When the argument was referred back to first principles in this way, the truth became apparent to his opponents too. And when he himself was setting out a detailed argument, he used to proceed by such stages as were generally agreed, because he thought that this was the infallible method of argument. Consequently, when he was talking, he used to win the agreement of his audience more than anyone else I have known. He used to say that Homer himself attributed to Odysseus the quality of being an infallible speaker, because he could base his arguments on the accepted beliefs of his hearers.
Xenophon, Memorabilia 4.6.11, in Xenophon, Conversations of Socrates, Tredennick & Waterfield, trs. & eds. Penguin (New York: 1990) p.211