In the present volume Proclus describes the 'creation' of the soul that animates the entire universe. This is not a literal creation, for Proclus argues that Plato means only to convey the eternal dependence of the World Soul upon higher causes. In his exegesis of Plato's text, Proclus addresses a range of issues in Pythagorean harmonic theory, as well as questions about the way in which the World Soul knows both forms and the visible reality that comprises its body. This part of Proclus' Commentary is particularly responsive to the interpretive tradition that precedes it. As a result, this volume is especially significant for the study of the Platonic tradition from the earliest commentators onwards.