Nicomachean Ethics

...could be further expanded upon, because they do not belong to the present speculation; and so let us approach the other part of philosophy, that is, the active part itself, which seems to pertain more to this our purpose. Therefore, active philosophy, which is also accustomed to be called practical, is itself also divided into three parts: into Ethics, Economics, and Politics. For since it contains the precepts of human life, and these indeed are divided threefold—for they establish our life either concerning morals, or concerning domestic matters, or concerning civil matters—active philosophy is deservedly divided into three species of doctrine. For by moral doctrine man instructs himself and his own habits; by economics, he arranges his home and family; and finally, by politics, he rules and governs the citizens and the commonwealth itself. Moreover, one ought to consider that to know and to speculate upon teachings of this kind is of very little account, unless we also bring them into action. For in those things which fall under action, the end is not to contemplate, as the Philosopher says, or to know individual things, but rather to act. Nor is it enough to know about virtue, but one must strive to possess and use it, and labor in every way so that we may be made good. Wherefore, in active philosophy, speculation is not the ultimate end, but is ordered toward operations themselves, from which, through frequent repetition, virtue arises, and finally through virtue that which, in the opinion of this Philosopher, is said to be human happiness. Nor does it escape me that human happiness is twofold: one active, the other contemplative, as the Philosopher shows most extensively in the tenth book of the Ethics. Wherefore the consideration of this matter must be deferred to that place; for now, it is only necessary to consider that the teachings of active philosophy are ordered toward action, as we have said, which is directed either toward ourselves or toward others: toward others, in turn, either toward few or toward many. If toward few, then the administration of domestic affairs arises; if toward many, the government of the city. First, however, it is necessary that we perfect

Parts of active philosophy.

Human happiness is twofold.