When I sit down at the typewriter, I write. Someone once asked me if I had a fixed routine before I start, like setting up exercises, sharpening pencils, or having a drink of orange juice. I said, "No, the only thing I do before I start writing is to make sure that I'm close enough to the typewriter to reach the keys."

I don't think I've ever held a racket in my hand ... There's got to be somebody in the US who isn't trying to play tennis and stinking up the court.

I wanted to be a psychological engineer, but we lacked the facilities, so I did the next best thing - I went into politics. It's practically the same thing.

Science is uncertain. Theories are subject to revision; observations are open to a variety of interpretations, and scientists quarrel amongst themselves. This is disillusioning for those untrained in the scientific method, who thus turn to the rigid certainty of the Bible instead. There is something comfortable about a view that allows for no deviation and that spares you the painful necessity of having to think.

Democracy cannot survive overpopulation. Human dignity cannot survive it. Convenience and decency cannot survive it. As you put more and more people into the world, the value of life not only declines, but it disappears. It doesn't matter if someone dies.

Mathematicians deal with large numbers sometimes, but never in their income.

A robot must protect its own existence as long as such protection does not conflict with the First or Second Laws.