Now imagine a world in which everyone, but especially people with power and influence, holds an expanded view of our place in the cosmos. With that perspective, our problems would shrink-or never arise at all-and we could celebrate our earthly differences while shunning the behavior of our predecessors who slaughtered each other because of them.

I can't think that leaving Earth once is enough.

They [scientists of centuries past] call on God only from the lonely and precarious edge of incomprehension. Where they feel certain about their explanations, however, God gets hardly a mention.

Life existed on Earth for nearly four billion years before anything remotely resembling a human being showed up. And even then, when we started to branch off from other apes about 10,000,000 years ago, our ancestors looked pretty different.

Lots of people think, well, we're humans; we're the most intelligent and accomplished species; we're in charge. Bacteria may have a different outlook: more bacteria live and work in one linear centimeter of your lower colon than all the humans who have ever lived. That's what's going on in your digestive tract right now. Are we in charge, or are we simply hosts for bacteria? It all depends on your outlook.

Since life on Earth is, so far, the only known example of life in the universe, our dilemma may simply be that we have no other examples to compare us with. If we did, then the life/non-life transition might look downright simple to us.

Dinosaurs are extinct today because they lacked opposable thumbs and the brainpower to build a space program.