The relationship between religion and politics is a bone of political contention and a source of deep confusion across the Islam–West divide. When most western liberals cast their gaze on Muslim societies today, what they see is deeply disconcerting. From their perspective there is simply too much religion in public life in the Arab-Islamic world, which raises serious questions for them about the prospects for democracy in this part of the world. This article critically explores the relationship between religion and political legitimacy with a geographical and cultural focus on the Muslim Middle East. The broad historical question that shapes this inquiry is: Why is religion a source of political legitimacy in Muslim societies today while in the West, broadly speaking, religion is a source of disagreement and illegitimacy?