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.

The idle man does not know what it is to enjoy rest.

How can it be that mathematics, being after all a product of human thought which is independent of experience, is so admirably appropriate to the objects of reality?

There is nothing divine about morality, it is a purely human affair.

I am doing just fine, considering that I have triumphantly survived Nazism and two wives.

Man, surrounded by facts, permitting himself no surprise, no intuitive flash, no great hypothesis, no risk, is in a locked cell. Ignorance cannot seal the mind and imagination more securely.

Everyone has two choices. We're either full of love... or full of fear.