Hence intellect[ual perception] is both a beginning and an end, for the demonstrations arise from these, and concern them. As a result, one ought to pay attention to the undemonstrated assertions and opinions of experienced and older people, or of the prudent, no less than to demonstrations, for, because the have an experienced eye, they see correctly.
A state is not a mere society, having a common place, established for the prevention of mutual crime and for the sake of exchange. Political society exists for the sake of noble actions, and not mere companionship.
Two characteristic marks have above all others been recognized as distinguishing that which has soul in it from that which has not - movement and sensation.
But the virtues we get by first exercising them, as also happens in the case of the arts as well. For the things we have to learn before we can do them, we learn by doing them, e.g. men become builders by building and lyre players by playing the lyre; so too we become just by doing just acts, temperate by doing temperate acts, brave by doing brave acts.
Conscientious and careful physicians allocate causes of disease to natural laws, while the ablest scientists go back to medicine for their first principles.