In feudalism, the economic basis of the social formations determined that ideology had the dominant role. This argument, however, runs into difficulties since Marx also believed that it was the Enlightenment which was the principal bourgeois critique of feudalism, obscurantism and religion. This chapter concerns the way in which Poulantzas has attempted to understand the role of religion in feudalism and its demise in capitalism. To argue that religion is dominant in feudalism would be to claim that it was functionally significant for the integration or maintenance of the system of economic relationships. The majority of sociologists of religion hold to what we might call the 'theory of the great divide'. Therefore in order to emphasise what might be termed the 'ideological gap' which existed between social classes in feudalism, we will consider three candidates for a 'dominant ideology': namely, theodicy, theocratic kingship and the sacrament of penance.