The limits of the possible can only be defined by going beyond them into the impossible.

Isn't killing people in the name of God a pretty good definition of insanity?

Only feeble minds are paralyzed by facts.

The best proof that there's intelligent life in the universe is that it hasn't come here.

'The Devil in the Dark' impressed me because it presented the idea, unusual in science fiction then and now, that something weird, and even dangerous, need not be malevolent. That is a lesson that many of today's politicians have yet to learn.

Overhead, without any fuss, the stars were going out.

To find anything comparable with our forthcoming ventures into space, we must go back far beyond Columbus, far beyond Odysseus-far, indeed, beyond the first ape-man. We must contemplate the moment, now irrevocably lost in the mists of time, when the ancestor off all of us came crawling out of the sea.