Pluralism and material substance: Thomas Aquinas and the problem of material constitution

A number of contemporary philosophers argue that puzzles about material objects such as the Ship of Theseus show that our common-sense intuitions about compound material objects are logically incompatible with one another. This “problem of material constitution” (PMC) thus suggests that common sense and logic are at odds where the nature of material objects is concerned. Most contemporary philosophers solve the PMC by defending the denial of a common-sense intuition about material objects, although there is no consensus on just which intuition should be denied. I argue in this dissertation that Thomas Aquinas's metaphysic of material objects allows for a solution to the PMC such that none of the common-sense intuitions about material objects need be denied. The Thomistic solution to the PMC is thus preferable to those contemporary solutions that advocate the denial of a common-sense intuition.; The first chapter of the dissertation explains how certain common-sense intuitions about compound material objects are supposed to raise the PMC, and also offers a survey of contemporary solutions. The second chapter takes a detailed look at the views of three contemporary philosophers who have made important contributions to the recent literature on material constitution. The third chapter introduces Aquinas's metaphysic of material objects through an examination of his concept of material substance. The fourth chapter discusses Aquinas's views on material composition, including his views on the different ways material substances are composed and his views on artifact composition. The fifth chapter explains Aquinas's views on the identity and individuation of material substances and artifacts. The sixth chapter shows how Aquinas's views on the composition and identity of material objects allow him to solve the PMC in a novel way. The seventh chapter defends this Thomistic solution to the PMC in light of the contemporary views examined in chapter two.