In Why the West Rules – For Now Ian Morris argues that to understand the development of East and West, we need to look beyond 'long-term lock-in' theories (that suggest it was inevitable) and 'short-term accident' theories. Instead, we need to measure social development – a group's ability to master its environment to get things done – and use the results to look at the patterns of history.

Why the West Rules – For Now briefly describes the methods used to calculate Eastern and Western social development scores since the ice age; in The Measure of Civilisation, Morris expands upon these methods, discussing possible objections to this approach, and providing fascinating accounts of his gathering of evidence for his calculations. It is a magnificent account of where our understanding of the development of East and West comes from, and an unusual insight into a master thinker at work.