Thomas Aquinas's Derivation of the Aristotelian Categories (Predicaments)

Thomas Aquinas's Derivation of the Aristotelian Categories (Predicaments) JOHN F. WIPPEL According to Thomas Aquinas, metaphysics is the science which studies being as being or which has as its subject being in general (ens commune)? For Thomas one of the most fundamental distinctions within the realm of finite being obtains between that which exists in itself or in its own right, and that which exists only in something else, that is to say, between substance and accident. 1. Following Aristotle upon this point, Thomas regards substance as the prime referent of being, even though both thinkers acknowledge that being is used in different senses. Aristotle accounts for this by his theory of the pros hen equivocation of being, and Thomas uses this same notion as part of his justification for his doctrine of analogy of being. As Thomas puts this while commenting on Aristotle's Metaphysics, IV, chap. ~, if being is predicated in different ways, every being is so named by reference to something that is one and first. This single principle is not to be regarded as an end or as an efficient cause but as a subject for other and secondary instantiations of being. Thus some things are described as beings or are said to be because ' See Sancti Thortu~ de Aquino Expositiosuper librumBoethiiDe Trinitate, ed. by B. Decker, 2d ed. (Leiden: E. J. Brill, 1959), qu. 5, art. 1, ad 6 (p. a71); qu. 5, art 4 (P. 194): "Et ideo pertractantur in illa doctrina, in qua ponuntur ea quae sunt communia omnibus entibus, quae habet subiectum ens in quantum est ens; et haec scientia apud eos scientia divina dicitur." Also see In duodecim librosMetaphysicorumAristoteli~expositio,ed. by M.-R. Cathala-R. M. Spiazzi(Turin -Rome: Marietti, a95o), Prooemium, 2: "... non tamen considerat quodlibet eorum ut subiecturn , sed ipsum solum ens commune." For more on this see Chap. I of my The Metaphysical Thought of ThomasAquinas, in progress. [131 14 JOURNAL OF THE HISTORY OF PHILOSOPHY they enjoy being in themselves (per se). These, of course, are substances. Therefore substances are beings in the principal and primary senseJ After following Aristotle in listing a number of other ways in which things are named beings, Thomas sums this up in his own way. The aforementioned modes of being may be reduced to four kinds. One of these is the weakest in its claim upon being and exists only in the order of thought, that is to say, negations and privations. A second class is almost as weak in its claim upon being in that its members still include some admixture of negation and privation. Here Thomas has in mind generation, corruption, and motion. Thirdly, still others are described as beings not because they share in nonbeing but because they enjoy only a weakened kind of being and do not exist in their own right (per se) but only in something else. Thomas lists qualities, quantities, and the properties of substance. Finally, there is the most perfect class, which both exists in reality without including privation and which enjoys what Thomas refers to as a firm and solid being (esse). This kind of being exists in its own right or per se and is, of course, identified by Thomas once again as substance, s For our present purposes we are especially concerned with Thomas's third and fourth divisions, that is, with the kinds of beings which do not exist in themselves but only in something else, and with others which do exist in themselves. Though Thomas has only mentioned qualities, quantities, and properties as members of this third class, we may assume that he wishes to include therein accidents in general. In short, in his third and fourth classes he has introduced the fundamental distinction between accidental being and substantial being. 4 The distinction between substance and accidents is often presented as an answer to the problem of becoming at the nonessential or nonsubstantial level. Various Neoscholastic interpreters of Aquinas favor this approach.~ Moreover, Aristotle's discussion of the principles of becoming in Physics I, See Aristotle, Metaphysics IV, chap. 2 (xoo3a 33-1oo3b x9). For Thomas see In IV Met., lect. l, n. 539. Note in...