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

It was the mark of a barbarian to destroy something one could not understand.

When the Sun shrinks to a dull red dwarf, it will not be dying. It will just be starting to live and everything that has gone before will merely be a prelude to its real history.

I suspect that religion is a necessary evil in the childhood of our particular species. And that's one of the interesting things about contact with other intelligences: we could see what role, if any, religion plays in their development. I think that religion may be some random by-product of mammalian reproduction. If that's true, would non-mammalian aliens have a religion?

One of the biggest roles of science fiction is to prepare people to accept the future without pain and to encourage a flexibility of the mind. Politicians should read science fiction, not westerns and detective stories.

Isaac Asimov is, in reality, based on something I had invented a few years previously.

That's one of those meaningless and unanswerable questions the mind keeps returning to endlessly, like the tongue exploring a broken tooth.