Legitimate Authority: Aquinas’s First Requirement of a Just War

1 For summary presentations on each of these thinkers and their place in the development of just war theory, see the relevant chapters in Gregory M. Reichberg, Henrik Syse, and Endre Begby, eds., The Ethics of War: Classic and Contemporary Readings (Oxford: Blackwell Publishing, 2006). 337 The Thomist 76 (2012): 337-69 LEGITIMATE AUTHORITY: AQUINAS’S FIRST REQUIREMENT OF A JUST WAR GREGORY M. REICHBERG Peace Research Institute Oslo (PRIO) Oslo, Norway I N THE OPENING respondeo of his “Question on War” (Summa Theologiae II-II, q. 40, a. 1) Thomas Aquinas famously writes that a war will be just only when it is conducted under the authority of a prince, for a just cause, and with an upright intention. In what follows I examine the first of these three conditions. The centrality of legitimate authority within Aquinas’s doctrine of just war has often been affirmed but its exact contours have rarely been studied. This is due in large measure to the terseness of his account. He leaves key steps in his reasoning unstated, and says little about the underlying textual sources. To fill in these gaps, the present article proposes a close reading of legitimate war-making authority as it appears in Aquinas’s “Quaestio de bello.” Supplementary reference is made to his short treatise on kingship (De regno ad regem Cypri) and to some related passages within his wider corpus of writings. The historical antecedents are likewise considered, Augustine certainly, but also and especially Aquinas’s immediate predecessors in just war theory: Pope Innocent IV, the penitential lawyer Raymond of Peñafort, and his glossator William of Rennes.1 Their more elaborate expositions GREGORY M. REICHBERG 338 2 “Primo quidem auctoritas principis, cuius mandado bellum est gerendum.” 3 Apropos the condition of right intention: “For it may happen that a war is declared by the legitimate authority, and for a just cause, and yet be rendered illicit through a vile intention.” The term legitima is borrowed from Augustine, Contra Faustum, 22.20 (cited in STh II-II, q. 40, a. 1, ad 1): “no one can take to the sword without the command or acquiescence of a superior or legitimate power” (superiori aut legitima potestate). on legitimate war-making authority open a valuable window on the status quaestionis as it stood in Aquinas’s day. Aquinas proposes two arguments why special authority is needed for war-making, one based on the juridical principle “no higher redress” (just war becomes operative only in the absence of established judicial procedures) and the other based on the idea that defense of the common good requires a chain of command with the prince at its head. Both are brief to the extreme, rendering their interpretation difficult and leaving much room for his successors to advance competing views. Organizing my treatment around these two prongs of Aquinas’s account, I begin (section I) with an examination of his first argument, treating it in light of its historical antecedents. Then (section II) I consider how he deals with two seeming exceptions to the rule that princes alone may use force, namely, self-defense and tyrannicide. Why effective war-making requires a commander-in-chief—Aquinas’s second argument for legitimate authority—is subsequently taken up in section III. As this argument is chiefly about the prince’s responsibility to protect the polity from harm, it entails a conception of virtuous leadership, which I discuss in section IV. Before embarking on this investigation, a few preliminary comments are in order. First, Aquinas employs several different terms to describe the auctoritas which is needed for a just war. In the first article of the “Quaestio de bello” this authority is initially characterized as pertaining to the “prince” (princeps).2 Several lines later it is termed “legitimate” (legitima),3 which suggests how more is at stake than de facto possession of power. To be legitimate, princely power must be acquired and exercised in accordance with the rule of law. Finally, in a parallel passage within the same sequence of quaestiones, competence to decide on war is attributed to the LEGITIMATE AUTHORITY AND JUST WAR 339 4 “In order for a war to be just, it must...