Today we take it for granted that war happens in smaller, poorer and more backward countries.

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.

After their return from Babylon, the practice of human sacrifice died out among the Jews, but survived as an ideal in one of its break-away sects, which believed that God accepted the torture-sacrifice of an innocent man in exchange for not visiting a worse fate on the rest of humanity. The sect is called Christianity.

Language is a window into human nature, but it is also a fistula, an open wound through which we're exposed to an infectious world.

It is true that raids and battles killed a tiny percentage of the numbers that die in modern warfare. But in tribal violence, the clashes are more frequent, the percentage of men in the population who fight is greater, and the rates of death per battle are higher.

Being smarter gives you a tailwind throughout life. People who are more intelligent earn more, live longer, get divorced less, are less likely to get addicted to alcohol and tobacco, and their children live longer.

My politics were pretty anarchistic until 1969 when the Montreal police went on strike. Within hours, mayhem and rioting broke out and the Mounties had to be called in to restore order. It instilled in me that one's convictions can be subjected to empirical test.