It is tough to think of a harder subject to tackle than demography. Vast, career-sized mantraps litter the way. Not only are there the perpetual disagreements over the science of the variables, there are also the considerable risks of telling a truth different from those in fashion.

In 1967 Peter Berger declared that American religiosity stood on the brink of decline. By the 1980s, with a visible upsurge in religious observance in the US (and the increasingly confident transfer of this observance into political activism), he was forced to recant. In 1968 Paul R Ehrlich