The commentary on Plato's Republic by Proclus (d. 485 CE), which takes the form of a series of essays, is the only sustained treatment of the dialogue to survive from antiquity. This three-volume edition presents the first complete English translation of Proclus' text, together with a general introduction that argues for the unity of Proclus' Commentary and orients the reader to the use which the Neoplatonists made of Plato's Republic in their educational program. Each volume is completed by a Greek word index and an English-Greek glossary that will help non-specialists to track the occurrence of key terms throughout the translated text. The second volume of the edition presents Proclus' essays on the tripartite soul and the virtues, female philosopher rulers, and the metaphysics and epistemology of the central books of the Republic. The longest of the essays in Volume II interprets the nature and significance of the 'marriage number' whose miscalculation leads to the degeneration of the ideal city-state.