This article analyzes the relationship, according to Aegidius Romanus, between spiritual power and temporal power. From the point of view of the Augustinian author, the autonomy of the world or that of second causes, following St. Thomas Aquinas, must be respected, so that the motions of nature are not usually hampered by any extraordinary intervention. However, this intervention will always be possible in the form of a miracle and according to a special law. Similarly, temporal power normally follows its own goals, without interventions ab extra, nevertheless, the Pope’s plenitude of power can suspend, if necessary (in casu), the power of the secular princes.