The medieval European, who shared the fundamental assumptions of his Muslim contemporary, would have agreed with him in ascribing religious movements to religious causes, and would have sought no further for an explanation. But when Europeans ceased to accord first place to religion in their thoughts, sentiments, interests, and loyalties, they also ceased to admit that other men, in other times and places, could have done so. To a rationalistic and materialistic generation, it was inconceivable that such great debates and mighty conflicts could have involved no more than 'merely' religious issues. And so historians, once they had passed the stage of amused contempt, devised a series of explanations, setting forth for what they described as the 'real' or 'ultimate' significance 'underlying' religious movements and differences. The clashes and squabbles of the early churches, the great Schism, the Reformation, all were reinterpreted in terms of motives and interests reasonable by the standards of the day--and for religious movements of Islam too explanations were found that tallied with the outlook and interests of the finders.