William of Ockham, though considered a theologian and philosopher, was motivated by circumstances to produce the rudiments of a political theology of taxation. In his political work most fully devoted to taxation, Ockham argued that a temporal ruler’s intent in levying a tax overrides human laws that would shelter church properties from taxation. Whether a Prince justifies royal taxation on the grounds that the kings who granted property to their subjects (including the church) must have done so with the expectation that the property would be used to support the monarchy in times of need. Ockham’s philosophical nominalism led him to favor governments that honor their individual citizens’ natural liberty. This emphasis dovetails with Ockham’s ethical voluntarism, i.e., his teaching that only voluntary acts have moral value. The result is Ockham’s belief that the temporal realm as well as the spiritual realm must make room for natural liberty. These elements tend to displace legal and political considerations from the center of human life in Ockham’s thought. Ockham also believed that the temporal and spiritual realms operate differently. The natural-yet-contingent quality of human government places royal taxation beyond the pope’s power of interference while, at the same time, subjecting it to the dictates of “right reason” and pure intent. The starkest illustration of Ockham’s dualism is his distinction between principate of lordship and principate of service. For Ockham, the paying of taxes is ultimately a way of renouncing principate of lordship in favor of principate of service.