Socrates said this quote

I went to interview a man with a high reputation for wisdom, because I felt that here if anywhere I should succeed in disproving the oracle and pointing out to my divine authority 'You said that I was the wisest of men, but here is a man who is wiser than I am.' Well, I gave a thorough examination to this person... and in conversation with him I formed the impression that although in many people's opinion, and especially in his own, he appeared to be wise, in fact he was not. Then when I began to try to show him that he only thought he was wise and was not really so, my efforts were resented both by him and by many of the other people present. However, I reflected as I walked away: 'Well, I am certainly wiser than this man. It is only too likely that neither of us has any knowledge to boast of; but he thinks that he knows something which he does not know, whereas I am quite conscious of my ignorance. At any rate it seems that I am wiser than he is to this small extent, that I do not think that I know what I do not know... [A]s I pursued my investigation at the god's command,... my honest impression was... that the people with the greatest reputations were almost entirely deficient, while others who were supposed to be their inferiors were much better qualified in practical intelligence.