Courage is not an ability one either possess or lacks. Courage is the willingness to engage in a risk-taking behavior regardless of whether the consequences are unknown or possibly adverse. We are capable of courageous behavior provided we are willing to engage in it. Given that life offers few guarantees, all living requires risk-taking.

A lie would have no sense unless the truth were felt as dangerous.

We only regard those unions as real examples of love and real marriages in which a fixed and unalterable decision has been taken. If men or women contemplate an escape, they do not collect all their powers for the task. In none of the serious and important tasks of life do we arrange such a "getaway." We cannot love and be limited.

The truth is often a terrible weapon of aggression. It is possible to lie, and even to murder, with the truth.

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.

Mathematics is pure language - the language of science. It is unique among languages in its ability to provide precise expression for every thought or concept that can be formulated in its terms.

Everything can always be different!