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

Do you see this egg? With this you can topple every theological theory, every church or temple in the world.

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.

All things must be examined, debated, investigated without exception and without regard for anyone's feelings... We must run roughshod over all these ancient puerilities, overturn the barriers that reason never erected, give back to the arts and sciences the liberty that is so precious to them.

It has been said that love robs those who have it of their wit, and gives it to those who have none.

In any country where talent and virtue produce no advancement, money will be the national god. Its inhabitants will either have to possess money or make others believe that they do. Wealth will be the highest virtue, poverty the greatest vice.

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.