Thomas Aquinas on Whole and Part

1 The secondary literature devoted to the problem is not vast. The following are particularly useful and fundamental contributions to Aquinas’s mereology. B. Bro, “La notion métaphysique de tout et son application au problème théologique de l’union hypostatique,” part 1, “La notion de tout en Saint Thomas,” Revue Thomiste 67 (1967): 32-61; part 2, “Analytiques de la notion de tout,” Revue Thomiste 67 (1967): 561-83; L. Oeing-Hanhoff, “Das Ganze und seine substantialen Teile,” in Ens et unum convertuntur, Stellung und Gehalt des Grundsatzes in der Philosophie des hl. Thomas von Aquin (Münster, 1953), 155-63; idem, Ganzes/Teil, in Historisches Wörterbuch der Philosophie, ed. J. Ritter and K. Gruender, Band 3 (Basel and Stuttgart: Schwabe und Co. AG, 1976), col. 3-11; P. H. Desmond, Medieval Mereology, Bochumer Studien zur Philosophie, 16 (Amsterdam: B. R. Gruener, 1992); C. A. Lofy, “The Meaning of ‘Potential Whole’ in St. Thomas Aquinas,” The Modern Schoolman 37 (1959): 39-48. Also useful are R. Cross, “Ockham on Part and Whole,” Vivarium 37 (1999): 143-67; A. W. Arlig, A Study in early Medieval Mereology: Boethius, Abelard and Pseudo-Joscelin (Ph.D. diss., The Ohio State University, 2005); idem, “Is There a Medieval Mereology?”, in Methods and Methodologies: Aristotelian Logic East and West, 500–1500, ed. M. Cameron and J. Marenbon (Leiden: Brill, 2011), 161-89; idem, Medieval Mereology, in The Stanford Encyclopedia of Philosophy (Fall 2011 edition), ed. Edward N. Zalta, 273 The Thomist 76 (2012): 273-304 THOMAS AQUINAS ON WHOLE AND PART DAVID SVOBODA Charles University Prague, Czech Republic T HE DOCTRINE OF whole and part (mereology) plays an important and irreplaceable part in the thinking of Thomas Aquinas. Aquinas uses these concepts in his account of many crucial problems such as the structure of being as such, the properties of substantial and accidental being, the ontological composition of supposit or person, the structure of common nature, the ordering of all created world and each individual being with respect to the ultimate end (God), the properties of quantitative beings, the properties of cardinal virtues, the determination of the properties of univocal categorical concepts and their relationship to subordinate natures, and so on.1 Yet it is DAVID SVOBODA 274 http://plato.stanford.edu/entries/mereology-medieval/#SelSecSou; D. Svoboda, “The Logical and Metaphysical Structure of a Common Nature (A Hidden Aspect of Aquinas’ Mereology),” Organon F 17, 2 (2010): 185-200. 2 I have attempted to present the division and thorough characteristics of all types of wholes elsewhere: D. Svoboda, Metafyzické myšlení Tomáše Akvinského (Prague: Krystal, 2012). Aquinas divides the concept of whole in several ways: according to the type of its unity, which is how a quantitative whole (e.g., a man who is a unity absolutely) differs from an aggregate, which is absolutely many and one only in a certain respect (see STh I-II, q. 17, a. 4); according to the form of the whole (the principle of the unity and ordering of the parts of the whole), which is how an animal as an integral whole (the principle of the unity and ordering of integral parts of which is, together with quantity, the soul proper and immanent to the animal) differs from a collective whole (e.g., a state society, whose principle of unity remarkable that the Angelic Doctor did not pay much attention to the analysis of these concepts in his vast work. Aquinas considers whole and part in various parts of his writings, mostly in the context of solving other problems which provide occasion to formulate some fundamental thoughts concerning mereology. The most extensive explication of the concept of whole (and part) is to be found in his commentary on the fifth book of Metaphysics, but this is by no means a complete and comprehensive exposition. The aim of this paper is to reconstruct Aquinas’s concept of whole (and part) as such and thus contribute to clearer understanding of this topic. The article is divided into three main parts. The first part presents the basic division of wholes (and parts) that can be found in Aquinas’s work. In the second part...