The comprehensibility of the world seems to me a wonder or eternal secret. Here lies the sense of wonder which increases even more with the development of our knowledge.

[Max Planck] was one of the finest people I have ever known... but he really didn't understand physics, [because] during the eclipse of 1919 he stayed up all night to see if it would confirm the bending of light by the gravitational field. If he had really understood [general relativity], he would have gone to bed the way I did

Creativity is seeing what others see and thinking what no one else has ever thought.

If a man aspires towards a righteous life, his first act of abstinence is from injury to animals.

It is abhorrent to me when a fine intelligence is paired with an unsavory character.

I never commit to memory anything that can easily be looked up in a book

The mere formulation of a problem is far more essential than its solution, which may be merely a matter of mathematical or experimental skills. To raise new questions, new possibilities, to regard old problems from a new angle requires creative imagination and marks real advances in science.