Crunchy Con Rod Dreher is re-reading Samuel Huntington's The Clash of Civilizations, and Dreher worries that perhaps the neo-cons are wrong, and Islam and the West really are incompatible after all. Part of what this is about is how people with fundamentally incompatible beliefs can live together -- or whether they can live together.
Recently, (kinda sorta) Catholic Andrew Sullivan and atheist Sam Harris have been having a series of exchanges about the grounds of religious belief. Now, my own view is that Harris has been mopping the floor with Andrew Sullivan, but at the same time, I could well be influenced by the fact that I agreed with Harris before the discussion even began. It seems pretty clear that Harris and Sullivan have views that are fundamentally irreconcilable. At the same time, however, Sullivan and Harris probably have a working agreement on the fundamental architecture of a secular liberal democratic state. They're willing to live in the same country governed by same basic rules and institutions. About religion, they may well disagree vociferously, but they are willing to agree to disagree.
And that is, at some level, the foundation of Western Civilization. People reach a point where their fundamental presuppositions are so different that persuasion and reason simply are not possible. When that happens, they can do one of two things: agree to disagree, or duke it out, using force and violence. The whole edifice of separation of church and state is an agreement to let people disagree about certain fundamental questions.
For many people, religion is about spiritual matters, or questions of how to live one's life. But others see religion as providing "the answer to everything" -- that is, they think that every legal and political institution must flow directly from a certain religious understanding. The Christian Reconstructionists have such views -- they think that literally everything flows from their Christian doctrine. Such views are, of course, fundamentally inconsistent with a secular liberal state.
Now here's the kicker, though. Christian Reconstructionists are scary sorts, but the country that gave us Britney Spears, Jessica Simpson and Yasmine Bleeth is not going to lapse into a Handmaid's Tale-style Christian theocracy. Really, it ain't. The Christian Reconstructionsists represent a tiny minority, even among right-wing bible-thumping Evangelical Christians.
The unfortunate fact, however, is that the Muslim equivalents of Christian Resconstructionists are pretty common. A politician in the United States who advocated "Biblical Law" would at a minimum be subjected to scorn and ridicule and would probably lose most elections, depending on how nutty he seemed. But there are whole countries governed by Sharia Law, and the view that it ought to be implemented is not considered "nutty" in the Muslim world. The view that every major social and legal institution should flow from religion is quite common among Muslims. Don't get me wrong -- there are undoubtedly Muslims out there who are happy to accept the agree-to-disagree paradigm of Western Civilization. But it's not a done deal.
And if large numbers of Muslims cannot accept the "agree to disagree" position, well, the 21st Century will be interesting indeed.