"The thing that bothered me about it was that I was doing work for the military, and I didn't like that."

"By the way, Professor, you know that paper in which you say those quantities are analogous... Did you know they're proportional?"

"I have a great deal of difficulty with the idea of 'truth' in the philosophical sense."

"There is no harm in doubt and skepticism, for it is through these that new discoveries are made."

"I would often go to these conferences where they would talk about the ultimate theory, and I would always say, 'What's the ultimate experiment?'"