Thomas Aquinas on the Will as Rational Appetite

Thomas Aquinas on the Will as Rational Appetite DAVID GALLAGHER THOMAS AQUINAS DESCRIBES THE WILL AS rational appetite. This simple notion appears so often in his works that not even his most casual reader could fail to recognize it. Yet if one should ask just how the will is rational, or precisely what sort of rationality is involved in its acts, even serious students of Aquinas's philosophy might be perplexed. Indeed, when we look for responses to these questions and search out the various texts where Thomas addresses them, we encounter a surprisingly wide variety of answers. In some texts the rationality involved is that of relating means and ends. In others it is the capacity for reflection on one's practical judgments. In yet others, this rationality lies in an ability to desire universal objects or simply particular objects as instances of some wider universal. No single one of these descriptions seems fully to capture the will's rationality. In order, then, to understand fully Thomas's concept of the will, one must gather together his various descriptions of the will and its rationality, and from them piece together a more general account than we find in any single one. When Thomas introduces the will and wishes to characterize it, he almost invariably follows the same procedure. His first step is to distinguish appetite or inclination in general as an internal source of desire and motion from external movers which produce violent motion. According to his view of nature , for example, a stone thrown upward is moved violently--contrary to its own inclination--while the same stone falling back toward the earth is now moved by its own internal inclination.' The second step is to introduce a division of three levels of appetite which are encountered in experience. Of these the first is natural inclination or natural appetite which is found in beings ' For Thomas's understanding of nature and natural motion, seeJ. Weisheipl, "The Concept of Nature," in Nature and Motion in the Middle Ages, ed. W. Carroll (Washington, D.C.: The Catholic University of America Press, 1985), 1-23. For an interesting discussion of falling bodies, see "The Spector of Motor Coniunctus in Medieval Physics," 1o i- 108 in the same volume. [5591 560 JOURNAL OF THE HISTORY OF PHILOSOPHY 29:4 OCTOBER 1991 without any cognition. Such would be the stone's natural inclination to fall toward the earth, and also included in this category would be the natural inclination of a plant to sink its roots or to flower in springtime. This first level is distinguished from the two higher ones because it neither depends upon nor follows from any sort of cognition. In the two higher levels, on the contrary , desire for and motion toward an object arise only when that object has been perceived in some way by the being which desires and moves. In the third step, among those beings whose appetite follows upon cognition, Thomas distinguishes those in which an appetite follows sense cognition from those in which appetite follows rational or intellectual cognition. This results in the distinction between sense or animal appetite and rational appetite or will. Thus at the conclusion of this process, the will is characterized as the sort of appetite that follows upon rational cognition. This may seem a simple enough procedure on Thomas's part; yet he seldom contents himself with anything so straightforward. Rather, each of the several steps is developed, usually rather extensively, and almost every time he goes through the procedure the development is cast in a somewhat different form. Sometimes the three levels are distinguished in terms of the materiality or immateriality of the appetite involved;9at other times in terms of the forms by which an appetite is the principle of motion;3 at yet other times in terms of the control which an agent exercises over its own appetite.4 Depending upon the basis of distinction employed, we arrive at different characterizations of the will. Consequently I wish, in this study, to take up the various discussions in which Thomas carries out his division of the different levels of appetite as a means of arriving at a fuller...