Toward a Scotistic Modal Metaphysics :: Philosophy Philosophical Essays

Toward a Scotistic Modal Metaphysics ABSTRACT: The problem I tackle in this essay is: Do we have in Scotus a modal logic or a counterpart theory? We need to take a rather roundabout path to handle this problem. This is because, whether it be in Lewis's original formulation or in others' applications, the crucial concept of 'counterpart' has never been clearly explicated. In section two, I shall therefore examine the recent controversy concerning Leibniz's views on modalities which centers around the counterpart relation. By fully exploiting the lessons learned from such an examination, I shall then launch a trilemma against a Leibnizian in section three. Section four shall make the claim that unlike Leibniz's case, Scotus's position is not endangered by the trilemma. One important premise will be adopted from my thesis presented elsewhere regarding the different between Scotus's haecceitas and Leibniz's individual essence. Another will be secured from a brief report on Scotus's views on similarity, which might be utterl y original to modern eyes jaundiced by contemporary set theories. 1. The Problem: Scotistic Modal Logic vs. Scotistic Counterpart Theory Thanks to the resurgence of interest in modalities in the twentieth century, the history of modal logic has been studied more extensively than ever. One of the more important lessons is that Scotus rather than Leibniz is the father of the modern conception of logical possibility. (1) Insofar as it is not merely historical curiosity but a test of our intuition about modalities that we are interested in the predecessors of modern modal logic, we face the urgent task of reconstructing the Scotistic system of modalities. In fact, Douglas C. Langston recently raised an interesting question as to which way of understanding possible worlds Scotus might endorse: the counterpart view or the canonical view? Based on Ordinatio, Book I, d. 44, q. 1, n. 11, he presents two alternative readings. Ultimately, however, he opts for the counterpart reading on the ground that it is more consistent with Scotus's remarks on how God knows contingents. An important consequence from the counterpart reading is that individuals are "world-bound" for Scotus. (2) Yet Langston's interpretation invites serious criticism. According to Simo Knuuttila, if the individuals in Scotus's model were world-bound, they would not have synchronic de re alternatives, which is not compatible with Scotus's reform in obligational principles. Knuuttila further points out that Scotus's well-known doctrine of human free will excludes the possibility of world-bound individuals.