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.

It has yet to be proven that intelligence has any survival value.

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 the universe is full of intelligent life. It's just been too intelligent to come here.

Though the man-apes often fought and wrestled one another, their disputes very seldom resulted in serious injuries. Having no claws or fighting canine teeth, and being well protected by hair, they could not inflict much harm on one another. In any event, they had little surplus energy for such unproductive behavior; snarling and threatening was a much more efficient way of asserting their points of view.

Now times had changed, and the inherited wisdom of the past had become folly.

One can imagine a time when men who still inhabit organic bodies are regarded with pity by those who have passed on to an infinitely richer mode of existence, capable of throwing their consciousness or sphere of attention instantaneously to any point on land, sea, or sky where there is a suitable sensing organ. In adolescence we leave childhood behind; one day there may be a second and more portentous adolescence, when we bid farewell to the flesh.