Don't listen to the person who has the answers; listen to the person who has the questions.

... a person who is religiously enlightened appears to me to be one who has, to the best of his ability, liberated himself from the fetters of his selfish desires and is preoccupied with thoughts, feelings, and aspirations to which he clings because of their superpersonal value.

All means prove but blunt instruments, if they have not behind them a living spirit.

Lasting harmony with a woman (was) an undertaking in which I twice failed rather disgracefully.

Classical thermodynamics ... is the only physical theory of universal content which I am convinced ... will never be overthrown.

I have never belonged wholeheartedly to a country, a state, nor to a circle of friends, nor even to my own family. When I was still a rather precocious young man, I already realized most vividly the futility of the hopes and aspirations that most men pursue throughout their lives. Well-being and happiness never appeared to me as an absolute aim. I am even inclined to compare such moral aims to the ambitions of a pig.

Long live impudence. It was my guardian angel in this world.