For those who like to categorise East Asia under the overall rubric of “Confucian culture”, a paradox arises: why are birth rates in Japan and South Korea — where people are free to have as many children as they please — lower than China’s? With total fertility rates of just 1.4 and 1.3 children per woman respectively, Japan and South Korea are heading towards a demographic cliff. The United Nations projects that if fertility does not change, the number of women of child-bearing age in South Korea will fall from 12.5 million today to only 3.4 million at the end of the century. In Japan, the count will decline from 26 million to only 8 million. The UN projections for China seem almost as dire, but they stem from assumptions that may be entirely wrong. There has been endless discussion of China’s coming population crisis, but we simply don’t know how bad China’s demographic crisis might be, or whether it is a crisis to begin with.

It is the greatest migration in world history, and it has wrought great cultural changes; a Chinese friend mentions that he has no common language with his grandfather, who speaks only a provincial dialect that the grandson never learned. Yet the ties that bind Chinese families together appear to have survived this displacement, perhaps far better than in the other East Asian nations. World fertility, to be sure, has declined steady for the past 200 years. In traditional rural life, children were wealth as well as security. With a life expectancy at birth of 25 years, the level that prevailed from Roman times until the early 19th century, the average woman had to give birth five times simply in order to maintain a stable population. Farmers did well to bear more children as family labour. Before the era of government pensions, children provided for their parents in old age. An Englishman at the turn of the 20th century, when life expectancy had just reached 50 years, would need five children to be sure that one would be alive when he turned 65.

In 1950, 70 per cent of the world’s population were farmers, and women on average bore five children. Urbanisation, antibiotics and social security removed the old reasons to have five children, and world fertility fell from six children per woman worldwide in 1950 to 2.5 children in 2015. The poorer countries of the southern hemisphere repeated the great fertility transition that characterised the industrial world over the past two centuries. That much is explained by simple economic incentives. What is harder to explain, and far more relevant, is why in some countries the transition leads to fertility around replacement levels while in other countries fertility plunges to levels that lead to national extinction within a century. Economics does not explain this; we have to look to the spiritual condition of peoples in this transition.

The great transition we associated with urbanisation, education and industrialisation did more than change incentives: they substituted a regime of personal choice for the old certainties of traditional society. As women shed the bonds of traditional society they eschewed motherhood. As Oswald Spengler wrote in The Decline of the West, “The primary woman, the peasant woman, is mother. The whole vocation towards which she has yearned from childhood is included in that one word. But now emerges the Ibsen woman, the comrade, the heroine of a whole megalopolitan literature from Northern drama to Parisian novel. Instead of children, she has soul-conflicts; marriage is a craft-art for the achievement of ‘mutual understanding’.”

Traditional life faces the same doom in many of today’s poor countries. Iranian women bore seven children on average in 1979, but today bear fewer than two. That is the fastest fertility decline in recorded history, and probably took place in Iran because it was the first Muslim country to achieve near-universal adult literacy thanks to the Shah. The once-Catholic countries of Europe from Hungary to Ireland have seen the fastest decline in fertility, and often seem most eager to jettison the old family-centred culture.