Abstract
As part of a more general project which consists in identifying the process by which the modern ontology of power and action came to replace the Aristotelian ontology of in-potency and act, this article questions some fundamental features of Aquinas’ use and reworking of the Aristotelian concepts of dunamis and energeia. First, I ask, how Aquinas can characterise God as being pure act and omnipotent at the same time given that for Aristotle pure act radically excludes all potency. It appears that the Thomistic act not only admits potency-as-power, but also signifies the full power of being so that we can detect in Aquinas the conjunction in the first being - of power with being itself Second, I show how the symmetrical reinterpretation of the Aristotelian concept of in-potency comes to be modified by means of the concept - inherited from Neo-Platonism - of epitedeiotes. Thus understood as receptive capacity, in-potency no longer signifies the principle within each substance of its own proper and immanent act but rather its dependence on the first act, the primary being. In the end, the concept of potency is redistributed by Aquinas between the Creator’s full power of being, and the creature’s mere capacity for being.