Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.

There exists a passion for comprehension, just as there exists a passion for music. That passion is rather common in children, but gets lost in most people later on. Without this passion there would be neither mathematics nor natural science.

If one studies too zealously, one easily loses his pants.

Science is a wonderful thing if one does not have to earn one's living at it. One should earn one's living by work of which one is sure one is capable. Only when we do not have to be accountable to anybody can we find joy in scientific endeavor.

The more cruel the wrong that men commit against an individual or a people, the deeper their hatred and contempt for their victim.

External conditions can, to a certain extent, reduce, but never cancel individual repsonsibility.

It seems to me an utterly futile task to prescribe rules and limitations for the conduct of war. War is not a game; hence one cannot wage war by rules as one would in playing games. Our fight must be against war itself. The masses of people can most effectively fight the institution of war by establishing an organization for the absolute refusal of military service.