The true delight is in the finding out rather than in the knowing.

The energy requirements for interstellar travel are so great that it is inconceivable to me that any creatures piloting their ships across the vast depths of space would do so only in order to play games with us over a period of decades. If they want to make contact, they would make contact; if not, they would save their energy and go elsewhere.

I am all for cultural diversity and would be willing to see each recognizable group value its cultural heritage. I am a New York patriot, for instance, and if I lived in Los Angeles, I would love to get together with other New York expatriates and sing "Give My Regards to Broadway".

The dangers that face the world can, every one of them, be traced back to science. The salvations that may save the world will, every one of them, be traced back to science.

On Earth, we are unmanned by our longing for a pastoral past that never really existed; and that, if it had existed, could never exist again...on the Moon, there is no past to long for or dream about. There is no direction but forward.

Even as a youngster, though, I could not bring myself to believe that if knowledge presented danger, the solution was ignorance. To me, it always seemed that the solution had to be wisdom. You did not refuse to look at danger, rather you learned how to handle it safely.

The appearance of strength is all about you. It would seem to last forever. However... the rotten tree-trunk, until the very moment when the storm-blast breaks it in two, has all the appearance of might it ever had. The storm-blast whistles through the branches of the Empire even now. Listen... and you will hear the creaking.