This is not very important what I'm doing. I'm just proving something.

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.

To not know math is a severe limitation to understanding the world.

Experiment is the sole judge of the validity of any idea.

There is no learning without having to pose a question. And a question requires doubt.

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?"