Thomas Aquinas on Christ’s Esse: A Metaphysics of the Incarnation

The Thomist 70 (2006): 577-603 THOMAS AQUINAS ON CHRIST'S ESSE: A METAPHYSICS OF THE INCARNATION VICTOR SALAS, JR. Saint Louis University Saint Louis, Missouri THE FOURTH ARTICLE of Thomas Aquinas's Quaestio disputata De Unione Verbi incarnati has for centuries perplexed and frustrated the interpretive efforts of his most earnest and faithfol commentators. The difficulty stems, in part, from Aquinas's introduction of a second, human esse (in addition to the divine esse) into the metaphysical constitution of Christ. He thus departs from and even seems to contradict his standard account of Christ's esse, for, time and again, he insists that Christ has only one esse, the divine and eternal esse of the Word.1 This difficulty is compounded by the fact that De Unione itself offers little to no explanation as to what metaphysical status Aquinas is willing to grant Christ's human esse. He does state that the human esse is not accidental, but neither is it, he adds, the primary or substantial esse whereby Christ subsists.2 This leads to the obvious questions: what is the human esse, what role does it serve, and how is this account compatible with whatAquinas says elsewhere? 1 See Summa Theologiae III, q. 17, a. 2; III Sent., d. 6, q. 2, a. 2; Quaestiones de quolibet 9, q. 2, a. 2; Compendium Theologiae, c. 212. 2 Quaestio disputata De Unione Verbi incamati, a. 4: "Which being, although it is not accidental-since 'man' is not predicated accidentally of the Son of God, as is shown above-is not, however, the principle being of its supposit, but secondary" ("Quod esse, etsi non sit esse accidenrale--quia homo non praedicatur accidentaliter de Filio Dei, ut supra [art. 1] habitum est--non tamen est esse principale sui suppositi, sed secundarium" [Quaestiones Disputatae, ed. P. Bazzi et al. (Turin: Marietti, 1949), 2:432]). 577 578 VICTOR SALAS, JR. In what follows I shall offer a way of reading De Unione that agrees both with Aquinas's other Christological texts and with his standard metaphysical account of Christ's esse. But, mindful that one cannot expect more certainty than his subject allowsespecially when it involves offering a textual interpretation of an exceedingly vague text-in the present case I can only propose a plausible interpretation, one developed, moreover, in conjunction with texts other than De Unione itself. Indeed, given the vague character of this text, it seems to me that no interpretation of it can boast of apodictic certainty; and so, if my account casts even the dimmest light upon what seems to be a contradiction, it is worthy of consideration. I submit that, contrary to appearance, there is no contradiction involved in Aquinas's treatment of the Incarnation in De Unione with respect to esse. Ultimately, I shall argue that the key to resolving the above-mentioned difficulty rests in Aquinas's notion of Christ as a composite person. This very notion has allowed him, as Michael Gorman has shown,3 to escape a number of criticisms launched at his Christology, especially by contemporary thinkers. My contention is that Aquinas's understanding of Christ as a composite person can also shed some light-in a manner consistent both with his metaphysical commitments and with his other Christological writings-on the human esse introduced in De Unione.4 I The easiest way to overcome the present difficulty would simply be to dismiss the problematic text or to disavow it as 3 Michael Gorman, "Christ as Composite according to Aquinas," Traditio 55 (2000): 14357 . 4 For a discussion on De Unione Verbi incamati-its authenticity, dating, and the scholarship concerning it-see Marie-Helene Deloffre, Thomas d'Aquin: Question Disputee L'Union Du Verbe Incame (De Unione Verbi incamati) (Paris: J. Vrin, 2000). See also A. Patfoort, L'unite d'etre dan le Christ d'apres S. Thomas: A la croisee de l'ontologie et de la Christologie (Paris: Desclee, 1964). THOMAS AQUINAS ON CHRIST'S ESSE 579 spurious. This is what some, such as Louis Billot,5 do, whereas others, Cajetan for instance, being more conservative in their assessment of the text's authenticity, argue that De Unione is an early text...