The man who alters his way of thinking to suit others is a fool.

The primary and most beautiful of Nature's qualities is motion, which agitates her at all times, but this motion is simply a perpetual consequence of crimes, she conserves it by means of crimes only.

The mechanism that directs government cannot be virtuous, because it is impossible to thwart every crime, to protect oneself from every criminal without being criminal too; that which directs corrupt mankind must be corrupt itself; and it will never be by means of virtue, virtue being inert and passive, that you will maintain control over vice, which is ever active: the governor must be more energetic than the governed.

Lycurgus, Numa, Moses, Jesus Christ, Mohammed, all these great rogues, all these great thought-tyrants, knew how to associate the divinities they fabricated with their own boundless ambition.

Every principle is a judgment, every judgment the outcome of experience, and experience is only acquired by the exercise of the senses . . .

Let us give ourselves indiscriminately to everything our passions suggest, and we will always be happy...Conscience is not the voice of Nature but only the voice of prejudice.

No kind of sensation is keener and more active than that of pain its impressions are unmistakable.