"I asked him once, 'How do you tell when a mathematical argument is correct?' He said, 'If it's beautiful, it's correct.'"

"It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong."

"I don't have to follow rules. I just have to find out what's true."

"I was also a little bit of a clown."

"I'm not a popularizer. I'm not trying to tell the public what to think. I'm just telling them what I think."