In most medieval tracts on political questions it is difficult to isolate theories on kingship from theories of two-power relations, since an extension of royal authority usually resulted in contacts with ecclesiastical liberties. If an author took the king's side, his assumptions concerning the secular power were likely to be obscured by his two-power critique. If his treatise were sharply polemical, he often selected only those faces of monarchy which justified certain of the king's actions, either existing or potential. In particular, political thinkers at the time of Philip the Fair applied their monarchical formulas to the tensions arising out of overlapping temporal-spiritual jurisdictions. This conflict of interests, in turn, served to condition the royal ideology of these theorists.