All the fifty years of conscious brooding have brought me no closer to answer the question, "What are light quanta?" Of course today every rascal thinks he knows the answer, but he is deluding himself.

If one asks the whence derives the authority of fundamental ends, since they cannot be stated and justified merely by reason, one can only answer: they exist in a healthy society as powerful traditions, which act upon the conduct and aspirations and judgments of the individuals; they are there, that is, as something living, without its being necessary to find justification for their existence.

A country cannot simultaneously prepare and prevent war.

It followed from the special theory of relativity that mass and energy are both but different manifestations of the same thing...

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

The chicken did not cross the road. The road passed beneath the chicken.

The majority of the stupid is invincible and guaranteed for all time. The terror of their tyranny, however, is alleviated by their lack of consistency.