Beyond isomorphism: Nominalism, necessity of logic and possibility of metaphysics in the young Leibniz and the young Wittgenstein

Abstract

In this paper, I examine some coincidences in the philosophical doctrines that Leibniz and Wittgenstein develop in their respective youth periods, especially in Leibniz’s “Dissertatio praeliminaris” (1670) and in Wittgenstein’s Tractatus logico-philosophicus (1922). Although there exist some studies concerning certain coincidences between both authors regarding the isomorphism they subscribe, there is another theorical axe they share, but which has escaped to the scrutiny of their scholars: the nominalism. From a survey of isomorphic doctrines that Leibniz and Wittgenstein develop and whose coincidences have already been observed by Willam Kneale, Sabine Plaud and Michal Piekarski (section 2), I examine, on the one hand, how this isomorphic doctrine is articulated with – what I call– a methodological nominalism through which both aim to a depuration of language, and, on the other hand, the consequences that this methodological nominalism entail, in each case, regarding two sensible points in their respective philosophical programmes, namely, the necessity of logic and the problem of the possibility of metaphysics (section 3).