Materialists and madmen never have doubts.

I have argued with him on almost every subject in the world, and we have always been on opposite sides, without affectation or animosity... It is necessary to disagree with him as much as I do, in order to admire him as I do; and I am proud of him as a foe even more than as a friend.

Buddhism is not a creed, it is a doubt.

The life of a thinking man will probably be divided into two parts -- the first in which he desires to exterminate modern thinkers, and the second in which he desires to watch them exterminating each other. ... Suppose, for instance, there is an old story and a new skeptic who is skeptical of the story. We have only to wait a little while for a yet newer skeptic who is skeptical of the skeptic. He will probably find the old notion actually a help in his new notion. This process is an abstract truth applying to anything, apart from agreement or disagreement.

Big Business and State Socialism are very much alike, especially Big Business.

Man is always something worse or something better than an animal; and a mere argument from animal perfection never touches him at all. Thus, in sex no animal is either chivalrous or obscene. And thus no animal invented anything so bad as drunkeness - or so good as drink.

Whether a man chooses to tell the truth in long sentences or short jokes is a problem analogous to whether he chooses to tell the truth in French or in German.