If an epileptic seizure is focused in a particular sweet spot in the temporal lobe, a person won´t have motor seizures, but instead something more subtle. The effect is something like a cognitive seizure, marked by changes of personality, hyperreligiosity (an obsession with religion and feelings of religious certainity), hypergraphia (extensive writing on a subject, usually about religion), the false sense of an external presence, and, often, the hearing voices that are attributed to a god. Some fraction of history´s prophets, martyrs, and leaders appear to have had temporal lobe epilepsy.

If choices and decisions derive from hidden mental processes, then free choice is either an illusion or, at minimum, more tightly constrained than previously considered.

One of the most pervasive mistakes is to believe that our visual system gives a faithful representation of what is "out there" in the same way that a movie camera would.

Brains are like representative democracies. They are built of multiple, overlapping experts who weigh in and compete over different choices.

Some men may be genetically inclined to have and hold a single partner, while some may not. In the near future, young women who stay current with the scientific literature may demand genetic tests of their boyfriends to assess how likely they are to make faithful husbands.

After all, across the population there are slight differences in brain function, and sometimes these translate directly into different ways of experiencing the world. And each individual believes his way is reality.

This is the hallmark of a robust biological system: political parties can perish in a tragic accident and the society will still run, sometimes with little more than a hiccup to the system. It may be that for every strange clinical case in which brain damage leads to a bizarre change in behavior or perception, there are hundreds of cases in which parts of the brain are damaged with no detectable clinical sign.