The Many Forms of Pluralism: Three Essays on the Medieval Unitarian/Pluralist Debate

My dissertation consists of three essays on the medieval debate between pluralists (those who believe that a substance can have more than one substantial form) and unitarians (those who think that a substance can have only one substantial form). In the first essay, I argue—contrary to a common assumption in the secondary literature—that at least some medieval philosophers recognize two fundamentally different kinds of pluralism. I use the writings of Aquinas as my main example, arguing that he distinguishes two kinds of pluralism and takes the time to argue against both. In the second essay, I challenge the assumption, common both to Aquinas and to many more recent commentators, that Aristotle holds a unitarian view of living things. I show that Aristotle’s view of living things might be categorized as pluralism, albeit a kind of pluralism that differs from that of medieval pluralists such as Scotus and Ockham. In the third essay, I argue that Ockham’s arguments for pluralism presuppose a version of mind-body dualism that differs from both substance and property dualism. I show that this Ockhamist dualism avoids a common objection to mind-body dualism, namely that dualism implies a morally and/or metaphysically problematic division between certain beings and the rest of nature