The main questions pursued in the present dissertation are, first, what happiness is for Aristotle, next, how this happiness is achieved, and, last, if this happiness is possible even under imperfect but common circumstances. These questions arise from the very last chapter of his Nicomachean Ethics, where he focuses on ethical virtue and political action in discussing how to become happy. Why does he stress practical pursuit, having declared contemplation to be perfect happiness? Presumably, could it be because happiness, whether it be theoretical or ethical, involves practical pursuit and because practical virtue somehow enables the achievement of happiness? Indeed, for Aristotle happiness is a composite good that includes ethical virtue and political pursuit. Further, it is not simply the sum of different goods but some organized whole of them, viz., the state of completion; being happy means being complete in every way, i.e., with respect to one's state, capacity, and resources. Given that happiness is the state of completion, we may think of two other points about happiness: one is that there should be some capacity to coordinate different goods in happiness and organize them into a structured whole, which will be shown to be the role of practical virtue; the other point is that happiness would be something that develops over time and in stages, which accords with Aristotle's idea that one should be educated in order to be happy. The fact that happiness requires education implies that we cannot become happy without the help and guidance of those who are more mature than we are. Moreover, those who educate others in virtue, in so doing, would also produce their own happiness. Thus, having others in our life, i.e., living in communities is essential to our happiness—we need both those who educate us to be good and those whom we may teach to be good. And happiness as Aristotle conceives it should be possible even in less than the best community, for a political allows some room for its members to pursue what they deem to be worthwhile.