Whether or not you can observe a thing depends upon the theory you use. It is the theory which decides what can be observed.

The process of scientific discovery is, in effect, a continual flight from wonder.

How do I work? I grope.

Science without religion is lame; religion without science is blind.

God casts the die, not the dice.

Not until the creation and maintenance of decent conditions of life for all men are recognized and accepted as a common obligation of all men ... shall we be able to speak of mankind as civilized.

Common sense is the collection of prejudices acquired by age 18.

Never do anything against conscience, even if the state demands it.

I believe the most important mission of the state is to protect the individual and make it possible for him to develop into a creative personality ... The state violates this principle when it compels us to do military service.

I have made no secret, either privately or publicly, of any sense of outrage over officially enforced military and war service. I regard it as a duty of conscience to fight against such barbarous enslavement of the individual with every means available.