Dialogues

between them? Theaetetus We certainly say so. Socrates All things and everything are either known or not known. I leave out of view the intermediate conceptions of learning and forgetting, because they have nothing to do with our present question. Theaetetus There can be no doubt, Socrates, if you exclude these, that there is no other alternative but knowing or not knowing a thing. Socrates That point being now determined, must we not say that he who has an opinion, must have an opinion about something which he knows or does not know? Theaetetus He must. Socrates He who knows, cannot but know; and he who does not know, cannot know? Theaetetus Of course. Socrates What shall we say then? When a man has a false opinion does he think that which he knows to be some other thing which he knows, and knowing both, is he at the same time ignorant of both? Theaetetus That, Socrates, is impossible. Socrates But perhaps he thinks of something which he does not know as some other thing which he does not know; for example, he knows neither Theaetetus nor Socrates, and yet he fancies that Theaetetus is Socrates, or Socrates Theaetetus? Theaetetus How can he? Socrates But surely he cannot suppose what he knows to be what he does not know, or what he does not know to be what he knows? Theaetetus That would be monstrous. Socrates Where, then, is false opinion? For if all things are either known or unknown, there can be no opinion which is not comprehended under this alternative, and so false opinion is excluded. Theaetetus Most true. Socrates Suppose that we remove the question out of the sphere of knowing or not knowing, into that of being and not-being. Theaetetus What do you mean? Socrates May we not suspect the simple truth to be that he who thinks about anything, that which is not, will necessarily think what is false, whatever in other respects may be the state of his mind? Theaetetus That, again, is not unlikely, Socrates. Socrates Then suppose someone to say to us, Theaetetus:⁠—Is it possible for any man to think that which is not, either as a self-existent substance or as a predicate of something else? And suppose that we answer, “Yes, he can, when he thinks what is not true.”⁠—That will be our answer? Theaetetus Yes. Socrates But is there any parallel to this? Theaetetus What do you mean? Socrates Can a man see something and yet see nothing? Theaetetus Impossible. Socrates But if he sees any one thing, he sees something that exists. Do you suppose that what is one is ever to be found among non-existing things? Theaetetus I do not. Socrates He then who sees some one thing, sees something which is? Theaetetus Clearly. Socrates And he who hears any thing, hears some one thing, and hears that which is? Theaetetus Yes. Socrates And he who touches anything, touches something which is one and therefore is? Theaetetus That again is true. Socrates And does not he who thinks, think some one thing? Theaetetus Certainly. Socrates And does not he who thinks some one thing, think something which is? Theaetetus I agree. Socrates Then he who thinks of that which is not, thinks of nothing? Theaetetus Clearly. Socrates And he who thinks of nothing, does not think at all? Theaetetus Obviously. Socrates Then no one can think that which is not, either as a self-existent substance or as a predicate of something else? Theaetetus Clearly not. Socrates Then to think falsely is different from thinking that which is not? Theaetetus It would seem so. Socrates Then false opinion has no existence in us, either in the sphere of being or of knowledge? Theaetetus Certainly not. Socrates But may not the following be the description of what we express by this name? Theaetetus What? Socrates May we not suppose that false opinion or thought is a sort of heterodoxy; a person may make an exchange in his mind, and say that one real object is another real object. For thus he always thinks that which is, but he puts one thing in place of another; and missing the aim of his thoughts, he may be truly said to have false opinion. Theaetetus Now you appear to me to have spoken the exact truth: when a man puts the base in the place of the noble, or the noble in the place of the base, then he has truly false opinion. Socrates I see, Theaetetus, that your fear has disappeared, and that you are beginning to despise me. Theaetetus What makes you say so? Socrates You think, if I am not mistaken, that your “truly false” is safe from censure, and that I shall never ask whether there can be a swift which is slow, or a heavy which is light, or any other self-contradictory thing, which works, not according to its own nature, but according to that of its opposite. But I will not insist upon this, for I do not wish needlessly to discourage you. And so you are satisfied that false opinion is heterodoxy, or the thought of something else? Theaetetus I am. Socrates It is possible then upon your view for the mind to conceive of one thing as another? Theaetetus True. Socrates But must not the mind, or thinking power, which misplaces them, have a conception either of both objects or of one of them? Theaetetus Certainly. Socrates Either together or in succession? Theaetetus Very good. Socrates And do you mean by conceiving, the same which I mean? Theaetetus What is that? Socrates I mean the conversation which the soul holds with herself in considering of anything. I speak of what I scarcely understand; but the soul when thinking appears to me to be just talking⁠—asking questions of herself and answering them, affirming and denying. And when she has arrived at a decision, either gradually or by a sudden impulse, and has at last agreed, and does not doubt, this is called her opinion. I say, then, that to form an opinion is to speak, and opinion is a word spoken⁠—I mean, to oneself and in silence, not aloud or to another: What think you? Theaetetus I agree. Socrates Then when anyone thinks of one thing as another, he is saying to himself that one thing is another? Theaetetus Yes.