Exitus and Reditus in the Theology of Thomas Aquinas

Dr. Lane Tipton discusses a recent course he taught addressing the Trinitarian theology of Thomas Aquinas and the exitus-reditus scheme evident in all his theology. The lectures aim to provide an in-depth understanding of Thomas Aquinas's Trinitarian theology, emphasizing that his entire body of work is governed by the concept of exitus (departure) and reditus (return) in the context of divine and human processions.

Primary texts such as the Summa Theologiae and the Summa Contra Gentiles, as well as notable scholars like Gilles Emery and Dominic Legge, will be explored to corroborate the course's central thesis. The series will delve into the trinitarian structure of Aquinas’s theology, focusing on the eternal and temporal processions of the Son and the Holy Spirit, and their implications on topics like Christology and sacramentology. This Trinitarian framework forms the backbone of Aquinas’s theological system, affecting every doctrinal topic it touches, from the nature of God to the ultimate end of human beings. Therefore, understanding Aquinas's Trinitarian framework is key to grasping his theological system as a whole. The course aims not only to provide a nuanced understanding of Aquinas's theology but also to offer a Reformed critique and alternative.

The exitus-reditus structure serves as the central framework for understanding the theology of Thomas Aquinas. In this structure, "exitus" refers to the process of departure or emanation, while "reditus" signifies return. This dyad is a governing principle not only in Aquinas's understanding of the Trinity but also in his complete theological system. In terms of the Trinity, the Son and the Holy Spirit emanate from the Father in "exitus," and then return to the Father in "reditus."

This trinitarian procession is considered the foundational cause for the existence and return of all creatures. The divine persons' internal processions serve as the model and cause for the external processions of rational creatures. In relation to human beings, "exitus" refers to their creation and departure from God. God is seen as the efficient cause from whom all things emanate. "Reditus," on the other hand, signifies the creatures' return to God, drawn towards their ultimate end—participation in divine beatitude or happiness.

This return can be understood at two levels: natural and supernatural. On the natural level, creatures return to God according to their inherent abilities. On the supernatural level, they are elevated through grace to participate in the divine essence itself, surpassing their natural capacities. The exitus-reditus structure thus provides a coherent, systematic framework that integrates every aspect of Aquinas's theology, from the doctrine of God to the doctrines of creation, grace, and eschatology.