Only morality in our actions can give beauty and dignity to life.

The mind can proceed only so far upon what it knows and can prove. There comes a point where the mind takes a higher plane of knowledge, but can never prove how it got there. All great discoveries have involved such a leap

I never think of the future. It comes soon enough. When visiting the U.S. from Germany for a winter academic stay.

I was very pleased with your kind letter. Until now I never dreamed of being something like a hero. But since you've given me the nomination I feel that I am one.

The pursuit of knowledge for its own sake, an almost fanatical love of justice and the desire for personal independence -- these are the features of the Jewish tradition which make me thank my stars that I belong to it.

If tomorrow were never to come, it would not be worth living today.

The most incomprehensible thing about the world is that it is comprehensible.