A man's value to the community depends primarily on how far his feelings, thoughts, and actions are directed towards promoting the good of his fellows.

The release of atomic energy has not created a new problem. It has merely made more urgent the necessity of solving an existing one.

Everything should be made as simple as possible ... But not simpler.

No, this trick won't work... How on earth are you ever going to explain in terms of chemistry and physics so important a biological phenomenon as first love?

Knowledge of what is does not open the door directly to what should be.

Logic will get you from A to B. Imagination will take you everywhere.