A fanatic's willingness to kill or be killed in the service of a cause cannot prove the rightness of that cause.

Let us settle down to the serious business of getting drunk.

It is a truism that the structure of a society is basically determined by its technology. Not in an absolute sense-there may be totally different cultures using identical tools-but the tools settle the possibilities; you can't have interstellar trade without spaceships. A race limited to a single planet, possessing a high knowledge of mechanics but with its basic machines of industry and war requiring a large capital investment, will inevitably tend toward collectivism under one name or another. Free enterprise needs elbow room.

I wrote the first book, Harvest of Stars, and as I was writing it, I saw that certain implications had barely been touched on... It's perfectly obvious that two completely revolutionary things are going on, with cybernetics, and biological science.

Happier are all men than the dwellers in Faerie – or the gods, for that matter…Better a life like a falling star, bright across the dark, than a deathlessness that can see naught above or beyond itself…the day draws nigh when Faerie shall fade, the Erlking himself shrink to a woodland sprite and then to nothing, and the gods go under. And the worst of it is, I cannot believe it wrong that the immortals will not live forever.

He had seen too much of the cosmos to have any great faith in man's ability to understand it.

Two lives met across death and centuries. To ask what it meant is meaningless. There is no destiny. But sometimes there is bravery