Science is what we have learned about how to keep from fooling ourselves.

Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it.

There is nothing more notable in Socrates than that he found time, when he was an old man, to learn music and dancing, and thought it time well spent.

Education is an ornament for the prosperous, a refuge for the unfortunate.

Better know nothing than half-know many things.

A little knowledge that acts is worth infinitely more than much knowledge that is idle.

It isn't what we don't know that gives us trouble, it's what we know that ain't so.

Language is courage: the ability to conceive a thought, to speak it, and by doing so to make it true.

It is what you read when you don't have to that determines what you will be when you can't help it.

I cannot teach anybody anything. I can only make them think

Just when I thought there wasn't room enough for another thought in my head, I had this great idea.

I like poems you can tack all over with a hammer and there are no hollow places.

I decided to teach because I think that any person who studies philosophy has to be involved actively.

What we know is a drop, what we don't know is an ocean.

Physics is like sex: sure, it may give some practical results, but that's not why we do it.

Real knowledge is to know the extent of one's ignorance.

Learning never exhausts the mind.

In mathematics you don't understand things. You just get used to them.

The man who is fond of books is usually a man of lofty thought, and elevated opinions.

I am so clever that sometimes I don't understand a single word of what I am saying.

Knowing is not enough; we must apply. Willing is not enough; we must do.