“There is only one virtue, justice; only one duty, to be happy; only one corollary, not to overvalue life and not to fear death.”

The bad gives rise to the good, the good inspires the better, the better produces the excellent, the excellent is followed by the bizarre

Ignorance is less remote from the truth than prejudice.

What is a monster? A being whose survival is incompatible with the existing order.

Integrity is the evidence of all civil virtues.

First move me, astonish me, break my heart, let me tremble, weep, stare, be enraged-only then regale my eyes.

If ever anybody dedicated his whole life to the “enthusiasm for truth and justice” using this phrase in the good sense it was Diderot.

There is less harm to be suffered in being mad among madmen than in being sane all by oneself.

Doctors are always working to preserve our health and cooks to destroy it, but the latter are the more often successful.

The wisest among us is very lucky never to have met the woman, be she beautiful or ugly, intelligent or stupid, who could drive him crazy enough to be fit to be put into an asylum.

My ideas are my whores.

There is only one passion, the passion for happiness.

Which is the greater merit, to enlighten the human race, which remains forever, or to save one’s fatherland, which is perishable?

Passions destroy more prejudices than philosophy does.

The infant runs toward it with its eyes closed, the adult is stationary, the old man approaches it with his back turned.

First of all move me, surprise me, rend my heart; make me tremble, weep, shudder; outrage me; delight my eyes afterwards if you can.

Scepticism is the first step towards truth.