- Analogy after Aquinas: Logical Problems, Thomistic Answers by Domenic D’Ettore
This excellent book traces the history of Thomistic accounts of analogy from the early fourteenth century to Francis Sylvestri of Ferrara and Chrysostom Javelli, writing in the 1520s and 1530s in the light of Cajetan’s magisterial De nominum analogia. D’Ettore starts with the philosopher who caused such difficulty for the logic of analogy: namely, John Duns Scotus. Scotus argued that both the principle of noncontradiction and syllogistic validity require univocal concepts, such that there is one ratio through which a name signifies reality. As the earliest Thomists saw, this directly threatens Aquinas’s denial of that very claim, in his assertion that analogy is sufficient for avoiding the fallacy of equivocation. D’Ettore argues that Aquinas’s account simply does not evince any awareness of these difficulties, and hence needs supplementation to enable it to provide answers to Scotus’s worries. A good part of the exposition is devoted to the divergent interpretations of [End Page 664] Aquinas proposed by the Thomists to shore up Aquinas’s position against the Scotist onslaught.
It is fashionable in some theological circles today to urge that Scotus’s target was Henry of Ghent, and thus that his criticisms do not touch Aquinas’s account. But that was decidedly not the opinion of the early Thomists, and they were clearly right to be worried. As D’Ettore puts it, “If a Thomist insists that Aquinas’s model(s) of analogous naming demand more than one ratio, then the Thomist must explain how this model dodges Scotus’s criticism that, without one and only one ratio for a term, demonstration is impossible. If a Thomist argues instead that there is one ratio involved in analogous signification, then the Thomist must explain the difference between his own position and that of Scotus, either admitting that analogy reduces semantically to univocity or challenging Scotus’s definition(s) of univocity and analogy” (31–32).
D’Ettore groups the philosophical and exegetical problems facing early interpreters of Aquinas under three useful headings: the rationes problem (whether analogous terms signify one or many rationes); the analogy-model problem (whether the theory of analogy is modeled on the relationship between one thing and another [unius ad alterum]—which D’Ettore labels the “Healthy Model”—or of two to a third [duorum ad tertium]—which he labels the “Principle Model”); and the equivocation problem (whether the use of analogous terms necessarily generates equivocation, as Scotus held). The discussion is quite dense, and the array of issues treated very complex. A helpful chart (186) aids the reader in tracking the manifold different answers offered by the subjects of this study: the early fourteenth-century thinkers Hervaeus Natalis and Thomas Sutton; the early fifteenth-century thinker John Capreolus; the late fifteenth-century philosophers Flandrensis and Socinas; and from the early sixteenth century Cajetan and the two Thomists mentioned above. All but the first three were associated with the Dominican studium in Bologna.
As Joshua Hochschild convincingly argued a few years ago (The Semantics of Analogy: Rereading Cajetan’s “De nominum analogia” [Notre Dame: University of Notre Dame Press, 2010]), Cajetan has a good right to claim to have solved Scotus’s objections by appealing to the analogy of proper proportionality. As D’Ettore puts it, “Proportional unity does not eliminate diversity, but it is, nevertheless, a real form of similarity such that whatever properties belong to one thing also belong proportionally to whatever is proportionally similar to it” (139). The different rationes have some kind of unity or identity—a proportional unity or identity—and as such “whatever belongs to one, belongs also to the other proportionally” (ibid., quoting Cajetan, De nominum analogia, c. 10, n. 106). This unity allows Cajetan to circumvent Scotus’s claim that syllogisms that include terms whose significations are related merely analogously ultimately have four (or more) terms. What grounds syllogistic validity and theological reasoning is that, in...