When time permits, I try to see interesting people in the cities I visit. In Seattle, I met Paul Allen, the co-founder of Microsoft, who is shy in personality but flamboyant in his philanthropy.

As every student in Philosophy 101 learns, nothing can force me to believe that anyone except me is conscious. This power to deny that other people have feelings is not just an academic exercise but an all-too-common vice, as we see in the long history of human cruelty.

In societies no less than individuals, acknowledging our limitations may ultimately be more humane than denying them.

Reading is a technology for perspective-taking. When someone else's thoughts are in your head, you are observing the world from that person's vantage point.

Nature is a hanging judge," goes an old saying. Many tragedies come from our physical and cognitive makeup. Our bodies are extraordinarily improbable arrangements of matter, with many ways for things to go wrong and only a few ways for things to go right. We are certain to die, and smart enough to know it. Our minds are adapted to a world that no longer exists, prone to misunderstandings correctable only by arduous education, and condemned to perplexity about the deepest questions we can ascertain.

We instinctively fear snakes, but we appear not to be afraid of fast cars, which are a real danger now. This suggests our emotions were shaped by our evolutionary environment not the one we grew up in.

As technology accumulates and people in more parts of the planet become interdependent, the hatred between them tends to decrease, for the simple reason that you can't kill someone and trade with him too.