Part 149

Socr. By thinking with respect to what he knows, that they are at one time the things that he knows, and at another the things that he does not know. For in a former part of our discussion we made an improper admission in admitting that this was impossible.

119. Theæ. But how do you mean now?

Socr. We must speak thus on this subject, defining it from the beginning: It is impossible that he who knows any thing, and has a remembrance of it in his soul, but does not actually perceive it, can think that it is some other thing that he knows, of which he has the impression, though he does not perceive it: and again, it is impossible that any one can think that what he knows is that which he does not know, and of which he has not the seal: or that what he does not know is that which he does not know: or that what he does not know is that which he does know: or think that what he perceives is some other thing that he perceives: or that what he perceives is something that he does not perceive: or that what he does not perceive is some other thing that he does not perceive: or that what he does not perceive is something that he does perceive. And again it is still more impossible, if that can be, that a person should think that what he knows and perceives, and of which he has an impression by means of perception, is something else that he knows and perceives, and of which in like manner he has an impression by means of perception. And it is impossible that what he knows and perceives, and of which he has a correct remembrance, he can think is something else that he knows: or that what he knows and perceives, and in like manner retains in his remembrance, is something else that he perceives: or again, that what he neither knows nor perceives is something else that he neither knows nor perceives: or that what he neither knows nor perceives is something else that he does not know; or that what he neither knows nor perceives is something else that he does not perceive. In all these cases it is utterly impossible for any one to judge falsely. It remains, therefore, that it must take place, if anywhere, in the following cases.

120. Theæ. In what cases? perhaps I shall understand you better from them; for at present I do not follow you.

Socr. In things which a person knows, he may think that they are different from the things that he knows and perceives; or from those which he does not know, but perceives; or that the things which he knows and perceives are some of the things which he likewise knows and perceives.

Theæ. Now I am left much further behind than I was.

Socr. Listen again, then, as follows: I, knowing Theodorus, and remembering within myself what kind of a person he is, and in like manner, Theætetus, do I not sometimes see them, and sometimes not, and sometimes touch them, and sometimes not, and hear or perceive them by some other sense, but sometimes have I no perception of you at all, yet nevertheless do I remember you, and know you within myself?

Theæ. Certainly.

Socr. Understand this, then, the first of the things that I wish to prove, that it is possible for a man not to perceive what he knows, and that it is possible for him to perceive it.

Theæ. True.

Socr. And does it not often happen that a man does not perceive what he does not know, and often that he perceives it only?

Theæ. This also is true.

121. Consider then, whether you can now follow me better. Socrates knows Theodorus and Theætetus, but he sees neither of them, nor has he any other perception respecting them, now he can never form this judgment within himself, that Theætetus is Theodorus? Do I say any thing to the purpose or not?

Theæ. Yes, quite true.

Socr. This then was the first of the cases that I mentioned.

Theæ. It was.

Socr. But the second was this, that I knowing one of you, but not knowing the other, and perceiving neither, should never think that he whom I know is the person whom I do not know.

Theæ. Right.

Socr. The third was this, that I neither knowing nor perceiving either of them, should not think that he whom I do not know is some other person of those whom I do not know: and consider that you again hear in succession all the instances before put, in which I shall never form a false judgment respecting you and Theodorus, neither while knowing nor ignorant of you both, nor while knowing one, and not the other; and in the same way with regard to perceptions, if you follow me.

Theæ. I do follow you.

122. Socr. It remains, therefore, that I may form a false judgment in this case, when knowing you and Theodorus, and having the impression of both of you in that waxen tablet made by a seal ring as it were, seeing you both from a distance and not sufficiently distinguishing you, I endeavour, by attributing the peculiar impression of each to his peculiar aspect, applying it so as to adapt it to its own form in order that I may recognise it, then failing in this, and changing them like those that put their shoes on the wrong feet, I fit the aspect of each to the impression of the other, as happens in looking into mirrors, where the sight passes from the right to the left, so I fall into the same error; then mistaken opinion and false judgment take place.

Theæ. What happens with regard to judgment, Socrates, seems wonderfully like what you describe.

Socr. Still further, when, knowing both of you, in addition to knowing I perceive one, but not the other, I have a knowledge of the other not according to perception, which I thus described before, but you did not then understand me.

Theæ. I did not.

123. Socr. I said this however, that a person who knows and perceives one and has a knowledge of him according to perception, will never think that he is some other person whom he knows and perceives, and of whom he has a knowledge according to perception. Was not this what I said?

Theæ. Yes.

Socr. There remained then the case that was just now mentioned, in which we said that false judgment takes place, when a person knowing you both and seeing you both, or having some other perception of you both, has not the impression of each according to the perception of each, but, like an unskilful archer, shoots beside the mark and misses, this then is called a falsehood.

Theæ. And very properly so.