eudaimon and most virtuous life is that of a philosopher.) Aristotle emphasizes throughout all his analyses of virtues that they aim at what is beautiful (kalos), effectively equating the good, at least for humans, with the beautiful (to kalon). Aristotle's analysis of ethics makes use of his metaphysical theory of potentiality and actuality. He defines eudaimonia in terms of this theory as an actuality (energeia); the virtues which allow eudaimonia (and enjoyment of the best and most constant pleasures) are dynamic-but-stable dispositions (hexeis) which are developed through habituation; and this pleasure in turn is another actuality that complements the actuality of euidaimon living. Practical ethics Aristotle believed that ethical knowledge is not only a theoretical knowledge, but rather that a person must have "experience of the actions in life" and have been "brought up in fine habits" to become good (NE 1095a3 and b5). For a person to become virtuous, he can't simply study what virtue is, but must actually do virtuous things. Aristotle's starting point The Aristotelian Ethics all aim to begin with approximate but uncontroversial starting points. In the Nicomachean Ethics Aristotle says explicitly that one must begin with what is familiar to us, and "the that" or "the fact that" (NE I.1095b2-13). Ancient commentators agree that what Aristotle means here is that his treatise must rely upon practical, everyday knowledge of virtuous actions as the starting points of his inquiry, and that he is supposing that his readers have some kind of experience-based understanding of such actions, and that they value noble and just actions to at least some degree. Elsewhere, Aristotle also seems to rely upon common conceptions of how the world works. In fact, some regard his ethical inquiries as using a method that relies upon popular opinion (his so-called "endoxic method" from the Grk. endoxa). There is some dispute, however, about exactly how such common conceptions fit into Aristotle's method in his ethical treatises, particularly since he also makes use of more formal arguments, especially the so-called "function argument," which is described below. Aristotle describes popular accounts about what kind of life would be a eudaimon one by classifying them into three most common types: a life dedicated to pleasure; a life dedicated to fame and honor; and a life dedicated to contemplation (NE I.1095b17-19). To reach his own conclusion about the best life, however, Aristotle tries to isolate the function of humans. The