There are some who are much pleased with themselves if, after setting up an absurd and self-contradictory subject, they succeed in discussing it in tolerable fashion; and men have grown old, some asserting that it is impossible to say, or to gainsay, what is false1, or to speak on both sides of the same questions, others maintaining that courage and wisdom and justice are identical2, and that we possess none of these as natural qualities, but that there is one sort of knowledge concerned with them all.; and still others waste their time in captious disputations that are not only entirely useless, but are sure to make trouble for their disciples.
1 So Antisthenes and the Cynics; cf. Plat. Soph. 240c.
2 A reference to the views of Plato and the Academy.