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

War is not the continuation of politics with different means, it is the greatest mass-crime perpetrated on the community of man.

Each generation has its few great mathematicians, and mathematics would not even notice the absence of the others. They are useful as teachers, and their research harms no one, but it is of no importance at all. A mathematician is great or he is nothing.

The only worthwhile achievements of man are those which are socially useful.

More important than innate disposition, objective experience, and environment is the subjective evaluation of these. Furthermore, this evaluation stands in a certain, often strange, relation to reality.

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.