You have to pay so much to see theater, even in Chicago. In the Greek theater, you didn't have to pay anything. You actually had to go, and you just sat there all day.

The Greek tragedies and comedies are like a roadmap to all the ways in which trying to live this rich, full life can go wrong. You could get into a war. You could find that you have members of your family on the wrong side of a political crisis. You could be raped. You could find that your child has gone crazy because of some horrible experience she's had.

With the rise of capitalism, it became more obvious that people pursue individual self-interest. The great nationalist in Italy, Giuseppe Mazzini, a wonderful philosopher, said that we need the nation. We need something that people can lean on, from which they can then reach out to the whole world. The idea of all humanity is too vague. It can't motivate human aspiration in a reliable way.

The thing that I find so bad about anger is the desire for payback. Of course, it is very human to wish for revenge. Your mother has died in the hospital, and the first thought a lot of people have is, I'll sue the doctor. You feel helpless, and you think, I'm less helpless if I'm doing something active that makes someone else pay. And social media make it easy to inflict all kinds of pain on other people. But what good does it do?

After all, the nation is not just an entity. It's a story. It's a story of what's salient, what brought us together, what we are willing to live and die for.

When a profession is protected by academic freedom and tenure, it tends to turn inward. To a large extent that's good.

The GDP approach doesn't address many aspects of human life: health, education, political liberty, religious liberty, employment opportunities. And these are not all that well correlated with gross domestic product. We also have to think about equality among groups. And freedom of speech and religion. China always ranks near the top of developing countries these days, but there are lots of things we might see as lacking in China.