Theaetetus Part 18
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 any one thinks of one thing as another, he is saying to himself that one thing is another?
THEAETETUS: Yes.
SOCRATES: But do you ever remember saying to yourself that the n.o.ble is certainly base, or the unjust just; or, best of all--have you ever attempted to convince yourself that one thing is another? Nay, not even in sleep, did you ever venture to say to yourself that odd is even, or anything of the kind?
THEAETETUS: Never.
SOCRATES: And do you suppose that any other man, either in his senses or out of them, ever seriously tried to persuade himself that an ox is a horse, or that two are one?
THEAETETUS: Certainly not.
SOCRATES: But if thinking is talking to oneself, no one speaking and thinking of two objects, and apprehending them both in his soul, will say and think that the one is the other of them, and I must add, that even you, lover of dispute as you are, had better let the word 'other'
alone (i.e. not insist that 'one' and 'other' are the same (Both words in Greek are called eteron: compare Parmen.; Euthyd.)). I mean to say, that no one thinks the n.o.ble to be base, or anything of the kind.
THEAETETUS: I will give up the word 'other,' Socrates; and I agree to what you say.
SOCRATES: If a man has both of them in his thoughts, he cannot think that the one of them is the other?
THEAETETUS: True.
SOCRATES: Neither, if he has one of them only in his mind and not the other, can he think that one is the other?
THEAETETUS: True; for we should have to suppose that he apprehends that which is not in his thoughts at all.
SOCRATES: Then no one who has either both or only one of the two objects in his mind can think that the one is the other. And therefore, he who maintains that false opinion is heterodoxy is talking nonsense; for neither in this, any more than in the previous way, can false opinion exist in us.
THEAETETUS: No.
SOCRATES: But if, Theaetetus, this is not admitted, we shall be driven into many absurdities.
THEAETETUS: What are they?
SOCRATES: I will not tell you until I have endeavoured to consider the matter from every point of view. For I should be ashamed of us if we were driven in our perplexity to admit the absurd consequences of which I speak. But if we find the solution, and get away from them, we may regard them only as the difficulties of others, and the ridicule will not attach to us. On the other hand, if we utterly fail, I suppose that we must be humble, and allow the argument to trample us under foot, as the sea-sick pa.s.senger is trampled upon by the sailor, and to do anything to us. Listen, then, while I tell you how I hope to find a way out of our difficulty.
THEAETETUS: Let me hear.
SOCRATES: I think that we were wrong in denying that a man could think what he knew to be what he did not know; and that there is a way in which such a deception is possible.
THEAETETUS: You mean to say, as I suspected at the time, that I may know Socrates, and at a distance see some one who is unknown to me, and whom I mistake for him--then the deception will occur?
SOCRATES: But has not that position been relinquished by us, because involving the absurdity that we should know and not know the things which we know?
THEAETETUS: True.
SOCRATES: Let us make the a.s.sertion 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?
THEAETETUS: Certainly you may.
SOCRATES: And another and another?
THEAETETUS: Yes.
SOCRATES: I 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.
THEAETETUS: I see.
SOCRATES: Let 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.
THEAETETUS: Very good.
SOCRATES: Now, when a person has this knowledge, and is considering something which he sees or hears, may not false opinion arise in the following manner?
THEAETETUS: In what manner?
SOCRATES: When 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.
THEAETETUS: And how would you amend the former statement?
SOCRATES: I 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.
THEAETETUS: What are they? If you tell me, I may perhaps understand you better; but at present I am unable to follow you.
SOCRATES: A 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.
THEAETETUS: I understand you less than ever now.
SOCRATES: Hear 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.
THEAETETUS: Very true.
SOCRATES: Then, first of all, I want you to understand that a man may or may not perceive sensibly that which he knows.
THEAETETUS: True.