There is no authority who decides what is a good idea.

It's because somebody knows something about it that we can't talk about physics. It's the things that nobody knows anything about we can discuss.

Everybody who reasons carefully about anything is making a contribution ... and if you abstract it away and send it to the Department of Mathematics they put it in books.

Scientists are explorers. Philosophers are tourists.

People who wish to analyze nature without using mathematics must settle for a reduced understanding.

We cannot define anything precisely. If we attempt to, we get into the paralysis of thought that comes to philosophers, who sit opposite each other, one saying to the other, "You don't know what you are talking about!" The second one says, "What do you mean by know? What do you mean by talking? What do you mean by you?"

Ordinary fools are all right; you can talk to them, and try to help them out. But pompous fools-guys who are fools and are covering it all over and impressing people as to how wonderful they are with all this hocus pocus-THAT, I CANNOT STAND! An ordinary fool isn't a faker; an honest fool is all right. But a dishonest fool is terrible!