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 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.

To all those who walk the path of human cooperation war must appear loathsome and inhuman.

You can be healed of depression if every day you begin the first thing in the morning to consider how you will bring a real joy to someone else.

It is well known that those who do not trust themselves never trust others.

My psychology belongs to everyone.

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