In Book One Section vii of the Nicomachean Ethics, Aristotle considers the nature of the good for man and what would be the ultimate end or object of human life. He answers that it is happiness, and he then develops an argument that human good is the activity of the soul expressing virtue. The good is the object of his search in this section, and he notes that the good normally differs according to what subject is under discussion. This means that the good in medicine and the good in another science will be different. What Aristotle wants, though, is the ultimate good, the good to which all human life is directed, that "any one thing that is the end of all actions" (73), and this he calls "the practical good" (73). This good, as noted, is happiness.
Aristotle further argues that not all ends are final ends, for some are the means to other ends. However, there has to be a final end in sight or the process would be infinite and never reach the good, the chief good that is something final. There can be only one final end, and that is the end human beings are seeking. Aristotle says that we call "any object pursued for its own sake" (73) more final than something we pursue for some other end or reason. Happiness is such an end. Happiness is always chosen for itself and not for any other reason, while for virtually all other valued ends we do choose them for some other reason, at least in part. .
Aristotle then considers another aspect of such a final end, that to be a perfect good it should be self-sufficient. Another way of saying this is that it would be all-inclusive, for Aristotle says that he does not mean "what is sufficient for oneself alone living a solitary life" (74) but rather sufficient in a way that includes parents, wife ad children, and even one's countrymen, "for man is by nature a social being" (74).
This leads to the central issue in this section, that "happiness is a virtuous activity of the soul" (75).
