Plato Charmides 172

for with error abolished, and rightness leading, in their every action men would be bound to do honorably and well under such conditions, and those who did well would be happy. Did we not so speak of temperance, I said, Critias, when we remarked how great a boon it was to know what one knows and what one does not know?
  To be sure we did, he replied.
  Whereas now, I went on, you see that nowhere can any such science be found.
  I see, he said. 172b Then may we say, I asked, that there is this good point in the knowledge of knowledge and of lack of knowledge, which we now find to be what temperance is, that he who has it will not only learn more easily whatever he learns, but will perceive everything more plainly, since besides the particular things that he learns he will behold the science; and hence he will probe more surely the state of other men respecting the things which he has learnt himself, while those who probe without such knowledge will do it more feebly and poorly? Are these, my friend, the kind of advantages that we shall gain 172c from temperance? But are we really looking at something greater, and requiring it to be something greater than it really is?
  Probably, he replied, that is so.
  I daresay, I said; and I daresay also our inquiry has been worthless. And this I conclude, because I observe certain strange facts about temperance, if it is anything like that. For suppose, if you please, we concede that there may possibly be a science of science, and let us grant, and not withdraw, our original proposition that temperance is the knowledge of what one knows and does not know; 172d granting all this, let us still more thoroughly inquire whether on these terms it will be of any profit to us. For our suggestion just now, that temperance of that sort, as our guide in ordering house or state, must be a great boon, was not, to my thinking, Critias, a proper admission.
  How so? he asked.
  Because, I replied, we too tightly admitted that it would be a great boon to mankind if each of us should do what he knows, but should place what he did not know in the hands of others who had the knowledge. 172e Well, was that, he asked, not a proper admission?
  Not to my mind, I answered.
  In very truth, your words are strange! he said, Socrates.
  Yes, by the Dog, I said, and they strike me too in the same way; and it was in view of this, just now, that I spoke of strange results that I noticed, and said I feared we were not inquiring rightly.