Pope Benedict XVI recently cited a Byzantine-era critique of Islam, and the usual hubbub of outrage ensued. Various self-appointed and official Islamic spokesmen (they're always men), including the head of Turkey's religious affairs directorate (why does Turkey have one?), responded sharply in the name of their faith. One might argue that a confident, evolved religion welcomes all kinds of open debate. Or one might in tone gravely that the West continues to mishandle its relations with the umma -- the sphere of active Muslim believers -- with the implied assumption that there is such a unified entity of tens of...