PhilebusPlato

A late dialogue on the question of what the good life is for a human being. Philebus has argued that the good is pleasure. Socrates answers that the good is knowledge. Each position breaks down on examination. A life of pure pleasure without any knowledge, memory, or awareness, Socrates shows, would not be desirable even to the one living it; a life of pure knowledge without any pleasure would not be chosen either. The good must therefore be a mixture.

The dialogue then asks in what proportions the mixture should be compounded, and which of the two ingredients stands closer to the good itself. Socrates introduces a fourfold division of all that exists: the unlimited, the limit, the mixed class that results when limit is imposed on the unlimited, and the cause of the mixing. Pleasure belongs with the unlimited, knowledge with the cause. A ranking of goods follows, with measure and proportion at the top, then beauty and symmetry, then intellect, then the pure pleasures of learning and of sense; the bodily pleasures rank last.

The Philebus is Plato's most careful treatment of pleasure as a moral category, and the place where the doctrine of the good as measure is worked out. Aristotle's discussion of pleasure in the Nicomachean Ethics is visibly a response to it.