If you aren't just brought up in your tribe but interact with other people either directly or vicariously, through journalism and literature, you see what life is like from other points of view and are less likely to demonize them or dehumanize others and more likely to empathize with them.

The rules of friendship are tacit, unconscious; they are not rational. In business, though, you have to think rationally.

A decent government with an effective, but not gratuitously violent, police force and a fair court system are essential. This deters and incapacitates psychopaths, bullies and hotheads - and if it earns the confidence of the people, they don't have to become violent in self-defence.

Language pedants hew to an oral tradition of shibboleths that have no basis in logic or style, that have been defied by great writers for centuries, and that have been disavowed by every thoughtful usage manual.

I teach classes 28 weeks of the year, but the rest of the time I do research and write books.

With violence, as with so many other concerns, human nature is the problem, but human nature is also the solution.

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.