"We cannot predict the new forces, powers, and discoveries that will be disclosed to us when we reach the other planets and set up new laboratories in space. They are as much beyond our vision today as fire or electricity would be beyond the imagination of a fish."

"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."

"I am afraid that this chapter will amply demonstrate the truth of Clarke's 69th Law, viz., "Reading computer manuals without the hardware is as frustrating as reading sex manuals without the software." In both cases the cure is simple though usually very expensive."

"Clarke's Law of Revolutionary Ideas: Every revolutionary idea — in science, politics, art, or whatever — seems to evoke three stages of reaction. They may be summed up by the phrases:(1) "It's completely impossible — don't waste my time"; (2) "It's possible, but it's not worth doing"; (3) "I said it was a good idea all along.""

"Clarke's Third Law: Any sufficiently advanced technology is indistinguishable from magic."

"It is not easy to see how the more extreme forms of nationalism can long survive when men have seen the Earth in its true perspective as a single small globe against the stars."

"Clarke's Second Law: The only way of discovering the limits of the possible is to venture a little way past them into the impossible."

"Clarke's First Law: When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong."

"When you are next out of doors on a summer night, turn your head towards the zenith. Almost vertically above you will be shining the brightest star of the northern skies — Vega of the Lyre, twenty-six years away at the speed of light, near enough to the point of no return for us short-lived creatures. Past this blue-white beacon, fifty times as brilliant as our sun, we may send our minds and bodies, but never our hearts. For no man will ever turn homewards beyond Vega, to greet again those he knew and loved on Earth."

"Space can be mapped and crossed and occupied without definable limit; but it can never be conquered. When our race has reached its ultimate achievements, and the stars themselves are scattered no more widely than the seed of Adam, even then we shall still be like ants crawling on the face of the Earth. The ants have covered the world, but have they conquered it — for what do their countless colonies know of it, or of each other? So it will be with us as we spread out from Earth, loosening the bonds of kinship and understanding, hearing faint and belated rumors at second — or third — or thousandth hand of an ever dwindling fraction of the entire human race. Though the Earth will try to keep in touch with her children, in the end all the efforts of her archivists and historians will be defeated by time and distance, and the sheer bulk of material. For the numbers of distinct human societies or nations, when our race is twice its present age, may be far greater than the total number of all the men who have ever lived up to the present time. We have left the realm of comprehension in our vain effort to grasp the scale of the universe; so it must ever be, sooner rather than later."

"To obtain a mental picture of the distance to the nearest star, compared to the nearest planet, you must imagine a world in which the closest object to you is only five feet away — and there is nothing else to see until you have travelled a thousand miles."

"We have abolished space here on the little Earth; we can never abolish the space that yawns between the stars. Once again, as in the days when Homer sang, we are face-to-face with immensity and must accept its grandeur and terror, its inspiring possibilities and its dreadful restraints."

"When the pioneers and adventurers of our past left their homes in search of new lands, they said good-bye forever to the place of their birth and the companions of their youth. Only a lifetime ago, parents waved farewell to their emigrating children in the virtual certainty that they would never meet again. And now, within one incredible generation, all this has changed."

"Our age is in many ways unique, full of events and phenomena that never occurred before and can never happen again. They distort our thinking, making us believe that what is true now will be true forever, though perhaps on a larger scale. Because we have annihilated distance on this planet, we imagine that we can do it once again. The facts are otherwise, and we see them more clearly if we forget the present and turn our minds towards the past."

"The goal of the future is full unemployment, so we can play. That’s why we have to destroy the present politico-economic system."

"Behind every man now alive stand 30 ghosts, for that is the ratio by which the dead outnumber the living."

"As our own species is in the process of proving, one cannot have superior science and inferior morals. The combination is unstable and self-destroying."

"Human judges can show mercy. But against the laws of nature, there is no appeal."

"Yet now, as he roared across the night sky toward an unknown destiny, he found himself facing that bleak and ultimate question which so few men can answer to their satisfaction. What have I done with my life, he asked himself, that the world will be poorer if I leave it."

"They will have time enough, in those endless aeons, to attempt all things, and to gather all knowledge ... no Gods imagined by our minds have ever possessed the powers they will command ... But for all that, they may envy us, basking in the bright afterglow of Creation; for we knew the Universe when it was young."

"He had discharged his destiny; now, perhaps, he could begin to live."

"It is not my duty as an historian to predict the future, only to observe and interpret the past. But its lesson is clear enough; we have lived too long out of contact with reality, and now the time has come to rebuild our lives."

"All explorers are seeking something they have lost. It is seldom that they find it, and more seldom still that the attainment brings them greater happiness than the quest."

"After a while Hilvar did his best to steer the conversation away from these meaningless morasses of theology in order to concentrate on the ascertainable facts."

"The fact was that he suffered from an incurable malady which, it seemed, attacked only Homo sapiens among all the intelligent races of the universe. That disease was religious mania. Throughout the earlier part of its history, the human race had brought forth an endless succession of prophets, seers, messiahs, and evangelists who convinced themselves and their followers that to them alone were the secrets of the universe revealed. Some of them succeeded in establishing religions which survived for many generations and influenced billions of men; others were forgotten even before their deaths. The rise of science, which with monotonous regularity refuted the cosmologies of the prophets and produced miracles which they could never match, eventually destroyed all these faiths. It did not destroy the awe, not the reverence and humility, which all intelligent beings felt as they contemplated the stupendous universe in which they found themselves. What it did weaken, and finally obliterate, were the countless religions, each of which claimed with unbelievable arrogance, that it was the sole repository of the truth and that its millions of rivals and predecessors were all mistaken."

"There was only one thing of which he could be certain now. Boredom would not be a serious problem for a considerable time to come."

"Khedron was content with the order of things as it was. True, he might upset that order from time to time—but only by a little. He was a critic, not a revolutionary. On the placidly flowing river of time, he wished only to make a few ripples; he shrank from diverting its course."

"There still remained, for all men to share, the linked worlds of love and art. Linked, because love without art is merely the slaking of desire, and art cannot be enjoyed unless it is approached with love."

"If we have learned one thing from the history of invention and discovery, it is that, in the long run — and often in the short one — the most daring prophecies seem laughably conservative."

"Somewhere back at the beginning I was chosen to be Jester, and there is only one Jester at a time in Diaspar. Most people think that is one too many."

"If the artist did not know his goal, even the most miraculous of tools could not find it for him."

"Overhead, without any fuss, the stars were going out."

"Science can destroy religion by ignoring it as well as by disproving its tenets. No one ever demonstrated, so far as I am aware, the non-existence of Zeus or Thor — but they have few followers now."

"We stand now at the turning point between two eras. Behind us is a past to which we can never return ... The coming of the rocket brought to an end a million years of isolation ... the childhood of our race was over and history as we know it began."