In Aristotle's Nicomachaen Ethics, the principle concern is the nature of human well-being. According to Aristotle, everything we do in life, we do for the sake of some good, or at least something perceived to be good (1094a1-3). When inquiring as to whether there is some good desired for its own sake, Aristotle envisioned a problem that either there is an infinite series of goods desired for the sake of something higher, in which case one's desires can never be satisfied, or there must be some highest good that is desired for its own sake and for which everything else is desired (1094a17-22). Then, according to Aristotle, the highest good must be final, it must be desired for its own sake and not for the sake of anything else; it must be self-sufficient (1097a25). In 1097b1, Aristotle labels happiness as the highest good, as "we always choose it because of itself, never because of something else." In order to understand and define happiness, Aristotle looked at happiness as a function of a human being. Aristotle examined the three parts of the soul as likely candidates for the function. The non-rational part of the soul can not be a function of the human being, as all living things take in nutrition and grow, and all animals posses desires/appetites. As the rational part of the soul, reason distinguishes human beings from all living things; Aristotle thought that the function of a human being would have to be found in "an activity of the soul in conformity with [reason]."(1098a7). Although, the function of a human being will be not simply to make use of his reasoning ability, but to make use of it in the best possible way, in virtue. For Aristotle, then, the function of a human being, happiness, is an "activity of the soul in conformity with virtue."(1098a16). Happiness is not an emotional state, but a way of life; happiness is revealed not in how we are, but in how we act.…