I made one great mistake in my life-when I signed the letter to President Roosevelt recommending that atom bombs be made but there was some justification-the danger that the Germans would make them.

I came- though the child of entirely irreligious (Jewish) parents - to a deep religiousness, which, however, reached an abrupt end at the age of twelve.

Feeling and longing are the motive forces behind all human endeavor and human creations.

To me it is enough to wonder at the secrets

Our death is not an end if we can live on in our children and the younger generation. For they are us; our bodies are only wilted leaves on the tree of life.

Human beings, in their thinking, feeling and acting are not free agents but are as causally bound as the stars in their motion.

The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.