Science is a wonderful thing if one does not have to earn one's living at it. One should earn one's living by work of which one is sure one is capable. Only when we do not have to be accountable to anybody can we find joy in scientific endeavor.

If there is no price to be paid, it is also not of value.

My comprehension of God comes from a deeply felt conviction of a superior intelligence that reveals itself in the knowable world.

My relationship to the Jewish people has become my strongest human bond, ever since I became fully aware of our precarious situation among the nations of the world.

Out yonder there was this huge world...which stands before us like a great eternal riddle.

The only thing that interferes with my learning is my education.

I appeal to all men and women, whether they be eminent or humble, to declare that they will refuse to give any further assistance to war or the preparation of war.