The theology of light in Thomas Aquinas

This dissertation explores the various ways that Thomas Aquinas uses light language in his theological work. There are three main ideas that are central to the project. First, light is a central motif that recurs throughout Aquinas’s work and exploring the ways that he uses light language provides important insights into his theology. Second, Aquinas maintains a three-fold hierarchy of light—the light of nature, the light of grace, and the light of glory—that shapes his understanding of how God manifests himself in the world, even as each light has its origin in God. Third, and most importantly, Aquinas’s theology of light is primarily Christological, as Aquinas believes that Christ comes to illuminate us about who God is and is also the means by which the beatific vision and its light of glory is made possible to humans.;In studying Aquinas’s theology of light, the first three chapters of the dissertation provide the background necessary to understanding how Aquinas uses light language. The first chapter explores the idea that the very act of studying theology requires illumination from God. The second chapter gives a detailed account of how Aquinas understood light and vision to work, with the key idea being that if we do not grasp his understanding of the physics of light, which are very different from ours, we run the risk of misunderstanding the metaphors and models he develops. The third chapter investigates how Aquinas uses light language metaphorically, analogically, and as a model throughout his theology.;With those background concepts described, the dissertation then explores how Aquinas uses light throughout his theological work. The fourth chapter deals with theology proper, looking at how the idea that “God is light” is understood by Aquinas in regard to the essential attributes of God as well as the Trinitarian expressions of light, particularly in the illuminating mission of the Son. The fifth chapter describes how the goodness of God’s light is expressed in creation, most especially in the creation of angels and humans. The sixth chapter explores how light and darkness are used in Aquinas’s moral theology as a way of describing the human condition in sin, the conversion from darkness to light, and the light of the law and the virtues. Each of chapters one through six, with the exception of the second chapter, concludes with a section on the Christological application of light with regard to the question under discussion. The seventh, and final, chapter focuses on the Christological elements of theological light that were unexplored in the previous chapters, including both ecclesial and sacramental means of illumination.