The Faculties of the Soul and Some Medieval Mind-Body Problems

1 Republic 436a (trans. G.M.A. Grube, rev. C.D.C. Reeve, in Plato: Complete Works, ed. John M. Collins [Indianapolis: Hackett, 1997], 1067). 2 I will use the term “faculty” (of the soul) interchangeably with the terms “capacity” and “ability,” and as synonymous with what the medievals usually called potentiae animae, although, as we’ll see below, the medieval term harbored some crucial ambiguities. 3 See Descartes, Meditations on First Philosophy 6 (Charles Adam and Paul Tannery, eds., Oeuvres de Descartes [Paris: J. Vrin, 1904], 7:86 ): “As for the faculties of willing, of understanding, of sensory perception and so on, these cannot be termed parts of the mind, since it is one and the same mind that wills, understands and has sensory perceptions.” See also Replies to the Fifth Set of Objections (Adam and Tannery, eds., Oeuvres 7:356): “I consider the mind not as part of the soul but as the thinking soul in its entirety” (trans. John Cottingham, Robert Stoothoff, and Dugald Murdoch, The Philosophical Writings of Descartes [Cambridge: Cambridge University Press, 1984], 2:59 and 246). 585 The Thomist 75 (2011): 585-636 THE FACULTIES OF THE SOUL AND SOME MEDIEVAL MIND-BODY PROBLEMS ADAM WOOD Fordham University Bronx, New York I N THE Republic Socrates asks “do we learn with one part of the soul, get angry with another, and with some third part desire the pleasures of food, drink, sex, and the others that are closely akin to them? Or when we set out after something, do we act with the whole of our soul, in each case?” This, he says, is “hard to determine up to the standards of our argument.”1 The medieval Scholastics seem to have agreed, in that they made the relationship between the soul and its faculties a central topic of philosophical conversation.2 It was still a sufficiently important issue by the time Descartes wrote the Meditations that he thought it necessary there to clarify his own view that the faculties of thinking, willing, and sensing are identical to the mind, which is in turn identical to the soul itself.3 ADAM WOOD 586 4 I borrow the latter term from Robert Pasnau, “The Mind-Soul Problem,” in Mind, Cognition, and Representation: The Tradition of Commentaries on Aristotle’s “De anima,” ed. Paul J. J. M. Bakker and Johannes M. M. H. Thijssen (Aldershot, U.K.: Ashgate, 2007), 3-20. This article tracks the discussion concerning the soul and its faculties from roughly the arrival of the libri naturales in the early thirteenth century until Descartes’s time. To cover this immodest swath of historical terrain, I make no pretense to comprehensiveness . I highlight only those figures, arguments, and episodes I judge to have contributed most to driving the debate forward from its Aristotelian and Augustinian origins to the Buridanian consensus which, I argue, became more or less predominant from the mid-fourteenth century onward. My claim will be that after abandoning the relatively stable position of Thomas Aquinas that the soul’s powers are proprietates distinct from its essence, Scholastics of the later Middle Ages were left unable to explain successfully how souls—and particularly human souls, with their faculties of thinking and willing—are related to bodies. This inability contributed to the rejection of Aristotelian psychology in the seventeenth century in favor of new philosophies of mind such as Cartesian dualism. Section I of the article examines the Aristotelian and Augustinian background to the medieval conversation. Section II looks at the development of various thirteenth-century views on the soul and its faculties, culminating in a presentation of Aquinas’s position. Section III turns to Henry of Ghent’s critique of the Thomist position, and some of the late-thirteenth and earlyfourteenth -century theories it inspired. The fourth and fifth sections focus on a pair of problems with one of these theories, John Buridan’s, which bought attractive theoretical parsimony at a steep price. Today we might call these “mind-body problems,” since they deal with the relationship between the soul and the body, although “soul-body problem” might be a better name for the first, and “mind-soul problem”4 a better name...