Perfectionism is a normative theory that treats the actualization of human nature as pivotal to an account of human good and moral obligation. Particularly for the Aristotelian perfectionist tradition, eudaimonia—happiness, or human flourishing—is the ultimate good or telos (end) for human beings; and living in a practically wise and virtuous manner is the primary obligation dictated by that end. Succinctly stated, human flourishing is understood by us to mean “the exercise of one's own practical wisdom.” Though there are some, as we shall see in “The Perfectionist Turn” chapter of Part II, who think that human flourishing and the goods and virtues that constitute it can be adequately understood apart from the actualization of human nature, we do not. As we shall argue there, we do not think that there is an ontological gap between what is a good human being and what is good for a human being. Indeed, we believe holding that human flourishing is the ultimate end and good for human beings is compatible with there being many diverse forms of human flourishing and with self-direction being vital to the very actuality of human flourishing, and we emphasize both in what follows. Finally, we further believe that acknowledging the self-directed and individualized character of human flourishing is compatible with its being both real and socially achieved. We thus seek to advance a neo- Aristotelian account of human flourishing, in which human good is characterized by these interrelated and interpenetrating features: (1) objectivity, (2) inclusivity, (3) individuality, (4) agent-relativity, (5) self-directedness, and (6) sociality.