 Read in this way, Aristotle is engaged in a project similar in some respects to the one Plato carried out in the Republic. One of Plato’s central points is that it is a great advantage to establish a hierarchical ordering of the elements in one’s soul; and he shows how the traditional virtues can be interpreted to foster or express the proper relation between reason and less rational elements of the psyche. Aristotle’s approach is similar: his “function argument” shows in a general way that our good lies in the dominance of reason, and the detailed studies of the particular virtues reveal how each of them involves the right kind of ordering of the soul. Aristotle’s goal is to arrive at conclusions like Plato’s, but without relying on the Platonic metaphysics that plays a central role in the argument of the Republic. He rejects the existence of Plato’s forms in general and the form of the good in particular; and he rejects the idea that in order to become fully virtuous one must study mathematics and the sciences, and see all branches of knowledge as a unified whole. Even though Aristotle’s ethical theory sometimes relies on philosophical distinctions that are more fully developed in his other works, he never proposes that students of ethics need to engage in a specialized study of the natural world, or mathematics, or eternal and changing objects. His project is to make ethics an autonomous field, and to show why a full understanding of what is good does not require expertise in any other field.