Explain Aristotle's account of the human function and its role in the Ethics. How does he identify the function? What role does it play in the account of human happiness, and of virtue? To what extent does his account of the human function include or exclude the physical body, and the various feelings to which the body is subject? What about the mind in the form of reason or thought? How does this account of the function relate to the claim, in Book X, that the best life is the life of study?