In this universe the night was falling; the shadows were lengthening towards an east that would not know another dawn. But elsewhere the stars were still young and the light of morning lingered; and along the path he once had followed, Man would one day go again.

It may be that our role on this planet is not to worship God - but to create him.

Any technology distinguishable from magic is insufficiently advanced.

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.

The space elevator will be built about 50 years after everyone stops laughing.

You don't believe in organized religion, yet a major theme in so many of your works seems to be a quest for God.

I have great faith in optimism as a guiding principle, if only because it offers us the opportunity of creating a self-fulfilling prophecy.