I would absolutely refuse any direct or indirect war service and would try to persuade my friends to do the same, regardless of the reasons for the cause of a war.

A little knowledge is a dangerous thing. So is a lot.

A successful man is he who receives a great deal from his fellow men, usually incomparably more than corresponds to his service to them. The value of a man, however, should be seen in what he gives and not in what he is able to receive.

Scientific greatness is less a matter of intelligence than character; if the scientist refuses to compromise or accept incomplete answers and persists in grappling the most basic and difficult questions.

I should very much like to remain in the darkness of not having been analyzed.

The most fundamental question we can ever ask ourselves is whether or not the universe we live in is friendly or hostile.

Imagination is more important than knowledge. For knowledge is limited to all we now know and understand, while imagination embraces the entire world, and all there ever will be to know and understand.