Theory and practice in Aristotle's ethics

In Book X of the Nicomachean Ethics Aristotle argues that happiness in the strict sense lies in theoria. Yet in the greater part of the Ethics, he assumes that happiness lies in right praxis--and he seems to return to this assumption in the closing chapter of Book X. Why does Aristotle proceed in this way? What understanding of theoria and praxis leads him to make, abandon, and then return to his initial assumption?The following study attempts to answer these questions by means of a careful examination of key books and passages in the Ethics. Aristotle's discussion of happiness in Book I supplies an answer to one of them: he initially assumes that happiness lies in the practice of the moral virtues because his intended audience does. Yet even in Book I Aristotle quietly questions the soundness of this assumption, and--appearances notwithstanding--his accounts of magnanimity and justice serve to bring his questions into sharper focus. For these accounts suggest that the "complete" virtue of the happy man transcends both the virtues as they are ordinarily understood and the understanding of those who practice them. Book VI provides a concrete alternative to the view that happiness lies in the exercise of the moral virtues: although the happy man must act and attend to human things, happiness in the strict sense lies in wisdom, in the activity of understanding objects far higher than man.However, this alternative--which finds its clearest expression in X.6-8--fails to explain why Aristotle suggests in X.9 that the happy man will not only act but act so that others might acquire the moral virtues. Aristotle's discussion of friendship and beneficence points to an answer. It makes sense for the man who loves wisdom to befriend, and befriend actively, those who live the moral life because that life is an image of his own: theoria and praxis are one by analogy. Finally, reflection on Aristotle's own "practice" in the Ethics helps one to see what form the philosopher's beneficence might take the Ethics itself is the final answer to the questions it raises about theoria and praxis.