Any civilization that doesn't develop space travel dies.

Centuries hence, when current social and political problems may seem as remote as the problems of the Thirty Years' War are to us, our age may be remembered chiefly for one fact: It was the time when the inhabitants of the earth first made contact with the vast cosmos in which their small planet is embedded.

Who is more humble? The scientist who looks at the universe with an open mind and accepts whatever the universe has to teach us, or somebody who says everything in this book must be considered the literal truth and never mind the fallibility of all the human beings involved?

Curiosity and the urge to solve problems are the emotional hallmarks of our species.

I think the discomfort that some people feel in going to the monkey cages at the zoo is a warning sign.

We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces.

If intelligence is our only edge, we must learn to use it better, to shape it, to understand its limitations and deficiencies -- to use it as cats use stealth, as katydids use camouflage -- to make it the tool of our survival.