What role has monotheism played in social, political, and economic developments over the last two millennia? Why have wars over religion been an all too common occurrence in Western history? What role have religious wars played in shaping the economic and political histories of Western Europe and the Middle East? Murat Iyigun addresses these questions in his fascinating book War, Peace & Prosperity in the Name of God. Iyigun's basic argument consists of multiple insights. First, he draws from a wide array of works from economics and sociology to argue that monotheism is good for social stability because of its “one true God” dogma. This permits an ecclesiastical monopoly that can legitimize and constrain rule while restraining political competition. Iyigun proceeds to argue that monotheistic societies therefore last longer and expand more rapidly. Convincing data are presented which show that, indeed, monotheistic polities have lasted longer and were larger on average than non-monotheistic polities since the founding of Judaism.
Next, Iyigun argues that the durability and size of monotheistic polities means that they must eventually come into contact with each other. This presents a problem for them: the importance of the “one true God” dogma in monotheistic faith—the very element that makes monotheistic polities so successful in the first place—means that they are more likely to come into conflict once in contact. The upshot is that monotheistic polities are strong, but conflict over religion is frequent—trumping other types of disagreements among co-religionists. In my opinion, this is the book's main takeaway. It provides an answer for why religious wars have been so common in Western history, and this insight permits Iyigun to make some specific—and far from obvious—assertions about how religious warfare has affected Western European and Middle Eastern political and economic history.
Iyigun focuses primarily on Ottoman history, which provides an ideal testing grounds for his theory. The Ottomans had frequent contact and conflict with Christian Europe, and their gaza (holy war) ideology—associated with a belief in the “one true God” dogma at the center of Iyigun's theory—was largely responsible for their incursions into Europe. He pulls from his excellent paper “Luther and Suleyman” (Quarterly Journal of Economics 123, no. 4 (2009): 1465–94), which argues that these intra-faith conflicts posed an existential threat to the Europeans. The important twist that Iyigun highlights is that the Reformation in part owes its success to the fact that European resources were geared towards preventing further Ottoman incursions. Unlike previous heresies, secular rulers did not have the resources to suppress the Protestant movement because their resources were employed to fend off the existential threat imposed by the Turks. Although Iyigun is not the first to note the positive impact the Ottomans had on the spread of the Reformation, he is the first to support this assertion with convincing data.
The rest of the book is full of interesting insights. Iyigun extends his clever use of Ottoman-European conflict data—and exploits the fact that many, but not all, Ottoman queen mothers were of European origin—to argue that European queen mothers were associated with fewer Ottoman intrusions into Europe but unrelated to Ottoman conflict in the East. He also merges these data with contemporary data on religious diversity and polity scores to argue that regions with more Muslim-Christian conflict in the past have less religious diversity today but higher quality polities.
I believe that one of the best critiques one can give an academic work is that the argument is clear and obvious ex post but not ex ante. This means that the reader had not really considered the argument before reading it, but cannot imagine a world where the argument is not correct after hearing it. Murat Iyigun accomplishes this feat in this book. All of the fascinating insights he documents come together to make one cohesive argument connecting monotheism, religious warfare, and social, economic, and political outcomes. It is an extremely readable book, and it provides a great example of how to summarize large quantities of data in an immediately understandable and compelling manner. Needless to say, I believe that it will interest anyone concerned with Ottoman or European history, conflict, religion, or political economy.
If there is one drawback of the book, it is that it does not go far enough. This is very much a “big think” book, but it does not truly address the primary “big think” questions that economic historians of this region and period care most about: “Why did Europe modernize first?” and “Why did the Ottoman Empire fail to modernize?” Iyigun has convinced me of the important and subtle connections between monotheistic faith, conflict, and political and economic outcomes, but it is not clear from this book the precise role that these connections played in propelling Europe and holding back the Middle East. Is it simply through the Ottoman impact on the Reformation? Is the connection between historical conflict and modern polity quality at the root of the relative economic stagnation of the Middle East? Of course, one cannot answer every question in the space of a book. And in any case, Iyigun has brought some new and important insights into the economic and political history of the Middle East and Western Europe—insights that “big think” scholars can ignore only at their own peril.
