Thomas Aquinas describes embryological development as a succession of vital principles, souls, or substantial forms of which the last places the developing being in its own species. In the case of human beings this form is the rational soul. Aquinas' well-known commitment to the view that there is only one substantial form for each composite and that a substantial form directly informs prime matter leads to the conclusion that the succession of soul kinds is non-cumulative. The problem is that this (...) view seems to entail discontinuity in the process of generation. Aquinas argues for the continuity of a conceived being by appealing to the teleological argument at the core of Aristotle's embryogenesis theory: according to Aristotle, embryonic development is a gradual actualization of the form of the species, potentially present in the embryo from the outset. Aquinas denies such a gradualist account due to his metaphysical commitments , arguing instead that the .. (shrink)

This paper presents Duns Scotus’s theory of mixture in the context of medieval discussions over Aristotle’s theory of mixed bodies. It revisits the accounts of mixture given by Avicenna, Averroes, and Thomas Aquinas, before presenting Scotus’s account as a reaction to Averroes. It argues that Duns Scotus rejected the Aristotelian theory of mixture altogether and that his account went contrary to the entire Latin tradition. Scotus denies that mixts arise out of the four classical elements and he maintains that both (...) the elemental forms and the elemental qualities are lost in the mixture. Consequently, he denies the distinction between the process of mixture and that of substantial change through generation and corruption. The reassessment of Scotus’s account modifies the current historical representation of this discussion, inherited from Anneliese Maier. (shrink)

Philosophers today have largely given up on the project of categorizing being. Aristotle’s ten categories now strike us as quaint, and no attempt to improve on that effort meets with much interest. Still, no one supposes that reality is smoothly distributed over space. The world at large comes in chunks, and there remains a widespread intuition, even among philosophers, that some of these chunks have a special sort of unity and persistence. These, we tend to suppose, are most truly agents (...) and subjects, and are what exist in the most proper sense of the term. We believe, in other words, in substances. (shrink)

I first examine John Duns Scotus’ view of contingency, pure possibility, and created possibilities, and his version of the celebrated distinction between ordained and absolute power. Scotus’ views on ethical natural law and his account of induction are characterised, and their dependence on the preceding doctrines detailed. I argue that there is an inconsistency in his treatments of the problem of induction and ethical natural law. Both proceed with God’s contingently willed creation of a given order of laws, which can (...) be revoked and replaced with a new order of laws. In the case of ethical natural law God promulgated the Decalogue, for example; in the case of nature, there are physical laws that can be known by induction. Scotus exalts the freedom of God and the mutability of ethical natural law in order to explain exceptions to it disclosed by revelation (for example, the Old Testament command to Abraham to kill Isaac). Yet he treats ethical natural laws as (mostly) not universal and immutable. In contrast, he holds that we can arrive at knowledge of the universal and immutable laws of nature, except for those regularities that result from free will. Finally, I present several ways of characterising this tension between Scotus’ doctrines. (shrink)

The four principal competing substance ontologies are substratum theory, bundle theory, primitive substance theory, and hylomorphism. Both historically and in the recent literature, most arguments pertaining to these four theories have been developed under the assumption that only one of them can be true. However there is room in this debate for various forms of pluralism: mild pluralism here refers to the view that while only one of these four theories is true of our world, there is at least one (...) other possible world in which a different substance ontology obtains; moderate pluralism refers to the view that while only one of these four theories is true of our world, there is at least one other possible world in which multiple substance ontologies obtain ; and extreme pluralism refers to the view that our own actual world contains substances belonging to different substance ontologies. In this paper I lay out a novel argument for a version of extreme pluralism. (shrink)