Abstract

Aquinas uses the concept of "natural priority" in many aspects of his thought, especially in his metaphysics. This study defines the concept in its various usages, traces its philosophical heritage, and applies it to the principles of esse and form within Aquinas' metaphysics. In particular, the study attempts to prove, against modern "existentialist" Thomists , the absence of natural priority of esse to form. The thesis has three conclusions: First, that there is no natural priority of either form or esse as metaphysical principles; second, that God alone is naturally prior among all beings and principles of being, and third, that Aquinas' principle of similitude between God and creature is not alone but the analogical sense of act as both form and esse. The study contains five chapters. The first chapter presents the views of three modern "existentialist" Thomists, and indicates the motivations and consequences of these views. The second chapter traces the notion of natural priority to Plato and Aristotle, and resolves a metaphysical tension within their usages of the notion. The third chapter examines Aquinas' transformation of the Greek use of the concept in his theory of causal order and creation. Aquinas' use of five general types of natural priority, viz. as "separability", as "absolute", natural priority in "being", "in reference to a principle" and in "origin", are argued to coincide in the unique candidate for natural priority, namely, God. Chapter four applies the concept of natural priority to the realm of finite substance, and concludes to the lack of any type of natural priority of esse to form once again. Chapter five replies to the three aforementioned existentialist Thomist positions, and argues that their views misinterpret Aquinas' metaphysics of causes, in addition to implying a natural priority of esse to form on both the transcendental and finite levels. Finally, an examination of both the infinite and created orders reveals the positive and necessary role of form, and the combination of both transcendent and immanent elements of natural priority in God according to Aquinas