Anything that is theoretically possible will be achieved in practice, no matter what the technical difficulties are, if it is desired greatly enough.

Science is the only religion of mankind.

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.'

Only small minds are impressed by large numbers.

There's no real objection to escapism, in the right places... We all want to escape occasionally. But science fiction is often very far from escapism, in fact you might say that science fiction is escape into reality... It's a fiction which does concern itself with real issues: the origin of man; our future. In fact I can't think of any form of literature which is more concerned with real issues, reality.

In this single galaxy of ours there are eighty-seven thousand million suns. [...] In challenging it, you would be like ants attempting to label and classify all the grains of sand in all the deserts of the world. [...] It is a bitter thought, but you must face it. The planets you may one day possess. But the stars are not for man.

The greatest tragedy in mankind's entire history may be the hijacking of morality by religion. However valuable-even necessary-that may have been in enforcing good behavior on primitive peoples, their association is now counterproductive. Yet at the very moment when they should be decoupled, sanctimonious nitwits are calling for a return to morals based on superstition.