If we have the courage to decide ourselves for peace we will have peace.

I know little about nature and hardly anything about men.

The Bible is a collection of honorable, but primitive legends which are still nevertheless pretty childish.

An attempt at visualizing the Fourth Dimension: Take a point, stretch it into a line, curl it into a circle, twist it into a sphere, and punch through the sphere.

The most important tool of the theoretical physicist is his wastebasket.

To my mind, to kill in war is not a whit better than to commit ordinary murder.

The theoretical idea ... does not arise apart from and independent of experience; nor can it be derived from experience by a purely logical procedure. It is produced by a creative act. Once a theoretical idea has been acquired, one does well to hold fast to it until it leads to an untenable conclusion.