I have gained this from philosophy: that I do without being commanded what others do only from fear of the law.

The tyrant, who in order to hold his power, suppresses every superiority, does away with good men, forbids education and light, controls every movement of the citizens and, keeping them under a perpetual servitude, wants them to grow accustomed to baseness and cowardice, has his spies everywhere to listen to what is said in the meetings, and spreads dissension and calumny among the citizens and impoverishes them, is obliged to make war in order to keep his subjects occupied and impose on them permanent need of a chief.

In poverty and other misfortunes of life, true friends are a sure refuge.

Wishing to be friends is quick work, but friendship is a slow ripening fruit.

Happiness seems to require a modicum of external prosperity.

It is evidently equally foolish to accept probable reasoning from a mathematician and to demand from a rhetorician demonstrative proofs.

The virtue of a faculty is related to the special function which that faculty performs. Now there are three elements in the soul which control action and the attainment of truth: namely, Sensation, Intellect, and Desire. Of these, Sensation never originates action, as is shown by the fact that animals have sensation but are not capable of action.