Of cases where a man is truthful both in speech and conduct when no considerations of honesty come in, from an habitual sincerity of disposition. Such sincerity may be esteemed a moral excellence; for the lover of truth, who is truthful even when nothing depends on it, will a fortiori be truthful when some interest is at stake, since having all along avoided falsehood for its own sake, he will assuredly avoid it when it is morally base; and this is a disposition that we praise.

The energy of the mind is the essence of life.

It is the active exercise of our faculties in conformity with virtue that causes happiness, and the opposite activities its opposite.

There is nothing grand or noble in having the use of a slave, in so far as he is a slave; or in issuing commands about necessary things. But it is an error to suppose that every sort of rule is despotic like that of a master over slaves, for there is as great a difference between the rule over freemen and the rule over slaves as there is between slavery by nature and freedom by nature . .

The pleasures arising from thinking and learning will make us think and learn all the more. 1153a 23

We should venture on the study of every kind of animal without distaste; for each and all will reveal to us something natural and something beautiful.

Patience is so like fortitude that she seems either her sister or her daughter.