Religion is the most malevolent of all mind viruses.

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

I can never look now at the Milky Way without wondering from which of those banked clouds of stars the emissaries are coming. If you will pardon so commonplace a simile, we have set off the fire alarm and have nothing to do but to wait. I do not think we will have to wait for long.

I'm sure we would not have had men on the Moon if it had not been for Wells and Verne and the people who write about this and made people think about it. I'm rather proud of the fact that I know several astronauts who became astronauts through reading my books.

I sometimes wonder how we spent leisure time before satellite television and Internet came along…and then I realise that I have spent more than half of my life in the ‘dark ages’!

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.

In fact, one of the arguments for searching for intelligent life in space, elsewhere, is that we have no evidence that intelligence has any survival value. The most successful creatures on this planet are the cockroaches. They've been around, what is it, 100 million years or so and I suspect they'll still be there 100 million years in the future. Maybe intelligence is an evolutionary aberration which dooms its possessors in the way armor may have doomed some of the dinosaurs.