Attempting to define science fiction is an undertaking almost as difficult, though not so popular, as trying to define pornography... In both pornography and SF, the problem lies in knowing exactly where to draw the line.

Science fiction does not attempt to predict. It extrapolates. It just says, "What if?" not what will be? Because you can never predict what will happen, particularly in politics and economics. You can to some extent predict in the technological sphere - flying, space travel, but even there we missed badly on some things, like computers. No one imagined the incredible impact of computers, even though robot brains of various kinds but the idea that one day every house would have a computer in every room and that one day we'd have computers built into our clothing, nobody ever thought of that.

If man survives for as long as the least successful of the dinosaurs-those creatures whom we often deride as nature's failures-then we may be certain of this: for all but a vanishingly brief instant near the dawn of history, the word 'ship' will mean- 'spaceship.'

If I didn't exist, I would have invented myself.

The more wonderful the means of communication, the more trivial, tawdry, or depressing its contents seemed to be.

Almost any seat was comfortable at one-sixth of a gravity.

The time was fast approaching when Earth, like all mothers, must say farewell to her children.