Plants, again, inasmuch as they are without locomotion, present no great variety in their heterogeneous pacts. For, when the functions are but few, few also are the organs required to effect them. ... Animals, however, that not only live but perceive, present a great multiformity of pacts, and this diversity is greater in some animals than in others, being most varied in those to whose share has fallen not mere life but life of high degree. Now such an animal is man.

In cases of this sort, let us say adultery, rightness and wrongness do not depend on committing it with the right woman at the right time and in the right manner, but the mere fact of committing such action at all is to do wrong.

A period may be defined as a portion of speech that has in itself a beginning and an end, being at the same time not too big to be taken in at a glance

Man first begins to philosophize when the necessities of life are supplied.

In part, art completes what nature cannot elaborate; and in part it imitates nature.

Neither by nature, then, nor contrary to nature do the virtues arise in us; rather we are adapted by nature to receive them, and are made perfect by habit.

A true friend is one soul in two bodies.