Desire is the very essence of man

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.

I do not know how to teach philosophy without becoming a disturber of established religion.

Philosophers conceive of the passions which harass us as vices into which men fall by their own fault, and, therefore, generally deride, bewail, or blame them, or execrate them, if they wish to seem unusually pious.

Many errors, of a truth, consist merely in the application of the wrong names of things. For if a man says that the lines which are drawn from the centre of the circle to the circumference are not equal, he understands by the circle, at all events for the time, something else than mathematicians understand by it.

Laws which prescribe what everyone must believe, and forbid men to say or write anything against this or that opinion, are often passed to gratify, or rather to appease the anger of those who cannot abide independent minds.

Love or hatred towards a thing, which we conceive to be free, must, other things being similar, be greater than if it were felt towards a thing acting by necessity.