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.

Religion is the most malevolent of all mind viruses.

I suspect that religion is a necessary evil in the childhood of our particular species. And that's one of the interesting things about contact with other intelligences: we could see what role, if any, religion plays in their development. I think that religion may be some random by-product of mammalian reproduction. If that's true, would non-mammalian aliens have a religion?

Now, before you make a movie, you have to have a script, and before you have a script, you have to have a story; though some avant-garde directors have tried to dispense with the latter item, you'll find their work only at art theaters.

I also believe - and hope - that politics and economics will cease to be as important in the future as they have been in the past; the time will come when most of our present controversies on these matters will seem as trivial, or as meaningless, as the theological debates in which the keenest minds of the Middle Ages dissipated their energies. Politics and economics are concerned with power and wealth, neither of which should be the primary, still less the exclusive, concern of full-grown men.

The person one loves never really exists, but is a projection focused through the lens of the mind onto whatever screen it fits with least distortion.

I'm quite fond of the writer who told a beginning author, "If you've got a message, use Western Union."