If an elderly but distinguished scientist says that something is possible, he is almost certainly right; but if he says that it is impossible, he is very probably wrong.

It is a good principle in science not to believe any 'fact'---however well attested---until it fits into some accepted frame of reference. Occasionally, of course, an observation can shatter the frame and force the construction of a new one, but that is extremely rare. Galileos and Einsteins seldom appear more than once per century, which is just as well for the equanimity of mankind.

One of the biggest roles of science fiction is to prepare people to accept the future without pain and to encourage a flexibility of the mind. Politicians should read science fiction, not westerns and detective stories.

The truth, as always, will be far stranger.

What was more, they had taken the first step toward genuine friendship. They had exchanged vulnerabilities.

In all the universe there is nothing more precious than mind.

Even if we never reach the stars by our own efforts, in the millions of years that lie ahead it is almost certain that the stars will come to us. Isolationism is neither a practical policy on the national or cosmic scale. And when the first contact with the outer universe is made, one would like to think that Mankind played an active and not merely a passive role-that we were the discoverers, not the discovered.