"You can know the name of a bird in all the languages of the world, but when you're finished, you'll know absolutely nothing whatever about the bird... So let's look at the bird and see what it's doing…"

"I don't believe in the idea of a 'good' or 'bad' atom. I just believe in atoms."

"I have a friend who is an artist and has some pictures which he thinks are very good... and he says, 'I am a value-free man. I don't believe in values.' And I say, 'Oh, really? Then why are your pictu…"

"I don't believe in God. I don't believe in anything. I'm a scientist."

"I don't think I'm a very good teacher. I just try to explain things clearly."