The crossing of space ... may do much to turn men's minds outwards and away from their present tribal squabbles. In this sense, the rocket, far from being one of the destroyers of civilisation, may provide the safety-value that is needed to preserve it.

The fact that we have not yet found the slightest evidence for life - much less intelligence - beyond this Earth does not surprise or disappoint me in the least. Our technology must still be laughably primitive, we may be like jungle savages listening for the throbbing of tom-toms while the ether around them carries more words per second than they could utter in a lifetime.

... chemistry is a trade for people without enough imagination to be physicists.

We stand now at the turning point between two eras. Behind us is a past to which we can never return...

Any sufficiently advanced technology is indistinguishable from magic.

If man can live in Manhattan, he can live anywhere.

The difference between machines and human beings is that human beings can be reproduced by unskilled labour.