It would be wryly interesting if in human history the cultivation of marijuana led generally to the invention of agriculture, and thereby to civilization.

But nature is always more subtle, more intricate, more elegant than what we are able to imagine.

After the earth dies, some 5 billion years from now, after it's burned to a crisp, or even swallowed by the Sun, there will be other worlds and stars and galaxies coming into being - and they will know nothing of a place once called Earth.

The words "question" and "quest" are cognates. Only through inquiry can we discover truth.

If I finish a book a week, I will read only a few thousand books in my lifetime, about a tenth of a percent of the contents of the greatest libraries of our time. The trick is to know which books to read.

I think the health of our civilization, the depth of our awareness about the underpinnings of our culture, and our concern for the future, can all be tested by how well we support our libraries.

What began in deadly competition has helped us to see that global cooperation is the essential precondition for our survival. Travel is broadening. It's time to hit the road again.