The reason I find fundamentalism so troubling — whether it is Christian, Jewish or Muslim — is not just its willingness to use violence (in the Islamist manifestation). It is its inability to integrate doubt into faith, its resistance to human reason, its tendency to pride and exclusion, and its inability to accept mystery as the core reality of any religious life. You find it troubling, I think, purely because it upholds truths that cannot be proved empirically or even, in some respects, logically. In that sense, of course, I think you have no reason to dislike or oppose it any more than you would oppose my kind of faith. Your argument allows for no solid distinctions within faiths; my argument depends on such distinctions.