The very existence of medieval political philosophy is sometimes questioned. The activities and problems that we think of as forming a distinctively political dimension of human life cannot, it is suggested, be isolated in the medieval period from other dimensions of human activity: centrally, that of religion. The regnum, the sphere of worldly administration, was only one half – and the lesser half at that – of the entire governance of humankind; the other being the sacerdotium, the priesthood, which is to direct us in our capacity to transcend this earthly existence. While worldly government was in the hands of the multifarious kingdoms, principalities, city-states, and feudal domains of medieval Europe, spiritual government was in the hands of the church and its head, the pope. In other words, what we call politics was then only a subordinate branch of religion: theology was the master-science of human life on earth, just as the church was its master-government – in theory at least.

I disagree with this way of thinking about the medieval attitude to the political. As I shall seek to show, medieval thinkers were quite capable of (and, moreover, deeply interested in) addressing the activities and problems of human beings relating to each other within a common public space as a distinctive sphere of human life. This was in part because they were heirs to an Antique discourse of the political which did just that. Medieval theologians certainly did not consider the rationale of politics in this sense separately from questions of the overall rationale of human life, which involved them immediately in questions of religion and the church.