Life is a language in which certain truths are conveyed to us; if we could learn them in some other way, we should not live.

The mother of useful arts is necessity; that of the fine arts is luxury. For father the former has intellect; the latter genius, which itself is a kind of luxury.

Every generation, no matter how paltry its character, thinks itself much wiser than the one immediately preceding it, let alone those that are more remote.

In order to increase his pleasures, man has intentionally added to the number and pressure of his needs, which in their original state were not much more difficult to satisfy than those of the brute. Hence luxury in all its forms; delicate food, the use of tobacco and opium, spirituous liquors, fine clothes, and the thousand and one things that he considers necessary to his existence.

All religions promise a reward beyond life, in eternity, for excellences of the will or heart, but none for excellences of the head or understanding.

If children were brought into the world by an act of pure reason alone, would the human race continue to exist? Would not a man rather have so much sympathy with the coming generation as to spare it the burden of existence, or at any rate not take it upon himself to impose that burden upon it in cold blood?

To free a man from error is to give, not to take away. Knowledge that a thing is false is a truth. Error always does harm; sooner or later it will bring mischief to the man who harbors it.