The fate of a nation has often depended upon the good or bad digestion of a prime minister.

Descartes constructed as noble a road of science, from the point at which he found geometry to that to which he carried it, as Newton himself did after him. ... He carried this spirit of geometry and invention into optics, which under him became a completely new art.

Monsieur l'abbé, I detest what you write, but I would give my life to make it possible for you to continue to write.

The only reward to be expected from literature is contempt if one fails and hatred if one succeeds.

Many are destined to reason wrongly; others, not to reason at all; and others, to persecute those who do reason.

The best is the enemy of the good.

The discovery of what is true and the practice of that which is good are the two most important aims of philosophy.