The theology of the Eucharist was central to the understanding of the functions and attributes of the priesthood in the sixteenth century. The role of the priesthood, and indeed the theological justification for its existence as a caste apart, exercised the minds of controversialists on both sides of the emerging religious divide. In evangelical works of controversy, clerical marriage was justified more by the value and virtue of marriage itself than by developments in eucharistic doctrine. However, the established link between clerical celibacy and the theology of the Mass, and the polemical capital afforded by the association, was not wasted by evangelical writers. The role of the Mass in promoting immoral behaviour had been a feature of English Reformation polemic since the 1520s, and was highlighted in the debate on clerical marriage in the middle decades of the century. Evangelical polemic on the relationship between clerical conduct and the Eucharist reveals the extent to which vows of celibacy.