The central empirical question to be answered, or the central fact—for a while I was calling it the great fact, but now I have decided to just call it the great enrichment—is that since 1776, let’s choose that as an important date in the history of the world, income per head in countries that have adopted liberal economic policies, of one sort or another, has increased by a factor of 30. Why?

The answer is liberalism and not state action. That it is the liberal idea, which does not have deep European roots. It is confined, really, to the long 18th century. That is when liberalism, the theory that there should be no masters, first emerged among intellectuals like Adam Smith, among French intellectuals like Anne Robert Jacques Turgot and Denis Diderot, and then became, briefly, the dominant thought in Britain, especially in the early 19th century.