Date of Submission



The aim of this thesis is to build an understanding of St Thomas's notion of participation within his foundation metaphysical principles. In the revival of philosophical interest in the thought of Thomas Aquinas that has been seen throughout the twentieth century and continues today, St Thomas's notion of participation has sometimes been nominated as offering a key insight to his metaphysics. This is an attractive proposition, although the scholarship, while of excellent quality, has now revealed fundamental points of contention. These points of contention, furthermore, seem to be fuelled by the differing philosophical allegiances of each scholar. In these circumstances, recent scholars with an interest in participation have been returning to the texts, seeking to re-construct St Thomas's notion within his own analysis. This thesis is a modest attempt at such a re-construction. The thesis consists of a close study of three of St Thomas's early works, namely, De principiis naturae, De ente et essentia and Expositio libri Boetii De ebdomadibus. In the course of studying these works I regularly refer also to some other of St Thomas's leading works, some of which also come from early in St Thomas's career, others of which are later. I have chosen the three works just mentioned by name for this reason: in the first two mentioned St Thomas lays out his basic metaphysical framework; this is found especially in his two modes of composition - each achieved through a structure of act and potency - and also in his distinction of essence and existence in all created substances. Also important here is the recognition of existence as actuality, and the sharp differentiation of the 'pure being' which is God from that 'universal being' by which everything else formally exists.


School of Philosophy

Document Type


Access Rights

Open Access


267 pages


Faculty of Theology and Philosophy