Good morning, Dr. Chandra. This is Hal. I am ready for my first lesson.

Religion is the most malevolent of all mind viruses.

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.

I believe any malevolent supercivilisation would have rapidly self-destructed as we may be in the process of doing ourselves. If we do have contact, physical contact with aliens, I think it will be benign.

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.

Politicians should read science fiction, not westerns and detective stories.

As his body became more and more defenseless, so his means of offense became steadily more frightful.