Plato's Apology 21 B – 21 E

But see why I say these things; for I am going to tell you whence the prejudice against me has arisen. For when I heard this, I thought to myself: "What in the world does the god mean, and what riddle is he propounding? For I am conscious that I am not wise either much or little. What then does he mean by declaring that I am the wisest? He certainly cannot be lying, for that is not possible for him. " And for a long time I was at a loss as to what he meant; then with great reluctance I proceeded to investigate him somewhat as follows.

I went to one of those who had a reputation for wisdom, thinking that there, if anywhere, I should prove the utterance wrong and should show the oracle "This man is wiser than I, but you said I was wisest. " So examining this man -- for I need not call him by name, but it was one of the public men with regard to whom I had this kind of experience, men of Athens -- and conversing with him, this man seemed to me to seem to be wise to many other people and especially to himself, but not to be so; and then I tried to show him that he thought he was wise, but was not. As a result, I became hateful to him and to many of those present; and so, as I went away, I thought to myself, "I am wiser than this man; for neither of us really knows anything fine and good, but this man thinks he knows something when he does not, whereas I, as I do not know anything, do not think I do either. I seem, then, in just this little thing to be wiser than this man at any rate, that what I do not know I do not think I know either. " From him I went to another of those who were reputed to be wiser than he, and these same things seemed to me to be true; and there I became hateful both to him and to many others.