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.

But the newest research is showing that many properties of the brain are genetically organized, and don't depend on information coming in from the senses.

So no, it's not all in the genes, but what isn't in the genes isn't in the family environment either. It can't be explained in terms of the overall personalities or the child-rearing practices of parents.

Consistent style prevents presentation from getting in the way of content.

Technology, ideology, and social and cultural changes periodically throw out new forms of violence for humanity to contend with.

No one knows what the nongenetic causes of individuality are. Perhaps people are shaped by modifications of genes that take place after conception, or by haphazard fluctuations in the chemical soup in the womb or the wiring up of the brain or the expression of the genes themselves.

The costs of an ignorance of science are nor just practical ones like misbegotten policies, forgone cures, and a unilateral disarmament in national competitiveness. There is a moral cost as well. It is an astonishing fact about our species that we understand so much about the history of the universe. the forces that make it tick, the stuff it's made of; the origin of living things, and the machinery of life. A failure to nurture this knowledge shows a philistine indifference to the magnificent achievements humanity is capable of; like allowing a great work of art to molder in a warehouse.