Why Is Plato’s Good Good?

The form of the Good in Plato’s Phaedo and Republic seems, by our standards, to do too much: it is presented as the metaphysical princi­ple, the epistemological principle and the principle of ethics. Yet this seemingly chimerical object makes good sense in the broader context of Plato’s philosophical project. He sought certain knowledge of neces­sary truths (in sharp contrast to the contingent truth of modern science). Thus, to be knowable the cosmos must be informed by timeless princi­ples; and this leads to teleology and the Good. The form of the Good, it is argued, is what makes the world knowable insofar as it is knowable. This interpretation plugs a significant gap in the scholarship on the Good and draws attention to a deep connection between Plato’s episte­mology and his teleological understanding of the cosmos.