“Tell your son to stop trying to fill your head with science — for to fill your heart with love is enough. ”

“You say you are a nameless man. You are not to your wife and to your child. You will not long remain so to your immediate colleagues if you can answer their simple questions when they come into your office. You are not nameless to me. Do not remain nameless to yourself — it is too sad a way to be. Know your place in the world and evaluate yourself fairly, not in terms of the naïve ideals of your own youth, nor in terms of what you erroneously imagine your teacher's ideals are.”

“Science is a way of trying not to fool yourself. The principle is that you must not fool yourself, and you are the easiest person to fool.”

“If you thought that science was certain - well, that is just an error on your part.”

“Of course, you only live one life, and you make all your mistakes, and learn what not to do, and that's the end of you.”

“Philosophy of science is about as useful to scientists as ornithology is to birds.”

“It doesn't make a difference how beautiful your guess is. It doesn't make a difference how smart you are, who made the guess, or what his name is. If it disagrees with experiment, it's wrong.”