We have to abandon the idea that schooling is something restricted to youth. How can it be, in a world where half the things a man knows at 20 are no longer true at 40 - and half the things he knows at 40 hadn't been discovered when he was 20?

In accordance with the terms of the Clarke-Asimov treaty, the second-best science writer dedicates this book to the second-best science-fiction writer. [dedication to Isaac Asimov from Arthur C. Clarke in his book Report on Planet Three]

Death focuses the mind on the things that really matter: why are we here, and what should we do?

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

Sometimes I think we're alone in the universe, and sometimes I think we're not. In either case the idea is quite staggering.

My objection to organized religion is the premature conclusion to ultimate truth that it represents.

It may be that the old astrologers had the truth exactly reversed, when they believed that the stars controlled the destinies of men. The time may come when men control the destinies of stars.