Human nature is complex. Even if we do have inclinations toward violence, we also have inclination to empathy, to cooperation, to self-control.

The linguistic clumsiness of tourists and students might be the price we pay for the linguistic genius we displayed as babies, just as the decrepitude of age in the price we pay for the vigor of youth.

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

Knowledge is a continuous fabric, in which ideas are connected to other ideas. Reason-free zones, in which people can assert arbitrary beliefs safe from ordinary standards of evaluation, can only corrupt this fabric, just as a contradiction can corrupt a system of logic, allowing falsehoods to proliferate through it.

Probably Hobbes got it right when he said that a leviathan, a third party with a monopoly on the use of legitimate use of force in a territory, might be among the biggest violence reduction techniques ever invented.

The idea that boys want to sleep with their mothers strikes most men as the silliest thing they have ever heard. Obviously, it did not seem so to Freud, who wrote that as a boy he once had an erotic reaction to watching his mother dressing. But Freud had a wet-nurse, and may not have experienced the early intimacy that would have tipped off his perceptual system that Mrs. Freud was his mother. The Westermarck theory has out-Freuded Freud.

If we are not to abandon values such as peace and equality, or our commitments to science and truth, then we must pry these values away from claims about our psychological makeup that are vulnerable to being proven false.