I am content in my later years. I have kept my good humor and take neither myself nor the next person seriously.

People like you and I, though mortal of course like everyone else, do not grow old no matter how long we live.

Hunger, love, pain, fear are some of those inner forces which rule the individual's instinct for self preservation.

You are the only person I know who has the same attitude towards physics as I have: belief in the comprehension of reality through something basically simple and unified... It seems hard to sneak a look at God's cards. But that He plays dice and uses 'telepathic' methods... is something that I cannot believe for a single moment.

Do you believe in immortality? No, and one life is enough for me.

It is very difficult to explain this feeling to anyone who is entirely without it, especially as there is no anthropomorphic conception of God corresponding to it. The individual feels the nothingness of human desires and aims and the sublimity and marvelous order which reveal themselves both in Nature and in the world of though. He looks upon individual existence as a sort of prison and wants to experience the universe as a single significant whole.

Our entire much-praised technological progress, and civilization generally, could be compared to an axe in the hand of a pathological criminal.