Saint Thomas Aquinas Thursday - 1

This series reflects on a short section of St. Thomas Aquinas’s massive work on theology, the Summa Theologiae. This work of synthesis is considered one of the greatest theological works in Christianity because of its structure, its breadth of sources and its depth of content. 

1 - Structure

Though not underappreciated by those who study Aquinas, one can never give too much attention to the wisdom and spirituality that Aquinas put into the very organization of his Summa. 

To appreciate this, we need to back up:

There is an idea in philosophy that finds its origin in the history of ideas long before Aquinas. Seeds of this idea can be found in ancient philosophy even before the birth of Jesus. It is called the dynamic of emanation and return. 

Emanation and return is an idea most popularly associated with the neo-Platonic philosopher, Plotinus. He understood God as the One, emphasizing the unity of God. This is similar to the Christian idea of Divine Simplicity, which Aquinas will speak to later in the Summa. Everything other than the One, like the world or us, emanates from it as an extension of it. It cannot be separate from the One because of the perfect unity in the One. Because this emanation is an extension of the One, the One will eventually draw it back to itself. This return happens to everything and the process is mirrored in everything. The universe, then, is a series of cycles that reflect this emanation and return. 

In Christianity, there is a similar idea in reference to God’s relationship with everything else. It is called the exitus and reditus. These words also mean “going forth” and “return” respectively, but because God is relational, Creation is not just an extension of God but something whose existence participates in God’s nature. When God became man in the Person of Jesus, this was the ultimate exitus because God Himself “exited” heaven and entered earth. At the end of his ministry, Jesus too “returned” to sit at the right hand of God at his Ascension. 

Now, back to Aquinas:

Aquinas divided his Summa into three parts. These three parts were meant to reflect the exitus and reditus that exists between God and Creation. 

Part I, begins with a focus on God in his nature. However, by the end of Part I Aquinas begins to examine the act of Creation and the nature of that Creation. This is where he examines angels, the human soul, and the first humans. This shows a movement outside of God. 

Part II stays with humanity but moves through human actions. This stays with Creation, the object of God’s exitus. 

It is in Part III that Aquinas’s structure becomes clear. Here, he establishes the means by which Creation can return to God, the one whom Catherine of Siena called “the bridge” between God and humanity: Jesus Christ. All of Part III is focused on Jesus because he is “the Way” of our return to relationship with God. 

While we did not get to explore any of Aquinas’s actual content yet, it was important we understand the structure as this acts as a sort of road map for understanding what Aquinas was trying to do in writing his Summa. It was not just a Catholic theology reference book. It really is meant to tell a story, a story that hopefully ends with its reader better seeing God in his mind so that he can see him perfectly in his soul.