My psychology belongs to everyone.

Violence as a way of gaining power... is being camouflaged under the guise of tradition, national honor [and] national security.

There is a law that man should love his neighbor as himself. In a few hundred years it should be as natural to mankind as breathing or the upright gait; but if he does not learn it he must perish.

In the company of friends, writers can discuss their books, economists the state of the economy, lawyers their latest cases, and businessmen their latest acquisitions, but mathematicians cannot discuss their mathematics at all. And the more profound their work, the less understandable it is.

What is courage? Courage is the willingness to risk failure...There is only one danger I find in life, and that, indeed, is a real one. You may take too many precautions.

Death is really a great blessing for humanity, without it there could be no real progress. People who lived for ever would not only hamper and discourage the young, but they would themselves lack sufficient stimulus to be creative.

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