 Complete the following phrase:  Cerularius found the issue politically useful in his conflict with the Latins. In popular opinion, the flour and water wafers of the Franks were not bread; their sacrifices were invalid; they were Jews not Christians. Their lifeless bread could only symbolize a soulless Christ; therefore, they had clearly fallen into the heresy of Apollinaris. The controversy became a key factor in producing the EastWest Schism, which persists to this day. This question of azyms brought forth a cloud of pamphlets, and made a deeper impression on the popular imagination than the abstruse controversy of the Filioque. But it caused little or no discussion among the theologians at the Councils of Lyons and 