The first promise exchanged by two beings of flesh was at the foot of a rock that was crumbling into dust; they took as witness for their constancy a sky that is not the same for a single instant; everything changed in them and around them, and they believed their hearts free of vicissitudes. O children! always children!

It seems to me that if one had kept silence up to now regarding religion, people would still be submerged in the most grotesque and dangerous superstition ... regarding government, we would still be groaning under the bonds of feudal government ... regarding morals, we would still be having to learn what is virtue and what is vice. To forbid all these discussions, the only ones worthy of occupying a good mind, is to perpetuate the reign of ignorance and barbarism.

I have not the hope of being immortal, because the desire of it has not given me that vanity.

The arbitrary rule of a just and enlightened prince is always bad. His virtues are the most dangerous and the surest form of seduction: they lull a people imperceptibly into the habit of loving, respecting, and serving his successor, whoever that successor may be, no matter how wicked or stupid.

To be born in imbecility, in the midst of pain and crisis; to be the plaything of ignorance, error, need, sickness, wickedness, and passions; to return step by step to imbecility, from the time of lisping to that of doting; to live among knaves and charlatans of all kinds; to die between one man who takes your pulse and another who troubles your head; never to know where you come from, why you come and where you are going! That is what is called the most important gift of our parents and nature. Life.

He whom we call a gentleman is no longer the man of Nature.

A nation which thinks that it is belief in God and not good law which makes people honest does not seem to me very advanced.