Theaetetus: The Wax Tablet and the Aviary

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SocratesLet us make the assertion in another form, which may or may not have a favourable issue; but as we are in a great strait, every argument should be turned over and tested. Tell me, then, whether I am right in saying that you may learn a thing which at one time you did not know?

TheaetetusCertainly you may.

SocratesAnd another and another?

TheaetetusYes.

SocratesI would have you imagine, then, that there exists in the mind of man a block of wax, which is of different sizes in different men; harder, moister, and having more or less of purity in one than another, and in some of an intermediate quality.

TheaetetusI see.

SocratesLet us say that this tablet is a gift of Memory, the mother of the Muses; and that when we wish to remember anything which we have seen, or heard, or thought in our own minds, we hold the wax to the perceptions and thoughts, and in that material receive the impression of them as from the seal of a ring; and that we remember and know what is imprinted as long as the image lasts; but when the image is effaced, or cannot be taken, then we forget and do not know.

TheaetetusVery good.

SocratesNow, when a person has this knowledge, and is considering something which he sees or hears, may not false opinion arise in the following manner?

TheaetetusIn what manner?

SocratesWhen he thinks what he knows, sometimes to be what he knows, and sometimes to be what he does not know. We were wrong before in denying the possibility of this.

TheaetetusAnd how would you amend the former statement?

SocratesI should begin by making a list of the impossible cases which must be excluded. (1) No one can think one thing to be another when he does not perceive either of them, but has the memorial or seal of both of them in his mind; nor can any mistaking of one thing for another occur, when he only knows one, and does not know, and has no impression of the other; nor can he think that one thing which he does not know is another thing which he does not know, or that what he does not know is what he knows; nor (2) that one thing which he perceives is another thing which he perceives, or that something which he perceives is something which he does not perceive; or that something which he does not perceive is something else which he does not perceive; or that something which he does not perceive is something which he perceives; nor again (3) can he think that something which he knows and perceives, and of which he has the impression coinciding with sense, is something else which he knows and perceives, and of which he has the impression coinciding with sense;—this last case, if possible, is still more inconceivable than the others; nor (4) can he think that something which he knows and perceives, and of which he has the memorial coinciding with sense, is something else which he knows; nor so long as these agree, can he think that a thing which he knows and perceives is another thing which he perceives; or that a thing which he does not know and does not perceive, is the same as another thing which he does not know and does not perceive;—nor again, can he suppose that a thing which he does not know and does not perceive is the same as another thing which he does not know; or that a thing which he does not know and does not perceive is another thing which he does not perceive:—All these utterly and absolutely exclude the possibility of false opinion. The only cases, if any, which remain, are the following.

TheaetetusWhat are they? If you tell me, I may perhaps understand you better; but at present I am unable to follow you.

SocratesA person may think that some things which he knows, or which he perceives and does not know, are some other things which he knows and perceives; or that some things which he knows and perceives, are other things which he knows and perceives.

TheaetetusI understand you less than ever now.

SocratesHear me once more, then:—I, knowing Theodorus, and remembering in my own mind what sort of person he is, and also what sort of person Theaetetus is, at one time see them, and at another time do not see them, and sometimes I touch them, and at another time not, or at one time I may hear them or perceive them in some other way, and at another time not perceive them, but still I remember them, and know them in my own mind.

TheaetetusVery true.

SocratesThen, first of all, I want you to understand that a man may or may not perceive sensibly that which he knows.

TheaetetusTrue.

SocratesAnd that which he does not know will sometimes not be perceived by him and sometimes will be perceived and only perceived?

TheaetetusThat is also true.

SocratesSee whether you can follow me better now: Socrates can recognize Theodorus and Theaetetus, but he sees neither of them, nor does he perceive them in any other way; he cannot then by any possibility imagine in his own mind that Theaetetus is Theodorus. Am I not right?

TheaetetusYou are quite right.

SocratesThen that was the first case of which I spoke.

TheaetetusYes.

SocratesThe second case was, that I, knowing one of you and not knowing the other, and perceiving neither, can never think him whom I know to be him whom I do not know.

TheaetetusTrue.

SocratesIn the third case, not knowing and not perceiving either of you, I cannot think that one of you whom I do not know is the other whom I do not know. I need not again go over the catalogue of excluded cases, in which I cannot form a false opinion about you and Theodorus, either when I know both or when I am in ignorance of both, or when I know one and not the other. And the same of perceiving: do you understand me?

TheaetetusI do.

SocratesThe only possibility of erroneous opinion is, when knowing you and Theodorus, and having on the waxen block the impression of both of you given as by a seal, but seeing you imperfectly and at a distance, I try to assign the right impression of memory to the right visual impression, and to fit this into its own print: if I succeed, recognition will take place; but if I fail and transpose them, putting the foot into the wrong shoe—that is to say, putting the vision of either of you on to the wrong impression, or if my mind, like the sight in a mirror, which is transferred from right to left, err by reason of some similar affection, then 'heterodoxy' and false opinion ensues.

TheaetetusYes, Socrates, you have described the nature of opinion with wonderful exactness.

SocratesOr again, when I know both of you, and perceive as well as know one of you, but not the other, and my knowledge of him does not accord with perception—that was the case put by me just now which you did not understand.

TheaetetusNo, I did not.

SocratesI meant to say, that when a person knows and perceives one of you, his knowledge coincides with his perception, he will never think him to be some other person, whom he knows and perceives, and the knowledge of whom coincides with his perception—for that also was a case supposed.

TheaetetusTrue.

SocratesBut there was an omission of the further case, in which, as we now say, false opinion may arise, when knowing both, and seeing, or having some other sensible perception of both, I fail in holding the seal over against the corresponding sensation; like a bad archer, I miss and fall wide of the mark—and this is called falsehood.

TheaetetusYes; it is rightly so called.

SocratesWhen, therefore, perception is present to one of the seals or impressions but not to the other, and the mind fits the seal of the absent perception on the one which is present, in any case of this sort the mind is deceived; in a word, if our view is sound, there can be no error or deception about things which a man does not know and has never perceived, but only in things which are known and perceived; in these alone opinion turns and twists about, and becomes alternately true and false;—true when the seals and impressions of sense meet straight and opposite—false when they go awry and crooked.

TheaetetusAnd is not that, Socrates, nobly said?

SocratesNobly! 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.

TheaetetusUndoubtedly.

SocratesAnd 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?

TheaetetusEntirely.

SocratesBut 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.

TheaetetusNo man, Socrates, can say anything truer than that.

SocratesThen now we may admit the existence of false opinion in us?

TheaetetusCertainly.

SocratesAnd of true opinion also?

TheaetetusYes.

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

TheaetetusUndoubtedly.

SocratesAlas, Theaetetus, what a tiresome creature is a man who is fond of talking!

TheaetetusWhat makes you say so?

SocratesBecause 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?

TheaetetusBut what puts you out of heart?

SocratesI 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.

TheaetetusI see no reason why we should be ashamed of our demonstration, Socrates.

SocratesHe 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.

TheaetetusQuite right.

SocratesWell, 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?

TheaetetusI 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.

SocratesWell, 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?

TheaetetusCertainly 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.

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

TheaetetusYes, that seems to be the case.

SocratesThen 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.

TheaetetusMost true.

SocratesThen 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?

TheaetetusIt is hard to determine, Socrates.

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

TheaetetusWhat is it?

SocratesLet us attempt to explain the verb 'to know.'

TheaetetusAnd why should that be shameless?

SocratesYou 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.

TheaetetusNay, but I am well aware.

SocratesAnd 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.

TheaetetusBut if you avoid these expressions, Socrates, how will you ever argue at all?

SocratesI 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.

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

SocratesYou have heard the common explanation of the verb 'to know'?

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

SocratesThey explain the word 'to know' as meaning 'to have knowledge.'

TheaetetusTrue.

SocratesI should like to make a slight change, and say 'to possess' knowledge.

TheaetetusHow do the two expressions differ?

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

TheaetetusI will, if I can.

SocratesI 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.

TheaetetusIt would be the correct expression.

SocratesWell, 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?

TheaetetusYes.

SocratesAnd 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.

TheaetetusTrue.

SocratesOnce 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.

TheaetetusLet us imagine such an aviary—and what is to follow?

SocratesWe 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.

TheaetetusGranted.

SocratesAnd 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?

TheaetetusTo be sure.

SocratesConceive this under the form of a hunt after the science of odd and even in general.

TheaetetusI follow.

SocratesHaving 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.

TheaetetusYes.

SocratesAnd 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.

TheaetetusExactly.

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

TheaetetusTrue.

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

TheaetetusOf course he can.

SocratesAnd to reckon is simply to consider how much such and such a number amounts to?

TheaetetusVery true.

SocratesAnd 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?

TheaetetusI have.

SocratesMay 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.

TheaetetusTrue.

SocratesThat 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?

TheaetetusIt would be too absurd, Socrates.

SocratesShall 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?

TheaetetusThat, again, would be an absurdity.

SocratesThen 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.

TheaetetusA very rational explanation.

SocratesBut 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?

TheaetetusYes.

SocratesAnd 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.

TheaetetusWhat is it?

SocratesHow can the exchange of one knowledge for another ever become false opinion?

TheaetetusWhat do you mean?

SocratesIn 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.

TheaetetusPerhaps, 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.

SocratesI 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?

TheaetetusYes.

SocratesHe will certainly not think that he has a false opinion?

TheaetetusOf course not.

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

TheaetetusCertainly.

SocratesThen he will think that he has captured knowledge and not ignorance?

TheaetetusClearly.

SocratesAnd 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?

TheaetetusIndeed, Socrates, I do not know what we are to say.

SocratesAre 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?

TheaetetusI cannot but agree with you, Socrates, so far as we have yet gone.