The commentary on Republic is actually a collection of seventeen essays on various topics in Republic. Proclus addresses Plato’s critique of Homer, the tripartitioning of the soul, the nature of the philosopher and his radical distinction from the so-called lovers of sights and sounds, the structure of the divided line, the difference between the superordinate Good and a Form of the Good that is a genus of types of goods, and the taxonomy of decline from the aristocratic man and the aristocratic state, ultimately to the tyrannical man and the tyrannical state. His longest essay is an analysis and meditation on the myth of Er in Republic x, focusing on the nature of wrongdoing and the moral responsibility of the individual. Each of these topics is set within the framework of the Platonic system, at the apex of which is the Idea of the Good or the One whose causal scope is shown to encompass everything that exists, including matter. Thus, epistemological, psychological, and moral problems found in the dialogue need to adduce not only the Good but also the fundamental principles of the system in order to achieve a satisfactory resolution.