How inappropriate to call this planet Earth when it is quite clearly Ocean.

Sometimes I think we're alone in the universe, and sometimes I think we're not. In either case the idea is quite staggering.

Whether we are based on carbon or on silicon makes no fundamental difference we should each be treated with appropriate respect.

... chemistry is a trade for people without enough imagination to be physicists.

Science fiction seldom attempts to predict the future. More often than not, it tries to prevent the future.

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.

Sometimes when I'm in a bookstore or library, I am overwhelmed by all the things that I do not know. Then I am seized by a powerful desire to read all the books, one by one.