The Development of Just-War Jurisprudence in the High Middle Ages, 1100–1274: Self-Defense, Authority, and Jurisdiction

Abstract

This dissertation argues that the development of just-war thought in the High Middle Ages was driven primarily by two jurisprudential commitments. On the one hand, jurists of the era by and large acknowledged self-defense to be an inalienable natural right; its exercise could be fettered by additional conditions only in limited ways. On the other, they conceived of war as requiring proper authority, with canonists in particular focusing on just wars requiring the authority of a "prince" (princeps). I argue that the problem of just war was doctrinal and was resolved doctrinally, with the credit belonging to three key figures in the history of canon law. Huguccio's commentary provides the first just-war juristic framework that explicitly and satisfactorily reconciles the requirement of proper authority with the natural right of self-defense. The origin of a more fully-fledged focus on legal status in war and violence was in the work of Innocent IV, who introduced the idea of war (bellum) as distinct from both defense (defensio) and the use of force against subordinates within one's jurisdiction---not a formal bellum but rather an executio iurisdictionis. But especially worthy of attention is Henricus de Segusio, who fleshed out this framework considerably and finally presented a version of it that was able to stand on its own and could have been used in the adjudication of conflicts and disputes. For just-war thought, the High Middle Ages were a time of innovation and discontinuity, with the canonists' jurisprudence standing firmly at the forefront.