I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.

Joy in looking and comprehending is nature's most beautiful gift.

Science is a wonderful thing if one does not have to earn one's living at it.

In my relativity theory I set up a clock at every point in space, but in reality I find it difficult to provide even one clock in my room.

To act intelligently in human affairs is only possible if an attempt is made to understand the thoughts, motives, and apprehension of one's opponent so fully that one can see the world through their eyes.

You never fail until you stop trying.

You cannot prepare for war and peace at the same time.