The author's wide ranging exploration of the question of why what most deem the "great divergence," and what he deems the "second great divergence" happened - why is it that the industrial revolution took place in northwestern Europe rather than elsewhere?

The author sets forth his thesis that it was primarily the polycentric nature of Western Europe that can explain it best historically.

The author begins with the Roman Empire. He points out how odd the Roman Empire was in the grand scheme of things - not just in the number of people over which it ruled, and for how long it ruled, but also the area over which it ruled. He does well at showing how well Rome was able to rule and the kind of quality of life enjoyed under the Empire, which in many respects would not be seen again until the modern era.

He explains how Rome was able to build itself up as a power and why that power was able to spread as it did: the militaristic culture, the high percentage of soldiers available, the size of armies, and the constant economic pressure to conquer more and more people until the development of the Empire itself. He then explored counterfactuals: under what situations would Rome not become what it was? The strongest counterfactuals stem from Roman origins and then the prospect of invasion from Alexander the Great. The rest stretched credulity; thus the strength of Rome in its moment is explained well.

Then the author tackles the question why no other empire was able to coalesce in Western Europe. He goes through a series of counterfactuals regarding every major power from Justinian to Napoleon and wondering what it would have taken for them to develop an empire like Rome. He is very persuasive at showing how no such power could have really built an empire once the fracture took place and Justinian's designs were frustrated by plague and collapse.

He then explains what he calls the first great divergence: the path Western Europe took toward polycentrism after the collapse of the Roman Empire whereas empires remained prevalent in eastern Europe and Asia. He shows powerfully the effect of geography and persuasively argues for a steppe effect: any agricultural-based power near the Eurasian/African steppe would likely develop into an empire since they have horses and a strong enemy at the ready. Southeast Asia and Western Europe are the only regions fully cut off from the steppe, and those are the places you find polycentrism. The author also looks at cultural reasons - religion, philosophy, etc. He shows how Catholicism maintains a common identity in Western Europe while in many respects fostering the fractured political entities of the day; nevertheless, he shows well that the cultures that developed in China vs. Western Europe were very much creatures of their particular context and are as much explained by the other factors as being an explaining factor in and of itself.

The author then explores the medieval and early modern era, primarily comparing and contrasting Western Europe and China. He shows why the way the Westerners fought each other led to developments in technology, and how the multiple states and their competition allowed for freer thought, discovering other lands, the sheltering of others' dissenters, the effect of the Reformation, etc., and ultimately the development of the mercantilist economies of the Netherlands and Britain that fostered the second great divergence. He persuasively explains why empires like the Ottomans and the Chinese proved less interested in investments technological development or journeys of discovery, focusing instead on their own survival and aggrandizement. He also shows how that was true of the late Roman Empire.

In the Epilogue he asks what Rome did for us, and his answer seems to be primarily that it went away and never returned. He's willing to consider Christianity and Latin as unifying premises fostering a kind of common identity despite polycentrism, but isn't convinced that the second great divergence would not follow the first had Rome ended while fully pagan.

This is a great historical analysis: the author is able to explain why certain developments and changes took place in northwestern Europe without relying at all on any kind of supremacist trope. This is a great work of post-white supremacy historical analysis: it is not a triumphalist tale, but a reminder that one group of people developed in a way they did because of their particular context, and if they had lived somewhere else, and another group lived where they lived, their circumstances would likely have followed their placement. There's still some room for historical accident - Alexander's death in particular stands out - but you walk away from this book with a much better handle as to why world history has played out like it has.

Long and involved but worthwhile. ( )