Illuminating Causality: The Role of Light in Thomas Aquinas’s Metaphysics of Being

In this article, we hold a strong thesis, i.e., that light is the conceptual resource that best explains the creative act in Thomas Aquinas’s metaphysics. Thus, inasmuch as being is the luminous act of the Uncreated Being, it bears resemblance to the Uncreated Being in its very principle. In this sense, we seek to present the role of light, in its meaning as manifestation, as an act that belongs to being. Indeed, in contrast with some contemporary interpretations, which place light within the order of formal causality, we argue that light, in its belonging to Aquinas’s participatory metaphysics, pertains to the order of efficient causality. Therefore, we hold that light has strong explanatory pretensions in Aquinas’ thought. Accordingly, after an introduction (1), this article is divided into the following sections: (2) The Meaning of Divine Causality; (3) Being as Light; (4) The Manifestative Character of Light; (5) Light Images: Analogies and Metaphors; and (6) Conclusions.