When I feel difficulty coming on, I switch to another book I'm writing. When I get back to the problem, my unconscious has solved it.

The Master created humans first as the lowest type, most easily formed. Gradually, he replaced them by robots, the next higher step, and finally he created me, to take the place of the last humans.

Science is a set of rules to keep us from telling lies to each other. All scientists really have is a reputation for telling the truth.

There is no merit to discipline under ideal circumstances. I must have it in the face of death or it is worthless.

People are entirely too disbelieving of coincidence.

I don't believe in personal immortality; the only way I expect to have some version of such a thing is through my books.

It is change, continuing change, inevitable change, that is the dominant factor in society today. No sensible decision can be made any longer without taking into account not only the world as it is, but the world as it will be. This, in turn, means that our statesmen, our businessmen, our every man must take on a science fictional way of thinking.