I see only with deep regret that God punishes so many of His children for their numerous stupidities, for which only He Himself can be held responsible; in my opinion, only His nonexistence could excuse Him.

A successful man is he who receives a great deal from his fellow men, usually incomparably more than corresponds to his service to them. The value of a man, however, should be seen in what he gives and not in what he is able to receive.

I do not believe in a personal God and I have never denied this but have expressed it clearly.

New frameworks are like climbing a mountain - the larger view encompasses rather than rejects the more restricted view.

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

A happy man is too satisfied with the present to dwell too much on the future.

If you do the same thing over and over again you cannot ever expect a different outcome.