According to Aristotle, nature (physis), habit or custom (ethos), and reason (logos) are the first principles of social explanation as well as the first principles of moral excellence. Just as we explain the order found in a polity as the product of natural, customary, and rationally stipulated kinds of order, so we become excellent persons through our good natural potential, the development of that potential in right habits, and sound ethical reflection upon those habits. For Aristotle, nature and convention are not mutually exclusive; rather, nature, custom, and reason form a hierarchy such that custom presupposes nature, but cannot be reduced to it, while reason presupposes custom, but cannot be reduced to custom. It is argued that Aristotle's account of social order is superior both to the prior Sophistic accounts and to the account in Aquinas. Because Aristotle roots the order of deliberate human action in the order of nature and the order of custom, he focuses his ethical analysis not on the abstract freedom of choice but on the concrete freedom of the person who must act.