Self-assured Meno, so certain that he understands what virtue is, admits to Socrates: “Truly my soul and my lips are numb, and I am not able to answer you. Yet, I have given many speeches about virtue hundreds of times before many people, and good ones too, as they seemed to me. But now I am unable to say anything at all” (80b). Euthyphro, ready to assure Socrates that he, Euthyphro, and not the Athenians, knows what piety is, finds himself admitting to Socrates: “I do not know how to say what I think: Somehow whatever we put forward keeps us moving about in a circle and is not willing to remain where we put it” (11b). Euthyphro blames Socrates for these wandering opinions: “You seem to me to be the Daedalus, since for me, they would have remained just so” (11d). Polemarchus, inheriting the argument from his father in the Republic, defines justice as helping your friends and harming your enemies, but after Socrates manipulates him into admitting that then the thief might be a just man, Polemarchus confesses: “I no longer know what I did mean. Yet this I still believe, that justice benefits friends and harms enemies” (334bc).

Socrates' challenge in each case is to bring about in his interlocutors that state of confusion, of aporia, that causes them to question the legacy of opinions that have guided their claims to knowledge.