A precondition for being a science fiction writer other than an interest in the future is that, an interest - at least an understanding of science, not necessarily a science degree but you must have a feeling for the science and its possibilities and its impossibilities, otherwise you're writing fantasy. Now, fantasy is also fine, but there is a distinction, although no one's ever been able to say just where the dividing lines come.

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.

The crossing of space ... may do much to turn men's minds outwards and away from their present tribal squabbles. In this sense, the rocket, far from being one of the destroyers of civilisation, may provide the safety-value that is needed to preserve it.

We seldom stop to think that we are still creatures of the sea, able to leave it only because, from birth to death, we wear the water-filled space suits of our skins.

Some dangers are so spectacular and so much beyond normal experience that the mind refuses to accept them as real, and watches the approach of doom without any sense of apprehension. The man who looks at the onrushing tidal wave, the descending avalanche, or the spinning funnel of the tornado, yet makes no attempt to flee, is not necessarily paralyzed with fright or resigned to an unavoidable fate. He may simply be unable to believe that the message of his eyes concerns him personally. It is all happening to somebody else.

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

A man who grows that much hair,' critics were fond of saying, 'must have a lot to hide.