Women are extraordinary in lacking the estrus, or period of heat. The females of most other primate species become sexually active, to the point of aggression, only at the time of ovulation. Why has sexual responsiveness become nearly continuous? Unusually frequent sexual activity between males and females served as the principle device for cementing the pair bond.

Thirty trillion dollars worth of services, scot-free to humanity, every year.

The brain and its satellite glands have now been probed to the point where no particular site remains that can reasonably be supposed to harbour a nonphysical mind.

Evolution by natural selection is not an idle hypothesis. The genetic variation on which selection acts is well understood in principle all the way down to the molecular level.

By any reasonable measure of achievement, the faith of the Enlightenment thinkers in science was justified. Today the greatest divide within humanity is not between races, or religions, or even, as is widely believed, between the literate and illiterate. It is the chasm that separates scientific from prescientific cultures.

The biological evolutionary perception of life and of human qualities is radically different from that of traditional religion, whether it's Southern Baptist or Islam or any religion that believes in a supernatural supervalance over humanity.

It may be argued that to know one kind of beetle is to know them all. But a species is not like a molecule in a cloud of molecules-it is a unique population.