Very true.

But in the case of hearing and sight, or in the power of self-motion, and the power of heat to burn, this relation to self will be regarded as incredible by some, but perhaps not by others. And some great man, my friend, is wanted, who will satisfactorily determine for us, whether there is nothing which has an inherent property of relation to self, or some things only and not others; and whether in this cla.s.s of self-related things, if there be such a cla.s.s, that science which is called wisdom or temperance is included. I altogether distrust my own power of determining these matters: I am not certain whether there is such a science of science at all; and even if there be, I should not acknowledge this to be wisdom or temperance, until I can also see whether such a science would or would not do us any good; for I have an impression that temperance is a benefit and a good. And therefore, O son of Callaeschrus, as you maintain that temperance or wisdom is a science of science, and also of the absence of science, I will request you to show in the first place, as I was saying before, the possibility, and in the second place, the advantage, of such a science; and then perhaps you may satisfy me that you are right in your view of temperance.

Critias heard me say this, and saw that I was in a difficulty; and as one person when another yawns in his presence catches the infection of yawning from him, so did he seem to be driven into a difficulty by my difficulty. But as he had a reputation to maintain, he was ashamed to admit before the company that he could not answer my challenge or determine the question at issue; and he made an unintelligible attempt to hide his perplexity. In order that the argument might proceed, I said to him, Well then Critias, if you like, let us a.s.sume that there is this science of science; whether the a.s.sumption is right or wrong may hereafter be investigated. Admitting the existence of it, will you tell me how such a science enables us to distinguish what we know or do not know, which, as we were saying, is self-knowledge or wisdom: so we were saying?

Yes, Socrates, he said; and that I think is certainly true: for he who has this science or knowledge which knows itself will become like the knowledge which he has, in the same way that he who has swiftness will be swift, and he who has beauty will be beautiful, and he who has knowledge will know. In the same way he who has that knowledge which is self-knowing, will know himself.

I do not doubt, I said, that a man will know himself, when he possesses that which has self-knowledge: but what necessity is there that, having this, he should know what he knows and what he does not know?

Because, Socrates, they are the same.

Very likely, I said; but I remain as stupid as ever; for still I fail to comprehend how this knowing what you know and do not know is the same as the knowledge of self.

What do you mean? he said.

This is what I mean, I replied: I will admit that there is a science of science;--can this do more than determine that of two things one is and the other is not science or knowledge?

No, just that.

But is knowledge or want of knowledge of health the same as knowledge or want of knowledge of justice?

Certainly not.

The one is medicine, and the other is politics; whereas that of which we are speaking is knowledge pure and simple.

Very true.

And if a man knows only, and has only knowledge of knowledge, and has no further knowledge of health and justice, the probability is that he will only know that he knows something, and has a certain knowledge, whether concerning himself or other men.

True.

Then how will this knowledge or science teach him to know what he knows?

Say that he knows health;--not wisdom or temperance, but the art of medicine has taught it to him;--and he has learned harmony from the art of music, and building from the art of building,--neither, from wisdom or temperance: and the same of other things.

That is evident.

How will wisdom, regarded only as a knowledge of knowledge or science of science, ever teach him that he knows health, or that he knows building?

It is impossible.

Then he who is ignorant of these things will only know that he knows, but not what he knows?

True.

Then wisdom or being wise appears to be not the knowledge of the things which we do or do not know, but only the knowledge that we know or do not know?

That is the inference.

Then he who has this knowledge will not be able to examine whether a pretender knows or does not know that which he says that he knows: he will only know that he has a knowledge of some kind; but wisdom will not show him of what the knowledge is?

Plainly not.

Neither will he be able to distinguish the pretender in medicine from the true physician, nor between any other true and false professor of knowledge. Let us consider the matter in this way: If the wise man or any other man wants to distinguish the true physician from the false, how will he proceed? He will not talk to him about medicine; and that, as we were saying, is the only thing which the physician understands.

True.

And, on the other hand, the physician knows nothing of science, for this has been a.s.sumed to be the province of wisdom.

True.

And further, since medicine is science, we must infer that he does not know anything of medicine.

Exactly.

Then the wise man may indeed know that the physician has some kind of science or knowledge; but when he wants to discover the nature of this he will ask, What is the subject-matter? For the several sciences are distinguished not by the mere fact that they are sciences, but by the nature of their subjects. Is not that true?

Quite true.

And medicine is distinguished from other sciences as having the subject-matter of health and disease?

Yes.

And he who would enquire into the nature of medicine must pursue the enquiry into health and disease, and not into what is extraneous?

True.

And he who judges rightly will judge of the physician as a physician in what relates to these?

He will.

He will consider whether what he says is true, and whether what he does is right, in relation to health and disease?

He will.

But can any one attain the knowledge of either unless he have a knowledge of medicine?

He cannot.

No one at all, it would seem, except the physician can have this knowledge; and therefore not the wise man; he would have to be a physician as well as a wise man.

Very true.

Then, a.s.suredly, wisdom or temperance, if only a science of science, and of the absence of science or knowledge, will not be able to distinguish the physician who knows from one who does not know but pretends or thinks that he knows, or any other professor of anything at all; like any other artist, he will only know his fellow in art or wisdom, and no one else.

That is evident, he said.

But then what profit, Critias, I said, is there any longer in wisdom or temperance which yet remains, if this is wisdom? If, indeed, as we were supposing at first, the wise man had been able to distinguish what he knew and did not know, and that he knew the one and did not know the other, and to recognize a similar faculty of discernment in others, there would certainly have been a great advantage in being wise; for then we should never have made a mistake, but have pa.s.sed through life the unerring guides of ourselves and of those who are under us; and we should not have attempted to do what we did not know, but we should have found out those who knew, and have handed the business over to them and trusted in them; nor should we have allowed those who were under us to do anything which they were not likely to do well; and they would be likely to do well just that of which they had knowledge; and the house or state which was ordered or administered under the guidance of wisdom, and everything else of which wisdom was the lord, would have been well ordered; for truth guiding, and error having been eliminated, in all their doings, men would have done well, and would have been happy. Was not this, Critias, what we spoke of as the great advantage of wisdom--to know what is known and what is unknown to us?

Very true, he said.