"Reality is merely an illusion, albeit a very persistent one."
"The only real valuable thing is intuition."
"A person starts to live when he can live outside himself."
"Weakness of attitude becomes weakness of character."
"The eternal mystery of the world is its comprehensibility."
"Sometimes one pays most for the things one gets for nothing."
"Anyone who has never made a mistake has never tried anything new."
"Everything should be made as simple as possible, but not simpler."
"Science is a wonderful thing if one does not have to earn one's living at it."
"The secret to creativity is knowing how to hide your sources."
"The whole of science is nothing more than a refinement of everyday thinking."
"God does not care about our mathematical difficulties. He integrates empirically."
"Intelligence makes clear to us the interrelationship of means and ends. But mere thinking cannot give us a sense of the ultimate and fundamental ends. To make clear these fundamental ends and valuations and to set them fast in the emotional life of the individual, seems to me precisely the most important function which religion has to form in the social life of man."