Why does Socrates favour definitional speech discussion of virtue’s instances and attributes? Why does he take such a dim view of applied ethics? In this article, I criticise the received answers to these questions and offer a different view. I argue that Socrates favours definitional dialogue because it actualises knowledge that the logic of his argument shows to be essential to virtue. By leading the interlocutor to a paradoxical definition of virtue as knowledge, Socrates engenders this knowledge in his soul.