The Ramans do everything in threes. — Arthur C. Clarke

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

"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."

"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."

"Others, one suspects, are afraid that the crossing of space, and above all contact with intelligent but nonhuman races, may destroy the foundations of their religious faith. They may be right, but in any event their attitude is one which does not bear logical examination — for a faith which cannot survive collision with the truth is not worth many regrets."

"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."

"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."