“One of the symptoms of an approaching nervous breakdown is the belief that one’s work is terribly important.”

“I think that there is far too much work done in the world, that immense harm is caused by the belief that work is virtuous, and that what needs to be preached in modern industrial countries is quite different from what always has been preached.”

“Man is a credulous animal, and must believe something; in the absence of good grounds for belief, he will be satisfied with bad ones.”

“In science, an observer states his results along with the “probable error”; but who ever heard of a theologian or a politician stating the probable error in his dogmas, or even admitting that any error is conceivable? That is because in science, where we approach nearest to real knowledge, a man can safely rely on the strength of his case, whereas, where nothing is known, blatant assertion and hypnotism are the usual ways of causing others to share our beliefs. If the fundamentalist thought they had a good case against evolution, they would not make the teaching of it illegal.”

“A fanatical belief in democracy makes democratic institutions impossible”

“I would never die for my beliefs because I might be wrong.”

“In various ways, methods of approaching the mathematician's ideal were sought, and the resulting suggestions were the source of much that was mistaken in metaphysics and theory of knowledge.”