Evil is... a moral entity and not a created one, an eternal and not a perishable entity: it existed before the world; it constituted the monstrous, the execrable being who was also to fashion such a hideous world. It will hence exist after the creatures which people this world

All universal moral principles are idle fancies.

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.

My manner of thinking, so you say, cannot be approved. Do you suppose I care? A poor fool indeed is he who adopts a manner of thinking to suit other people! My manner of thinking stems straight from my considered reflections; it holds with my existence, with the way I am made. It is not in my power to alter it; and were it, I'd not do so.

The impossibility of outraging nature is the greatest anguish man can know.

Happiness lies only in that which excites, and the only thing that excites is crime.

Prejudice is the sole author of infamies: how many acts are so qualified by an opinion forged out of naught but prejudice!