To one bent on age, death will come as a release. I feel this quite strongly now that I have grown old myself and have come to regard death like an old debt, at long last to be discharged.

I must seem like an ostrich who forever burries its head in the relativistic sands in order not to face the evil quanta.

I recently discussed with an intelligent and well-disposed man the threat of another war, which in my opinion would seriously endanger the existence of mankind, and I remarked that only a supranational organization would offer protection from that danger. Thereupon my visitor, very calmly and coolly, said to me: "Why are you so deeply opposed to the disappearance of the human race?".

Mathematics deals exclusively with the relations of concepts to each other without consideration of their relation to experience.

A country cannot simultaneously prepare and prevent war. I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones. The distinctions separating the social classes are false; in the last analysis they rest on force.

No path leads from a knowledge of that which is to that which should be.

To have a better life we must keep choosing how we are living.