The dialogue begins with Meno's peremptory request: ‘Can you tell me, Socrates, whether virtue can be taught, or is it acquired by practice, not teaching …?’ (70a). Socrates protests that he does not know what virtue is, and hence cannot know whether it is teachable or not, explaining that in general if one does not know what a thing is, τί ἐστι, one cannot know what it is like, ὁποῖον (71b). He insists that the prior question of what virtue is must be settled before consideration of the subsequent question of whether it is teachable or not.
In accordance with this principle, Socrates gets Meno to make attempts to offer a general definition of virtue. As in earlier dialogues, Socrates quickly reduces his interlocutor to aporia, and Meno refuses to make further attempts at defining virtue on the ground that no criterion of truth exists. Socrates sums up his argument thus: ‘It is impossible for a man to enquire into what he knows or into what he does not know. For he cannot enquire into what he knows, because he knows it, and there is no need for enquiry; nor again can he enquire into what he does not know, since he does not know about what he is to enquire into’ (80e). Socrates describes this paradox as a piece of eristic, but he does not dismiss it. To resolve it, he introduces the theory of recollection, ἀνάμησιρ (81a–e).