Plato, Socrates’ Defence Speech 21d
Here is part of Plato’s version of the speech that Socrates gave at his trial (often called his ‘apology’, an archaic use of the word which is misleading in its modern sense, since the speech is far from ‘apologetic’). After recalling an encounter with an unnamed politician, Socrates reflects on his realisation that neither of them could be called wise.
κινδυνεύει μὲν γὰρ ἡμῶν οὐδέτερος οὐδὲν καλὸν κἀγαθὸν εἰδέναι, ἀλλ’ οὗτος μὲν οἴεταί τι εἰδέναι οὐκ εἰδώς, ἐγὼ δέ, ὥσπερ οὖν οὐκ οἶδα, οὐδὲ οἴομαι· ἔοικα γοῦν τούτου γε σμικρῷ τινι αὐτῷ τούτῳ σοφώτερος εἶναι, ὅτι ἃ μὴ οἶδα οὐδὲ οἴομαι εἰδέναι.
It seems likely that neither of us knows anything good and beautiful; but he thinks he knows something, although he doesn’t know it, whereas I don’t know anything and don’t think that I do. So, in this one little way at least, it seems that I am wiser: I don’t think that I know the things which I don’t know.