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.

What a dull universe it would be if everything in it conformed to our expectations, if it held nothing to surprise or baffle us or confound our common sense. A century ago no one foresaw the existence of black holes, an expanding universe, oceans on Jupiter's moons, or DNA. What could be more enriching than to know that we share a common origin with all living things, that we are kin to chimpanzees, redwoods and mollusks? And isn't it a source of wonder to realize that the iron in our blood and the calcium in our bones were created in the bellies of supernovas?

One of my favourite kinds of movie is the American picaresque, in which the characters make their way across the country, learning about life against the gorgeous backdrops of that vast land.

All over the world, belief in the supernatural has authorised the sacrifice of people to propitiate bloodthirsty gods, and the murder of witches for their malevolent powers.

Cognitive psychology has shown that the mind best understands facts when they are woven into a conceptual fabric, such as a narrative, mental map, or intuitive theory. Disconnected facts in the mind are like unlinked pages on the Web: They might as well not exist.

One of the perks of being a psychologist is access to tools that allow you to carry out the injunction to know thyself.

There's guilt about our treatment of native peoples in modern intellectual life, and an unwillingness to acknowledge there could be anything good about Western culture.