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

A well-stocked mind is safe from boredom.

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.

The creation of wealth is certainly not to be despised, but in the long run the only human activities really worthwhile are the search for knowledge, and the creation of beauty. This is beyond argument, the only point of debate is which comes first.

I want to be remembered most as a writer - one who entertained readers, and, hopefully, stretched their imagination as well.

The only way to define your limits is by going beyond them.

Space is what stops everything from happening in the same place.