The happy man . . . will be always or at least most often employed in doing and contemplating the things that are in conformity with virtue. And he will bear changes of fortunes most nobly, and with perfect propriety in every way.
What is the highest good in all matters of action? To the name, there is almost complete agreement; for uneducated and educated alike call it happiness, and make happiness identical with the good life and successful living. They disagree, however, about the meaning of happiness.
Demonstration is also something necessary, because a demonstration cannot go otherwise than it does, ... And the cause of this lies with the primary premises/principles.
Conscientious and careful physicians allocate causes of disease to natural laws, while the ablest scientists go back to medicine for their first principles.