The dinosaurs disappeared because they could not adapt to their changing environment. We shall disappear if we cannot adapt to an environment that now contains spaceships, computers - and thermonuclear weapons.

Belief in God is apparently a psychological artifact of mammalian reproduction.

I think in the long run the money that s been put into the space program is one of the best investments this country has ever made . . .This is a downpayment on the future of mankind. It's as simple as that.

I want to be remembered most as a writer - one who entertained readers, and, hopefully, stretched their imagination as well.

I have great faith in optimism as a guiding principle, if only because it offers us the opportunity of creating a self-fulfilling prophecy.

The creation of wealth is certainly not to be despised, but in the long run the only human activities really worthwhile are the search for knowledge, and the creation of beauty. This is beyond argument, the only point of debate is which comes first.

A precondition for being a science fiction writer other than an interest in the future is that, an interest - at least an understanding of science, not necessarily a science degree but you must have a feeling for the science and its possibilities and its impossibilities, otherwise you're writing fantasy. Now, fantasy is also fine, but there is a distinction, although no one's ever been able to say just where the dividing lines come.