True virtue is life under the direction of reason.

Only that thing is free which exists by the necessities of its own nature, and is determined in its actions by itself alone.

self-preservation is the primary and only foundation of virtue.

I have resolved to demonstrate by a certain and undoubted course of argument, or to deduce from the very condition of human nature, not what is new and unheard of, but only such things as agree best with practice.

True knowledge of good and evil as we possess is merely abstract or general, and the judgment which we pass on the order of things and the connection of causes, with a view to determining what is good or bad for us in the present, is rather imaginary than real.

All laws which can be violated without doing any one any injury are laughed at. Nay, so far are they from doing anything to control the desires and passions of menб that, on the contrary, they direct and incite men's thoughts the more toward those very objects, for we always strive toward what is forbidden and desire the things we are not allowed to have. And men of leisure are never deficient in the ingenuity needed to enable them to outwit laws framed to regulate things which cannot be entirely forbidden... He who tries to determine everything by law will foment crime rather than lessen it.

Minds are not conquered by force, but by love and high-mindedness.