What is this world? A complex whole, subject to endless revolutions. All these revolutions show a continual tendency to destruction; a swift succession of beings who follow one another, press forward, and vanish; a fleeting symmetry; the order of a moment. I reproached you just now with estimating the perfection of things by your own capacity; and I might accuse you here of measuring its duration by the length of your own days.

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.

If the weather is too cold or rainy, I take shelter in the Regence Cafe, where I entertain myself by watching chess being played. Paris is the world center, and this cafe is the Paris centre for the finest skill at this game.

One must be oneself very little of a philosopher not to feel that the finest privilege of our reason consists in not believing in anything by the impulsion of a blind and mechanical instinct, and that it is to dishonour reason to put it in bonds as the Chaldeans did. Man is born to think for himself.

The world is the house of the strong.

The most dangerous madmen are those created by religion, and people whose aim is to disrupt society always know how to make good use of them on occasion.

How old the world is! I walk between two eternities.... What is my fleeting existence in comparison with that decaying rock, that valley digging its channel ever deeper, that forest that is tottering and those great masses above my head about to fall? I see the marble of tombs crumbling into dust; and yet I don't want to die!