the differences of articulate\nspeech and of musical notes? Yet how small a part of speech or of music\nis produced by the impression of the ear compared with that which is\nfurnished by the mind!\n\nAgain: the more refined faculty of sense, as in animals so also in man,\nseems often to be transmitted by inheritance. Neither must we forget\nthat in the use of the senses, as in his whole nature, man is a social\nbeing, who is always being educated by language, habit, and the teaching\nof other men as well as by his own observation. He knows distance\nbecause he is taught it by a more experienced judgment than his own; he\ndistinguishes sounds because he is told to remark them by a person of\na more discerning ear. And as we inherit from our parents or other\nancestors peculiar powers of sense or feeling, so we improve and\nstrengthen them, not only by regular teaching, but also by sympathy and\ncommunion with other persons.\n\n2. The second question, namely, that concerning the relation of the mind\nto external objects, is really a trifling one, though it has been made\nthe subject of a famous philosophy. We may if we like, with Berkeley,\nresolve objects of sense into sensations; but the change is one of name\nonly, and nothing is gained and something is lost by such a resolution\nor confusion of them. For we have not really made a single step towards\nidealism, and any arbitrary inversion of our ordinary modes of speech is\ndisturbing to the mind. The youthful metaphysician is delighted at his\nmarvellous discovery that nothing is, and that what we see or feel is\nour sensation only: for a day or two the world has a new interest to\nhim; he alone knows the secret which has been communicated to him by the\nphilosopher, that mind is all--when in fact he is going out of his mind\nin the first intoxication of a great thought. But he soon finds that\nall things remain as they were--the laws of motion, the properties of\nmatter, the qualities of substances. After having inflicted his theories\non any one who is willing to receive them 'first on his father and\nmother, secondly on some other patient listener, thirdly on his dog,'\nhe finds that he only differs from the rest of mankind in the use of a\nword. He had once hoped that by getting rid of the solidity of matter he\nmight open a passage to worlds beyond. He liked to think of the world as\nthe representation of the divine nature, and delighted to imagine angels\nand spirits wandering through space, present in the room in which he is\nsitting without coming through the door, nowhere and everywhere at the\nsame instant. At length he finds that he has been the victim of his own\nfancies; he has neither more nor less evidence of the supernatural than\nhe had before. He himself has become unsettled, but the laws of the\nworld remain fixed as at the beginning. He has discovered that his\nappeal to the fallibility of sense was really an illusion. For whatever\nuncertainty there may be in the appearances of nature, arises only out\nof the imperfection or variation of the human senses, or possibly from\nthe deficiency of certain branches of knowledge; when science is able to\napply her tests, the uncertainty is at an end. We are apt sometimes\nto think that moral and metaphysical philosophy are lowered by the\ninfluence which is exercised over them by physical science. But any\ninterpretation of nature by physical science is far in advance of such\nidealism. The philosophy of Berkeley, while giving unbounded license to\nthe imagination, is still grovelling on the level of sense.\n\nWe may, if we please, carry this scepticism a step further, and\ndeny, not only objects of sense, but the continuity of our sensations\nthemselves. We may say with Protagoras and Hume that what is appears,\nand that what appears appears only to individuals, and to the same\nindividual only at one instant. But then, as Plato asks,--and we must\nrepeat the question,--What becomes of the mind? Experience tells us by a\nthousand proofs that our sensations of colour, taste, and the like,\nare the same as they were an instant ago--that the act which we are\nperforming one minute is continued by us in the next--and also\nsupplies abundant proof that the perceptions of other men are, speaking\ngenerally, the same or nearly the same with our own. After having slowly\nand laboriously in the course of ages gained a conception of a whole and\nparts, of the constitution of the mind, of the relation of man to God\nand nature, imperfect indeed, but the best we can, we are asked to\nreturn again to the 'beggarly elements' of ancient scepticism, and\nacknowledge only atoms and sensations devoid of life or unity. Why\nshould we not go a step further still and doubt the existence of the\nsenses of all things? We are but 'such stuff as dreams are made of;'\nfor we have left ourselves no instruments of thought by which we can\ndistinguish man from the animals, or conceive of the existence even of a\nmollusc. And observe, this extreme scepticism has been allowed to spring\nup among us, not, like the ancient scepticism, in an age when nature and\nlanguage really seemed to be full of illusions, but in the eighteenth\nand nineteenth centuries, when men walk in the daylight of inductive\nscience.\n\nThe attractiveness of such speculations arises out of their true nature\nnot being perceived. They are veiled in graceful language; they are not\npushed to extremes; they stop where the human mind is disposed also to\nstop--short of a manifest absurdity. Their inconsistency is not observed\nby their authors or by mankind in general, who are equally inconsistent\nthemselves. They leave on the mind a pleasing sense of wonder and\nnovelty: in youth they seem to have a natural affinity to one class of\npersons as poetry has to another; but in later life either we drift\nback into common sense, or we make them the starting-points of a higher\nphilosophy.\n\nWe are often told that we should enquire into all things before we\naccept them;--with what limitations is this true? For we cannot use\nour senses without admitting that we have them, or think without\npresupposing that there is in us a power of thought, or affirm that all\nknowledge is derived from experience without implying that this first\nprinciple of knowledge is prior to experience. The truth seems to be\nthat we begin with the natural use of the mind as of the body, and\nwe seek to describe this as well as we can. We eat before we know the\nnature of digestion; we think before we know the nature of reflection.\nAs our knowledge increases, our perception of the mind enlarges also. We\ncannot indeed get beyond facts, but neither can we draw any line which\nseparates facts from ideas. And the mind is not something separate\nfrom them but included in them, and they in the mind, both having a\ndistinctness and individuality of their own. To reduce our conception of\nmind to a succession of feelings and sensations is like the attempt to\nview a wide prospect by inches through a microscope, or to calculate a\nperiod of chronology by minutes. The mind ceases to exist when it loses\nits continuity, which though far from being its highest determination,\nis yet necessary to any conception of it. Even an inanimate nature\ncannot be adequately represented as an endless succession of states or\nconditions.\n\nParagraph II. Another division of the subject has yet to be considered:\nWhy should the doctrine that knowledge is sensation, in ancient times,\nor of sensationalism or materialism in modern times, be allied to the\nlower rather than to the higher view of ethical philosophy? At\nfirst sight the nature and origin of knowledge appear to be wholly\ndisconnected from ethics and religion, nor can we deny that the ancient\nStoics were materialists, or that the materialist doctrines prevalent\nin modern times have been associated with great virtues, or that both\nreligious and philosophical idealism have not unfrequently parted\ncompany with practice. Still upon the whole it must be admitted that the\nhigher standard of duty has gone hand in hand with the higher conception\nof knowledge. It is Protagoras who is seeking to adapt himself to\nthe opinions of the world; it is Plato who rises above them: the one\nmaintaining that all knowledge is sensation; the other basing the\nvirtues on the idea of good. The reason of this phenomenon has now to be\nexamined.\n\nBy those who rest knowledge immediately upon sense, that explanation of\nhuman action is deemed to be the truest which is nearest to sense. As\nknowledge is reduced to sensation, so virtue is reduced to feeling,\nhappiness or good to pleasure. The different virtues--the various\ncharacters which exist in the world--are the disguises of self-interest.\nHuman nature is dried up; there is no place left for imagination, or in\nany higher sense for religion. Ideals of a whole, or of a state, or of a\nlaw of duty, or of a divine perfection, are out of place in an Epicurean\nphilosophy. The very terms in which they are expressed are suspected of\nhaving no meaning. Man is to bring himself back as far as he is able to\nthe condition of a rational beast. He is to limit himself to the pursuit\nof pleasure, but of this he is to make a far-sighted calculation;--he is\nto be rationalized, secularized, animalized: or he is to be an amiable\nsceptic, better than his own philosophy, and not falling below the\nopinions of the world.\n\nImagination has been called that 'busy faculty' which is always\nintruding upon us in the search after truth. But imagination is also\nthat higher power by which we rise above ourselves and the commonplaces\nof thought and life. The philosophical imagination is another name for\nreason finding an expression of herself in the outward world. To deprive\nlife of ideals is to deprive it of all higher and comprehensive aims and\nof the power of imparting and communicating them to others. For men are\ntaught, not by those who are on a level with them, but by those who rise\nabove them, who see the distant hills, who soar into the empyrean. Like\na bird in a cage, the mind confined to sense is always being brought\nback from the higher to the lower, from the wider to the narrower view\nof human knowledge. It seeks to fly but cannot: instead of aspiring\ntowards perfection, 'it hovers about this lower world and the earthly\nnature.' It loses the religious sense which more than any other seems to\ntake a man out of himself. Weary of asking 'What is truth?' it accepts\nthe 'blind witness of eyes and ears;' it draws around itself the curtain\nof the physical world and is satisfied. The strength of a sensational\nphilosophy lies in the ready accommodation of it to the minds of men;\nmany who have been metaphysicians in their youth, as they advance in\nyears are prone to acquiesce in things as they are, or rather appear to\nbe. They are spectators, not thinkers, and the best philosophy is that\nwhich requires of them the least amount of mental effort.\n\nAs a lower philosophy is easier to apprehend than a higher, so a lower\nway of life is easier to follow; and therefore such a philosophy seems\nto derive a support from the general practice of mankind. It appeals to\nprinciples which they all know and recognize: it gives back to them in a\ngeneralized form the results of their own experience. To the man of the\nworld they are the quintessence of his own reflections upon life. To\nfollow custom, to have no new ideas or opinions, not to be straining\nafter impossibilities, to enjoy to-day with just so much forethought as\nis necessary to provide for the morrow, this is regarded by the greater\npart of the world as the natural way of passing through existence. And\nmany who have lived thus have attained to a lower kind of happiness\nor equanimity. They have possessed their souls in peace without ever\nallowing them to wander into the region of religious or political\ncontroversy, and without any care for the higher interests of man. But\nnearly all the good (as well as some of the evil) which has ever been\ndone in this world has been the work of another spirit, the work of\nenthusiasts and idealists, of apostles and martyrs. The leaders\nof mankind have not been of the gentle Epicurean type; they have\npersonified ideas; they have sometimes also been the victims of them.\nBut they have always been seeking after a truth or ideal of which they\nfell short; and have died in a manner disappointed of their hopes that\nthey might lift the human race out of the slough in which they found\nthem. They have done little compared with their own visions and\naspirations; but they have done that little, only because they sought to\ndo, and once perhaps thought that they were doing, a great deal more.\n\nThe philosophies of Epicurus or Hume give no adequate or dignified\nconception of the mind. There is no organic unity in a succession of\nfeeling or sensations; no comprehensiveness in an infinity of separate\nactions. The individual never reflects upon himself as a whole; he can\nhardly regard one act or part of his life as the cause or effect of any\nother act or part. Whether in practice or speculation, he is to himself\nonly in successive instants. To such thinkers, whether in ancient or in\nmodern times, the mind is only the poor recipient of impressions--not\nthe heir of all the ages, or connected with all other minds. It\nbegins again with its own modicum of experience having only such vague\nconceptions of the wisdom of the past as are inseparable from language\nand popular opinion. It seeks to explain from the experience of the\nindividual what can only be learned from the history of the world. It\nhas no conception of obligation, duty, conscience--these are to the\nEpicurean or Utilitarian philosopher only names which interfere with our\nnatural perceptions of pleasure and pain.\n\nThere seem then to be several answers to the question, Why the theory\nthat all knowledge is sensation is allied to the lower rather than to\nthe higher view of ethical philosophy:--1st, Because it is easier to\nunderstand and practise; 2ndly, Because it is fatal to the pursuit of\nideals, moral, political, or religious; 3rdly, Because it deprives us of\nthe means and instruments of higher thought, of any adequate conception\nof the mind, of knowledge, of conscience, of moral obligation.\n\n...\n\nON THE NATURE AND LIMITS Of PSYCHOLOGY.\n\n     O gar arche men o me oide, teleute de kai ta metaxu ex ou me\n     oide sumpeplektai, tis mechane ten toiauten omologian pote\n     epistemen genesthai; Plato Republic.\n\n     Monon gar auto legeiv, osper gumnon kai aperemomenon apo ton\n     onton apanton, adunaton.  Soph.\n\nSince the above essay first appeared, many books on Psychology have been\ngiven to the world, partly based upon the views of Herbart and other\nGerman philosophers, partly independent of them. The subject has gained\nin bulk and extent; whether it has had any true growth is more doubtful.\nIt begins to assume the language and claim the authority of a science;\nbut it is only an hypothesis or outline, which may be filled up in many\nways according to the fancy of individual thinkers. The basis of it is\na precarious one,--consciousness of ourselves and a somewhat uncertain\nobservation of the rest of mankind. Its relations to other sciences\nare not yet determined: they seem to be almost too complicated to be\nascertained. It may be compared to an irregular building, run up hastily\nand not likely to last, because its foundations are weak, and in many\nplaces rest only on the surface of the ground. It has sought rather to\nput together scattered observations and to make them into a system than\nto describe or prove them. It has never severely drawn the line between\nfacts and opinions. It has substituted a technical phraseology for the\ncommon use of language, being neither able to win acceptance for the one\nnor to get rid of the other.\n\nThe system which has thus arisen appears to be a kind of metaphysic\nnarrowed to the point of view of the individual mind, through which, as\nthrough some new optical instrument limiting the sphere of vision, the\ninterior of thought and sensation is examined. But the individual mind\nin the abstract, as distinct from the mind of a particular individual\nand separated from the environment of circumstances, is a fiction only.\nYet facts which are partly true gather around this fiction and are\nnaturally described by the help of it. There is also a common type of\nthe mind which is derived from the comparison of many minds with one\nanother and with our own. The phenomena of which Psychology treats are\nfamiliar to us, but they are for the most part indefinite; they relate\nto a something inside the body, which seems also to overleap the limits\nof space. The operations of this something, when isolated, cannot be\nanalyzed by us or subjected to observation and experiment. And there is\nanother point to be considered. The mind, when thinking, cannot\nsurvey that part of itself which is used in thought. It can only\nbe contemplated in the past, that is to say, in the history of the\nindividual or of the world. This is the scientific method of studying\nthe mind. But Psychology has also some other supports, specious rather\nthan real. It is partly sustained by the false analogy of Physical\nScience and has great expectations from its near relationship to\nPhysiology. We truly remark that there is an infinite complexity of\nthe body corresponding to the infinite subtlety of the mind; we are\nconscious that they are very nearly connected. But in endeavouring to\ntrace the nature of the connexion we are baffled and disappointed. In\nour knowledge of them the gulf remains the same: no microscope has ever\nseen into thought; no reflection on ourselves has supplied the missing\nlink between mind and matter...These are the conditions of this very\ninexact science, and we shall only know less of it by pretending to\nknow more, or by assigning to it a form or style to which it has not yet\nattained and is not really entitled.\n\nExperience shows that any system, however baseless and ineffectual, in\nour own or in any other age, may be accepted and continue to be studied,\nif it seeks to satisfy some unanswered question or is based upon some\nancient tradition, especially if it takes the form and uses the language\nof inductive philosophy. The fact therefore that such a science exists\nand is popular, affords no evidence of its truth or value. Many who have\npursued it far into detail have never examined the foundations on which\nit rests. The have been many imaginary subjects of knowledge of which\nenthusiastic persons have made a lifelong study, without ever asking\nthemselves what is the evidence for them, what is the use of them, how\nlong they will last? They may pass away, like the authors of them, and\n'leave not a wrack behind;' or they may survive in fragments. Nor is it\nonly in the Middle Ages, or in the literary desert of China or of India,\nthat such systems have arisen; in our own enlightened age, growing up\nby the side of Physics, Ethics, and other really progressive sciences,\nthere is a weary waste of knowledge, falsely so-called. There are sham\nsciences which no logic has ever put to the test, in which the desire\nfor knowledge invents the materials of it.\n\nAnd therefore it is expedient once more to review the bases of\nPsychology, lest we should be imposed upon by its pretensions. The\nstudy of it may have done good service by awakening us to the sense of\ninveterate errors familiarized by language, yet it may have fallen into\nstill greater ones; under the pretence of new investigations it may be\nwasting the lives of those who are engaged in it. It may also be found\nthat the discussion of it will throw light upon some points in the\nTheaetetus of Plato,--the oldest work on Psychology which has come down\nto us. The imaginary science may be called, in the language of ancient\nphilosophy, 'a shadow of a part of Dialectic or Metaphysic' (Gorg.).\n\nIn this postscript or appendix we propose to treat, first, of the true\nbases of Psychology; secondly, of the errors into which the students of\nit are most likely to fall; thirdly, of the principal subjects which\nare usually comprehended under it; fourthly, of the form which facts\nrelating to the mind most naturally assume.\n\nWe may preface the enquiry by two or three remarks:--\n\n(1) We do not claim for the popular Psychology the position of a science\nat all; it cannot, like the Physical Sciences, proceed by the Inductive\nMethod: it has not the necessity of Mathematics: it does not, like\nMetaphysic, argue from abstract notions or from internal coherence. It\nis made up of scattered observations. A few of these, though they may\nsometimes appear to be truisms, are of the greatest value, and free\nfrom all doubt. We are conscious of them in ourselves; we observe them\nworking in others; we are assured of them at all times. For example, we\nare absolutely certain, (a) of the influence exerted by the mind over\nthe body or by the body over the mind: (b) of the power of association,\nby which the appearance of some person or the occurrence of some event\nrecalls to mind, not always but often, other persons and events: (c)\nof the effect of habit, which is strongest when least disturbed by\nreflection, and is to the mind what the bones are to the body: (d) of\nthe real, though not unlimited, freedom of the human will: (e) of the\nreference, more or less distinct, of our sensations, feelings, thoughts,\nactions, to ourselves, which is called consciousness, or, when in\nexcess, self-consciousness: (f) of the distinction of the 'I' and 'Not\nI,' of ourselves and outward objects. But when we attempt to gather up\nthese elements in a single system, we discover that the links by which\nwe combine them are apt to be mere words. We are in a country which\nhas never been cleared or surveyed; here and there only does a gleam of\nlight come through the darkness of the forest.\n\n(2) These fragments, although they can never become science in the\nordinary sense of the word, are a real part of knowledge and may be of\ngreat value in education. We may be able to add a good deal to them from\nour own experience, and we may verify them by it. Self-examination\nis one of those studies which a man can pursue alone, by attention to\nhimself and the processes of his individual mind. He may learn much\nabout his own character and about the character of others, if he will\n'make his mind sit down' and look at itself in the glass. The great, if\nnot the only use of such a study is a practical one,--to know, first,\nhuman nature, and, secondly, our own nature, as it truly is.\n\n(3) Hence it is important that we should conceive of the mind in the\nnoblest and simplest manner. While acknowledging that language has been\nthe greatest factor in the formation of human thought, we must endeavour\nto get rid of the disguises, oppositions, contradictions, which\narise out of it. We must disengage ourselves from the ideas which the\ncustomary use of words has implanted in us. To avoid error as much as\npossible when we are speaking of things unseen, the principal terms\nwhich we use should be few, and we should not allow ourselves to be\nenslaved by them. Instead of seeking to frame a technical language,\nwe should vary our forms of speech, lest they should degenerate into\nformulas. A difficult philosophical problem is better understood when\ntranslated into the vernacular.\n\nI.a. Psychology is inseparable from language, and early language\ncontains the first impressions or the oldest experience of man\nrespecting himself. These impressions are not accurate representations\nof the truth; they are the reflections of a rudimentary age of\nphilosophy. The first and simplest forms of thought are rooted so deep\nin human nature that they can never be got rid of; but they have been\nperpetually enlarged and elevated, and the use of many words has been\ntransferred from the body to the mind. The spiritual and intellectual\nhave thus become separated from the material--there is a cleft between\nthem; and the heart and the conscience of man rise above the dominion\nof the appetites and create a new language in which they too find\nexpression. As the differences of actions begin to be perceived, more\nand more names are needed. This is the first analysis of the human mind;\nhaving a general foundation in popular experience, it is moulded to\na certain extent by hierophants and philosophers. (See Introd. to\nCratylus.)\n\nb. This primitive psychology is continually receiving additions from the\nfirst thinkers, who in return take a colour from the popular language\nof the time. The mind is regarded from new points of view, and becomes\nadapted to new conditions of knowledge. It seeks to isolate itself\nfrom matter and sense, and to assert its independence in thought. It\nrecognizes that it is independent of the external world. It has five\nor six natural states or stages:--(1) sensation, in which it is almost\nlatent or quiescent: (2) feeling, or inner sense, when the mind is just\nawakening: (3) memory, which is decaying sense, and from time to time,\nas with a spark or flash, has the power of recollecting or reanimating\nthe buried past: (4) thought, in which images pass into abstract notions\nor are intermingled with them: (5) action, in which the mind moves\nforward, of itself, or under the impulse of want or desire or pain,\nto attain or avoid some end or consequence: and (6) there is the\ncomposition of these or the admixture or assimilation of them in various\ndegrees. We never see these processes of the mind, nor can we tell the\ncauses of them. But we know them by their results, and learn from other\nmen that so far as we can describe to them or they to us the workings of\nthe mind, their experience is the same or nearly the same with our own.\n\nc. But the knowledge of the mind is not to any great extent derived\nfrom the observation of the individual by himself. It is the growing\nconsciousness of the human race, embodied in language, acknowledged\nby experience, and corrected from time to time by the influence of\nliterature and philosophy. A great, perhaps the most important, part of\nit is to be found in early Greek thought. In the Theaetetus of Plato it\nhas not yet become fixed: we are still stumbling on the threshold.\nIn Aristotle the process is more nearly completed, and has gained\ninnumerable abstractions, of which many have had to be thrown away\nbecause relative only to the controversies of the time. In the interval\nbetween Thales and Aristotle were realized the distinctions of mind and\nbody, of universal and particular, of infinite and infinitesimal, of\nidea and phenomenon; the class conceptions of faculties and virtues, the\nantagonism of the appetites and the reason; and connected with this, at\na higher stage of development, the opposition of moral and intellectual\nvirtue; also the primitive conceptions of unity, being, rest, motion,\nand the like. These divisions were not really scientific, but rather\nbased on popular experience. They were not held with the precision of\nmodern thinkers, but taken all together they gave a new existence to the\nmind in thought, and greatly enlarged and more accurately defined man's\nknowledge of himself and of the world. The majority of them have been\naccepted by Christian and Western nations. Yet in modern times we have\nalso drifted so far away from Aristotle, that if we were to frame a\nsystem on his lines we should be at war with ordinary language and\nuntrue to our own consciousness. And there have been a few both in\nmediaeval times and since the Reformation who have rebelled against the\nAristotelian point of view. Of these eccentric thinkers there have been\nvarious types, but they have all a family likeness. According to them,\nthere has been too much analysis and too little synthesis, too much\ndivision of the mind into parts and too little conception of it as a\nwhole or in its relation to God and the laws of the universe. They have\nthought that the elements of plurality and unity have not been duly\nadjusted. The tendency of such writers has been to allow the personality\nof man to be absorbed in the universal, or in the divine nature, and to\ndeny the distinction between matter and mind, or to substitute one for\nthe other. They have broken some of the idols of Psychology: they have\nchallenged the received meaning of words: they have regarded the mind\nunder many points of view. But though they may have shaken the old, they\nhave not established the new; their views of philosophy, which seem like\nthe echo of some voice from the East, have been alien to the mind of\nEurope.\n\nd. The Psychology which is found in common language is in some degree\nverified by experience, but not in such a manner as to give it\nthe character of an exact science. We cannot say that words always\ncorrespond to facts. Common language represents the mind from different\nand even opposite points of view, which cannot be all of them equally\ntrue (compare Cratylus). Yet from diversity of statements and opinions\nmay be obtained a nearer approach to the truth than is to be gained\nfrom any one of them. It also tends to correct itself, because it is\ngradually brought nearer to the common sense of mankind. There are\nsome leading categories or classifications of thought, which, though\nunverified, must always remain the elements from which the science or\nstudy of the mind proceeds. For example, we must assume ideas before we\ncan analyze them, and also a continuing mind to which they belong;\nthe resolution of it into successive moments, which would say, with\nProtagoras, that the man is not the same person which he was a minute\nago, is, as Plato implies in the Theaetetus, an absurdity.\n\ne. The growth of the mind, which may be traced in the histories of\nreligions and philosophies and in the thoughts of nations, is one of the\ndeepest and noblest modes of studying it. Here we are dealing with the\nreality, with the greater and, as it may be termed, the most sacred part\nof history. We study the mind of man as it begins to be inspired by a\nhuman or divine reason, as it is modified by circumstances, as it is\ndistributed in nations, as it is renovated by great movements, which go\nbeyond the limits of nations and affect human society on a scale still\ngreater, as it is created or renewed by great minds, who, looking down\nfrom above, have a wider and more comprehensive vision. This is an\nambitious study, of which most of us rather 'entertain conjecture'\nthan arrive at any detailed or accurate knowledge. Later arises the\nreflection how these great ideas or movements of the world have\nbeen appropriated by the multitude and found a way to the minds of\nindividuals. The real Psychology is that which shows how the increasing\nknowledge of nature and the increasing experience of life have always\nbeen slowly transforming the mind, how religions too have been modified\nin the course of ages 'that God may be all and in all.' E pollaplasion,\neoe, to ergon e os nun zeteitai prostatteis.\n\nf. Lastly, though we speak of the study of mind in a special sense, it\nmay also be said that there is no science which does not contribute to\nour knowledge of it. The methods of science and their analogies are new\nfaculties, discovered by the few and imparted to the many. They are\nto the mind, what the senses are to the body; or better, they may be\ncompared to instruments such as the telescope or microscope by which the\ndiscriminating power of the senses, or to other mechanical inventions,\nby which the strength and skill of the human body is so immeasurably\nincreased.\n\nII. The new Psychology, whatever may be its claim to the authority of a\nscience, has called attention to many facts and corrected many errors,\nwhich without it would have been unexamined. Yet it is also itself\nvery liable to illusion. The evidence on which it rests is vague and\nindefinite. The field of consciousness is never seen by us as a whole,\nbut only at particular points, which are always changing. The veil\nof language intercepts facts. Hence it is desirable that in making an\napproach to the study we should consider at the outset what are the\nkinds of error which most easily affect it, and note the differences\nwhich separate it from other branches of knowledge.\n\na. First, we observe the mind by the mind. It would seem therefore that\nwe are always in danger of leaving out the half of that which is the\nsubject of our enquiry. We come at once upon the difficulty of what is\nthe meaning of the word. Does it differ as subject and object in the\nsame manner? Can we suppose one set of feelings or one part of the mind\nto interpret another? Is the introspecting thought the same with the\nthought which is introspected? Has the mind the power of surveying its\nwhole domain at one and the same time?--No more than the eye can take in\nthe whole human body at a glance. Yet there may be a glimpse round the\ncorner, or a thought transferred in a moment from one point of view to\nanother, which enables us to see nearly the whole, if not at once,\nat any rate in succession. Such glimpses will hardly enable us to\ncontemplate from within the mind in its true proportions. Hence the\nfirmer ground of Psychology is not the consciousness of inward feelings\nbut the observation of external actions, being the actions not only of\nourselves, but of the innumerable persons whom we come across in life.\n\nb. The error of supposing partial or occasional explanation of\nmental phenomena to be the only or complete ones. For example, we are\ndisinclined to admit of the spontaneity or discontinuity of the mind--it\nseems to us like an effect without a cause, and therefore we suppose the\ntrain of our thoughts to be always called up by association. Yet it is\nprobable, or indeed certain, that of many mental phenomena there are no\nmental antecedents, but only bodily ones.\n\nc. The false influence of language. We are apt to suppose that when\nthere are two or more words describing faculties or processes of the\nmind, there are real differences corresponding to them. But this is not\nthe case. Nor can we determine how far they do or do not exist, or\nby what degree or kind of difference they are distinguished. The same\nremark may be made about figures of speech. They fill up the vacancy of\nknowledge; they are to the mind what too much colour is to the eye; but\nthe truth is rather concealed than revealed by them.\n\nd. The uncertain meaning of terms, such as Consciousness, Conscience,\nWill, Law, Knowledge, Internal and External Sense; these, in the\nlanguage of Plato, 'we shamelessly use, without ever having taken the\npains to analyze them.'\n\ne. A science such as Psychology is not merely an hypothesis, but\nan hypothesis which, unlike the hypotheses of Physics, can never be\nverified. It rests only on the general impressions of mankind, and there\nis little or no hope of adding in any considerable degree to our stock\nof mental facts.\n\nf. The parallelism of the Physical Sciences, which leads us to analyze\nthe mind on the analogy of the body, and so to reduce mental operations\nto the level of bodily ones, or to confound one with the other.\n\ng. That the progress of Physiology may throw a new light on Psychology\nis a dream in which scientific men are always tempted to indulge. But\nhowever certain we may be of the connexion between mind and body, the\nexplanation of the one by the other is a hidden place of nature which\nhas hitherto been investigated with little or no success.\n\nh. The impossibility of distinguishing between mind and body. Neither\nin thought nor in experience can we separate them. They seem to act\ntogether; yet we feel that we are sometimes under the dominion of the\none, sometimes of the other, and sometimes, both in the common use of\nlanguage and in fact, they transform themselves, the one into the good\nprinciple, the other into the evil principle; and then again the 'I'\ncomes in and mediates between them. It is also difficult to distinguish\noutward facts from the ideas of them in the mind, or to separate the\nexternal stimulus to a sensation from the activity of the organ, or this\nfrom the invisible agencies by which it reaches the mind, or any process\nof sense from its mental antecedent, or any mental energy from its\nnervous expression.\n\ni. The fact that mental divisions tend to run into one another, and that\nin speaking of the mind we cannot always distinguish differences of kind\nfrom differences of degree; nor have we any measure of the strength and\nintensity of our ideas or feelings.\n\nj. Although heredity has been always known to the ancients as well as\nourselves to exercise a considerable influence on human character, yet\nwe are unable to calculate what proportion this birth-influence bears to\nnurture and education. But this is the real question. We cannot pursue\nthe mind into embryology: we can only trace how, after birth, it begins\nto grow. But how much is due to the soil, how much to the original\nlatent seed, it is impossible to distinguish. And because we are certain\nthat heredity exercises a considerable, but undefined influence, we must\nnot increase the wonder by exaggerating it.\n\nk. The love of system is always tending to prevail over the historical\ninvestigation of the mind, which is our chief means of knowing it. It\nequally tends to hinder the other great source of our knowledge of the\nmind, the observation of its workings and processes which we can make\nfor ourselves.\n\nl. The mind, when studied through the individual, is apt to be\nisolated--this is due to the very form of the enquiry; whereas, in\ntruth, it is indistinguishable from circumstances, the very language\nwhich it uses being the result of the instincts of long-forgotten\ngenerations, and every word which a man utters being the answer to some\nother word spoken or suggested by somebody else.\n\nIII. The tendency of the preceding remarks has been to show that\nPsychology is necessarily a fragment, and is not and cannot be a\nconnected system. We cannot define or limit the mind, but we can\ndescribe it. We can collect information about it; we can enumerate the\nprincipal subjects which are included in the study of it. Thus we are\nable to rehabilitate Psychology to some extent, not as a branch of\nscience, but as a collection of facts bearing on human life, as a\npart of the history of philosophy, as an aspect of Metaphysic. It is a\nfragment of a science only, which in all probability can never make any\ngreat progress or attain to much clearness or exactness. It is however\na kind of knowledge which has a great interest for us and is always\npresent to us, and of which we carry about the materials in our own\nbosoms. We can observe our minds and we can experiment upon them, and\nthe knowledge thus acquired is not easily forgotten, and is a help to us\nin study as well as in conduct.\n\nThe principal subjects of Psychology may be summed up as follows:--\n\na. The relation of man to the world around him,--in what sense and\nwithin what limits can he withdraw from its laws or assert himself\nagainst them (Freedom and Necessity), and what is that which we suppose\nto be thus independent and which we call ourselves? How does the inward\ndiffer from the outward and what is the relation between them, and where\ndo we draw the line by which we separate mind from matter, the soul\nfrom the body? Is the mind active or passive, or partly both? Are its\nmovements identical with those of the body, or only preconcerted and\ncoincident with them, or is one simply an aspect of the other?\n\nb. What are we to think of time and space? Time seems to have a nearer\nconnexion with the mind, space with the body; yet time, as well as\nspace, is necessary to our idea of either. We see also that they have\nan analogy with one another, and that in Mathematics they often\ninterpenetrate. Space or place has been said by Kant to be the form of\nthe outward, time of the inward sense. He regards them as parts or\nforms of the mind. But this is an unfortunate and inexpressive way of\ndescribing their relation to us. For of all the phenomena present to the\nhuman mind they seem to have most the character of objective existence.\nThere is no use in asking what is beyond or behind them; we cannot get\nrid of them. And to throw the laws of external nature which to us are\nthe type of the immutable into the subjective side of the antithesis\nseems to be equally inappropriate.\n\nc. When in imagination we enter into the closet of the mind and withdraw\nourselves from the external world, we seem to find there more or less\ndistinct processes which may be described by the words, 'I perceive,' 'I\nfeel,' 'I think,' 'I want,' 'I wish,' 'I like,' 'I dislike,' 'I fear,'\n'I know,' 'I remember,' 'I imagine,' 'I dream,' 'I act,' 'I endeavour,'\n'I hope.' These processes would seem to have the same notions attached\nto them in the minds of all educated persons. They are distinguished\nfrom one another in thought, but they intermingle. It is possible to\nreflect upon them or to become conscious of them in a greater or less\ndegree, or with a greater or less continuity or attention, and thus\narise the intermittent phenomena of consciousness or self-consciousness.\nThe use of all of them is possible to us at all times; and therefore\nin any operation of the mind the whole are latent. But we are able to\ncharacterise them sufficiently by that part of the complex action which\nis the most prominent. We have no difficulty in distinguishing an act\nof sight or an act of will from an act of thought, although thought is\npresent in both of them. Hence the conception of different faculties or\ndifferent virtues is precarious, because each of them is passing into\nthe other, and they are all one in the mind itself; they appear and\nreappear, and may all be regarded as the ever-varying phases or aspects\nor differences of the same mind or person.\n\nd. Nearest the sense in the scale of the intellectual faculties\nis memory, which is a mode rather than a faculty of the mind, and\naccompanies all mental operations. There are two principal kinds of it,\nrecollection and recognition,--recollection in which forgotten things\nare recalled or return to the mind, recognition in which the mind finds\nitself again among things once familiar. The simplest way in which we\ncan represent the former to ourselves is by shutting our eyes and trying\nto recall in what we term the mind's eye the picture of the\nsurrounding scene, or by laying down the book which we are reading and\nrecapitulating what we can remember of it. But many times more powerful\nthan recollection is recognition, perhaps because it is more assisted by\nassociation. We have known and forgotten, and after a long interval the\nthing which we have seen once is seen again by us, but with a different\nfeeling, and comes back to us, not as new knowledge, but as a thing to\nwhich we ourselves impart a notion already present to us; in Plato's\nwords, we set the stamp upon the wax. Every one is aware of the\ndifference between the first and second sight of a place, between a\nscene clothed with associations or bare and divested of them. We say to\nourselves on revisiting a spot after a long interval: How many things\nhave happened since I last saw this! There is probably no impression\never received by us of which we can venture to say that the vestiges are\naltogether lost, or that we might not, under some circumstances, recover\nit. A long-forgotten knowledge may be easily renewed and therefore is\nvery different from ignorance. Of the language learnt in childhood not\na word may be remembered, and yet, when a new beginning is made, the\nold habit soon returns, the neglected organs come back into use, and the\nriver of speech finds out the dried-up channel.\n\ne. 'Consciousness' is the most treacherous word which is employed in\nthe study of the mind, for it is used in many senses, and has rarely,\nif ever, been minutely analyzed. Like memory, it accompanies all mental\noperations, but not always continuously, and it exists in various\ndegrees. It may be imperceptible or hardly perceptible: it may be the\nliving sense that our thoughts, actions, sufferings, are our own. It\nis a kind of attention which we pay to ourselves, and is intermittent\nrather than continuous. Its sphere has been exaggerated. It is sometimes\nsaid to assure us of our freedom; but this is an illusion: as there\nmay be a real freedom without consciousness of it, so there may be a\nconsciousness of freedom without the reality. It may be regarded as a\nhigher degree of knowledge when we not only know but know that we know.\nConsciousness is opposed to habit, inattention, sleep, death. It may be\nillustrated by its derivative conscience, which speaks to men, not only\nof right and wrong in the abstract, but of right and wrong actions in\nreference to themselves and their circumstances.\n\nf. Association is another of the ever-present phenomena of the human\nmind. We speak of the laws of association, but this is an expression\nwhich is confusing, for the phenomenon itself is of the most capricious\nand uncertain sort. It may be briefly described as follows. The simplest\ncase of association is that of sense. When we see or hear separately\none of two things, which we have previously seen or heard together, the\noccurrence of the one has a tendency to suggest the other. So the sight\nor name of a house may recall to our minds the memory of those who once\nlived there. Like may recall like and everything its opposite. The parts\nof a whole, the terms of a series, objects lying near, words having\na customary order stick together in the mind. A word may bring back a\npassage of poetry or a whole system of philosophy; from one end of the\nworld or from one pole of knowledge we may travel to the other in an\nindivisible instant. The long train of association by which we pass from\none point to the other, involving every sort of complex relation, so\nsudden, so accidental, is one of the greatest wonders of mind...This\nprocess however is not always continuous, but often intermittent: we can\nthink of things in isolation as well as in association; we do not mean\nthat they must all hang from one another. We can begin again after an\ninterval of rest or vacancy, as a new train of thought suddenly arises,\nas, for example, when we wake of a morning or after violent exercise.\nTime, place, the same colour or sound or smell or taste, will often\ncall up some thought or recollection either accidentally or naturally\nassociated with them. But it is equally noticeable that the new thought\nmay occur to us, we cannot tell how or why, by the spontaneous action of\nthe mind itself or by the latent influence of the body. Both science and\npoetry are made up of associations or recollections, but we must observe\nalso that the mind is not wholly dependent on them, having also the\npower of origination.\n\nThere are other processes of the mind which it is good for us to study\nwhen we are at home and by ourselves,--the manner in which thought\npasses into act, the conflict of passion and reason in many stages, the\ntransition from sensuality to love or sentiment and from earthly love to\nheavenly, the slow and silent influence of habit, which little by little\nchanges the nature of men, the sudden change of the old nature of man\ninto a new one, wrought by shame or by some other overwhelming impulse.\nThese are the greater phenomena of mind, and he who has thought of\nthem for himself will live and move in a better-ordered world, and will\nhimself be a better-ordered man.\n\nAt the other end of the 'globus intellectualis,' nearest, not to earth\nand sense, but to heaven and God, is the personality of man, by which\nhe holds communion with the unseen world. Somehow, he knows not how,\nsomewhere, he knows not where, under this higher aspect of his being he\ngrasps the ideas of God, freedom and immortality; he sees the forms of\ntruth, holiness and love, and is satisfied with them. No account of the\nmind can be complete which does not admit the reality or the possibility\nof another life. Whether regarded as an ideal or as a fact, the highest\npart of man's nature and that in which it seems most nearly to approach\nthe divine, is a phenomenon which exists, and must therefore be included\nwithin the domain of Psychology.\n\nIV. We admit that there is no perfect or ideal Psychology. It is not a\nwhole in the same sense in which Chemistry, Physiology, or Mathematics\nare wholes: that is to say, it is not a connected unity of knowledge.\nCompared with the wealth of other sciences, it rests upon a small number\nof facts; and when we go beyond these, we fall into conjectures and\nverbal discussions. The facts themselves are disjointed; the causes of\nthem run up into other sciences, and we have no means of tracing\nthem from one to the other. Yet it may be true of this, as of other\nbeginnings of knowledge, that the attempt to put them together has\ntested the truth of them, and given a stimulus to the enquiry into them.\n\nPsychology should be natural, not technical. It should take the form\nwhich is the most intelligible to the common understanding, because it\nhas to do with common things, which are familiar to us all. It should\naim at no more than every reflecting man knows or can easily verify for\nhimself. When simple and unpretentious, it is least obscured by words,\nleast liable to fall under the influence of Physiology or Metaphysic.\nIt should argue, not from exceptional, but from ordinary phenomena. It\nshould be careful to distinguish the higher and the lower elements of\nhuman nature, and not allow one to be veiled in the disguise of the\nother, lest through the slippery nature of language we should pass\nimperceptibly from good to evil, from nature in the higher to nature in\nthe neutral or lower sense. It should assert consistently the unity of\nthe human faculties, the unity of knowledge, the unity of God and law.\nThe difference between the will and the affections and between the\nreason and the passions should also be recognized by it.\n\nIts sphere is supposed to be narrowed to the individual soul; but it\ncannot be thus separated in fact. It goes back to the beginnings of\nthings, to the first growth of language and philosophy, and to the whole\nscience of man. There can be no truth or completeness in any study of\nthe mind which is confined to the individual. The nature of language,\nthough not the whole, is perhaps at present the most important element\nin our knowledge of it. It is not impossible that some numerical laws\nmay be found to have a place in the relations of mind and matter, as in\nthe rest of nature. The old Pythagorean fancy that the soul 'is or has\nin it harmony' may in some degree be realized. But the indications\nof such numerical harmonies are faint; either the secret of them lies\ndeeper than we can discover, or nature may have rebelled against the use\nof them in the composition of men and animals. It is with qualitative\nrather than with quantitative differences that we are concerned\nin Psychology. The facts relating to the mind which we obtain from\nPhysiology are negative rather than positive. They show us, not the\nprocesses of mental action, but the conditions of which when deprived\nthe mind ceases to act. It would seem as if the time had not yet arrived\nwhen we can hope to add anything of much importance to our knowledge\nof the mind from the investigations of the microscope. The elements of\nPsychology can still only be learnt from reflections on ourselves, which\ninterpret and are also interpreted by our experience of others. The\nhistory of language, of philosophy, and religion, the great thoughts or\ninventions or discoveries which move mankind, furnish the larger moulds\nor outlines in which the human mind has been cast. From these the\nindividual derives so much as he is able to comprehend or has the\nopportunity of learning.\n\n\n\n\nTHEAETETUS\n\n\nPERSONS OF THE DIALOGUE: Socrates, Theodorus, Theaetetus.\n\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\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 looking\nfor you, and wondering that I could not find you.\n\nEUCLID: But I was not in the city.\n\nTERPSION: Where then?\n\nEUCLID: As I was going down to the harbour, I met Theaetetus--he was\nbeing carried up to Athens from the army at Corinth.\n\nTERPSION: Was he alive or dead?\n\nEUCLID: He was scarcely alive, for he has been badly wounded; but he was\nsuffering even more from the sickness which has broken out in the army.\n\nTERPSION: The dysentery, you mean?\n\nEUCLID: Yes.\n\nTERPSION: Alas! what a loss he will be!\n\nEUCLID: Yes, Terpsion, he is a noble fellow; only to-day I heard some\npeople highly praising his behaviour in this very battle.\n\nTERPSION: 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\nEUCLID: He wanted to get home: although I entreated and advised him to\nremain, he would not listen to me; so I set him on his way, and turned\nback, and then I remembered what Socrates had said of him, and thought\nhow remarkably this, like all his predictions, had been fulfilled.\nI believe that he had seen him a little before his own death, when\nTheaetetus was a youth, and he had a memorable conversation with him,\nwhich he repeated to me when I came to Athens; he was full of admiration\nof his genius, and said that he would most certainly be a great man, if\nhe lived.\n\nTERPSION: The prophecy has certainly been fulfilled; but what was the\nconversation? can you tell me?\n\nEUCLID: No, indeed, not offhand; but I took notes of it as soon as I got\nhome; these I filled up from memory, writing them out at leisure; and\nwhenever I went to Athens, I asked Socrates about any point which I had\nforgotten, and on my return I made corrections; thus I have nearly the\nwhole conversation written down.\n\nTERPSION: 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, why\nshould we not read it through?--having just come from the country, I\nshould greatly like to rest.\n\nEUCLID: I too shall be very glad of a rest, for I went with Theaetetus\nas far as Erineum. Let us go in, then, and, while we are reposing, the\nservant shall read to us.\n\nTERPSION: Very good.\n\nEUCLID: Here is the roll, Terpsion; I may observe that I have introduced\nSocrates, not as narrating to me, but as actually conversing with the\npersons whom he mentioned--these were, Theodorus the geometrician (of\nCyrene), and Theaetetus. I have omitted, for the sake of convenience,\nthe interlocutory words 'I said,' 'I remarked,' which he used when he\nspoke of himself, and again, 'he agreed,' or 'disagreed,' in the answer,\nlest the repetition of them should be troublesome.\n\nTERPSION: Quite right, Euclid.\n\nEUCLID: 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 would ask\nyou whether there are any rising geometricians or philosophers in that\npart of the world. But I am more interested in our own Athenian youth,\nand I would rather know who among them are likely to do well. I observe\nthem as far as I can myself, and I enquire of any one whom they follow,\nand I see that a great many of them follow you, in which they are quite\nright, considering your eminence in geometry and in other ways. Tell me\nthen, if you have met 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 your\nattention. If he had been a beauty I should have been afraid to praise\nhim, lest you should suppose that I was in love with him; but he is no\nbeauty, and you must not be offended if I say that he is very like you;\nfor he has a snub nose and projecting eyes, although these features are\nless marked in him than in you. Seeing, then, that he has no personal\nattractions, I may freely say, that in all my acquaintance, which is\nvery large, I never knew any one who was his equal in natural gifts: for\nhe has a quickness of apprehension which is almost unrivalled, and he\nis exceedingly gentle, and also the most courageous of men; there is a\nunion of qualities in him such as I have never seen in any other, and\nshould scarcely have thought possible; for those who, like him, have\nquick and ready and retentive wits, have generally also quick tempers;\nthey are ships without ballast, and go darting about, and are mad rather\nthan courageous; and the steadier sort, when they have to face study,\nprove stupid and cannot remember. Whereas he moves surely and smoothly\nand successfully 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\nSOCRATES: That is good news; whose son is he?\n\nTHEODORUS: The name of his father I have forgotten, but the youth\nhimself is the middle one of those who are approaching us; he and his\ncompanions have been anointing themselves in the outer court, and now\nthey seem to have finished, and are coming towards us. Look and see\nwhether you know him.\n\nSOCRATES: I know the youth, but I do not know his name; he is the son of\nEuphronius the Sunian, who was himself an eminent man, and such another\nas his son is, according to your account of him; I believe that he left\na considerable fortune.\n\nTHEODORUS: Theaetetus, Socrates, is his name; but I rather think that\nthe property disappeared in the hands of trustees; notwithstanding which\nhe is wonderfully liberal.\n\nSOCRATES: He must be a fine fellow; tell him to come and sit by me.\n\nTHEODORUS: I will. Come hither, Theaetetus, and sit by Socrates.\n\nSOCRATES: By all means, Theaetetus, in order that I may see the\nreflection of myself in your face, for Theodorus says that we are alike;\nand yet if each of us held in his hands a lyre, and he said that they\nwere tuned alike, should we at once take his word, or should we ask\nwhether he who said so was or was not a musician?\n\nTHEAETETUS: We should ask.\n\nSOCRATES: And if we found that he was, we should take his word; and if\nnot, not?\n\nTHEAETETUS: True.\n\nSOCRATES: And if this supposed likeness of our faces is a matter of any\ninterest to us, we should enquire whether he who says that we are alike\nis a painter or not?\n\nTHEAETETUS: Certainly we should.\n\nSOCRATES: And is Theodorus a painter?\n\nTHEAETETUS: I never heard that he was.\n\nSOCRATES: Is he a geometrician?\n\nTHEAETETUS: Of course he is, Socrates.\n\nSOCRATES: And is he an astronomer and calculator and musician, and in\ngeneral an educated man?\n\nTHEAETETUS: I think so.\n\nSOCRATES: 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\nTHEAETETUS: I should say not.\n\nSOCRATES: But if he praises the virtue or wisdom which are the mental\nendowments of either of us, then he who hears the praises will naturally\ndesire to examine him who is praised: and he again should be willing to\nexhibit himself.\n\nTHEAETETUS: Very true, Socrates.\n\nSOCRATES: 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 one\nas he has been praising you.\n\nTHEAETETUS: I am glad to hear it, Socrates; but what if he was only in\njest?\n\nSOCRATES: Nay, Theodorus is not given to jesting; and I cannot allow you\nto retract your consent on any such pretence as that. If you do, he will\nhave to swear to his words; and we are perfectly sure that no one will\nbe found to impugn him. Do not be shy then, but stand to your word.\n\nTHEAETETUS: I suppose I must, if you wish it.\n\nSOCRATES: In the first place, I should like to ask what you learn of\nTheodorus: something of geometry, perhaps?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And astronomy and harmony and calculation?\n\nTHEAETETUS: I do my best.\n\nSOCRATES: 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 pretty\nwell in general; but there is a little difficulty which I want you and\nthe company to aid me in investigating. Will you answer me a question:\n'Is not learning growing wiser about that which you learn?'\n\nTHEAETETUS: Of course.\n\nSOCRATES: And by wisdom the wise are wise?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And is that different in any way from knowledge?\n\nTHEAETETUS: What?\n\nSOCRATES: Wisdom; are not men wise in that which they know?\n\nTHEAETETUS: Certainly they are.\n\nSOCRATES: Then wisdom and knowledge are the same?\n\nTHEAETETUS: Yes.\n\nSOCRATES: Herein lies the difficulty which I can never solve to my\nsatisfaction--What is knowledge? Can we answer that question? What say\nyou? which of us will speak first? whoever misses shall sit down, as at\na game of ball, and shall be donkey, as the boys say; he who lasts out\nhis competitors in the game without missing, shall be our king,\nand shall have the right of putting to us any questions which he\npleases...Why is there no reply? I hope, Theodorus, that I am not\nbetrayed into rudeness by my love of conversation? I only want to make\nus talk and be friendly and sociable.\n\nTHEODORUS: 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\nI shall, 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 not\nlet him off.\n\nSOCRATES: Do you hear, Theaetetus, what Theodorus says? The philosopher,\nwhom you would not like to disobey, and whose word ought to be a command\nto a young man, bids me interrogate you. Take courage, then, and nobly\nsay what you think that knowledge is.\n\nTHEAETETUS: Well, Socrates, I will answer as you and he bid me; and if I\nmake a mistake, you will doubtless correct me.\n\nSOCRATES: We will, if we can.\n\nTHEAETETUS: 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\nSOCRATES: Too much, Theaetetus, too much; the nobility and liberality of\nyour nature make you give many and diverse things, when I am asking for\none simple thing.\n\nTHEAETETUS: What do you mean, Socrates?\n\nSOCRATES: 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\nTHEAETETUS: Just so.\n\nSOCRATES: And when you speak of carpentering, you mean the art of making\nwooden implements?\n\nTHEAETETUS: I do.\n\nSOCRATES: In both cases you define the subject matter of each of the two\narts?\n\nTHEAETETUS: True.\n\nSOCRATES: 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 the\nnature of knowledge in the abstract. Am I not right?\n\nTHEAETETUS: Perfectly right.\n\nSOCRATES: Let me offer an illustration: Suppose that a person were to\nask about some very trivial and obvious thing--for example, What is\nclay? and we were to reply, that there is a clay of potters, there is\na clay of oven-makers, there is a clay of brick-makers; would not the\nanswer be ridiculous?\n\nTHEAETETUS: Truly.\n\nSOCRATES: 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\nTHEAETETUS: He cannot.\n\nSOCRATES: Then he who does not know what science or knowledge is, has no\nknowledge of the art or science of making shoes?\n\nTHEAETETUS: None.\n\nSOCRATES: Nor of any other science?\n\nTHEAETETUS: No.\n\nSOCRATES: And when a man is asked what science or knowledge is, to\ngive in answer the name of some art or science is ridiculous; for the\nquestion is, 'What is knowledge?' and he replies, 'A knowledge of this\nor that.'\n\nTHEAETETUS: True.\n\nSOCRATES: Moreover, he might answer shortly and simply, but he makes an\nenormous circuit. For example, when asked about the clay, he might have\nsaid simply, that clay is moistened earth--what sort of clay is not to\nthe point.\n\nTHEAETETUS: 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\nSOCRATES: What was that, Theaetetus?\n\nTHEAETETUS: Theodorus was writing out for us something about roots, such\nas the roots of three or five, showing that they are incommensurable by\nthe unit: he selected other examples up to seventeen--there he stopped.\nNow as there are innumerable roots, the notion occurred to us of\nattempting to include them all under one name or class.\n\nSOCRATES: And did you find such a class?\n\nTHEAETETUS: I think that we did; but I should like to have your opinion.\n\nSOCRATES: Let me hear.\n\nTHEAETETUS: We divided all numbers into two classes: those which are\nmade up of equal factors multiplying into one another, which we compared\nto square figures and called square or equilateral numbers;--that was\none class.\n\nSOCRATES: Very good.\n\nTHEAETETUS: The intermediate numbers, such as three and five, and every\nother number which is made up of unequal factors, either of a greater\nmultiplied by a less, or of a less multiplied by a greater, and when\nregarded as a figure, is contained in unequal sides;--all these we\ncompared to oblong figures, and called them oblong numbers.\n\nSOCRATES: Capital; and what followed?\n\nTHEAETETUS: The lines, or sides, which have for their squares the\nequilateral plane numbers, were called by us lengths or magnitudes; and\nthe lines which are the roots of (or whose squares are equal to) the\noblong numbers, were called powers or roots; the reason of this latter\nname being, that they are commensurable with the former [i.e., with the\nso-called lengths or magnitudes] not in linear measurement, but in the\nvalue of the superficial content of their squares; and the same about\nsolids.\n\nSOCRATES: Excellent, my boys; I think that you fully justify the praises\nof Theodorus, and that he will not be found guilty of false witness.\n\nTHEAETETUS: 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\nSOCRATES: 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\nTHEAETETUS: Certainly not.\n\nSOCRATES: 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\nTHEAETETUS: By heaven, they should be the top of all perfection!\n\nSOCRATES: 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\nTHEAETETUS: I am eager enough, Socrates, if that would bring to light\nthe truth.\n\nSOCRATES: 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\nTHEAETETUS: 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 shake\noff a feeling of anxiety.\n\nSOCRATES: These are the pangs of labour, my dear Theaetetus; you have\nsomething within you which you are bringing to the birth.\n\nTHEAETETUS: I do not know, Socrates; I only say what I feel.\n\nSOCRATES: And have you never heard, simpleton, that I am the son of a\nmidwife, brave and burly, whose name was Phaenarete?\n\nTHEAETETUS: Yes, I have.\n\nSOCRATES: And that I myself practise midwifery?\n\nTHEAETETUS: No, never.\n\nSOCRATES: 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; and\ntherefore they only say of me, that I am the strangest of mortals and\ndrive men to their wits' end. Did you ever hear that too?\n\nTHEAETETUS: Yes.\n\nSOCRATES: Shall I tell you the reason?\n\nTHEAETETUS: By all means.\n\nSOCRATES: Bear in mind the whole business of the midwives, and then you\nwill see my meaning better:--No woman, as you are probably aware, who is\nstill able to conceive and bear, attends other women, but only those who\nare past bearing.\n\nTHEAETETUS: Yes, I know.\n\nSOCRATES: 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 herself;\nbut she could not allow the barren to be midwives, because human nature\ncannot know the mystery of an art without experience; and therefore she\nassigned this office to those who are too old to bear.\n\nTHEAETETUS: I dare say.\n\nSOCRATES: And I dare say too, or rather I am absolutely certain, that\nthe midwives know better than others who is pregnant and who is not?\n\nTHEAETETUS: Very true.\n\nSOCRATES: 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 bear\nwho have a difficulty in bearing, and if they think fit they can smother\nthe embryo in the womb.\n\nTHEAETETUS: They can.\n\nSOCRATES: Did you ever remark that they are also most cunning\nmatchmakers, and have a thorough knowledge of what unions are likely to\nproduce a brave brood?\n\nTHEAETETUS: No, never.\n\nSOCRATES: 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 earth,\nwill be most likely to know in what soils the several plants or seeds\nshould be deposited.\n\nTHEAETETUS: Yes, the same art.\n\nSOCRATES: And do you suppose that with women the case is otherwise?\n\nTHEAETETUS: I should think not.\n\nSOCRATES: Certainly not; but midwives 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\nTHEAETETUS: Clearly.\n\nSOCRATES: Such are the midwives, whose task is a very important one, but\nnot so important as mine; for women do not bring into the world at one\ntime real children, and at another time counterfeits which are with\ndifficulty distinguished from them; if they did, then the discernment of\nthe true and false birth would be the crowning achievement of the art of\nmidwifery--you would think so?\n\nTHEAETETUS: Indeed I should.\n\nSOCRATES: Well, my art of midwifery is in most respects like theirs; but\ndiffers, in that I attend men and not women; and look after their souls\nwhen they are in labour, and not after their bodies: and the triumph of\nmy art is in thoroughly examining whether the thought which the mind of\nthe young man brings forth is a false idol or a noble and true birth.\nAnd like the midwives, I am barren, and the reproach which is often\nmade against me, that I ask questions of others and have not the wit to\nanswer them myself, is very just--the reason is, that the god compels me\nto be a midwife, but does not allow me to bring forth. And therefore\nI am not myself at all wise, nor have I anything to show which is\nthe invention or birth of my own soul, but those who converse with me\nprofit. Some of them appear dull enough at first, but afterwards, as\nour acquaintance ripens, if the god is gracious to them, they all make\nastonishing progress; and this in the opinion of others as well as in\ntheir own. It is quite clear that they never learned anything from me;\nthe many fine discoveries to which they cling are of their own making.\nBut to me and the god they owe their delivery. And the proof of my words\nis, that many of them in their ignorance, either in their self-conceit\ndespising me, or falling under the influence of others, have gone away\ntoo soon; and have not only lost the children of whom I had previously\ndelivered them by an ill bringing up, but have stifled whatever else\nthey had in them by evil communications, being fonder of lies and shams\nthan of the truth; and they have at last ended by seeing themselves, as\nothers see them, to be great fools. Aristeides, the son of Lysimachus,\nis one of them, and there are many others. The truants often return to\nme, and beg that I would consort with them again--they are ready to\ngo to me on their knees--and then, if my familiar allows, which is not\nalways the case, I receive them, and they begin to grow again. Dire\nare the pangs which my art is able to arouse and to allay in those who\nconsort with me, just like the pangs of women in childbirth; night and\nday they are full of perplexity and travail which is even worse than\nthat of the women. So much for them. And there are others, Theaetetus,\nwho come to me apparently having nothing in them; and as I know that\nthey have no need of my art, I coax them into marrying some one, and\nby the grace of God I can generally tell who is likely to do them good.\nMany of them I have given away to Prodicus, and many to other inspired\nsages. I tell you this long story, friend Theaetetus, because I suspect,\nas indeed you seem to think yourself, that you are in labour--great with\nsome conception. Come then to me, who am a midwife's son and myself a\nmidwife, and do your best to answer the questions which I will ask you.\nAnd if I abstract and expose your first-born, because I discover upon\ninspection that the conception which you have formed is a vain shadow,\ndo not quarrel with me on that account, as the manner of women is when\ntheir first children are taken from them. For I have actually known some\nwho were ready to bite me when I deprived them of a darling folly; they\ndid not perceive that I acted from goodwill, not knowing that no god is\nthe enemy of man--that was not within the range of their ideas; neither\nam I their enemy in all this, but it would be wrong for me to admit\nfalsehood, or to stifle the truth. Once more, then, Theaetetus, I repeat\nmy old question, 'What is knowledge?'--and do not say that you cannot\ntell; but quit yourself like a man, and by the help of God you will be\nable to tell.\n\nTHEAETETUS: 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 he\nknows, and, as far as I can see at present, knowledge is perception.\n\nSOCRATES: Bravely said, boy; that is the way in which you should express\nyour opinion. And now, let us examine together this conception of yours,\nand see whether it is a true birth or a mere wind-egg:--You say that\nknowledge is perception?\n\nTHEAETETUS: Yes.\n\nSOCRATES: Well, you have delivered yourself of a very important doctrine\nabout knowledge; it is indeed the opinion of Protagoras, who has another\nway of expressing it. Man, he says, is the measure of all things, of the\nexistence of things that are, and of the non-existence of things that\nare not:--You have read him?\n\nTHEAETETUS: O yes, again and again.\n\nSOCRATES: 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\nTHEAETETUS: Yes, he says so.\n\nSOCRATES: 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 cold\nand the other not, or one may be slightly and the other very cold?\n\nTHEAETETUS: Quite true.\n\nSOCRATES: Now is the wind, regarded not in relation to us but\nabsolutely, cold or not; or are we to say, with Protagoras, that the\nwind is cold to him who is cold, and not to him who is not?\n\nTHEAETETUS: I suppose the last.\n\nSOCRATES: Then it must appear so to each of them?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And 'appears to him' means the same as 'he perceives.'\n\nTHEAETETUS: True.\n\nSOCRATES: Then appearing and perceiving coincide in the case of hot and\ncold, and in similar instances; for things appear, or may be supposed to\nbe, to each one such as he perceives them?\n\nTHEAETETUS: Yes.\n\nSOCRATES: Then perception is always of existence, and being the same as\nknowledge is unerring?\n\nTHEAETETUS: Clearly.\n\nSOCRATES: In the name of the Graces, what an almighty wise man\nProtagoras must have been! He spoke these things in a parable to the\ncommon herd, like you and me, but told the truth, 'his Truth,' (In\nallusion to a book of Protagoras' which bore this title.) in secret to\nhis own disciples.\n\nTHEAETETUS: What do you mean, Socrates?\n\nSOCRATES: I am about to speak of a high argument, in which all things\nare said 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 and\nthe heavy light--there is no single thing or quality, but out of motion\nand change and admixture all things are becoming relatively to one\nanother, which 'becoming' is by us incorrectly called being, but is\nreally becoming, for nothing ever is, but all things are becoming.\nSummon all philosophers--Protagoras, Heracleitus, Empedocles, and the\nrest of them, one after another, and with the exception of Parmenides\nthey will agree with you in this. Summon the great masters of either\nkind of poetry--Epicharmus, the prince of Comedy, and Homer of Tragedy;\nwhen the latter sings of\n\n'Ocean whence sprang the gods, and mother Tethys,'\n\ndoes he not mean that all things are the offspring, of flux and motion?\n\nTHEAETETUS: I think so.\n\nSOCRATES: And who could take up arms against such a great army having\nHomer for its general, and not appear ridiculous? (Compare Cratylus.)\n\nTHEAETETUS: Who indeed, Socrates?\n\nSOCRATES: Yes, Theaetetus; and there are plenty of other proofs\nwhich will 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 other\nthings, are born of movement and of friction, which is a kind of\nmotion;--is not this the origin of fire?\n\nTHEAETETUS: It is.\n\nSOCRATES: And the race of animals is generated in the same way?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: And is not the bodily habit spoiled by rest and idleness, but\npreserved for a long time by motion and exercise?\n\nTHEAETETUS: True.\n\nSOCRATES: 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 study,\nis uninformed, and speedily forgets whatever she has learned?\n\nTHEAETETUS: True.\n\nSOCRATES: Then motion is a good, and rest an evil, to the soul as well\nas to the body?\n\nTHEAETETUS: Clearly.\n\nSOCRATES: 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 and\nare preserved, but if they were chained up and their motions ceased,\nthen all things would be destroyed, and, as the saying is, turned upside\ndown.\n\nTHEAETETUS: I believe, Socrates, that you have truly explained his\nmeaning.\n\nSOCRATES: Then now apply his doctrine to perception, my good friend, and\nfirst of all to vision; that which you call white colour is not in your\neyes, and is not a distinct thing which exists out of them. And you must\nnot assign any place to it: for if it had position it would be, and be\nat rest, and there would be no process of becoming.\n\nTHEAETETUS: Then what is colour?\n\nSOCRATES: Let us carry the principle which has just been affirmed, that\nnothing is self-existent, and then we shall see that white, black,\nand every 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 the\nseveral colours appear to a dog or to any animal whatever as they appear\nto you?\n\nTHEAETETUS: Far from it.\n\nSOCRATES: Or that anything appears the same to you as to another man?\nAre you 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\nTHEAETETUS: The latter.\n\nSOCRATES: And if that with which I compare myself in size, or which\nI apprehend 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\nor hot, could this, when unchanged from within, become changed by any\napproximation or affection of any other thing. The fact is that in\nour ordinary way of speaking we allow ourselves to be driven into most\nridiculous and wonderful contradictions, as Protagoras and all who take\nhis line of argument would remark.\n\nTHEAETETUS: How? and of what sort do you mean?\n\nSOCRATES: 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 you\nor any one maintain the contrary?\n\nTHEAETETUS: Very true.\n\nSOCRATES: Well, then, suppose that Protagoras or some one asks whether\nanything can become greater or more if not by increasing, how would you\nanswer him, Theaetetus?\n\nTHEAETETUS: I should say 'No,' Socrates, if I were to speak my mind\nin reference to this last question, and if I were not afraid of\ncontradicting my former answer.\n\nSOCRATES: Capital! excellent! spoken like an oracle, my boy! And if you\nreply 'Yes,' there will be a case for Euripides; for our tongue will be\nunconvinced, but not our mind. (In allusion to the well-known line of\nEuripides, Hippol.: e gloss omomoch e de thren anomotos.)\n\nTHEAETETUS: Very true.\n\nSOCRATES: The thoroughbred Sophists, who know all that can be known\nabout the mind, and argue only out of the superfluity of their wits,\nwould have had a regular sparring-match over this, and would have\nknocked their 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\nTHEAETETUS: Yes, that would be my desire.\n\nSOCRATES: And mine too. But since this is our feeling, and there is\nplenty of time, why should we not calmly and patiently review our own\nthoughts, 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\nTHEAETETUS: Yes.\n\nSOCRATES: Secondly, that without addition or subtraction there is no\nincrease or diminution of anything, but only equality.\n\nTHEAETETUS: Quite true.\n\nSOCRATES: Thirdly, that what was not before cannot be afterwards,\nwithout becoming and having become.\n\nTHEAETETUS: Yes, truly.\n\nSOCRATES: These three axioms, if I am not mistaken, are fighting with\none another 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 height,\nbe not so tall--not that I should have lost, but that you would have\nincreased. In such a case, I am afterwards what I once was not, and yet\nI have not become; for I could not have become without becoming, neither\ncould I have become less without losing somewhat of my height; and I\ncould give you ten thousand examples of similar contradictions, if\nwe admit them at all. I believe that you follow me, Theaetetus; for I\nsuspect that you have thought of these questions before now.\n\nTHEAETETUS: Yes, Socrates, and I am amazed when I think of them; by the\nGods I am! and I want to know what on earth they mean; and there are\ntimes when my head quite swims with the contemplation of them.\n\nSOCRATES: I see, my dear Theaetetus, that Theodorus had a true insight\ninto your nature when he said that you were a philosopher, for wonder\nis the feeling of a philosopher, and philosophy begins in wonder. He was\nnot a bad genealogist who said that Iris (the messenger of heaven)\nis the child of Thaumas (wonder). But do you begin to see what is the\nexplanation of this perplexity on the hypothesis which we attribute to\nProtagoras?\n\nTHEAETETUS: Not as yet.\n\nSOCRATES: Then you will be obliged to me if I help you to unearth the\nhidden 'truth' of a famous man or school.\n\nTHEAETETUS: To be sure, I shall be very much obliged.\n\nSOCRATES: Take a look round, then, and see that none of the uninitiated\nare listening. Now by the uninitiated I mean the people who believe in\nnothing but what they can grasp in their hands, and who will not allow\nthat action or generation or anything invisible can have real existence.\n\nTHEAETETUS: Yes, indeed, Socrates, they are very hard and impenetrable\nmortals.\n\nSOCRATES: 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 of\nwhich we were just now speaking are supposed to depend: there is nothing\nbut motion, which has two forms, one active and the other passive, both\nin endless number; and out of the union and friction of them there is\ngenerated a progeny endless in number, having two forms, sense and the\nobject of sense, which are ever breaking forth and coming to the birth\nat the same moment. The senses are variously named hearing, seeing,\nsmelling; there is the sense of heat, cold, pleasure, pain, desire,\nfear, and many more which have names, as well as innumerable others\nwhich are without them; each has its kindred object,--each variety\nof colour has a corresponding variety of sight, and so with sound and\nhearing, and with the rest of the senses and the objects akin to them.\nDo you see, Theaetetus, the bearings of this tale on the preceding\nargument?\n\nTHEAETETUS: Indeed I do not.\n\nSOCRATES: Then attend, and I will try to finish the story. The purport\nis that 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 elements\nhave their motions in the same place and with reference to things near\nthem, and so they beget; but what is begotten is swifter, for it\nis carried to fro, and moves from place to place. Apply this to\nsense:--When the eye and the appropriate object meet together and give\nbirth to whiteness and the sensation connatural with it, which could not\nhave been given by either of them going elsewhere, then, while the\nsight is flowing from the eye, whiteness proceeds from the object which\ncombines in producing the colour; and so the eye is fulfilled with\nsight, and really sees, and becomes, not sight, but a seeing eye;\nand the object which combined to form the colour is fulfilled with\nwhiteness, and becomes not whiteness but a white thing, whether wood or\nstone or whatever the object may be which happens to be coloured white.\nAnd this is true of all sensible objects, hard, warm, and the like,\nwhich are similarly to be regarded, as I was saying before, not as\nhaving any absolute existence, but as being all of them of whatever kind\ngenerated by motion in their intercourse with one another; for of the\nagent and patient, as existing in separation, no trustworthy conception,\nas they say, can be formed, for the agent has no existence until united\nwith the patient, and the patient has no existence until united with\nthe agent; and that which by uniting with something becomes an agent, by\nmeeting with some other thing is converted into a patient. And from\nall these considerations, as I said at first, there arises a general\nreflection, that there is no one self-existent thing, but everything\nis becoming and in relation; and being must be altogether abolished,\nalthough from habit and ignorance we are compelled even in this\ndiscussion to retain the use of the term. But great philosophers tell us\nthat we are not to allow either the word 'something,' or 'belonging to\nsomething,' or 'to me,' or 'this,' or 'that,' or any other detaining\nname to be used, in the language of nature all things are being created\nand destroyed, coming into being and passing into new forms; nor can any\nname fix or detain them; he who attempts to fix them is easily refuted.\nAnd this should be the way of speaking, not only of particulars but\nof aggregates; such aggregates as are expressed in the word 'man,' or\n'stone,' or any name of an animal or of a class. O Theaetetus, are not\nthese speculations sweet as honey? And do you not like the taste of them\nin the mouth?\n\nTHEAETETUS: 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 draw\nme out.\n\nSOCRATES: You forget, my friend, that I neither know, nor profess to\nknow, anything of these matters; you are the person who is in labour, I\nam the barren midwife; and this is why I soothe you, and offer you one\ngood thing after another, that you may taste them. And I hope that I may\nat last help to bring your own opinion into the light of day: when this\nhas been accomplished, then we will determine whether what you have\nbrought forth is only a wind-egg or a real and genuine birth. Therefore,\nkeep up your spirits, and answer like a man what you think.\n\nTHEAETETUS: Ask me.\n\nSOCRATES: 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 which\nwe were just now mentioning?\n\nTHEAETETUS: 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 assent.\n\nSOCRATES: Let us not leave the argument unfinished, then; for there\nstill remains to be considered an objection which may be raised about\ndreams and diseases, in particular about madness, and the various\nillusions of hearing and sight, or of other senses. For you know that\nin all these cases the esse-percipi theory appears to be unmistakably\nrefuted, since in dreams and illusions we certainly have false\nperceptions; and far from saying that everything is which appears, we\nshould rather say that nothing is which appears.\n\nTHEAETETUS: Very true, Socrates.\n\nSOCRATES: But then, my boy, how can any one contend that knowledge is\nperception, or that to every man what appears is?\n\nTHEAETETUS: I am afraid to say, Socrates, that I have nothing to answer,\nbecause you rebuked me just now for making this excuse; but I certainly\ncannot undertake to argue that madmen or dreamers think truly, when they\nimagine, some of them that they are gods, and others that they can fly,\nand are flying in their sleep.\n\nSOCRATES: Do you see another question which can be raised about these\nphenomena, notably about dreaming and waking?\n\nTHEAETETUS: What question?\n\nSOCRATES: A question which I think that you must often have heard\npersons ask:--How can you determine whether at this moment we are\nsleeping, and all our thoughts are a dream; or whether we are awake, and\ntalking to one another in the waking state?\n\nTHEAETETUS: Indeed, Socrates, I do not know how to prove the one\nany more 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 when\nin a dream we seem to be narrating dreams, the resemblance of the two\nstates is quite astonishing.\n\nSOCRATES: 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\nor in a dream. And as our time is equally divided between sleeping\nand waking, in either sphere of existence the soul contends that the\nthoughts which are present to our minds at the time are true; and during\none half of our lives we affirm the truth of the one, and, during the\nother half, of the other; and are equally confident of both.\n\nTHEAETETUS: Most true.\n\nSOCRATES: And may not the same be said of madness and other disorders?\nthe difference is only that the times are not equal.\n\nTHEAETETUS: Certainly.\n\nSOCRATES: And is truth or falsehood to be determined by duration of\ntime?\n\nTHEAETETUS: That would be in many ways ridiculous.\n\nSOCRATES: But can you certainly determine by any other means which of\nthese opinions is true?\n\nTHEAETETUS: I do not think that I can.\n\nSOCRATES: Listen, then, to a statement of the other side of the\nargument, which is made by the champions of appearance. They would say,\nas I imagine--Can that which is wholly other than something, have the\nsame quality as that from which it differs? and observe, Theaetetus,\nthat the word 'other' means not 'partially,' but 'wholly other.'\n\nTHEAETETUS: Certainly, putting the question as you do, that which is\nwholly other cannot either potentially or in any other way be the same.\n\nSOCRATES: And must therefore be admitted to be unlike?\n\nTHEAETETUS: True.\n\nSOCRATES: 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\nTHEAETETUS: Certainly.\n\nSOCRATES: Were we not saying that there are agents many and infinite,\nand patients many and infinite?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And also that different combinations will produce results\nwhich are not the same, but different?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: 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\nTHEAETETUS: You mean to compare Socrates in health as a whole, and\nSocrates in sickness as a whole?\n\nSOCRATES: Exactly; that is my meaning.\n\nTHEAETETUS: I answer, they are unlike.\n\nSOCRATES: And if unlike, they are other?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: And would you not say the same of Socrates sleeping and\nwaking, or in any of the states which we were mentioning?\n\nTHEAETETUS: I should.\n\nSOCRATES: All agents have a different patient in Socrates, accordingly\nas he is well or ill.\n\nTHEAETETUS: Of course.\n\nSOCRATES: And I who am the patient, and that which is the agent, will\nproduce something different in each of the two cases?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: The wine which I drink when I am in health, appears sweet and\npleasant to me?\n\nTHEAETETUS: True.\n\nSOCRATES: For, as has been already acknowledged, the patient and agent\nmeet together and produce sweetness and a perception of sweetness, which\nare in simultaneous motion, and the perception which comes from the\npatient makes the tongue percipient, and the quality of sweetness which\narises out of and is moving about the wine, makes the wine both to be\nand to appear sweet to the healthy tongue.\n\nTHEAETETUS: Certainly; that has been already acknowledged.\n\nSOCRATES: But when I am sick, the wine really acts upon another and a\ndifferent person?\n\nTHEAETETUS: Yes.\n\nSOCRATES: The combination of the draught of wine, and the Socrates\nwho is sick, produces quite another result; which is the sensation of\nbitterness in the tongue, and the motion and creation of bitterness in\nand about the wine, which becomes not bitterness but something bitter;\nas I myself become not perception but percipient?\n\nTHEAETETUS: True.\n\nSOCRATES: There is no other object of which I shall ever have the same\nperception, for another object would give another perception, and would\nmake the percipient other and different; nor can that object which\naffects me, meeting another subject, produce the same, or become\nsimilar, for that too would produce another result from another subject,\nand become different.\n\nTHEAETETUS: True.\n\nSOCRATES: Neither can I by myself, have this sensation, nor the object\nby itself, this quality.\n\nTHEAETETUS: Certainly not.\n\nSOCRATES: When I perceive I must become percipient of something--there\ncan be 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 no\none.\n\nTHEAETETUS: Certainly not.\n\nSOCRATES: 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 to\nthe other, but not to any other existence, nor each of us to himself;\nand therefore we can only be bound to one another; so that whether\na person says that a thing is or becomes, he must say that it is or\nbecomes to or of or in relation to something else; but he must not\nsay or allow any one else to say that anything is or becomes\nabsolutely:--such is our conclusion.\n\nTHEAETETUS: Very true, Socrates.\n\nSOCRATES: 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\nTHEAETETUS: Of course.\n\nSOCRATES: Then my perception is true to me, being inseparable from my\nown being; and, as Protagoras says, to myself I am judge of what is and\nwhat is not to me.\n\nTHEAETETUS: I suppose so.\n\nSOCRATES: 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\nTHEAETETUS: You cannot.\n\nSOCRATES: Then you were quite right in affirming that knowledge is only\nperception; and the meaning turns out to be the same, whether with Homer\nand Heracleitus, and all that company, you say that all is motion and\nflux, or with the great sage Protagoras, that man is the measure of all\nthings; or with Theaetetus, that, given these premises, perception is\nknowledge. Am I not right, Theaetetus, and is not this your new-born\nchild, of which I have delivered you? What say you?\n\nTHEAETETUS: I cannot but agree, Socrates.\n\nSOCRATES: Then this is the child, however he may turn out, which you and\nI have with difficulty brought into the world. And now that he is born,\nwe must run round the hearth with him, and see whether he is worth\nrearing, or is only a wind-egg and a sham. Is he to be reared in any\ncase, and not exposed? or will you bear to see him rejected, and not get\ninto a passion if I take away your first-born?\n\nTHEODORUS: 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\nSOCRATES: You, Theodorus, are a lover of theories, and now you\ninnocently fancy that I am a bag full of them, and can easily pull one\nout which will overthrow its predecessor. But you do not see that in\nreality none of these theories come from me; they all come from him who\ntalks with me. I only know just enough to extract them from the wisdom\nof another, and to receive them in a spirit of fairness. And now I shall\nsay nothing myself, but shall endeavour to elicit something from our\nyoung friend.\n\nTHEODORUS: Do as you say, Socrates; you are quite right.\n\nSOCRATES: Shall I tell you, Theodorus, what amazes me in your\nacquaintance Protagoras?\n\nTHEODORUS: What is it?\n\nSOCRATES: I am charmed with his doctrine, that what appears is to\neach one, 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 stranger\nmonster which has sensation, is the measure of all things; then he might\nhave shown a magnificent contempt for our opinion of him by informing\nus at the outset that while we were reverencing him like a God for\nhis wisdom he was no better than a tadpole, not to speak of his\nfellow-men--would not this have produced an overpowering effect? For\nif truth is only sensation, and no man can discern another's feelings\nbetter than he, or has any superior right to determine whether his\nopinion is true or false, but each, as we have several times repeated,\nis to himself the sole judge, and everything that he judges is true and\nright, why, my friend, should Protagoras be preferred to the place\nof wisdom and instruction, and deserve to be well paid, and we poor\nignoramuses have to go to him, if each one is the measure of his own\nwisdom? Must he not be talking 'ad captandum' in all this? I say nothing\nof the ridiculous predicament in which my own midwifery and the whole\nart of dialectic is placed; for the attempt to supervise or refute the\nnotions or opinions of others would be a tedious and enormous piece of\nfolly, if to each man his own are right; and this must be the case if\nProtagoras' Truth is the real truth, and the philosopher is not merely\namusing himself by giving oracles out of the shrine of his book.\n\nTHEODORUS: 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 seemed\nto answer very nicely.\n\nSOCRATES: 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 opportunity\nof judging of your own person?\n\nTHEODORUS: 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\nSOCRATES: Your will is my will, Theodorus, as the proverbial\nphilosophers say, and therefore I will return to the sage Theaetetus:\nTell me, Theaetetus, in reference to what I was saying, are you not\nlost in wonder, like myself, when you find that all of a sudden you are\nraised to the level of the wisest of men, or indeed of the gods?--for\nyou would assume the measure of Protagoras to apply to the gods as well\nas men?\n\nTHEAETETUS: Certainly I should, and I confess to you that I am lost in\nwonder. At first hearing, I was quite satisfied with the doctrine, that\nwhatever appears is to each one, but now the face of things has changed.\n\nSOCRATES: Why, my dear boy, you are young, and therefore your ear\nis quickly caught and your mind influenced by popular arguments.\nProtagoras, or some one speaking on his behalf, will doubtless say in\nreply,--Good people, young and old, you meet and harangue, and bring\nin the gods, whose existence or non-existence I banish from writing and\nspeech, or you talk about the reason of man being degraded to the level\nof the brutes, which is a telling argument with the multitude, but not\none word of proof or demonstration do you offer. All is probability with\nyou, and yet surely you and Theodorus had better reflect whether you\nare disposed to admit of probability and figures of speech in matters\nof such importance. He or any other mathematician who argued from\nprobabilities and likelihoods in geometry, would not be worth an ace.\n\nTHEAETETUS: But neither you nor we, Socrates, would be satisfied with\nsuch arguments.\n\nSOCRATES: Then you and Theodorus mean to say that we must look at the\nmatter in some other way?\n\nTHEAETETUS: Yes, in quite another way.\n\nSOCRATES: And the way will be to ask whether perception is or is not the\nsame as knowledge; for this was the real point of our argument, and with\na view to this we raised (did we not?) those many strange questions.\n\nTHEAETETUS: Certainly.\n\nSOCRATES: 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 the\nlanguage 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\nTHEAETETUS: 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 the\nsound of them; but we do not perceive by sight and hearing, or know,\nthat which grammarians and interpreters teach about them.\n\nSOCRATES: Capital, Theaetetus; and about this there shall be no dispute,\nbecause I want you to grow; but there is another difficulty coming,\nwhich you will also have to repulse.\n\nTHEAETETUS: What is it?\n\nSOCRATES: 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\nTHEAETETUS: Impossible, Socrates; the supposition is monstrous.\n\nSOCRATES: Am I talking nonsense, then? Think: is not seeing perceiving,\nand is not sight perception?\n\nTHEAETETUS: True.\n\nSOCRATES: And if our recent definition holds, every man knows that which\nhe has seen?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And you would admit that there is such a thing as memory?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And is memory of something or of nothing?\n\nTHEAETETUS: Of something, surely.\n\nSOCRATES: Of things learned and perceived, that is?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: Often a man remembers that which he has seen?\n\nTHEAETETUS: True.\n\nSOCRATES: And if he closed his eyes, would he forget?\n\nTHEAETETUS: Who, Socrates, would dare to say so?\n\nSOCRATES: But we must say so, if the previous argument is to be\nmaintained.\n\nTHEAETETUS: What do you mean? I am not quite sure that I understand you,\nthough I have a strong suspicion that you are right.\n\nSOCRATES: As thus: he who sees knows, as we say, that which he sees; for\nperception and sight and knowledge are admitted to be the same.\n\nTHEAETETUS: Certainly.\n\nSOCRATES: 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\nTHEAETETUS: True.\n\nSOCRATES: And seeing is knowing, and therefore not-seeing is\nnot-knowing?\n\nTHEAETETUS: Very true.\n\nSOCRATES: Then the inference is, that a man may have attained the\nknowledge of something, which he may remember and yet not know, because\nhe does not see; and this has been affirmed by us to be a monstrous\nsupposition.\n\nTHEAETETUS: Most true.\n\nSOCRATES: Thus, then, the assertion that knowledge and perception are\none, involves a manifest impossibility?\n\nTHEAETETUS: Yes.\n\nSOCRATES: Then they must be distinguished?\n\nTHEAETETUS: I suppose that they must.\n\nSOCRATES: Once more we shall have to begin, and ask 'What is knowledge?'\nand yet, Theaetetus, what are we going to do?\n\nTHEAETETUS: About what?\n\nSOCRATES: Like a good-for-nothing cock, without having won the victory,\nwe walk away from the argument and crow.\n\nTHEAETETUS: How do you mean?\n\nSOCRATES: After the manner of disputers (Lys.; Phaedo; Republic), we\nwere satisfied with mere verbal consistency, and were well pleased if in\nthis way we could gain an advantage. Although professing not to be mere\nEristics, but philosophers, I suspect that we have unconsciously fallen\ninto the error of that ingenious class of persons.\n\nTHEAETETUS: I do not as yet understand you.\n\nSOCRATES: 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 he\nhad his eyes shut and could not see, and then he would at the same\ntime remember and not know. But this was an impossibility. And so the\nProtagorean fable came to nought, and yours also, who maintained that\nknowledge is the same as perception.\n\nTHEAETETUS: True.\n\nSOCRATES: And yet, my friend, I rather suspect that the result would\nhave been different if Protagoras, who was the father of the first of\nthe two 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 I must\ntake up his cause myself, and see justice done?\n\nTHEODORUS: 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 grateful\nto you if you assist him.\n\nSOCRATES: 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 are\ncommonly used in argument, he may be involved even in greater paradoxes\nthan these. Shall I explain this matter to you or to Theaetetus?\n\nTHEODORUS: To both of us, and let the younger answer; he will incur less\ndisgrace if he is discomfited.\n\nSOCRATES: Then now let me ask the awful question, which is this:--Can a\nman know and also not know that which he knows?\n\nTHEODORUS: How shall we answer, Theaetetus?\n\nTHEAETETUS: He cannot, I should say.\n\nSOCRATES: 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\nTHEAETETUS: I should answer, 'Not with that eye but with the other.'\n\nSOCRATES: Then you see and do not see the same thing at the same time.\n\nTHEAETETUS: Yes, in a certain sense.\n\nSOCRATES: 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 not\nknow. You have been proved to see that which you do not see; and you\nhave already admitted that seeing is knowing, and that not-seeing is\nnot-knowing: I leave you to draw the inference.\n\nTHEAETETUS: Yes; the inference is the contradictory of my assertion.\n\nSOCRATES: 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 have a\nsharp and also a dull knowledge, and whether you can know near, but not\nat a distance, or know the same thing with more or less intensity,\nand so on without end. Such questions might have been put to you by a\nlight-armed mercenary, who argued for pay. He would have lain in wait\nfor you, and when you took up the position, that sense is knowledge,\nhe would have made an assault upon hearing, smelling, and the other\nsenses;--he would have shown you no mercy; and while you were lost in\nenvy and admiration of his wisdom, he would have got you into his\nnet, out of which you would not have escaped until you had come to an\nunderstanding about the sum to be paid for your release. Well, you ask,\nand how will Protagoras reinforce his position? Shall I answer for him?\n\nTHEAETETUS: By all means.\n\nSOCRATES: 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 remember\nand not know the same thing, and the boy said No, because he was\nfrightened, and could not see what was coming, and then Socrates made\nfun of poor me. The truth is, O slatternly Socrates, that when you ask\nquestions about any assertion of mine, and the person asked is found\ntripping, if he has answered as I should have answered, then I am\nrefuted, but if he answers something else, then he is refuted and not\nI. For do you really suppose that any one would admit the memory which a\nman has of an impression which has passed away to be the same with that\nwhich he experienced at the time? Assuredly not. Or would he hesitate to\nacknowledge that the same man may know and not know the same thing? Or,\nif he is afraid of making this admission, would he ever grant that one\nwho has become unlike is the same as before he became unlike? Or would\nhe admit that a man is one at all, and not rather many and infinite as\nthe changes which take place in him? I speak by the card in order to\navoid entanglements of words. But, O my good sir, he will say, come to\nthe argument in a more generous spirit; and either show, if you can,\nthat our sensations are not relative and individual, or, if you admit\nthem to be so, prove that this does not involve the consequence that the\nappearance becomes, or, if you will have the word, is, to the individual\nonly. As to your talk about pigs and baboons, you are yourself behaving\nlike a pig, and you teach your hearers to make sport of my writings in\nthe same ignorant manner; but this is not to your credit. For I declare\nthat the truth is as I have written, and that each of us is a measure\nof existence and of non-existence. Yet one man may be a thousand times\nbetter than another in proportion as different things are and appear\nto him. And 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\nI would beg you not to press my words in the letter, but to take the\nmeaning of 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 to\nthe man in health the opposite of bitter. Now I cannot conceive that one\nof these men can be or ought to be made wiser than the other: nor can\nyou assert that the sick man because he has one impression is foolish,\nand the healthy man because he has another is wise; but the one state\nrequires to be changed into the other, the worse into the better. As\nin education, a change of state has to be effected, and the sophist\naccomplishes by words the change which the physician works by the aid\nof drugs. Not that any one ever made another think truly, who previously\nthought falsely. For no one can think what is not, or, think anything\ndifferent from that which he feels; and this is always true. But as the\ninferior habit of mind has thoughts of kindred nature, so I conceive\nthat a good mind causes men to have good thoughts; and these which the\ninexperienced call true, I maintain to be only better, and not truer\nthan others. And, O my dear Socrates, I do not call wise men tadpoles:\nfar from it; I say that they are the physicians of the human body, and\nthe husbandmen of plants--for the husbandmen also take away the evil and\ndisordered sensations of plants, and infuse into them good and healthy\nsensations--aye and true ones; and the wise and good rhetoricians\nmake the good instead of the evil to seem just to states; for whatever\nappears to a state to be just and fair, so long as it is regarded as\nsuch, is just and fair to it; but the teacher of wisdom causes the good\nto take the place of the evil, both in appearance and in reality. And in\nlike manner the Sophist who is able to train his pupils in this spirit\nis a wise man, and deserves to be well paid by them. And so one man is\nwiser than 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 an\nopposite argument, or if you like you may put questions to me--a method\nto which no intelligent person will object, quite the reverse. But I\nmust beg you to put fair questions: for there is great inconsistency\nin saying that you have a zeal for virtue, and then always behaving\nunfairly in argument. The unfairness of which I complain is that you do\nnot distinguish between mere disputation and dialectic: the disputer\nmay trip up his opponent as often as he likes, and make fun; but the\ndialectician will be in earnest, and only correct his adversary when\nnecessary, telling him the errors into which he has fallen through his\nown fault, or that of the company which he has previously kept. If\nyou do so, your adversary will lay the blame of his own confusion and\nperplexity on himself, and not on you. He will follow and love you, and\nwill hate himself, and escape from himself into philosophy, in order\nthat he may become different from what he was. But the other mode of\narguing, which is practised by the many, will have just the opposite\neffect upon him; and as he grows older, instead of turning philosopher,\nhe will come to hate philosophy. I would recommend you, therefore, as\nI said before, not to encourage yourself in this polemical and\ncontroversial temper, but to find out, in a friendly and congenial\nspirit, what we really mean when we say that all things are in motion,\nand that to every individual and state what appears, is. In this manner\nyou will consider whether knowledge and sensation are the same or\ndifferent, but you will not argue, as you were just now doing, from the\ncustomary use of names and words, which the vulgar pervert in all sorts\nof ways, causing infinite perplexity to one another. Such, Theodorus, is\nthe very 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 style.\n\nTHEODORUS: You are jesting, Socrates; indeed, your defence of him has\nbeen most valorous.\n\nSOCRATES: Thank you, friend; and I hope that you observed Protagoras\nbidding us be serious, as the text, 'Man is the measure of all things,'\nwas a solemn one; and he reproached us with making a boy the medium of\ndiscourse, and said that the boy's timidity was made to tell against his\nargument; he also declared that we made a joke of him.\n\nTHEODORUS: How could I fail to observe all that, Socrates?\n\nSOCRATES: Well, and shall we do as he says?\n\nTHEODORUS: By all means.\n\nSOCRATES: 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 another,\nfor you see that the rest of us are nothing but boys. In no other way\ncan we escape the imputation, that in our fresh analysis of his thesis\nwe are making fun with boys.\n\nTHEODORUS: Well, but is not Theaetetus better able to follow a\nphilosophical enquiry than a great many men who have long beards?\n\nSOCRATES: 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 and\nsufficient for themselves in astronomy and geometry, and the other\nbranches of knowledge in which you are supposed to excel them.\n\nTHEODORUS: He who is sitting by you, Socrates, will not easily avoid\nbeing drawn into an argument; and when I said just now that you would\nexcuse me, and not, like the Lacedaemonians, compel me to strip and\nfight, I was talking nonsense--I should rather compare you to Scirrhon,\nwho threw travellers from the rocks; for the Lacedaemonian rule is\n'strip or depart,' but you seem to go about your work more after the\nfashion of Antaeus: you will not allow any one who approaches you to\ndepart until you have stripped him, and he has been compelled to try a\nfall with you in argument.\n\nSOCRATES: 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, mighty\nin words, has broken my head; nevertheless I am always at this rough\nexercise, which inspires me like a passion. Please, then, to try a fall\nwith me, whereby you will do yourself good as well as me.\n\nTHEODORUS: I consent; lead me whither you will, for I know that you are\nlike destiny; no man can escape from any argument which you may weave\nfor him. But I am not disposed to go further than you suggest.\n\nSOCRATES: Once will be enough; and now take particular care that we\ndo not again unwittingly expose ourselves to the reproach of talking\nchildishly.\n\nTHEODORUS: I will do my best to avoid that error.\n\nSOCRATES: In the first place, let us return to our old objection, and\nsee whether we were right in blaming and taking offence at Protagoras\non the 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\nTHEODORUS: Very true.\n\nSOCRATES: Had Protagoras been living and answered for himself, instead\nof our answering for him, there would have been no need of our reviewing\nor reinforcing the argument. But as he is not here, and some one may\naccuse us of speaking without authority on his behalf, had we not better\ncome to a clearer agreement about his meaning, for a great deal may be\nat stake?\n\nTHEODORUS: True.\n\nSOCRATES: Then let us obtain, not through any third person, but from his\nown statement and in the fewest words possible, the basis of agreement.\n\nTHEODORUS: In what way?\n\nSOCRATES: In this way:--His words are, 'What seems to a man, is to him.'\n\nTHEODORUS: Yes, so he says.\n\nSOCRATES: 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 in\nknowledge? Is not the world full of men in their several employments,\nwho are looking for teachers and rulers of themselves and of the\nanimals? and there are plenty who think that they are able to teach\nand able to rule. Now, in all this is implied that ignorance and wisdom\nexist among them, at least in their own opinion.\n\nTHEODORUS: Certainly.\n\nSOCRATES: And wisdom is assumed by them to be true thought, and\nignorance to be false opinion.\n\nTHEODORUS: Exactly.\n\nSOCRATES: How then, Protagoras, would you have us treat the argument?\nShall we say that the opinions of men are always true, or sometimes true\nand sometimes false? In either case, the result is the same, and their\nopinions are not always true, but sometimes true and sometimes false.\nFor tell me, Theodorus, do you suppose that you yourself, or any other\nfollower of Protagoras, would contend that no one deems another ignorant\nor mistaken in his opinion?\n\nTHEODORUS: The thing is incredible, Socrates.\n\nSOCRATES: And yet that absurdity is necessarily involved in the thesis\nwhich declares man to be the measure of all things.\n\nTHEODORUS: How so?\n\nSOCRATES: Why, suppose that you determine in your own mind something to\nbe true, and declare your opinion to me; let us assume, as he argues,\nthat this is true to you. Now, if so, you must either say that the rest\nof us are not the judges of this opinion or judgment of yours, or that\nwe judge you always to have a true opinion? But are there not thousands\nupon thousands who, whenever you form a judgment, take up arms against\nyou and are of an opposite judgment and opinion, deeming that you judge\nfalsely?\n\nTHEODORUS: Yes, indeed, Socrates, thousands and tens of thousands, as\nHomer says, who give me a world of trouble.\n\nSOCRATES: Well, but are we to assert that what you think is true to you\nand false to the ten thousand others?\n\nTHEODORUS: No other inference seems to be possible.\n\nSOCRATES: And how about Protagoras himself? If neither he nor the\nmultitude thought, as indeed they do not think, that man is the measure\nof all things, must it not follow that the truth of which Protagoras\nwrote would be true to no one? But if you suppose that he himself\nthought this, and that the multitude does not agree with him, you must\nbegin by allowing that in whatever proportion the many are more than\none, in that proportion his truth is more untrue than true.\n\nTHEODORUS: That would follow if the truth is supposed to vary with\nindividual opinion.\n\nSOCRATES: 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 admits\nthat the opinions of all men are true.\n\nTHEODORUS: Certainly.\n\nSOCRATES: 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\nTHEODORUS: Of course.\n\nSOCRATES: Whereas the other side do not admit that they speak falsely?\n\nTHEODORUS: They do not.\n\nSOCRATES: And he, as may be inferred from his writings, agrees that this\nopinion is also true.\n\nTHEODORUS: Clearly.\n\nSOCRATES: Then all mankind, beginning with Protagoras, will contend,\nor rather, I should say that he will allow, when he concedes that his\nadversary has a true opinion--Protagoras, I say, will himself allow that\nneither a dog nor any ordinary man is the measure of anything which he\nhas not learned--am I not right?\n\nTHEODORUS: Yes.\n\nSOCRATES: And the truth of Protagoras being doubted by all, will be true\nneither to himself to any one else?\n\nTHEODORUS: I think, Socrates, that we are running my old friend too\nhard.\n\nSOCRATES: But I 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 would\nhave overthrown both of us again and again, me for talking nonsense and\nyou for assenting to me, and have been off and underground in a trice.\nBut as he is not within call, we must make the best use of our own\nfaculties, such as they are, and speak out what appears to us to be\ntrue. And one thing which no one will deny is, that there are great\ndifferences in the understandings of men.\n\nTHEODORUS: In that opinion I quite agree.\n\nSOCRATES: And is there not most likely to be firm ground in the\ndistinction which we were indicating on behalf of Protagoras, viz. that\nmost things, and all immediate sensations, such as hot, dry, sweet,\nare only such as they appear; if however difference of opinion is to be\nallowed at all, surely we must allow it in respect of health or disease?\nfor every woman, child, or living creature has not such a knowledge of\nwhat conduces to health as to enable them to cure themselves.\n\nTHEODORUS: I quite agree.\n\nSOCRATES: 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 determining\nthese matters no individual or state is wiser than another, still the\nfollowers of Protagoras will not deny that in determining what is or is\nnot expedient for the community one state is wiser and one counsellor\nbetter than another--they will scarcely venture to maintain, that what\na city enacts in the belief that it is expedient will always be really\nexpedient. But in the other case, I mean when they speak of justice and\ninjustice, piety and impiety, they are confident that in nature these\nhave no existence or essence of their own--the truth is that which is\nagreed on at the time of the agreement, and as long as the agreement\nlasts; and this is the philosophy of many who do not altogether go along\nwith Protagoras. Here arises a new question, Theodorus, which threatens\nto be more serious than the last.\n\nTHEODORUS: Well, Socrates, we have plenty of leisure.\n\nSOCRATES: That is true, and your remark recalls to my mind an\nobservation which I have often made, that those who have passed their\ndays in the pursuit of philosophy are ridiculously at fault when they\nhave to appear and speak in court. How natural is this!\n\nTHEODORUS: What do you mean?\n\nSOCRATES: I mean to say, that those who have been trained in philosophy\nand liberal pursuits are as unlike those who from their youth upwards\nhave been knocking about in the courts and such places, as a freeman is\nin breeding unlike a slave.\n\nTHEODORUS: In what is the difference seen?\n\nSOCRATES: In the leisure spoken of by you, which a freeman can always\ncommand: he has his talk out in peace, and, like ourselves, he wanders\nat will from one subject to another, and from a second to a third,--if\nthe fancy takes him, he begins again, as we are doing now, caring not\nwhether his words are many or few; his only aim is to attain the truth.\nBut the lawyer is always in a hurry; there is the water of the clepsydra\ndriving him on, and not allowing him to expatiate at will: and there is\nhis adversary standing over him, enforcing his rights; the indictment,\nwhich in their phraseology is termed the affidavit, is recited at\nthe time: and from this he must not deviate. He is a servant, and is\ncontinually disputing about a fellow-servant before his master, who is\nseated, and has the cause in his hands; the trial is never about some\nindifferent matter, but always concerns himself; and often the race\nis for his life. The consequence has been, that he has become keen and\nshrewd; he has learned how to flatter his master in word and indulge him\nin deed; but his soul is small and unrighteous. His condition, which has\nbeen that of a slave from his youth upwards, has deprived him of growth\nand uprightness and independence; dangers and fears, which were too\nmuch for 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 retaliation,\nand has become stunted and warped. And so he has passed out of youth\ninto manhood, having no soundness in him; and is now, as he thinks,\na master in wisdom. Such is the lawyer, Theodorus. Will you have the\ncompanion picture of the philosopher, who is of our brotherhood; or\nshall we return to the argument? Do not let us abuse the freedom of\ndigression which we claim.\n\nTHEODORUS: Nay, Socrates, not until we have finished what we are about;\nfor you truly said that we belong to a brotherhood which is free, and\nare not the servants of the argument; but the argument is our servant,\nand must wait our leisure. Who is our judge? Or where is the spectator\nhaving any right to censure or control us, as he might the poets?\n\nSOCRATES: 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 place,\nthe lords of philosophy have never, from their youth upwards, known\ntheir way to the Agora, or the dicastery, or the council, or any other\npolitical assembly; they neither see nor hear the laws or decrees,\nas they are called, of the state written or recited; the eagerness of\npolitical societies in the attainment of offices--clubs, and banquets,\nand revels, and singing-maidens,--do not enter even into their dreams.\nWhether any event has turned out well or ill in the city, what disgrace\nmay have descended to any one from his ancestors, male or female, are\nmatters of which the philosopher no more knows than he can tell, as they\nsay, how many pints are contained in the ocean. Neither is he conscious\nof his ignorance. For he does not hold aloof in order that he may gain a\nreputation; but the truth is, that the outer form of him only is in the\ncity: his mind, disdaining the littlenesses and nothingnesses of human\nthings, is 'flying all abroad' as Pindar says, measuring earth and\nheaven and the things which are under and on the earth and above\nthe heaven, interrogating the whole nature of each and all in their\nentirety, but not condescending to anything which is within reach.\n\nTHEODORUS: What do you mean, Socrates?\n\nSOCRATES: I will illustrate my meaning, Theodorus, by the jest which the\nclever witty Thracian handmaid is said to have made about Thales, when\nhe fell into a well as he was looking up at the stars. She said, that he\nwas so eager to know what was going on in heaven, that he could not see\nwhat was before his feet. This is a jest which is equally applicable to\nall philosophers. For the philosopher is wholly unacquainted with his\nnext-door neighbour; he is ignorant, not only of what he is doing, but\nhe hardly knows whether he is a man or an animal; he is searching into\nthe essence of man, and busy in enquiring what belongs to such a nature\nto do or suffer different from any other;--I think that you understand\nme, Theodorus?\n\nTHEODORUS: I do, and what you say is true.\n\nSOCRATES: 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 any\nplace 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 through\nhis inexperience. His awkwardness is fearful, and gives the impression\nof imbecility. When he is reviled, he has nothing personal to say in\nanswer to the civilities of his adversaries, for he knows no scandals\nof any one, and they do not interest him; and therefore he is laughed at\nfor his sheepishness; and when others are being praised and glorified,\nin the simplicity of his heart he cannot help going into fits of\nlaughter, so that he seems to be a downright idiot. When he hears a\ntyrant or king eulogized, he fancies that he is listening to the\npraises of some keeper of cattle--a swineherd, or shepherd, or perhaps a\ncowherd, who is congratulated on the quantity of milk which he squeezes\nfrom them; and he remarks that the creature whom they tend, and out of\nwhom they squeeze the wealth, is of a less tractable and more insidious\nnature. Then, again, he observes that the great man is of necessity as\nill-mannered and uneducated as any shepherd--for he has no leisure,\nand he is surrounded by a wall, which is his mountain-pen. Hearing\nof enormous landed proprietors of ten thousand acres and more, our\nphilosopher deems this to be a trifle, because he has been accustomed to\nthink of the whole earth; and when they sing the praises of family, and\nsay that some one is a gentleman because he can show seven generations\nof wealthy ancestors, he thinks that their sentiments only betray a\ndull and narrow vision in those who utter them, and who are not educated\nenough to look at the whole, nor to consider that every man has had\nthousands and ten thousands of progenitors, and among them have been\nrich and poor, kings and slaves, Hellenes and barbarians, innumerable.\nAnd when people pride themselves on having a pedigree of twenty-five\nancestors, which goes back to Heracles, the son of Amphitryon, he cannot\nunderstand their poverty of ideas. Why are they unable to calculate that\nAmphitryon had a twenty-fifth ancestor, who might have been anybody,\nand was such as fortune made him, and he had a fiftieth, and so on? He\namuses himself with the notion that they cannot count, and thinks that a\nlittle arithmetic would have got rid of their senseless vanity. Now, in\nall these cases our philosopher is derided by the vulgar, partly because\nhe is thought to despise them, and also because he is ignorant of what\nis before him, and always at a loss.\n\nTHEODORUS: That is very true, Socrates.\n\nSOCRATES: But, O my friend, when he draws the other into upper air,\nand gets 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 about\nthe 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 that\nnarrow, keen, little legal mind is called to account about all this, he\ngives the philosopher his revenge; for dizzied by the height at which\nhe is hanging, whence he looks down into space, which is a strange\nexperience to him, he being dismayed, and lost, and stammering\nbroken words, is laughed at, not by Thracian handmaidens or any other\nuneducated persons, for they have no eye for the situation, but by every\nman who has not been brought up a slave. Such are the two characters,\nTheodorus: the one of the freeman, who has been trained in liberty and\nleisure, whom you call the philosopher,--him we cannot blame because\nhe appears simple and of no account when he has to perform some menial\ntask, such as packing up bed-clothes, or flavouring a sauce or fawning\nspeech; the other character is that of the man who is able to do all\nthis kind of service smartly and neatly, but knows not how to wear his\ncloak like a gentleman; still less with the music of discourse can he\nhymn the true life aright which is lived by immortals or men blessed of\nheaven.\n\nTHEODORUS: If you could only persuade everybody, Socrates, as you do me,\nof the truth of your words, there would be more peace and fewer evils\namong men.\n\nSOCRATES: Evils, Theodorus, can never pass away; for there must always\nremain something which is antagonistic to good. Having no place among\nthe gods in heaven, of necessity they hover around the mortal nature,\nand this earthly sphere. Wherefore we ought to fly away from earth to\nheaven as quickly as we can; and to fly away is to become like God,\nas far as this is possible; and to become like him, is to become holy,\njust, and wise. But, O my friend, you cannot easily convince mankind\nthat they should pursue virtue or avoid vice, not merely in order that a\nman may seem to be good, which is the reason given by the world, and in\nmy judgment is only a repetition of an old wives' fable. Whereas,\nthe truth is that God is never in any way unrighteous--he is perfect\nrighteousness; and he of us who is the most righteous is most like him.\nHerein is seen the true cleverness of a man, and also his nothingness\nand want of manhood. For to know this is true wisdom and virtue, and\nignorance of this is manifest folly and vice. All other kinds of wisdom\nor cleverness, which seem only, such as the wisdom of politicians, or\nthe wisdom of the arts, are coarse and vulgar. The unrighteous man, or\nthe sayer and doer of unholy things, had far better not be encouraged\nin the illusion that his roguery is clever; for men glory in their\nshame--they fancy that they hear others saying of them, 'These are not\nmere good-for-nothing persons, mere burdens of the earth, but such as\nmen should be who mean to dwell safely in a state.' Let us tell them\nthat they are all the more truly what they do not think they are because\nthey do not know it; for they do not know the penalty of injustice,\nwhich above all things they ought to know--not stripes and death, as\nthey suppose, which evil-doers often escape, but a penalty which cannot\nbe escaped.\n\nTHEODORUS: What is that?\n\nSOCRATES: There are two patterns eternally set before them; the one\nblessed and divine, the other godless and wretched: but they do not see\nthem, or perceive that in their utter folly and infatuation they are\ngrowing 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 unless\nthey depart from their cunning, the place of innocence will not receive\nthem after death; and that here on earth, they will live ever in the\nlikeness of their own evil selves, and with evil friends--when they hear\nthis they in their superior cunning will seem to be listening to the\ntalk of idiots.\n\nTHEODORUS: Very true, Socrates.\n\nSOCRATES: Too true, my friend, as I well know; there is, however, one\npeculiarity in their case: when they begin to reason in private about\ntheir dislike of philosophy, if they have the courage to hear the\nargument out, and do not run away, they grow at last strangely\ndiscontented with themselves; their rhetoric fades away, and they become\nhelpless as children. These however are digressions from which we must\nnow desist, or they will overflow, and drown the original argument; to\nwhich, if you please, we will now return.\n\nTHEODORUS: 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\nSOCRATES: 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 commanded\nand thought just, were just to the state which imposed them, while they\nwere in force; this was especially asserted of justice; but as to the\ngood, no one had any longer the hardihood to contend of any ordinances\nwhich the state thought and enacted to be good that these, while they\nwere in force, were really good;--he who said so would be playing with\nthe name 'good,' and would not touch the real question--it would be a\nmockery, would it not?\n\nTHEODORUS: Certainly it would.\n\nSOCRATES: He ought not to speak of the name, but of the thing which is\ncontemplated under the name.\n\nTHEODORUS: Right.\n\nSOCRATES: 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 all\nlaws with a view to the greatest expediency; can legislation have any\nother aim?\n\nTHEODORUS: Certainly not.\n\nSOCRATES: But is the aim attained always? do not mistakes often happen?\n\nTHEODORUS: Yes, I think that there are mistakes.\n\nSOCRATES: The possibility of error will be more distinctly recognised,\nif we put the question in reference to the whole class under which the\ngood or expedient falls. 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\nTHEODORUS: Very true.\n\nSOCRATES: Suppose now, that we ask Protagoras, or one of his disciples,\na question:--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 what\nis and is true to himself. Is it not so?\n\nTHEODORUS: Yes.\n\nSOCRATES: And do you extend your doctrine, Protagoras (as we shall\nfurther say), to the future as well as to the present; and has he the\ncriterion not only of what in his opinion is but of what will be, and do\nthings always happen to him as he expected? For example, take the case\nof heat:--When an ordinary man thinks that he is going to have a fever,\nand that this kind of heat is coming on, and another person, who is a\nphysician, thinks the contrary, whose opinion is likely to prove right?\nOr are they both right?--he will have a heat and fever in his own\njudgment, and not have a fever in the physician's judgment?\n\nTHEODORUS: How ludicrous!\n\nSOCRATES: And the vinegrower, if I am not mistaken, is a better judge of\nthe sweetness or dryness of the vintage which is not yet gathered than\nthe harp-player?\n\nTHEODORUS: Certainly.\n\nSOCRATES: 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\nTHEODORUS: Of course.\n\nSOCRATES: 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 in\npreparation; for of present or past pleasure we are not as yet arguing;\nbut can we say that every one will be to himself the best judge of the\npleasure which will seem to be and will be to him in the future?--nay,\nwould not you, Protagoras, better guess which arguments in a court would\nconvince any one of us than the ordinary man?\n\nTHEODORUS: Certainly, Socrates, he used to profess in the strongest\nmanner that he was the superior of all men in this respect.\n\nSOCRATES: 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\nTHEODORUS: Who indeed?\n\nSOCRATES: 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\nTHEODORUS: Quite true.\n\nSOCRATES: 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 measure:\nbut I, who know nothing, am not at all obliged to accept the honour\nwhich the advocate of Protagoras was just now forcing upon me, whether I\nwould or not, of being a measure of anything.\n\nTHEODORUS: That is the best refutation of him, Socrates; although he is\nalso caught when he ascribes truth to the opinions of others, who give\nthe lie direct to his own opinion.\n\nSOCRATES: There are many ways, Theodorus, in which the doctrine that\nevery opinion of every man is true may be refuted; but there is more\ndifficulty in proving that states of feeling, which are present to a\nman, and out of which arise sensations and opinions in accordance with\nthem, are also untrue. And very likely I have been talking nonsense\nabout them; for they may be unassailable, and those who say that there\nis clear evidence of them, and that they are matters of knowledge, may\nprobably be right; in which case our friend Theaetetus was not so far\nfrom the mark when he identified perception and knowledge. And therefore\nlet us draw nearer, as the advocate of Protagoras desires; and give the\ntruth of the universal flux a ring: is the theory sound or not? at any\nrate, no small war is raging about it, and there are combination not a\nfew.\n\nTHEODORUS: No small, war, indeed, for in Ionia the sect makes rapid\nstrides; the disciples of Heracleitus are most energetic upholders of\nthe doctrine.\n\nSOCRATES: Then we are the more bound, my dear Theodorus, to examine the\nquestion from the foundation as it is set forth by themselves.\n\nTHEODORUS: 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 their\ntext-books, they are always in motion; but as for dwelling upon an\nargument or a question, and quietly asking and answering in turn, they\ncan no more do so than they can fly; or rather, the determination of\nthese fellows not to have a particle of rest in them is more than\nthe utmost powers of negation can express. If you ask any of them a\nquestion, he will produce, as from a quiver, sayings brief and dark, and\nshoot them at you; and if you inquire the reason of what he has said,\nyou will be hit by some other new-fangled word, and will make no way\nwith any of them, nor they with one another; their great care is, not\nto allow of any settled principle either in their arguments or in\ntheir minds, conceiving, as I imagine, that any such principle would be\nstationary; for they are at war with the stationary, and do what they\ncan to drive it out everywhere.\n\nSOCRATES: I suppose, Theodorus, that you have only seen them when they\nwere fighting, and have never stayed with them in time of peace,\nfor they 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\nTHEODORUS: 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 neighbour\nthat he knows nothing. From these men, then, as I was going to remark,\nyou will never get a reason, whether with their will or without their\nwill; we must take the question out of their hands, and make the\nanalysis ourselves, as if we were doing geometrical problem.\n\nSOCRATES: Quite right too; but as touching the aforesaid problem, have\nwe not heard from the ancients, who concealed their wisdom from the many\nin poetical figures, that Oceanus and Tethys, the origin of all things,\nare streams, and that nothing is at rest? And now the moderns, in their\nsuperior wisdom, have declared the same openly, that the cobbler too may\nhear and learn of them, and no longer foolishly imagine that some things\nare at rest and others in motion--having learned that all is motion,\nhe will duly honour his teachers. I had almost forgotten the opposite\ndoctrine, Theodorus,\n\n     'Alone 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 no\nplace in which to move. What shall we do, friend, with all these people;\nfor, advancing step by step, we have imperceptibly got between the\ncombatants, and, unless we can protect our retreat, we shall pay the\npenalty of our rashness--like the players in the palaestra who are\ncaught upon the line, and are dragged different ways by the two parties.\nTherefore I think that we had better begin by considering those whom we\nfirst accosted, 'the river-gods,' and, if we find any truth in them, we\nwill help them to pull us over, and try to get away from the others. But\nif the partisans of 'the whole' appear to speak more truly, we will fly\noff from the party which would move the immovable, to them. And if I\nfind that neither of them have anything reasonable to say, we shall\nbe in a ridiculous position, having so great a conceit of our own poor\nopinion and rejecting that of ancient and famous men. O Theodorus, do\nyou think that there is any use in proceeding when the danger is so\ngreat?\n\nTHEODORUS: Nay, Socrates, not to examine thoroughly what the two parties\nhave to say would be quite intolerable.\n\nSOCRATES: 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 rather\nincline to think, two? I should like to have your opinion upon this\npoint in addition to my own, that I may err, if I must err, in your\ncompany; tell me, then, when a thing changes from one place to another,\nor goes round in the same place, is not that what is called motion?\n\nTHEODORUS: Yes.\n\nSOCRATES: 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\nTHEODORUS: I think so.\n\nSOCRATES: Say rather that it must be so. Of motion then there are these\ntwo kinds, 'change,' and 'motion in place.'\n\nTHEODORUS: You are right.\n\nSOCRATES: And now, having made this distinction, let us address\nourselves to those who say that all is motion, and ask them whether all\nthings according to them have the two kinds of motion, and are changed\nas well as move in place, or is one thing moved in both ways, and\nanother in one only?\n\nTHEODORUS: Indeed, I do not know what to answer; but I think they would\nsay that all things are moved in both ways.\n\nSOCRATES: Yes, comrade; for, if not, they would have to say that the\nsame things 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\nTHEODORUS: To be sure.\n\nSOCRATES: And if they are to be in motion, and nothing is to be devoid\nof motion, all things must always have every sort of motion?\n\nTHEODORUS: Most true.\n\nSOCRATES: Consider a further point: did we not understand them to\nexplain the generation of heat, whiteness, or anything else, in some\nsuch manner as the following:--were they not saying that each of them\nis moving between the agent and the patient, together with a perception,\nand that the patient ceases to be a perceiving power and becomes a\npercipient, and the agent a quale instead of a quality? I suspect that\nquality may appear a strange and uncouth term to you, and that you\ndo not understand the abstract expression. Then I will take concrete\ninstances: I mean to say that the producing power or agent becomes\nneither heat nor whiteness but hot and white, and the like of other\nthings. For I must repeat what I said before, that neither the agent\nnor patient have any absolute existence, but when they come together\nand generate sensations and their objects, the one becomes a thing of a\ncertain quality, and the other a percipient. You remember?\n\nTHEODORUS: Of course.\n\nSOCRATES: We may leave the details of their theory unexamined, but\nwe must not forget to ask them the only question with which we are\nconcerned: Are all things in motion and flux?\n\nTHEODORUS: Yes, they will reply.\n\nSOCRATES: And they are moved in both those ways which we distinguished,\nthat is to say, they move in place and are also changed?\n\nTHEODORUS: Of course, if the motion is to be perfect.\n\nSOCRATES: 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 and\nflux?\n\nTHEODORUS: Exactly.\n\nSOCRATES: 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 any\ncolour be rightly used at all?\n\nTHEODORUS: How is that possible, Socrates, either in the case of this\nor of any other quality--if while we are using the word the object is\nescaping in the flux?\n\nSOCRATES: 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\nTHEODORUS: Certainly not, if all things are in motion.\n\nSOCRATES: 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\nTHEODORUS: Certainly not.\n\nSOCRATES: Yet perception is knowledge: so at least Theaetetus and I were\nsaying.\n\nTHEODORUS: Very true.\n\nSOCRATES: Then when we were asked what is knowledge, we no more answered\nwhat is knowledge than what is not knowledge?\n\nTHEODORUS: I suppose not.\n\nSOCRATES: 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 at\nrest, every answer upon whatever subject is equally right: you may say\nthat a thing is or is not thus; or, if you prefer, 'becomes' thus; and\nif we say 'becomes,' we shall not then hamper them with words expressive\nof rest.\n\nTHEODORUS: Quite true.\n\nSOCRATES: Yes, Theodorus, except in saying 'thus' and 'not thus.' But\nyou ought 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 perfectly\nindefinite.\n\nTHEODORUS: Yes, that is a manner of speaking in which they will be quite\nat home.\n\nSOCRATES: 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 perpetual\nflux, unless perchance our friend Theaetetus is able to convince us that\nit is.\n\nTHEODORUS: Very good, Socrates; and now that the argument about the\ndoctrine of Protagoras has been completed, I am absolved from answering;\nfor this was the agreement.\n\nTHEAETETUS: 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\nTHEODORUS: You, Theaetetus, who are a young rogue, must not instigate\nyour elders to a breach of faith, but should prepare to answer Socrates\nin the remainder of the argument.\n\nTHEAETETUS: Yes, if he wishes; but I would rather have heard about the\ndoctrine of rest.\n\nTHEODORUS: Invite Socrates to an argument--invite horsemen to the open\nplain; do but ask him, and he will answer.\n\nSOCRATES: Nevertheless, Theodorus, I am afraid that I shall not be able\nto comply with the request of Theaetetus.\n\nTHEODORUS: Not comply! for what reason?\n\nSOCRATES: 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 Homeric\nlanguage he may be called;--him I should be ashamed to approach in a\nspirit unworthy of him. I met him when he was an old man, and I was a\nmere youth, and he appeared to me to have a glorious depth of mind.\nAnd I am afraid that we may not understand his words, and may be still\nfurther from understanding his meaning; above all I fear that the nature\nof knowledge, which is the main subject of our discussion, may be thrust\nout of sight by the unbidden guests who will come pouring in upon our\nfeast of discourse, if we let them in--besides, the question which is\nnow stirring is of immense extent, and will be treated unfairly if only\nconsidered by the way; or if treated adequately and at length, will put\ninto the shade the other question of knowledge. Neither the one nor the\nother can be allowed; but I must try by my art of midwifery to deliver\nTheaetetus of his conceptions about knowledge.\n\nTHEAETETUS: Very well; do so if you will.\n\nSOCRATES: Then now, Theaetetus, take another view of the subject: you\nanswered that knowledge is perception?\n\nTHEAETETUS: I did.\n\nSOCRATES: And if any one were to ask you: With what does a man see black\nand white colours? and with what does he hear high and low sounds?--you\nwould say, if I am not mistaken, 'With the eyes and with the ears.'\n\nTHEAETETUS: I should.\n\nSOCRATES: The free use of words and phrases, rather than minute\nprecision, is generally characteristic of a liberal education, and\nthe opposite is pedantic; but sometimes precision is necessary, and I\nbelieve that the answer which you have just given is open to the charge\nof incorrectness; for which is more correct, to say that we see or hear\nwith the eyes and with the ears, or through the eyes and through the\nears.\n\nTHEAETETUS: I should say 'through,' Socrates, rather than 'with.'\n\nSOCRATES: Yes, my boy, for no one can suppose that in each of us, as\nin a sort of Trojan horse, there are perched a number of unconnected\nsenses, which do not all meet in some one nature, the mind, or whatever\nwe please to call it, of which they are the instruments, and with which\nthrough them we perceive objects of sense.\n\nTHEAETETUS: I agree with you in that opinion.\n\nSOCRATES: 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 refer\nall such perceptions to the body. Perhaps, however, I had better allow\nyou to answer for yourself and not interfere. Tell me, then, are not\nthe organs through which you perceive warm and hard and light and sweet,\norgans of the body?\n\nTHEAETETUS: Of the body, certainly.\n\nSOCRATES: 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 sight\nthrough hearing?\n\nTHEAETETUS: Of course not.\n\nSOCRATES: 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\nTHEAETETUS: It cannot.\n\nSOCRATES: How about sounds and colours: in the first place you would\nadmit that they both exist?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And that either of them is different from the other, and the\nsame with itself?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: And that both are two and each of them one?\n\nTHEAETETUS: Yes.\n\nSOCRATES: You can further observe whether they are like or unlike one\nanother?\n\nTHEAETETUS: I dare say.\n\nSOCRATES: But through what do you perceive all this about them? for\nneither through hearing nor yet through seeing can you apprehend that\nwhich 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 some\nother.\n\nTHEAETETUS: Certainly; the faculty of taste.\n\nSOCRATES: Very good; and now tell me what is the power which discerns,\nnot only in sensible objects, but in all things, universal notions, such\nas 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\nTHEAETETUS: You are thinking of being and not being, likeness and\nunlikeness, sameness and difference, and also of unity and other numbers\nwhich are applied to objects of sense; and you mean to ask, through\nwhat bodily organ the soul perceives odd and even numbers and other\narithmetical conceptions.\n\nSOCRATES: You follow me excellently, Theaetetus; that is precisely what\nI am asking.\n\nTHEAETETUS: 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 things.\n\nSOCRATES: 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 releasing me\nfrom a very long discussion, if you are clear that the soul views some\nthings by herself and others through the bodily organs. For that was my\nown opinion, and I wanted you to agree with me.\n\nTHEAETETUS: I am quite clear.\n\nSOCRATES: And to which class would you refer being or essence; for this,\nof all our notions, is the most universal?\n\nTHEAETETUS: I should say, to that class which the soul aspires to know\nof herself.\n\nSOCRATES: And would you say this also of like and unlike, same and\nother?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And would you say the same of the noble and base, and of good\nand evil?\n\nTHEAETETUS: 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\nSOCRATES: And does she not perceive the hardness of that which is hard\nby the touch, and the softness of that which is soft equally by the\ntouch?\n\nTHEAETETUS: Yes.\n\nSOCRATES: But their essence and what they are, and their opposition\nto one another, and the essential nature of this opposition, the soul\nherself endeavours to decide for us by the review and comparison of\nthem?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: The simple sensations which reach the soul through the body\nare given 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\nTHEAETETUS: Assuredly.\n\nSOCRATES: And can a man attain truth who fails of attaining being?\n\nTHEAETETUS: Impossible.\n\nSOCRATES: And can he who misses the truth of anything, have a knowledge\nof that thing?\n\nTHEAETETUS: He cannot.\n\nSOCRATES: Then knowledge does not consist in impressions of sense, but\nin reasoning about them; in that only, and not in the mere impression,\ntruth and being can be attained?\n\nTHEAETETUS: Clearly.\n\nSOCRATES: And would you call the two processes by the same name, when\nthere is so great a difference between them?\n\nTHEAETETUS: That would certainly not be right.\n\nSOCRATES: And what name would you give to seeing, hearing, smelling,\nbeing cold and being hot?\n\nTHEAETETUS: I should call all of them perceiving--what other name could\nbe given to them?\n\nSOCRATES: Perception would be the collective name of them?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: Which, as we say, has no part in the attainment of truth any\nmore than of being?\n\nTHEAETETUS: Certainly not.\n\nSOCRATES: And therefore not in science or knowledge?\n\nTHEAETETUS: No.\n\nSOCRATES: Then perception, Theaetetus, can never be the same as\nknowledge or science?\n\nTHEAETETUS: Clearly not, Socrates; and knowledge has now been most\ndistinctly proved to be different from perception.\n\nSOCRATES: 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 all,\nbut in that other process, however called, in which the mind is alone\nand engaged with being.\n\nTHEAETETUS: You mean, Socrates, if I am not mistaken, what is called\nthinking or opining.\n\nSOCRATES: You conceive truly. And now, my friend, please to begin\nagain at 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 say\nwhat is knowledge.\n\nTHEAETETUS: I cannot say, Socrates, that all opinion is knowledge,\nbecause there may be a false opinion; but I will venture to assert, that\nknowledge is true opinion: let this then be my reply; and if this is\nhereafter disproved, I must try to find another.\n\nSOCRATES: 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 shall be\nless likely to think that we know what we do not know--in either case we\nshall be richly rewarded. And now, what are you saying?--Are there\ntwo sorts of opinion, one true and the other false; and do you define\nknowledge to be the true?\n\nTHEAETETUS: Yes, according to my present view.\n\nSOCRATES: Is it still worth our while to resume the discussion touching\nopinion?\n\nTHEAETETUS: To what are you alluding?\n\nSOCRATES: 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 out\nthe nature or origin of the mental experience to which I refer.\n\nTHEAETETUS: Pray what is it?\n\nSOCRATES: 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 begin over again in a new way.\n\nTHEAETETUS: Begin again, Socrates,--at least if you think that there is\nthe slightest necessity for doing so. Were not you and Theodorus just\nnow remarking very truly, that in discussions of this kind we may take\nour own time?\n\nSOCRATES: 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\nTHEAETETUS: Certainly.\n\nSOCRATES: 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 opinion,\nas though there were some natural distinction between them?\n\nTHEAETETUS: We certainly say so.\n\nSOCRATES: All things and everything are either known or not known.\nI leave out of view the intermediate conceptions of learning and\nforgetting, because they have nothing to do with our present question.\n\nTHEAETETUS: There can be no doubt, Socrates, if you exclude these, that\nthere is no other alternative but knowing or not knowing a thing.\n\nSOCRATES: 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\nTHEAETETUS: He must.\n\nSOCRATES: He who knows, cannot but know; and he who does not know,\ncannot know?\n\nTHEAETETUS: Of course.\n\nSOCRATES: 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, and\nknowing both, is he at the same time ignorant of both?\n\nTHEAETETUS: That, Socrates, is impossible.\n\nSOCRATES: 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 Socrates,\nor Socrates Theaetetus?\n\nTHEAETETUS: How can he?\n\nSOCRATES: 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\nTHEAETETUS: That would be monstrous.\n\nSOCRATES: 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\nTHEAETETUS: Most true.\n\nSOCRATES: Suppose that we remove the question out of the sphere of\nknowing or not knowing, into that of being and not-being.\n\nTHEAETETUS: What do you mean?\n\nSOCRATES: May we not suspect the simple truth to be that he who thinks\nabout anything, that which is not, will necessarily think what is false,\nwhatever in other respects may be the state of his mind?\n\nTHEAETETUS: That, again, is not unlikely, Socrates.\n\nSOCRATES: Then suppose some one to say to us, Theaetetus:--Is\nit possible for any man to think that which is not, either as a\nself-existent substance or as a predicate of something else? And suppose\nthat we answer, 'Yes, he can, when he thinks what is not true.'--That\nwill be our answer?\n\nTHEAETETUS: Yes.\n\nSOCRATES: But is there any parallel to this?\n\nTHEAETETUS: What do you mean?\n\nSOCRATES: Can a man see something and yet see nothing?\n\nTHEAETETUS: Impossible.\n\nSOCRATES: But if he sees any one thing, he sees something that exists.\nDo you suppose that what is one is ever to be found among non-existing\nthings?\n\nTHEAETETUS: I do not.\n\nSOCRATES: He then who sees some one thing, sees something which is?\n\nTHEAETETUS: Clearly.\n\nSOCRATES: And he who hears anything, hears some one thing, and hears\nthat which is?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And he who touches anything, touches something which is one\nand therefore is?\n\nTHEAETETUS: That again is true.\n\nSOCRATES: And does not he who thinks, think some one thing?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: And does not he who thinks some one thing, think something\nwhich is?\n\nTHEAETETUS: I agree.\n\nSOCRATES: Then he who thinks of that which is not, thinks of nothing?\n\nTHEAETETUS: Clearly.\n\nSOCRATES: And he who thinks of nothing, does not think at all?\n\nTHEAETETUS: Obviously.\n\nSOCRATES: Then no one can think that which is not, either as a\nself-existent substance or as a predicate of something else?\n\nTHEAETETUS: Clearly not.\n\nSOCRATES: Then to think falsely is different from thinking that which is\nnot?\n\nTHEAETETUS: It would seem so.\n\nSOCRATES: Then false opinion has no existence in us, either in the\nsphere of being or of knowledge?\n\nTHEAETETUS: Certainly not.\n\nSOCRATES: But may not the following be the description of what we\nexpress by this name?\n\nTHEAETETUS: What?\n\nSOCRATES: 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 one\nreal object is another real object. For thus he always thinks that which\nis, but he puts one thing in place of another; and missing the aim of\nhis thoughts, he may be truly said to have false opinion.\n\nTHEAETETUS: Now you appear to me to have spoken the exact truth: when a\nman puts the base in the place of the noble, or the noble in the place\nof the base, then he has truly false opinion.\n\nSOCRATES: I see, Theaetetus, that your fear has disappeared, and that\nyou are beginning to despise me.\n\nTHEAETETUS: What makes you say so?\n\nSOCRATES: 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\na swift which is slow, or a heavy which is light, or any other\nself-contradictory thing, which works, not according to its own nature,\nbut according to that of its opposite. But I will not insist upon this,\nfor I do not wish needlessly to discourage you. And so you are satisfied\nthat false opinion is heterodoxy, or the thought of something else?\n\nTHEAETETUS: I am.\n\nSOCRATES: It is possible then upon your view for the mind to conceive of\none thing as another?\n\nTHEAETETUS: True.\n\nSOCRATES: But must not the mind, or thinking power, which misplaces\nthem, have a conception either of both objects or of one of them?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: Either together or in succession?\n\nTHEAETETUS: Very good.\n\nSOCRATES: And do you mean by conceiving, the same which I mean?\n\nTHEAETETUS: What is that?\n\nSOCRATES: I mean the conversation which the soul holds with herself in\nconsidering of anything. I speak of what I scarcely understand; but the\nsoul when thinking appears to me to be just talking--asking questions\nof herself and answering them, affirming and denying. And when she has\narrived at a decision, either gradually or by a sudden impulse, and has\nat last agreed, and does not doubt, this is called her opinion. I\nsay, then, that to form an opinion is to speak, and opinion is a word\nspoken,--I mean, to oneself and in silence, not aloud or to another:\nWhat think you?\n\nTHEAETETUS: I agree.\n\nSOCRATES: Then when any one thinks of one thing as another, he is saying\nto himself that one thing is another?\n\nTHEAETETUS: Yes.\n\nSOCRATES: But do you ever remember saying to yourself that the noble\nis certainly base, or the unjust just; or, best of all--have you ever\nattempted to convince yourself that one thing is another? Nay, not even\nin sleep, did you ever venture to say to yourself that odd is even, or\nanything of the kind?\n\nTHEAETETUS: Never.\n\nSOCRATES: 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 a\nhorse, or that two are one?\n\nTHEAETETUS: Certainly not.\n\nSOCRATES: But if thinking is talking to oneself, no one speaking and\nthinking of two objects, and apprehending them both in his soul, will\nsay and think that the one is the other of them, and I must add, that\neven you, lover of dispute as you are, had better let the word 'other'\nalone (i.e. not insist that 'one' and 'other' are the same (Both words\nin Greek are called eteron: compare Parmen.; Euthyd.)). I mean to say,\nthat no one thinks the noble to be base, or anything of the kind.\n\nTHEAETETUS: I will give up the word 'other,' Socrates; and I agree to\nwhat you say.\n\nSOCRATES: If a man has both of them in his thoughts, he cannot think\nthat the one of them is the other?\n\nTHEAETETUS: True.\n\nSOCRATES: Neither, if he has one of them only in his mind and not the\nother, can he think that one is the other?\n\nTHEAETETUS: True; for we should have to suppose that he apprehends that\nwhich is not in his thoughts at all.\n\nSOCRATES: Then no one who has either both or only one of the two objects\nin his mind can think that the one is the other. And therefore, he who\nmaintains that false opinion is heterodoxy is talking nonsense; for\nneither in this, any more than in the previous way, can false opinion\nexist in us.\n\nTHEAETETUS: No.\n\nSOCRATES: But if, Theaetetus, this is not admitted, we shall be driven\ninto many absurdities.\n\nTHEAETETUS: What are they?\n\nSOCRATES: 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 which\nI speak. But if we find the solution, and get away from them, we may\nregard them only as the difficulties of others, and the ridicule will\nnot attach to us. On the other hand, if we utterly fail, I suppose that\nwe must be humble, and allow the argument to trample us under foot,\nas the sea-sick passenger is trampled upon by the sailor, and to do\nanything to us. Listen, then, while I tell you how I hope to find a way\nout of our difficulty.\n\nTHEAETETUS: Let me hear.\n\nSOCRATES: 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\nTHEAETETUS: 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 whom\nI mistake for him--then the deception will occur?\n\nSOCRATES: 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\nTHEAETETUS: True.\n\nSOCRATES: Let us make the assertion in another form, which may or may\nnot have 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 not\nknow?\n\nTHEAETETUS: Certainly you may.\n\nSOCRATES: And another and another?\n\nTHEAETETUS: Yes.\n\nSOCRATES: 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 another,\nand in some of an intermediate quality.\n\nTHEAETETUS: I see.\n\nSOCRATES: 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 impression of\nthem as from the seal of a ring; and that we remember and know what is\nimprinted as long as the image lasts; but when the image is effaced, or\ncannot be taken, then we forget and do not know.\n\nTHEAETETUS: Very good.\n\nSOCRATES: 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\nTHEAETETUS: In what manner?\n\nSOCRATES: 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\nTHEAETETUS: And how would you amend the former statement?\n\nSOCRATES: 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 impression\nof the other; nor can he think that one thing which he does not know is\nanother thing which he does not know, or that what he does not know\nis what he knows; nor (2) that one thing which he perceives is another\nthing which he perceives, or that something which he perceives is\nsomething which he does not perceive; or that something which he does\nnot perceive is something else which he does not perceive; or that\nsomething which he does not perceive is something which he perceives;\nnor again (3) can he think that something which he knows and perceives,\nand of which he has the impression coinciding with sense, is something\nelse which he knows and perceives, and of which he has the impression\ncoinciding with sense;--this last case, if possible, is still more\ninconceivable than the others; nor (4) can he think that something which\nhe knows and perceives, and of which he has the memorial coinciding with\nsense, is something else which he knows; nor so long as these agree,\ncan he think that a thing which he knows and perceives is another thing\nwhich he perceives; or that a thing which he does not know and does not\nperceive, is the same as another thing which he does not know and does\nnot perceive;--nor again, can he suppose that a thing which he does not\nknow and does not perceive is the same as another thing which he does\nnot know; or that a thing which he does not know and does not perceive\nis another thing which he does not perceive:--All these utterly and\nabsolutely exclude the possibility of false opinion. The only cases, if\nany, which remain, are the following.\n\nTHEAETETUS: What are they? If you tell me, I may perhaps understand you\nbetter; but at present I am unable to follow you.\n\nSOCRATES: A person may think that some things which he knows, or which\nhe perceives and does not know, are some other things which he knows and\nperceives; or that some things which he knows and perceives, are other\nthings which he knows and perceives.\n\nTHEAETETUS: I understand you less than ever now.\n\nSOCRATES: Hear me once more, then:--I, knowing Theodorus, and\nremembering in my own mind what sort of person he is, and also what sort\nof person Theaetetus is, at one time see them, and at another time do\nnot see them, and sometimes I touch them, and at another time not, or\nat one time I may hear them or perceive them in some other way, and at\nanother time not perceive them, but still I remember them, and know them\nin my own mind.\n\nTHEAETETUS: Very true.\n\nSOCRATES: Then, first of all, I want you to understand that a man may or\nmay not perceive sensibly that which he knows.\n\nTHEAETETUS: True.\n\nSOCRATES: And that which he does not know will sometimes not be\nperceived by him and sometimes will be perceived and only perceived?\n\nTHEAETETUS: That is also true.\n\nSOCRATES: See whether you can follow me better now: Socrates can\nrecognize Theodorus and Theaetetus, but he sees neither of them,\nnor does 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\nTHEAETETUS: You are quite right.\n\nSOCRATES: Then that was the first case of which I spoke.\n\nTHEAETETUS: Yes.\n\nSOCRATES: The second case was, that I, knowing one of you and not\nknowing the other, and perceiving neither, can never think him whom I\nknow to be him whom I do not know.\n\nTHEAETETUS: True.\n\nSOCRATES: 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 whom\nI do not know. I need not again go over the catalogue of excluded cases,\nin which I cannot form a false opinion about you and Theodorus, either\nwhen I know both or when I am in ignorance of both, or when I know one\nand not the other. And the same of perceiving: do you understand me?\n\nTHEAETETUS: I do.\n\nSOCRATES: The only possibility of erroneous opinion is, when knowing you\nand Theodorus, and having on the waxen block the impression of both of\nyou given as by a seal, but seeing you imperfectly and at a distance,\nI try to assign the right impression of memory to the right visual\nimpression, and to fit this into its own print: if I succeed,\nrecognition will take place; but if I fail and transpose them, putting\nthe foot into the wrong shoe--that is to say, putting the vision of\neither of you on to the wrong impression, or if my mind, like the sight\nin a mirror, which is transferred from right to left, err by reason of\nsome similar affection, then 'heterodoxy' and false opinion ensues.\n\nTHEAETETUS: Yes, Socrates, you have described the nature of opinion with\nwonderful exactness.\n\nSOCRATES: Or again, when I know both of you, and perceive as well as\nknow one of you, but not the other, and my knowledge of him does not\naccord with perception--that was the case put by me just now which you\ndid not understand.\n\nTHEAETETUS: No, I did not.\n\nSOCRATES: I meant to say, that when a person knows and perceives one of\nyou, his knowledge coincides with his perception, he will never think\nhim to be some other person, whom he knows and perceives, and the\nknowledge of whom coincides with his perception--for that also was a\ncase supposed.\n\nTHEAETETUS: True.\n\nSOCRATES: 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 miss\nand fall wide of the mark--and this is called falsehood.\n\nTHEAETETUS: Yes; it is rightly so called.\n\nSOCRATES: When, therefore, perception is present to one of the seals\nor impressions 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 sort\nthe mind is deceived; in a word, if our view is sound, there can be no\nerror or deception about things which a man does not know and has never\nperceived, but only in things which are known and perceived; in these\nalone opinion turns and twists about, and becomes alternately true and\nfalse;--true when the seals and impressions of sense meet straight and\nopposite--false when they go awry and crooked.\n\nTHEAETETUS: And is not that, Socrates, nobly said?\n\nSOCRATES: 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\nTHEAETETUS: Undoubtedly.\n\nSOCRATES: 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 perfectly\ntempered, then the impressions which pass through the senses and sink\ninto the heart of the soul, as Homer says in a parable, meaning to\nindicate the likeness of the soul to wax (Kerh Kerhos); these, I say,\nbeing pure and clear, and having a sufficient depth of wax, are also\nlasting, and minds, such as these, easily learn and easily retain,\nand are not liable to confusion, but have true thoughts, for they have\nplenty of room, and having clear impressions of things, as we term them,\nquickly distribute them into their proper places on the block. And such\nmen are called wise. Do you agree?\n\nTHEAETETUS: Entirely.\n\nSOCRATES: 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 soft\nare good at learning, but apt to forget; and the hard are the reverse;\nthe shaggy and rugged and gritty, or those who have an admixture of\nearth or dung in their composition, have the impressions indistinct,\nas also the hard, for there is no depth in them; and the soft too are\nindistinct, for their impressions are easily confused and effaced. Yet\ngreater is the indistinctness when they are all jostled together in a\nlittle soul, which has no room. These are the natures which have false\nopinion; for when they see or hear or think of anything, they are\nslow in assigning the right objects to the right impressions--in their\nstupidity they confuse them, and are apt to see and hear and think\namiss--and such men are said to be deceived in their knowledge of\nobjects, and ignorant.\n\nTHEAETETUS: No man, Socrates, can say anything truer than that.\n\nSOCRATES: Then now we may admit the existence of false opinion in us?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: And of true opinion also?\n\nTHEAETETUS: Yes.\n\nSOCRATES: We have at length satisfactorily proven beyond a doubt there\nare these two sorts of opinion?\n\nTHEAETETUS: Undoubtedly.\n\nSOCRATES: Alas, Theaetetus, what a tiresome creature is a man who is\nfond of talking!\n\nTHEAETETUS: What makes you say so?\n\nSOCRATES: Because I am disheartened at my own stupidity and tiresome\ngarrulity; for what other term will describe the habit of a man who\nis always arguing on all sides of a question; whose dulness cannot be\nconvinced, and who will never leave off?\n\nTHEAETETUS: But what puts you out of heart?\n\nSOCRATES: 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 you\nindeed discovered that false opinion arises neither in the comparison of\nperceptions with one another nor yet in thought, but in union of thought\nand perception? Yes, I shall say, with the complacence of one who thinks\nthat he has made a noble discovery.\n\nTHEAETETUS: I see no reason why we should be ashamed of our\ndemonstration, Socrates.\n\nSOCRATES: He will say: You mean to argue that the man whom we only think\nof and do not see, cannot be confused with the horse which we do not see\nor touch, but only think of and do not perceive? That I believe to be my\nmeaning, I shall reply.\n\nTHEAETETUS: Quite right.\n\nSOCRATES: Well, then, he will say, according to that argument, the\nnumber eleven, which is only thought, can never be mistaken for twelve,\nwhich is only thought: How would you answer him?\n\nTHEAETETUS: 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\nSOCRATES: Well, but do you think that no one ever put before his own\nmind five and seven,--I do not mean five or seven men or horses, but\nfive or seven in the abstract, which, as we say, are recorded on the\nwaxen block, and in which false opinion is held to be impossible; did\nno man ever ask himself how many these numbers make when added together,\nand answer that they are eleven, while another thinks that they are\ntwelve, or would all agree in thinking and saying that they are twelve?\n\nTHEAETETUS: Certainly not; many would think that they are eleven, and\nin the higher numbers the chance of error is greater still; for I assume\nyou to be speaking of numbers in general.\n\nSOCRATES: Exactly; and I want you to consider whether this does not\nimply that the twelve in the waxen block are supposed to be eleven?\n\nTHEAETETUS: Yes, that seems to be the case.\n\nSOCRATES: 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 afforded\nan irresistible proof of the non-existence of false opinion, because\notherwise the same person would inevitably know and not know the same\nthing at the same time.\n\nTHEAETETUS: Most true.\n\nSOCRATES: 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\nTHEAETETUS: It is hard to determine, Socrates.\n\nSOCRATES: 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\nTHEAETETUS: What is it?\n\nSOCRATES: Let us attempt to explain the verb 'to know.'\n\nTHEAETETUS: And why should that be shameless?\n\nSOCRATES: You seem not to be aware that the whole of our discussion from\nthe very beginning has been a search after knowledge, of which we are\nassumed not to know the nature.\n\nTHEAETETUS: Nay, but I am well aware.\n\nSOCRATES: And is it not shameless when we do not know what knowledge is,\nto be explaining the verb 'to know'? The truth is, Theaetetus, that we\nhave long been infected with logical impurity. Thousands of times have\nwe repeated the words 'we know,' and 'do not know,' and 'we have or have\nnot science or knowledge,' as if we could understand what we are saying\nto one another, so long as we remain ignorant about knowledge; and at\nthis moment we are using the words 'we understand,' 'we are ignorant,'\nas though we could still employ them when deprived of knowledge or\nscience.\n\nTHEAETETUS: But if you avoid these expressions, Socrates, how will you\never argue at all?\n\nSOCRATES: I could not, being the man I am. The case would be different\nif I were a true hero of dialectic: and O that such an one were present!\nfor he would have told us to avoid the use of these terms; at the same\ntime he would not have spared in you and me the faults which I have\nnoted. But, seeing that we are no great wits, shall I venture to say\nwhat knowing is? for I think that the attempt may be worth making.\n\nTHEAETETUS: Then by all means venture, and no one shall find fault with\nyou for using the forbidden terms.\n\nSOCRATES: You have heard the common explanation of the verb 'to know'?\n\nTHEAETETUS: I think so, but I do not remember it at the moment.\n\nSOCRATES: They explain the word 'to know' as meaning 'to have\nknowledge.'\n\nTHEAETETUS: True.\n\nSOCRATES: I should like to make a slight change, and say 'to possess'\nknowledge.\n\nTHEAETETUS: How do the two expressions differ?\n\nSOCRATES: Perhaps there may be no difference; but still I should like\nyou to hear my view, that you may help me to test it.\n\nTHEAETETUS: I will, if I can.\n\nSOCRATES: I should distinguish 'having' from 'possessing': for example,\na man 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 the\ngarment.\n\nTHEAETETUS: It would be the correct expression.\n\nSOCRATES: Well, may not a man 'possess' and yet not 'have' knowledge\nin the 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 in\nan aviary which he has constructed at home; we might say of him in one\nsense, that he always has them because he possesses them, might we not?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And yet, in another sense, he has none of them; but they are\nin his 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 as\nhe pleases.\n\nTHEAETETUS: True.\n\nSOCRATES: 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 man\nthere is an aviary of all sorts of birds--some flocking together apart\nfrom the rest, others in small groups, others solitary, flying anywhere\nand everywhere.\n\nTHEAETETUS: Let us imagine such an aviary--and what is to follow?\n\nSOCRATES: We may suppose that the birds are kinds of knowledge, and that\nwhen we were children, this receptacle was empty; whenever a man has\ngotten and detained in the enclosure a kind of knowledge, he may be\nsaid to have learned or discovered the thing which is the subject of the\nknowledge: and this is to know.\n\nTHEAETETUS: Granted.\n\nSOCRATES: 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 'catching'\nof them and the original 'possession' in the same words? I will make\nmy meaning clearer by an example:--You admit that there is an art of\narithmetic?\n\nTHEAETETUS: To be sure.\n\nSOCRATES: Conceive this under the form of a hunt after the science of\nodd and even in general.\n\nTHEAETETUS: I follow.\n\nSOCRATES: Having the use of the art, the arithmetician, if I am not\nmistaken, has the conceptions of number under his hand, and can transmit\nthem to another.\n\nTHEAETETUS: Yes.\n\nSOCRATES: And when transmitting them he may be said to teach them, and\nwhen receiving to learn them, and when receiving to learn them, and when\nhaving them in possession in the aforesaid aviary he may be said to know\nthem.\n\nTHEAETETUS: Exactly.\n\nSOCRATES: Attend to what follows: must not the perfect arithmetician\nknow all numbers, for he has the science of all numbers in his mind?\n\nTHEAETETUS: True.\n\nSOCRATES: And he can reckon abstract numbers in his head, or things\nabout him which are numerable?\n\nTHEAETETUS: Of course he can.\n\nSOCRATES: And to reckon is simply to consider how much such and such a\nnumber amounts to?\n\nTHEAETETUS: Very true.\n\nSOCRATES: 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 he\nknows all numbers;--you have heard these perplexing questions raised?\n\nTHEAETETUS: I have.\n\nSOCRATES: 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 and\nholding in the hands that which is possessed already. And thus, when a\nman has learned and known something long ago, he may resume and get hold\nof the knowledge which he has long possessed, but has not at hand in his\nmind.\n\nTHEAETETUS: True.\n\nSOCRATES: That was my reason for asking how we ought to speak when an\narithmetician sets about numbering, or a grammarian about reading? Shall\nwe say, that although he knows, he comes back to himself to learn what\nhe already knows?\n\nTHEAETETUS: It would be too absurd, Socrates.\n\nSOCRATES: 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\nTHEAETETUS: That, again, would be an absurdity.\n\nSOCRATES: Then shall we say that about names we care nothing?--any one\nmay twist and turn the words 'knowing' and 'learning' in any way which\nhe likes, but since we have determined that the possession of knowledge\nis not the having or using it, we do assert that a man cannot not\npossess that which he possesses; and, therefore, in no case can a man\nnot know that which he knows, but he may get a false opinion about it;\nfor he may have the knowledge, not of this particular thing, but of some\nother;--when the various numbers and forms of knowledge are flying about\nin the aviary, and wishing to capture a certain sort of knowledge out\nof the general store, he takes the wrong one by mistake, that is to say,\nwhen he thought eleven to be twelve, he got hold of the ring-dove which\nhe had in his mind, when he wanted the pigeon.\n\nTHEAETETUS: A very rational explanation.\n\nSOCRATES: 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 opinion\nmay exist, and the difficulties which were previously raised disappear.\nI dare say that you agree with me, do you not?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And so we are rid of the difficulty of a man's not knowing\nwhat he 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\nTHEAETETUS: What is it?\n\nSOCRATES: How can the exchange of one knowledge for another ever become\nfalse opinion?\n\nTHEAETETUS: What do you mean?\n\nSOCRATES: 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 ignorance,\nbut by reason of his own knowledge? And, again, is it not an extreme\nabsurdity that he should suppose another thing to be this, and this to\nbe another thing;--that, having knowledge present with him in his mind,\nhe should still know nothing and be ignorant of all things?--you might\nas well argue that ignorance may make a man know, and blindness make him\nsee, as that knowledge can make him ignorant.\n\nTHEAETETUS: Perhaps, Socrates, we may have been wrong in making only\nforms of knowledge our birds: whereas there ought to have been forms of\nignorance as well, flying about together in the mind, and then he who\nsought to take one of them might sometimes catch a form of knowledge,\nand sometimes a form of ignorance; and thus he would have a false\nopinion from ignorance, but a true one from knowledge, about the same\nthing.\n\nSOCRATES: I cannot help praising you, Theaetetus, and yet I must beg you\nto reconsider your words. Let us grant what you say--then, according to\nyou, he who takes ignorance will have a false opinion--am I right?\n\nTHEAETETUS: Yes.\n\nSOCRATES: He will certainly not think that he has a false opinion?\n\nTHEAETETUS: Of course not.\n\nSOCRATES: He will think that his opinion is true, and he will fancy that\nhe knows the things about which he has been deceived?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: Then he will think that he has captured knowledge and not\nignorance?\n\nTHEAETETUS: Clearly.\n\nSOCRATES: And thus, after going a long way round, we are once more face\nto face with our original difficulty. The hero of dialectic will retort\nupon us:--'O my excellent friends, he will say, laughing, if a man knows\nthe form of ignorance and the form of knowledge, can he think that one\nof them which he knows is the other which he knows? or, if he knows\nneither of them, can he think that the one which he knows not is another\nwhich he knows not? or, if he knows one and not the other, can he think\nthe one which he knows to be the one which he does not know? or the one\nwhich he does not know to be the one which he knows? or will you tell me\nthat there are other forms of knowledge which distinguish the right and\nwrong birds, and which the owner keeps in some other aviaries or graven\non waxen blocks according to your foolish images, and which he may be\nsaid to know while he possesses them, even though he have them not at\nhand in his mind? And thus, in a perpetual circle, you will be compelled\nto go round and round, and you will make no progress.' What are we to\nsay in reply, Theaetetus?\n\nTHEAETETUS: Indeed, Socrates, I do not know what we are to say.\n\nSOCRATES: 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 false\nopinion?\n\nTHEAETETUS: I cannot but agree with you, Socrates, so far as we have yet\ngone.\n\nSOCRATES: Then, once more, what shall we say that knowledge is?--for we\nare not going to lose heart as yet.\n\nTHEAETETUS: Certainly, I shall not lose heart, if you do not.\n\nSOCRATES: What definition will be most consistent with our former views?\n\nTHEAETETUS: I cannot think of any but our old one, Socrates.\n\nSOCRATES: What was it?\n\nTHEAETETUS: Knowledge was said by us to be true opinion; and true\nopinion is surely unerring, and the results which follow from it are all\nnoble and good.\n\nSOCRATES: He who led the way into the river, Theaetetus, said 'The\nexperiment will show;' and perhaps if we go forward in the search, we\nmay stumble upon the thing which we are looking for; but if we stay\nwhere we are, nothing will come to light.\n\nTHEAETETUS: Very true; let us go forward and try.\n\nSOCRATES: The trail soon comes to an end, for a whole profession is\nagainst us.\n\nTHEAETETUS: How is that, and what profession do you mean?\n\nSOCRATES: 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 convince\nothers of the truth about acts of robbery or violence, of which\nthey were not eye-witnesses, while a little water is flowing in the\nclepsydra?\n\nTHEAETETUS: Certainly not, they can only persuade them.\n\nSOCRATES: And would you not say that persuading them is making them have\nan opinion?\n\nTHEAETETUS: To be sure.\n\nSOCRATES: When, therefore, judges are justly persuaded about matters\nwhich you can know only by seeing them, and not in any other way, and\nwhen thus judging of them from report they attain a true opinion about\nthem, they judge without knowledge, and yet are rightly persuaded, if\nthey have judged well.\n\nTHEAETETUS: Certainly.\n\nSOCRATES: And yet, O my friend, if true opinion in law courts and\nknowledge are the same, the perfect judge could not have judged rightly\nwithout knowledge; and therefore I must infer that they are not the\nsame.\n\nTHEAETETUS: 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\nno reason 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\nSOCRATES: 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\nTHEAETETUS: I do not know whether I can recall it; but if another person\nwould tell me, I think that I could follow him.\n\nSOCRATES: Let me give you, then, a dream in return for a\ndream:--Methought that I too had a dream, and I heard in my dream that\nthe primeval letters or elements out of which you and I and all other\nthings are compounded, have no reason or explanation; you can only name\nthem, but no predicate can be either affirmed or denied of them, for in\nthe one 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 each,\nor alone, or this, or the like; for these go about everywhere and are\napplied to all things, but are distinct from them; whereas, if the first\nelements could be described, and had a definition of their own, they\nwould be spoken of apart from all else. But none of these primeval\nelements can be defined; they can only be named, for they have nothing\nbut a name, and the things which are compounded of them, as they are\ncomplex, are expressed by a combination of names, for the combination\nof names is the essence of a definition. Thus, then, the elements or\nletters are only objects of perception, and cannot be defined or known;\nbut the syllables or combinations of them are known and expressed, and\nare apprehended by true opinion. When, therefore, any one forms the true\nopinion of anything without rational explanation, you may say that his\nmind is truly exercised, but has no knowledge; for he who cannot give\nand receive a reason for a thing, has no knowledge of that thing; but\nwhen he adds rational explanation, then, he is perfected in knowledge\nand may be all that I have been denying of him. Was that the form in\nwhich the dream appeared to you?\n\nTHEAETETUS: Precisely.\n\nSOCRATES: And you allow and maintain that true opinion, combined with\ndefinition or rational explanation, is knowledge?\n\nTHEAETETUS: Exactly.\n\nSOCRATES: Then may we assume, Theaetetus, that to-day, and in this\ncasual manner, we have found a truth which in former times many wise men\nhave grown old and have not found?\n\nTHEAETETUS: At any rate, Socrates, I am satisfied with the present\nstatement.\n\nSOCRATES: Which is probably correct--for how can there be knowledge\napart from definition and true opinion? And yet there is one point in\nwhat has been said which does not quite satisfy me.\n\nTHEAETETUS: What was it?\n\nSOCRATES: What might seem to be the most ingenious notion of all:--That\nthe elements or letters are unknown, but the combination or syllables\nknown.\n\nTHEAETETUS: And was that wrong?\n\nSOCRATES: We shall soon know; for we have as hostages the instances\nwhich the author of the argument himself used.\n\nTHEAETETUS: What hostages?\n\nSOCRATES: 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\nTHEAETETUS: Yes; he did.\n\nSOCRATES: 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\nTHEAETETUS: I think so.\n\nSOCRATES: 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\nTHEAETETUS: I should reply S and O.\n\nSOCRATES: That is the definition which you would give of the syllable?\n\nTHEAETETUS: I should.\n\nSOCRATES: I wish that you would give me a similar definition of the S.\n\nTHEAETETUS: 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\nSOCRATES: Then, I suppose, my friend, that we have been so far right in\nour idea about knowledge?\n\nTHEAETETUS: Yes; I think that we have.\n\nSOCRATES: Well, but have we been right in maintaining that the syllables\ncan be known, but not the letters?\n\nTHEAETETUS: I think so.\n\nSOCRATES: And do we mean by a syllable two letters, or if there are\nmore, all of them, or a single idea which arises out of the combination\nof them?\n\nTHEAETETUS: I should say that we mean all the letters.\n\nSOCRATES: Take the case of the two letters S and O, which form the first\nsyllable of my own name; must not he who knows the syllable, know both\nof them?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: He knows, that is, the S and O?\n\nTHEAETETUS: Yes.\n\nSOCRATES: But can he be ignorant of either singly and yet know both\ntogether?\n\nTHEAETETUS: Such a supposition, Socrates, is monstrous and unmeaning.\n\nSOCRATES: But if he cannot know both without knowing each, then if he is\never to know the syllable, he must know the letters first; and thus the\nfine theory has again taken wings and departed.\n\nTHEAETETUS: Yes, with wonderful celerity.\n\nSOCRATES: 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\nTHEAETETUS: Very true; and a more likely notion than the other.\n\nSOCRATES: Take care; let us not be cowards and betray a great and\nimposing theory.\n\nTHEAETETUS: No, indeed.\n\nSOCRATES: Let us assume then, as we now say, that the syllable is\na simple form arising out of the several combinations of harmonious\nelements--of letters or of any other elements.\n\nTHEAETETUS: Very good.\n\nSOCRATES: And it must have no parts.\n\nTHEAETETUS: Why?\n\nSOCRATES: Because that which has parts must be a whole of all the parts.\nOr would you say that a whole, although formed out of the parts, is a\nsingle notion different from all the parts?\n\nTHEAETETUS: I should.\n\nSOCRATES: And would you say that all and the whole are the same, or\ndifferent?\n\nTHEAETETUS: I am not certain; but, as you like me to answer at once, I\nshall hazard the reply, that they are different.\n\nSOCRATES: I approve of your readiness, Theaetetus, but I must take time\nto think whether I equally approve of your answer.\n\nTHEAETETUS: Yes; the answer is the point.\n\nSOCRATES: According to this new view, the whole is supposed to differ\nfrom all?\n\nTHEAETETUS: Yes.\n\nSOCRATES: 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 speaking of\nthe same or of different numbers?\n\nTHEAETETUS: Of the same.\n\nSOCRATES: That is of six?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And in each form of expression we spoke of all the six?\n\nTHEAETETUS: True.\n\nSOCRATES: Again, in speaking of all (in the plural) is there not one\nthing which we express?\n\nTHEAETETUS: Of course there is.\n\nSOCRATES: And that is six?\n\nTHEAETETUS: Yes.\n\nSOCRATES: Then in predicating the word 'all' of things measured by\nnumber, we predicate at the same time a singular and a plural?\n\nTHEAETETUS: Clearly we do.\n\nSOCRATES: Again, the number of the acre and the acre are the same; are\nthey not?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And the number of the stadium in like manner is the stadium?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And the army is the number of the army; and in all similar\ncases, the entire number of anything is the entire thing?\n\nTHEAETETUS: True.\n\nSOCRATES: And the number of each is the parts of each?\n\nTHEAETETUS: Exactly.\n\nSOCRATES: Then as many things as have parts are made up of parts?\n\nTHEAETETUS: Clearly.\n\nSOCRATES: But all the parts are admitted to be the all, if the entire\nnumber is the all?\n\nTHEAETETUS: True.\n\nSOCRATES: Then the whole is not made up of parts, for it would be the\nall, if consisting of all the parts?\n\nTHEAETETUS: That is the inference.\n\nSOCRATES: But is a part a part of anything but the whole?\n\nTHEAETETUS: Yes, of the all.\n\nSOCRATES: You make a valiant defence, Theaetetus. And yet is not the all\nthat of which nothing is wanting?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: And is not a whole likewise that from which nothing is absent?\nbut that from which anything is absent is neither a whole nor all;--if\nwanting in anything, both equally lose their entirety of nature.\n\nTHEAETETUS: I now think that there is no difference between a whole and\nall.\n\nSOCRATES: But were we not saying that when a thing has parts, all the\nparts will be a whole and all?\n\nTHEAETETUS: Certainly.\n\nSOCRATES: Then, as I was saying before, must not the alternative be that\neither the syllable is not the letters, and then the letters are not\nparts of the syllable, or that the syllable will be the same with the\nletters, and will therefore be equally known with them?\n\nTHEAETETUS: You are right.\n\nSOCRATES: And, in order to avoid this, we suppose it to be different\nfrom them?\n\nTHEAETETUS: Yes.\n\nSOCRATES: But if letters are not parts of syllables, can you tell me of\nany other parts of syllables, which are not letters?\n\nTHEAETETUS: No, indeed, Socrates; for if I admit the existence of parts\nin a syllable, it would be ridiculous in me to give up letters and seek\nfor other parts.\n\nSOCRATES: Quite true, Theaetetus, and therefore, according to our\npresent view, a syllable must surely be some indivisible form?\n\nTHEAETETUS: True.\n\nSOCRATES: But do you remember, my friend, that only a little while ago\nwe admitted and approved the statement, that of the first elements out\nof which 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 or\nelements were indefinable and unknown?\n\nTHEAETETUS: I remember.\n\nSOCRATES: And is not this also the reason why they are simple and\nindivisible? I can see no other.\n\nTHEAETETUS: No other reason can be given.\n\nSOCRATES: Then is not the syllable in the same case as the elements or\nletters, if it has no parts and is one form?\n\nTHEAETETUS: To be sure.\n\nSOCRATES: If, then, a syllable is a whole, and has many parts or\nletters, the letters as well as the syllable must be intelligible and\nexpressible, since all the parts are acknowledged to be the same as the\nwhole?\n\nTHEAETETUS: True.\n\nSOCRATES: But if it be one and indivisible, then the syllables and the\nletters are alike undefined and unknown, and for the same reason?\n\nTHEAETETUS: I cannot deny that.\n\nSOCRATES: We cannot, therefore, agree in the opinion of him who says\nthat the syllable can be known and expressed, but not the letters.\n\nTHEAETETUS: Certainly not; if we may trust the argument.\n\nSOCRATES: Well, but will you not be equally inclined to disagree with\nhim, when you remember your own experience in learning to read?\n\nTHEAETETUS: What experience?\n\nSOCRATES: Why, that in learning you were kept trying to distinguish the\nseparate letters both by the eye and by the ear, in order that, when\nyou heard them spoken or saw them written, you might not be confused by\ntheir position.\n\nTHEAETETUS: Very true.\n\nSOCRATES: And is the education of the harp-player complete unless he can\ntell what string answers to a particular note; the notes, as every one\nwould allow, are the elements or letters of music?\n\nTHEAETETUS: Exactly.\n\nSOCRATES: Then, if we argue from the letters and syllables which we know\nto other simples and compounds, we shall say that the letters or simple\nelements as a class are much more certainly known than the syllables,\nand much more indispensable to a perfect knowledge of any subject; and\nif some one says that the syllable is known and the letter unknown,\nwe shall consider that either intentionally or unintentionally he is\ntalking nonsense?\n\nTHEAETETUS: Exactly.\n\nSOCRATES: 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 the\nquestion before us, which is the meaning of the statement, that right\nopinion with rational definition or explanation is the most perfect form\nof knowledge.\n\nTHEAETETUS: We must not.\n\nSOCRATES: Well, and what is the meaning of the term 'explanation'? I\nthink that we have a choice of three meanings.\n\nTHEAETETUS: What are they?\n\nSOCRATES: 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\nTHEAETETUS: Certainly; he who so manifests his thought, is said to\nexplain himself.\n\nSOCRATES: 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 explanation;\nnor will right opinion be anywhere found to exist apart from knowledge.\n\nTHEAETETUS: True.\n\nSOCRATES: Let us not, therefore, hastily charge him who gave this\naccount of knowledge with uttering an unmeaning word; for perhaps he\nonly intended to say, that when a person was asked what was the nature\nof anything, he should be able to answer his questioner by giving the\nelements of the thing.\n\nTHEAETETUS: As for example, Socrates...?\n\nSOCRATES: As, for example, when Hesiod says that a waggon is made up\nof a hundred planks. Now, neither you nor I could describe all of\nthem individually; 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\nTHEAETETUS: Certainly.\n\nSOCRATES: And our opponent will probably laugh at us, just as he would\nif we professed to be grammarians and to give a grammatical account of\nthe name of Theaetetus, and yet could only tell the syllables and not\nthe letters of your name--that would be true opinion, and not knowledge;\nfor knowledge, as has been already remarked, is not attained until,\ncombined with true opinion, there is an enumeration of the elements out\nof which anything is composed.\n\nTHEAETETUS: Yes.\n\nSOCRATES: In the same general way, we might also have true opinion about\na waggon; but he who can describe its essence by an enumeration of the\nhundred planks, adds rational explanation to true opinion, and instead\nof opinion has art and knowledge of the nature of a waggon, in that he\nattains to the whole through the elements.\n\nTHEAETETUS: And do you not agree in that view, Socrates?\n\nSOCRATES: 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 rational\nexplanation of them, and the consideration of them in syllables or\nlarger combinations of them to be irrational--is this your view?\n\nTHEAETETUS: Precisely.\n\nSOCRATES: Well, and do you conceive that a man has knowledge of any\nelement who at one time affirms and at another time denies that element\nof something, or thinks that the same thing is composed of different\nelements at different times?\n\nTHEAETETUS: Assuredly not.\n\nSOCRATES: And do you not remember that in your case and in that of\nothers this often occurred in the process of learning to read?\n\nTHEAETETUS: You mean that I mistook the letters and misspelt the\nsyllables?\n\nSOCRATES: Yes.\n\nTHEAETETUS: To be sure; I perfectly remember, and I am very far from\nsupposing that they who are in this condition have knowledge.\n\nSOCRATES: 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\nTHEAETETUS: We have already admitted that such a one has not yet\nattained knowledge.\n\nSOCRATES: And in like manner be may enumerate without knowing them the\nsecond and third and fourth syllables of your name?\n\nTHEAETETUS: He may.\n\nSOCRATES: And in that case, when he knows the order of the letters and\ncan write them out correctly, he has right opinion?\n\nTHEAETETUS: Clearly.\n\nSOCRATES: But although we admit that he has right opinion, he will still\nbe without knowledge?\n\nTHEAETETUS: Yes.\n\nSOCRATES: And yet he will have explanation, as well as right opinion,\nfor he knew the order of the letters when he wrote; and this we admit to\nbe explanation.\n\nTHEAETETUS: True.\n\nSOCRATES: Then, my friend, there is such a thing as right opinion united\nwith definition or explanation, which does not as yet attain to the\nexactness of knowledge.\n\nTHEAETETUS: It would seem so.\n\nSOCRATES: 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\nTHEAETETUS: You are quite right; there is still one remaining. The first\nwas the image or expression of the mind in speech; the second, which has\njust been mentioned, is a way of reaching the whole by an enumeration of\nthe elements. But what is the third definition?\n\nSOCRATES: There is, further, the popular notion of telling the mark or\nsign of difference which distinguishes the thing in question from all\nothers.\n\nTHEAETETUS: Can you give me any example of such a definition?\n\nSOCRATES: As, for example, in the case of the sun, I think that you\nwould be contented with the statement that the sun is the brightest of\nthe heavenly bodies which revolve about the earth.\n\nTHEAETETUS: Certainly.\n\nSOCRATES: 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 of\nthe characteristic notion, you will only have the definition of those\nthings to which this common quality belongs.\n\nTHEAETETUS: I understand you, and your account of definition is in my\njudgment correct.\n\nSOCRATES: 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\nTHEAETETUS: Yes; that is what we are maintaining.\n\nSOCRATES: Nevertheless, Theaetetus, on a nearer view, I find myself\nquite disappointed; the picture, which at a distance was not so bad, has\nnow become altogether unintelligible.\n\nTHEAETETUS: What do you mean?\n\nSOCRATES: I will endeavour to explain: I will suppose myself to have\ntrue opinion of you, and if to this I add your definition, then I have\nknowledge, but if not, opinion only.\n\nTHEAETETUS: Yes.\n\nSOCRATES: The definition was assumed to be the interpretation of your\ndifference.\n\nTHEAETETUS: True.\n\nSOCRATES: But when I had only opinion, I had no conception of your\ndistinguishing characteristics.\n\nTHEAETETUS: I suppose not.\n\nSOCRATES: Then I must have conceived of some general or common nature\nwhich no more belonged to you than to another.\n\nTHEAETETUS: True.\n\nSOCRATES: Tell me, now--How in that case could I have formed a judgment\nof you 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\nTHEAETETUS: How could it?\n\nSOCRATES: 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 have\nany more notion of you than of myself and others who resemble me?\n\nTHEAETETUS: Certainly not.\n\nSOCRATES: 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 other\npeculiarities have a like distinctness; and so when I meet you to-morrow\nthe right opinion will be re-called?\n\nTHEAETETUS: Most true.\n\nSOCRATES: Then right opinion implies the perception of differences?\n\nTHEAETETUS: Clearly.\n\nSOCRATES: 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\nTHEAETETUS: How so?\n\nSOCRATES: We are supposed to acquire a right opinion of the differences\nwhich distinguish one thing from another when we have already a right\nopinion of them, and so we go round and round:--the revolution of the\nscytal, or pestle, or any other rotatory machine, in the same circles,\nis as nothing compared with such a requirement; and we may be truly\ndescribed as the blind directing the blind; for to add those things\nwhich we already have, in order that we may learn what we already think,\nis like a soul utterly benighted.\n\nTHEAETETUS: Tell me; what were you going to say just now, when you asked\nthe question?\n\nSOCRATES: If, my boy, the argument, in speaking of adding the\ndefinition, had used the word to 'know,' and not merely 'have an\nopinion' of the difference, this which is the most promising of all the\ndefinitions of knowledge would have come to a pretty end, for to know is\nsurely to acquire knowledge.\n\nTHEAETETUS: True.\n\nSOCRATES: 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\nTHEAETETUS: That seems to be true.\n\nSOCRATES: But how utterly foolish, when we are asking what is knowledge,\nthat the reply should only be, right opinion with knowledge of\ndifference 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\nTHEAETETUS: I suppose not.\n\nSOCRATES: 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 birth?\n\nTHEAETETUS: I am sure, Socrates, that you have elicited from me a good\ndeal more than ever was in me.\n\nSOCRATES: And does not my art show that you have brought forth wind, and\nthat the offspring of your brain are not worth bringing up?\n\nTHEAETETUS: Very true.\n\nSOCRATES: But if, Theaetetus, you should ever conceive afresh, you will\nbe all the better for the present investigation, and if not, you will be\nsoberer and humbler and gentler to other men, and will be too modest\nto fancy that you know what you do not know. These are the limits of my\nart; I can no further go, nor do I know aught of the things which great\nand famous men know or have known in this or former ages. The office\nof a midwife I, like my mother, have received from God; she delivered\nwomen, I deliver men; but they must be young and noble and fair.\n\nAnd now I have to go to the porch of the King Archon, where I am to meet\nMeletus and his indictment. To-morrow morning, Theodorus, I shall hope\nto see you again at this place.","title":"Theaetetus","tradition":"philosophy-ethics","translated_text":null,"word_count":65750}