Not a single one of the cells that compose you knows who you are, or cares.

Cults and prophets proclaiming the imminent end of the world have been with us for several millennia, and it has been another sour sort of fun to ridicule them the morning after, when they discover that their calculations were a little off. But, just as with Marxists, there are some among them who are working hard to "hasten the inevitable," not merely anticipating the End Days with joy in their hearts, but taking political action to bring about the conditions they think are the prerequisites for that occasion.

Has it ever occurred to you how lucky you are to be alive? More than 99 percent of all the creatures that have ever lived have died without progeny, but not a single one of your ancestors falls into that group! ... Not a single one of your ancestors, all the way back to the bacteria, succumbed to predation before reproducing, or lost out in the competition for a mate.

Problems in science are sometimes made easier by adding complications.

What you can imagine depends on what you know. Philosophers who know only philosophy consign themselves to a janitorial role in the great enterprises of exploration that are illuminating the mysteries of our lives.

I look around the world and see so many wonderful things that I love and enjoy and benefit from, whether it's art or music or clothing or food and all the rest. And I'd like to add a little to that goodness.

The chief trick to making good mistakes is not to hide them-especially not from yourself.