Education with inert ideas is not only useless; it is above all things harmful.

Many a scientist has patiently designed experiments for the purpose of substantiating his belief that animal operations are motivated by no purposes. He has perhaps spent his spare time in writing articles to prove that human beings are as other animals so that 'purpose' is a category irrelevant for the explanation of their bodily activities, his own activities included. Scientists animated by the purpose of proving that they are purposeless constitute an interesting subject for study.

Almost all new ideas have a certain aspect of foolishness when they are first produced.

Each generation criticizes the unconscious assumptions made by its parent. It may assent to them, but it brings them out in the open.

Art flourishes where there is a sense of adventure, a sense of nothing having been done before, of complete freedom to experiment.

In formal logic, a contradiction is the signal of defeat, but in the evolution of real knowledge it marks the first step in progress toward a victory.

It is a safe rule to apply that, when a mathematical or philosophical author writes with a misty profundity, he is talking nonsense.