Therefore we call final without qualification that which is always desirable in itself and never for the sake of something else. Happiness is defined as the final end . Now happiness more than anything else seems unconditionally complete, since we always choose it because of itself, never because of something else. Happiness is so complete that we choose it for its own sake. Happiness, then, is apparently something complete and self-sufficient, since it is the end of the things pursued in action.
Happiness is the most fulfilling end, the sum of all other ends.
Now we take the human function to be a certain kind of life, and take this life to be the soul's activity and actions that express reason, and the function of a good man to be the good and noble performance of these. Each function is completed well when its completion expresses the proper virtue. Therefore, the human good turns out to be the soul's activity that expresses virtue. And if there are more virtues than one, the good will express the best and most complete virtue. Moreover, it will be in a complete life.