Acting according to reason means acting virtuously. Happiness is the first from principle from which our inquiry will advance. Precision in its definition should be sought in accordance with the nature of the concept. Those of the soul are most important, and a person's actions fall into this category. Our definition of happiness includes all the other things that people commonly think of as the good virtue, prudence, wisdom, pleasure, etc.
Noble actions are inherently pleasant to a virtuous man.
The good, the noble and the pleasant are all interconnected, because they all go along with the best activities, the best of which is happiness. Happiness also requires a minimal amount of external goods. The end of politics is the highest good, and consequently politics must try to cultivate dispositions to noble actions in citizens. Happiness consists in a complete life lived according to virtue. It is difficult to say whether the happiness of a person after death should depend on the fortunes of his descendants.