Science fiction does not attempt to predict. It extrapolates. It just says, "What if?" not what will be? Because you can never predict what will happen, particularly in politics and economics. You can to some extent predict in the technological sphere - flying, space travel, but even there we missed badly on some things, like computers. No one imagined the incredible impact of computers, even though robot brains of various kinds but the idea that one day every house would have a computer in every room and that one day we'd have computers built into our clothing, nobody ever thought of that.

I also believe - and hope - that politics and economics will cease to be as important in the future as they have been in the past; the time will come when most of our present controversies on these matters will seem as trivial, or as meaningless, as the theological debates in which the keenest minds of the Middle Ages dissipated their energies. Politics and economics are concerned with power and wealth, neither of which should be the primary, still less the exclusive, concern of full-grown men.

There were some things that only time could cure. Evil men could be destroyed, but nothing could be done with good men who were deluded.

I'm sometimes asked how I would like to be remembered. I've had a diverse career as a writer, underwater explorer, space promoter and science populariser. Of all these, I want to be remembered most as a writer - one who entertained readers, and, hopefully, stretched their imagination as well.

Behind every man now alive stand thirty ghosts, for that is the ratio by which the dead outnumber the living.

There is hopeful symbolism in the fact that flags do not wave in a vacuum.

Guns are the crutches of the impotent.