Quackery gives birth to nothing; gives death to all things.

Laughter is one of the very privileges of reason, being confined to the human species.

I don't like to talk much with people who always agree with me. It is amusing to coquette with an echo for a little while, but one soon tires of it.

They wrong man greatly who say he is to be seduced by ease. Difficulty, abnegation, martyrdom, death are the allurements that act on the heart of man.

The true university of these days is a collection of books.

It is now almost my sole rule of life to clear myself of cants and formulas, as of poisonous Nessus shirts.

War is a quarrel between two thieves too cowardly to fight their own battle; therefore they take boys from one village and another village, stick them into uniforms, equip them with guns, and let them loose like wild beasts against one other.