In the public religious controversies of sixteenth-century France, no subject received more attention or provoked greater passion that the eucharist. In this study of Reformation theologies of the eucharist, Christopher Elwood contends that the doctrine for which French Protestants argued played a pivotal role in the development of Calvinist revolutionary politics. By focusing on the new understandings of signs and symbols purveyed in Protestant writing on the sacrament of the Lords Supper, Elwood shows how adherents to the Reformation movement came to interpret the nature of power and the relation between society and the sacred in ways that departed radically from the views of their Catholic neighbors. The clash of religious, social, and political ideals focused in interpretations of the sacrament led eventually to political violence that tore France apart in the latter half of the sixteenth century.