The real question of government versus private enterprise is argued on too philosophical and abstract a basis. Theoretically, planning may be good. But nobody has ever figured out the cause of government stupidity — and until they do (and find the cure), all ideal plans will fall into quicksand.

(From a 1963 letter to his wife Gweneth, written while attending a gravity conference in Communist-era Warsaw.) - What Do You Care What Other People Think? (1988)