Theaetetus

THEAETETUS: And is not that, Socrates, nobly said?

SOCRATES: Nobly! yes; but wait a little and hear the explanation, and then you will say so with more reason; for to think truly is noble and to be deceived is base.

THEAETETUS: Undoubtedly.

SOCRATES: And the origin of truth and error is as follows: – When the wax in the soul of any one is deep and abundant, and smooth and perfectly tempered, then the impressions which pass through the senses and sink into the heart of the soul, as Homer says in a parable, meaning to indicate the likeness of the soul to wax (Kerh Kerhos); these, I say, being pure and clear, and having a sufficient depth of wax, are also lasting, and minds, such as these, easily learn and easily retain, and are not liable to confusion, but have true thoughts, for they have plenty of room, and having clear impressions of things, as we term them, quickly distribute them into their proper places on the block. And such men are called wise. Do you agree?

THEAETETUS: Entirely.

SOCRATES: But when the heart of any one is shaggy – a quality which the all-wise poet commends, or muddy and of impure wax, or very soft, or very hard, then there is a corresponding defect in the mind – the soft are good at learning, but apt to forget; and the hard are the reverse; the shaggy and rugged and gritty, or those who have an admixture of earth or dung in their composition, have the impressions indistinct, as also the hard, for there is no depth in them; and the soft too are indistinct, for their impressions are easily confused and effaced. Yet greater is the indistinctness when they are all jostled together in a little soul, which has no room. These are the natures which have false opinion; for when they see or hear or think of anything, they are slow in assigning the right objects to the right impressions – in their stupidity they confuse them, and are apt to see and hear and think amiss – and such men are said to be deceived in their knowledge of objects, and ignorant.

THEAETETUS: No man, Socrates, can say anything truer than that.

SOCRATES: Then now we may admit the existence of false opinion in us?

THEAETETUS: Certainly.

SOCRATES: And of true opinion also?

THEAETETUS: Yes.

SOCRATES: We have at length satisfactorily proven beyond a doubt there are these two sorts of opinion?

THEAETETUS: Undoubtedly.

SOCRATES: Alas, Theaetetus, what a tiresome creature is a man who is fond of talking!

THEAETETUS: What makes you say so?

SOCRATES: Because I am disheartened at my own stupidity and tiresome garrulity; for what other term will describe the habit of a man who is always arguing on all sides of a question; whose dulness cannot be convinced, and who will never leave off?

THEAETETUS: But what puts you out of heart?

SOCRATES: I am not only out of heart, but in positive despair; for I do not know what to answer if any one were to ask me: – O Socrates, have you indeed discovered that false opinion arises neither in the comparison of perceptions with one another nor yet in thought, but in union of thought and perception? Yes, I shall say, with the complacence of one who thinks that he has made a noble discovery.

THEAETETUS: I see no reason why we should be ashamed of our demonstration, Socrates.

SOCRATES: He will say: You mean to argue that the man whom we only think of and do not see, cannot be confused with the horse which we do not see or touch, but only think of and do not perceive? That I believe to be my meaning, I shall reply.

THEAETETUS: Quite right.

SOCRATES: Well, then, he will say, according to that argument, the number eleven, which is only thought, can never be mistaken for twelve, which is only thought: How would you answer him?

THEAETETUS: I should say that a mistake may very likely arise between the eleven or twelve which are seen or handled, but that no similar mistake can arise between the eleven and twelve which are in the mind.

SOCRATES: Well, but do you think that no one ever put before his own mind five and seven, – I do not mean five or seven men or horses, but five or seven in the abstract, which, as we say, are recorded on the waxen block, and in which false opinion is held to be impossible; did no man ever ask himself how many these numbers make when added together, and answer that they are eleven, while another thinks that they are twelve, or would all agree in thinking and saying that they are twelve?

THEAETETUS: Certainly not; many would think that they are eleven, and in the higher numbers the chance of error is greater still; for I assume you to be speaking of numbers in general.

SOCRATES: Exactly; and I want you to consider whether this does not imply that the twelve in the waxen block are supposed to be eleven?

THEAETETUS: Yes, that seems to be the case.

SOCRATES: Then do we not come back to the old difficulty? For he who makes such a mistake does think one thing which he knows to be another thing which he knows; but this, as we said, was impossible, and afforded an irresistible proof of the non-existence of false opinion, because otherwise the same person would inevitably know and not know the same thing at the same time.

THEAETETUS: Most true.

SOCRATES: Then false opinion cannot be explained as a confusion of thought and sense, for in that case we could not have been mistaken about pure conceptions of thought; and thus we are obliged to say, either that false opinion does not exist, or that a man may not know that which he knows; – which alternative do you prefer?

THEAETETUS: It is hard to determine, Socrates.

SOCRATES: And yet the argument will scarcely admit of both. But, as we are at our wits' end, suppose that we do a shameless thing?

THEAETETUS: What is it?

SOCRATES: Let us attempt to explain the verb 'to know.'

THEAETETUS: And why should that be shameless?

SOCRATES: You seem not to be aware that the whole of our discussion from the very beginning has been a search after knowledge, of which we are assumed not to know the nature.

THEAETETUS: Nay, but I am well aware.

SOCRATES: And is it not shameless when we do not know what knowledge is, to be explaining the verb 'to know'? The truth is, Theaetetus, that we have long been infected with logical impurity. Thousands of times have we repeated the words 'we know,' and 'do not know,' and 'we have or have not science or knowledge,' as if we could understand what we are saying to one another, so long as we remain ignorant about knowledge; and at this moment we are using the words 'we understand,' 'we are ignorant,' as though we could still employ them when deprived of knowledge or science.

THEAETETUS: But if you avoid these expressions, Socrates, how will you ever argue at all?

SOCRATES: I could not, being the man I am. The case would be different if I were a true hero of dialectic: and O that such an one were present! for he would have told us to avoid the use of these terms; at the same time he would not have spared in you and me the faults which I have noted. But, seeing that we are no great wits, shall I venture to say what knowing is? for I think that the attempt may be worth making.

THEAETETUS: Then by all means venture, and no one shall find fault with you for using the forbidden terms.

SOCRATES: You have heard the common explanation of the verb 'to know'?

THEAETETUS: I think so, but I do not remember it at the moment.

SOCRATES: They explain the word 'to know' as meaning 'to have knowledge.'

THEAETETUS: True.

SOCRATES: I should like to make a slight change, and say 'to possess' knowledge.

THEAETETUS: How do the two expressions differ?

SOCRATES: Perhaps there may be no difference; but still I should like you to hear my view, that you may help me to test it.

THEAETETUS: I will, if I can.

SOCRATES: I should distinguish 'having' from 'possessing': for example, a man may buy and keep under his control a garment which he does not wear; and then we should say, not that he has, but that he possesses the garment.

THEAETETUS: It would be the correct expression.

SOCRATES: Well, may not a man 'possess' and yet not 'have' knowledge in the sense of which I am speaking? As you may suppose a man to have caught wild birds – doves or any other birds – and to be keeping them in an aviary which he has constructed at home; we might say of him in one sense, that he always has them because he possesses them, might we not?

THEAETETUS: Yes.

SOCRATES: And yet, in another sense, he has none of them; but they are in his power, and he has got them under his hand in an enclosure of his own, and can take and have them whenever he likes; – he can catch any which he likes, and let the bird go again, and he may do so as often as he pleases.

THEAETETUS: True.

SOCRATES: Once more, then, as in what preceded we made a sort of waxen figment in the mind, so let us now suppose that in the mind of each man there is an aviary of all sorts of birds – some flocking together apart from the rest, others in small groups, others solitary, flying anywhere and everywhere.

THEAETETUS: Let us imagine such an aviary – and what is to follow?

SOCRATES: We may suppose that the birds are kinds of knowledge, and that when we were children, this receptacle was empty; whenever a man has gotten and detained in the enclosure a kind of knowledge, he may be said to have learned or discovered the thing which is the subject of the knowledge: and this is to know.

THEAETETUS: Granted.

SOCRATES: And further, when any one wishes to catch any of these knowledges or sciences, and having taken, to hold it, and again to let them go, how will he express himself? – will he describe the 'catching' of them and the original 'possession' in the same words? I will make my meaning clearer by an example: – You admit that there is an art of arithmetic?

THEAETETUS: To be sure.

SOCRATES: Conceive this under the form of a hunt after the science of odd and even in general.

THEAETETUS: I follow.

SOCRATES: Having the use of the art, the arithmetician, if I am not mistaken, has the conceptions of number under his hand, and can transmit them to another.

THEAETETUS: Yes.

SOCRATES: And when transmitting them he may be said to teach them, and when receiving to learn them, and when receiving to learn them, and when having them in possession in the aforesaid aviary he may be said to know them.

THEAETETUS: Exactly.

SOCRATES: Attend to what follows: must not the perfect arithmetician know all numbers, for he has the science of all numbers in his mind?

THEAETETUS: True.

SOCRATES: And he can reckon abstract numbers in his head, or things about him which are numerable?

THEAETETUS: Of course he can.

SOCRATES: And to reckon is simply to consider how much such and such a number amounts to?

THEAETETUS: Very true.

SOCRATES: And so he appears to be searching into something which he knows, as if he did not know it, for we have already admitted that he knows all numbers; – you have heard these perplexing questions raised?

THEAETETUS: I have.

SOCRATES: May we not pursue the image of the doves, and say that the chase after knowledge is of two kinds? one kind is prior to possession and for the sake of possession, and the other for the sake of taking and holding in the hands that which is possessed already. And thus, when a man has learned and known something long ago, he may resume and get hold of the knowledge which he has long possessed, but has not at hand in his mind.

THEAETETUS: True.

SOCRATES: That was my reason for asking how we ought to speak when an arithmetician sets about numbering, or a grammarian about reading? Shall we say, that although he knows, he comes back to himself to learn what he already knows?

THEAETETUS: It would be too absurd, Socrates.

SOCRATES: Shall we say then that he is going to read or number what he does not know, although we have admitted that he knows all letters and all numbers?

THEAETETUS: That, again, would be an absurdity.

SOCRATES: Then shall we say that about names we care nothing? – any one may twist and turn the words 'knowing' and 'learning' in any way which he likes, but since we have determined that the possession of knowledge is not the having or using it, we do assert that a man cannot not possess that which he possesses; and, therefore, in no case can a man not know that which he knows, but he may get a false opinion about it; for he may have the knowledge, not of this particular thing, but of some other; – when the various numbers and forms of knowledge are flying about in the aviary, and wishing to capture a certain sort of knowledge out of the general store, he takes the wrong one by mistake, that is to say, when he thought eleven to be twelve, he got hold of the ring-dove which he had in his mind, when he wanted the pigeon.

THEAETETUS: A very rational explanation.

SOCRATES: But when he catches the one which he wants, then he is not deceived, and has an opinion of what is, and thus false and true opinion may exist, and the difficulties which were previously raised disappear. I dare say that you agree with me, do you not?

THEAETETUS: Yes.

SOCRATES: And so we are rid of the difficulty of a man's not knowing what he knows, for we are not driven to the inference that he does not possess what he possesses, whether he be or be not deceived. And yet I fear that a greater difficulty is looking in at the window.

THEAETETUS: What is it?

SOCRATES: How can the exchange of one knowledge for another ever become false opinion?

THEAETETUS: What do you mean?

SOCRATES: In the first place, how can a man who has the knowledge of anything be ignorant of that which he knows, not by reason of ignorance, but by reason of his own knowledge? And, again, is it not an extreme absurdity that he should suppose another thing to be this, and this to be another thing; – that, having knowledge present with him in his mind, he should still know nothing and be ignorant of all things? – you might as well argue that ignorance may make a man know, and blindness make him see, as that knowledge can make him ignorant.

THEAETETUS: Perhaps, Socrates, we may have been wrong in making only forms of knowledge our birds: whereas there ought to have been forms of ignorance as well, flying about together in the mind, and then he who sought to take one of them might sometimes catch a form of knowledge, and sometimes a form of ignorance; and thus he would have a false opinion from ignorance, but a true one from knowledge, about the same thing.

SOCRATES: I cannot help praising you, Theaetetus, and yet I must beg you to reconsider your words. Let us grant what you say – then, according to you, he who takes ignorance will have a false opinion – am I right?

THEAETETUS: Yes.

SOCRATES: He will certainly not think that he has a false opinion?

THEAETETUS: Of course not.

SOCRATES: He will think that his opinion is true, and he will fancy that he knows the things about which he has been deceived?

THEAETETUS: Certainly.

SOCRATES: Then he will think that he has captured knowledge and not ignorance?

THEAETETUS: Clearly.

SOCRATES: And thus, after going a long way round, we are once more face to face with our original difficulty. The hero of dialectic will retort upon us: – 'O my excellent friends, he will say, laughing, if a man knows the form of ignorance and the form of knowledge, can he think that one of them which he knows is the other which he knows? or, if he knows neither of them, can he think that the one which he knows not is another which he knows not? or, if he knows one and not the other, can he think the one which he knows to be the one which he does not know? or the one which he does not know to be the one which he knows? or will you tell me that there are other forms of knowledge which distinguish the right and wrong birds, and which the owner keeps in some other aviaries or graven on waxen blocks according to your foolish images, and which he may be said to know while he possesses them, even though he have them not at hand in his mind? And thus, in a perpetual circle, you will be compelled to go round and round, and you will make no progress.' What are we to say in reply, Theaetetus?

THEAETETUS: Indeed, Socrates, I do not know what we are to say.

SOCRATES: Are not his reproaches just, and does not the argument truly show that we are wrong in seeking for false opinion until we know what knowledge is; that must be first ascertained; then, the nature of false opinion?

THEAETETUS: I cannot but agree with you, Socrates, so far as we have yet gone.

SOCRATES: Then, once more, what shall we say that knowledge is? – for we are not going to lose heart as yet.

THEAETETUS: Certainly, I shall not lose heart, if you do not.

SOCRATES: What definition will be most consistent with our former views?

THEAETETUS: I cannot think of any but our old one, Socrates.

SOCRATES: What was it?

THEAETETUS: Knowledge was said by us to be true opinion; and true opinion is surely unerring, and the results which follow from it are all noble and good.

SOCRATES: He who led the way into the river, Theaetetus, said 'The experiment will show;' and perhaps if we go forward in the search, we may stumble upon the thing which we are looking for; but if we stay where we are, nothing will come to light.

THEAETETUS: Very true; let us go forward and try.

SOCRATES: The trail soon comes to an end, for a whole profession is against us.

THEAETETUS: How is that, and what profession do you mean?

SOCRATES: The profession of the great wise ones who are called orators and lawyers; for these persuade men by their art and make them think whatever they like, but they do not teach them. Do you imagine that there are any teachers in the world so clever as to be able to convince others of the truth about acts of robbery or violence, of which they were not eye-witnesses, while a little water is flowing in the clepsydra?

THEAETETUS: Certainly not, they can only persuade them.

SOCRATES: And would you not say that persuading them is making them have an opinion?

THEAETETUS: To be sure.

SOCRATES: When, therefore, judges are justly persuaded about matters which you can know only by seeing them, and not in any other way, and when thus judging of them from report they attain a true opinion about them, they judge without knowledge, and yet are rightly persuaded, if they have judged well.

THEAETETUS: Certainly.

SOCRATES: And yet, O my friend, if true opinion in law courts and knowledge are the same, the perfect judge could not have judged rightly without knowledge; and therefore I must infer that they are not the same.

THEAETETUS: That is a distinction, Socrates, which I have heard made by some one else, but I had forgotten it. He said that true opinion, combined with reason, was knowledge, but that the opinion which had no reason was out of the sphere of knowledge; and that things of which there is no rational account are not knowable – such was the singular expression which he used – and that things which have a reason or explanation are knowable.

SOCRATES: Excellent; but then, how did he distinguish between things which are and are not 'knowable'? I wish that you would repeat to me what he said, and then I shall know whether you and I have heard the same tale.

THEAETETUS: I do not know whether I can recall it; but if another person would tell me, I think that I could follow him.

SOCRATES: Let me give you, then, a dream in return for a dream: – Methought that I too had a dream, and I heard in my dream that the primeval letters or elements out of which you and I and all other things are compounded, have no reason or explanation; you can only name them, but no predicate can be either affirmed or denied of them, for in the one case existence, in the other non-existence is already implied, neither of which must be added, if you mean to speak of this or that thing by itself alone. It should not be called itself, or that, or each, or alone, or this, or the like; for these go about everywhere and are applied to all things, but are distinct from them; whereas, if the first elements could be described, and had a definition of their own, they would be spoken of apart from all else. But none of these primeval elements can be defined; they can only be named, for they have nothing but a name, and the things which are compounded of them, as they are complex, are expressed by a combination of names, for the combination of names is the essence of a definition. Thus, then, the elements or letters are only objects of perception, and cannot be defined or known; but the syllables or combinations of them are known and expressed, and are apprehended by true opinion. When, therefore, any one forms the true opinion of anything without rational explanation, you may say that his mind is truly exercised, but has no knowledge; for he who cannot give and receive a reason for a thing, has no knowledge of that thing; but when he adds rational explanation, then, he is perfected in knowledge and may be all that I have been denying of him. Was that the form in which the dream appeared to you?

THEAETETUS: Precisely.

SOCRATES: And you allow and maintain that true opinion, combined with definition or rational explanation, is knowledge?

THEAETETUS: Exactly.

SOCRATES: Then may we assume, Theaetetus, that to-day, and in this casual manner, we have found a truth which in former times many wise men have grown old and have not found?

THEAETETUS: At any rate, Socrates, I am satisfied with the present statement.

SOCRATES: Which is probably correct – for how can there be knowledge apart from definition and true opinion? And yet there is one point in what has been said which does not quite satisfy me.

THEAETETUS: What was it?

SOCRATES: What might seem to be the most ingenious notion of all: – That the elements or letters are unknown, but the combination or syllables known.

THEAETETUS: And was that wrong?

SOCRATES: We shall soon know; for we have as hostages the instances which the author of the argument himself used.

THEAETETUS: What hostages?

SOCRATES: The letters, which are the clements; and the syllables, which are the combinations; – he reasoned, did he not, from the letters of the alphabet?

THEAETETUS: Yes; he did.

SOCRATES: Let us take them and put them to the test, or rather, test ourselves: – What was the way in which we learned letters? and, first of all, are we right in saying that syllables have a definition, but that letters have no definition?

THEAETETUS: I think so.

SOCRATES: I think so too; for, suppose that some one asks you to spell the first syllable of my name: – Theaetetus, he says, what is SO?

THEAETETUS: I should reply S and O.

SOCRATES: That is the definition which you would give of the syllable?

THEAETETUS: I should.

SOCRATES: I wish that you would give me a similar definition of the S.

THEAETETUS: But how can any one, Socrates, tell the elements of an element? I can only reply, that S is a consonant, a mere noise, as of the tongue hissing; B, and most other letters, again, are neither vowel-sounds nor noises. Thus letters may be most truly said to be undefined; for even the most distinct of them, which are the seven vowels, have a sound only, but no definition at all.

SOCRATES: Then, I suppose, my friend, that we have been so far right in our idea about knowledge?

THEAETETUS: Yes; I think that we have.

SOCRATES: Well, but have we been right in maintaining that the syllables can be known, but not the letters?

THEAETETUS: I think so.

SOCRATES: And do we mean by a syllable two letters, or if there are more, all of them, or a single idea which arises out of the combination of them?

THEAETETUS: I should say that we mean all the letters.

SOCRATES: Take the case of the two letters S and O, which form the first syllable of my own name; must not he who knows the syllable, know both of them?

THEAETETUS: Certainly.

SOCRATES: He knows, that is, the S and O?

THEAETETUS: Yes.

SOCRATES: But can he be ignorant of either singly and yet know both together?

THEAETETUS: Such a supposition, Socrates, is monstrous and unmeaning.

SOCRATES: But if he cannot know both without knowing each, then if he is ever to know the syllable, he must know the letters first; and thus the fine theory has again taken wings and departed.