I know that I am intelligent, because I know that I know nothing.

It is a mania shared by philosophers of all ages to deny what exists and to explain what does not exist.

When Britain and the U.S. invaded Iraq, it was with the reasonable expectation that it was going to increase the threat of terror, as it has.

I don't know if you ever really feel like you've made it.

Nearly every man who develops an idea works it up to the point where it looks impossible, and then he gets discouraged. That's not the place to become discouraged.