Robert Dowd, in his thought-provoking and discerning work, Christianity, Islam, and Liberal Democracy, explores how religious diversity influences the ways that Christian and Muslim communities have “applied religion to politics” over time in sub-Saharan Africa. Religious diversity has, Dowd argues, often increased the willingness of religious leaders and communities to embrace “live and let live” political theologies conducive to liberal democracy, but the processes that lead from religious diversification to greater religious freedom are necessarily conflictual. For its timely focus on understudied questions, clear exposition, and its valuable original data collection and analysis, this work will advance important discussion in scholarly and policy settings alike.

Dowd's theory focuses on religious leaders and their construction of context-specific political theologies, i.e., a community's religiously inspired ideas about what constitutes legitimate authority and the proper relationship between believers and government. Following Max Weber and other major scholars of religion and politics, Dowd assumes that religious leaders construct meaning selectively from their inherently multi-vocal religious traditions. His goal is to explain how religious diversity influences religious leaders' decisions to promote politically engaged, “live and let live” theologies.

Put simply, Dowd argues that things must get worse before they get better. When and where long-dominant religions face new competition (i.e., increasing religious diversity), Dowd anticipates that their political theology will encourage political activism to protect the group's hegemony. When a new religious organization gains converts and approaches parity with the formerly dominant group's population share, polarization increases and conflict is likely. Over time, however, religious leaders will realize that the costs of conflict outweigh the benefits. Ultimately, Dowd argues, such leaders urge their followers to use political activism “to ensure that no religious group gains special state-granted privileges over the others” (48). In contrast to research that emphasizes the role of the state in fomenting identity-based conflict (through elite manipulation or federal systems, for example), the state is absent from Dowd's argument.

It is important to highlight the analytic, normative, and policy-level implications of this argument. Analytically, Dowd distinguishes between two types of religious peace: One is a “superficial” religious peace defined by the absence of religious conflict in religiously homogenous societies. The other is a deeper peace that evolves in (some) religiously diverse contexts, where religious leaders actively promulgate a liberal political theology. While the ideal-typical superficial peace is compatible with autocracy and religious monopoly, deeper religious peace has an affinity for religious freedom and liberal democracy. And, while policymakers enlist segregation or partition to promote shallow peace, Dowd argues that more meaningful religious peace requires more, not less, inter-religious contact, including periods wherein religious leaders embrace combative political theologies.

Of course, focusing on diversity as a causal variable raises the question of potential endogeneity. Theoretically, a homogenous religious society with a tolerant political theology could precede and “cause” religious diversification by inducing in-migration of persecuted minorities, for example. To defend his case, Dowd mobilizes historical evidence from the Americas and Europe, and also uses the relatively unique historical experiences of many sub-Saharan African cases to illustrate the variation he is interested in. Many African states have been religiously diverse for a long time due to indigenous cultural diversity and historic colonial encounters with Islam and Christianity. Yet, religious leaders have only actively promoted political activism to protect religious freedom in particular places at particular times. Dowd seeks to explain how religious diversity might influence religious leaders to endorse this position in a given socio-historical context. Given the dearth of rigorous comparative research on religion and politics in sub-Saharan Africa, Dowd's focus on African cases is welcome.

The volume's empirical analyses rely heavily on cross-sectional quantitative analyses. Comparative historical process tracing and time series analyses would be better suited to test Dowd's theory, which emphasizes temporal processes. The volume nevertheless makes notable empirical contributions in Chapters 5 and 6, which present original survey data collected in Nigeria, Senegal, and Uganda in 2006–2007. Dowd uses this data to examine intriguing corollaries of his theory. For instance, Dowd finds that, at a cross-national level, greater religious observance is more likely to positively impact religious tolerance in the religiously diverse state of Nigeria than in either predominately Muslim Senegal or predominately Christian Uganda. At the sub-national level, however, results are much more mixed. Dowd presents these results honestly and clearly, using qualitative evidence to provide context. He also offers up several promising hypotheses about integration and the role of cross-cutting or reinforcing ethnic ties, which are ripe for future analysis. Finally, in the book's exemplary concluding chapter, Dowd clarifies precisely what conclusions are — and are not — justified and offers up even more ideas for future investigation.

Ultimately, Dowd succeeds in casting doubt on the notion that religious diversity is incompatible with religious freedom and liberal democracy — an idea prevalent in popular discourse (e.g., Freedom House's 2001 Annual Report). The main thrust of this volume is therefore consistent with research by Robert Fish, Robin Brooks, and others, who also insist on more nuanced analysis and thinking. Additionally, the book reinforces arguments made by Paul Pierson, Al Stepan, and Ashutosh Varshney, among others, who insist that we take seriously temporal processes, context, and the potential benefits of diversity.

The most original contribution in Christianity, Islam, and Liberal Democracy is Dowd's process-based argument that in societies where a long-dominant religious group faces a growing competitor, conflict is both likely and can eventually breed tolerant religious peace. Although the volume's empirical analyses neither fully confirm nor disconfirm the theory, they will effectively convince readers that there are policy-relevant, scholarly gains to come from studying the dynamic relation between religion and politics across African cases over time. Indeed, Dowd's analysis of original data from cases across sub-Saharan Africa — a religiously diverse but understudied region — significantly advances the broader literature on religious diversity, conflict, and tolerance.