Man knows much more than he understands.

What do you first do when you learn to swim? You make mistakes, do you not? And what happens? You make other mistakes, and when you have made all the mistakes you possibly can without drowning - and some of them many times over - what do you find? That you can swim? Well - life is just the same as learning to swim! Do not be afraid of making mistakes, for there is no other way of learning how to live!

The test of one's behavior pattern is their relationship to society, relationship to work and relationship to sex.

The mathematical life of a mathematician is short. Work rarely improves after the age of twenty-five or thirty. If little has been accomplished by then, little will ever be accomplished.

There is no thing as a man who does not create mathematics and yet is a fine mathematics teacher. Textbooks, course material-these do not approach in importance the communication of what mathematics is really about, of where it is going, and of where it currently stands with respect to the specific branch of it being taught. What really matters is the communication of the spirit of mathematics. It is a spirit that is active rather than contemplative-a spirit of disciplined search for adventures of the intellect. Only as adventurer can really tell of adventures.

To be human means to feel inferior.

The chief danger in life is that you may take too many precautions.