We welcome Dr. Lane Tipton back to the studio on the heels of teaching a new course on the theology of Thomas Aquinas. In this course, Dr. Tipton aims 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. 

In the course, Dr. Tipton analyzes primary texts such as the Summa Theologiae and the Summa Contra Gentiles, as well as works by notable Thomistic scholars such as Gilles Emery and Dominic Legge as he dives 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. Tipton contends that 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

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 rational creatures, “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.