The electron is a theory we use; it is so useful in understanding the way nature works that we can almost call it real.

An ordinary fool isn't a faker; an honest fool is all right. But a dishonest fool is terrible!

But see that the imagination of nature is far, far greater than the imagination of man.

If we want to solve a problem that we have never solved before, we must leave the door to the unknown ajar.

I have a friend who's an artist, and he sometimes takes a view which I don't agree with. He'll hold up a flower and say, "Look how beautiful it is," and I'll agree. But then he'll say, "I, as an artist, can see how beautiful a flower is. But you, as a scientist, take it all apart and it becomes dull." I think he's kind of nutty. [...] There are all kinds of interesting questions that come from a knowledge of science, which only adds to the excitement and mystery and awe of a flower. It only adds. I don't understand how it subtracts.

Ordinarily it would take me about fifteen minutes to get a hallucination going," wrote Feynman, "but on a few occasions, when I smoked some marijuana beforehand, it came very quickly.

If you think you understand quantum mechanics, you don't understand quantum mechanics.