In fact, one of the arguments for searching for intelligent life in space, elsewhere, is that we have no evidence that intelligence has any survival value. The most successful creatures on this planet are the cockroaches. They've been around, what is it, 100 million years or so and I suspect they'll still be there 100 million years in the future. Maybe intelligence is an evolutionary aberration which dooms its possessors in the way armor may have doomed some of the dinosaurs.

Death focuses the mind on the things that really matter: why are we here, and what should we do?

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.

One can imagine a time when men who still inhabit organic bodies are regarded with pity by those who have passed on to an infinitely richer mode of existence, capable of throwing their consciousness or sphere of attention instantaneously to any point on land, sea, or sky where there is a suitable sensing organ. In adolescence we leave childhood behind; one day there may be a second and more portentous adolescence, when we bid farewell to the flesh.

Any technology distinguishable from magic is insufficiently advanced.

Until we get rid of religion, we won't be able to conduct the search for God.

I'm sure we would not have had men on the Moon if it had not been for Wells and Verne and the people who write about this and made people think about it. I'm rather proud of the fact that I know several astronauts who became astronauts through reading my books.