Reading the Charmides, Apology, and Republic, this chapter articulates how, while one definition of self-knowledge in the dialogue (“knowledge of itself and other knowledges and the absence of knowledge”) is refuted, another definition, closer to the sort of wisdom we find in the Apology, remains unrefuted (self-knowledge as a knowledge of what one knows and does not know). The author locates the presence of this notion of self-knowledge in the opening pages of the Charmides, only to insist that it promptly vanishes with the emergence of Critias as Socrates’ principal interlocutor. Self-knowledge is not theoretical knowledge. It is not something achieved once and for all, but the ongoing challenge of the philosophical life itself. It cannot be asserted propositionally but rather must be lived by adopting an aporetic stance that never ceases to question.