The supposedly immaterial soul, we now know, can be bisected with a knife, altered by chemicals, started or stopped by electricity, and extinguished by a sharp blow or by insufficient oxygen.

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.

Of course, genes can't pull the levers of our behavior directly. But they affect the wiring and workings of the brain, and the brain is the seat of our drives, temperaments and patterns of thought.

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 reason I'm not a neurobiologist but a cognitive psychologist is that I think looking at brain tissue is often the wrong level of analysis. You have to look at a higher level of organization.

Consciousness surely does not depend on language. Babies, many animals, and patients robbed of speech by brain damage are not insensate robots; they have reactions like ours that indicate that someone's home.