The important point is not just that atheism is unable to compete with religion in attracting followers, but also that the lifestyle of practical atheism seems to produce listless tribes that cannot even reproduce themselves. Sociologists Pippa Norris and Ron Inglehart note that many richer, more secular countries are “producing only about half as many children as would be needed to replace the adult population” while many poorer, more religious countries are “producing two or three times as many children as would be needed to replace the adult population.” The consequence, so predictable that one might almost call it a law, is that “the religious population is growing fast, while the secular number is shrinking.”

Russia is one of the most atheist countries in the world, and abortions there outnumber live births by a ratio of two to one. Russia’s birth rate has fallen so low that the nation is now losing 700,000 people a year. Japan, perhaps the most secular country in Asia, is also on a kind of population diet: its 130 million people are expected to drop to around 100 million in the next few decades. Canada, Australia, and New Zealand find themselves in a similar predicament.

Then there is Europe. The most secular continent on the globe is decadent in the quite literal sense that its population is rapidly shrinking. Birth rates are abysmally low in France, Italy, Spain, the Czech Republic, and Sweden. The nations of Western Europe today show some of the lowest birth rates ever recorded, and Eastern European birth rates are comparably low. Historians have noted that Europe is suffering the most sustained reduction in its population since the Black Death in the fourteenth century, when one in three Europeans succumbed to the plague. Lacking the strong religious identity that once characterized Christendom, atheist Europe seems to be a civilization on its way out. Nietzsche predicted that European decadence would produce a miserable “last man” devoid of any purpose beyond making life comfortable and making provision for regular fornication. Well, Nietzsche’s “last man” is finally here, and his name is Sven.

Eric Kaufmann has noted that in America, where high levels of immigration have helped to compensate for falling native birth rates, birth rates among religious people are almost twice as high as those among secular people. This trend has also been noticed in Europe.11 What this means is that, by a kind of natural selection, the West is likely to evolve in a more religious direction. This tendency will likely accelerate if Western societies continue to import immigrants from more religious societies, whether they are Christian or Muslim. Thus we can expect even the most secular regions of the world, through thesheer logic of demography, to become less secular over time.

In previous decades, scholars have tried to give a purely economic explanation for demographic trends. The general idea was that population was a function of affluence. Sociologists noted that as people and countries became richer, they had fewer children. Presumably, primitive societies needed children to help in the fields, and more prosperous societies no longer did. Poor people were also believed to have more children because sex provided one of their only means of recreation. Moreover, poor people are often ignorant about birth control or don’t have access to it. From this perspective, large families were explained as a phenomenon of poverty and ignorance.