Since I started this blog partway through year 4 of a ten-year plan, I’ve tried to go back from time to time to comment on some of my reading from the first three-and-a-half years. Today I’ll look back a bit at Thomas Aquinas’s Summa Theologica.
The first time I tried reading Thomas, he made no sense to me at all. I don’t know which hindered me more: my illness at the time or my inexperience with Aristotle. The second time I tried reading the Summa, it seemed surprisingly clear. I had a few more years of living, a bit more knowledge of history and philosophy and logic, and some beginning experience with Aristotle. But I also had Mortimer Adler’s ten-year-plan, which assigned in the first year a small section of the Summa appropriate for beginners, and I had a commentary by Peter Kreeft. Now I just read and learn every year.
In my present plan, I spend five or six weeks each year with Thomas, and I still won’t get through the book in ten years. But I started at the beginning, and I still refer back to my notes on those first pages every year to help make sense of all the rest. The theme of the entire Summa is human knowledge of God, the goal of our lives, so the Doctor begins with several pages on the need for theology for two good reasons: to introduce his subject and to justify his method. Thomas says clearly in this introductory “question” (each chapter, we might say, discusses a single topic and is called a question) that man is directed to God as an “end beyond the grasp of human reason,” but that man can nevertheless arrive at some knowledge of God through reason based on premises revealed in Scripture. Natural reason alone, he says, can only tell us that God is, not what He is.
After a question presenting five ways natural reason can show us the existence of God, Thomas goes on to several questions on the attributes of God that revealed knowledge and reason together give us. The first is the simplicity of God. God has various qualities in a manner of speaking, but these are not separable add-ons. You can take away the white from the horse, because a horse may be different colors; in this way, a horse is a composition. But God is simple in that all the things we can say of God are inseparably unified. For instance, God is his own essence. For a human to be his own essence, that individual human would have to be the same thing as humanity. Well, I am not the same as humanity, but God is the same as deity: there is no separate essence or self-existing definition of God that God merely exemplifies.
Next comes the perfection of God, not that He is complete, as if there could be anything missing from God, but in that He is completely actual with no potentiality. Knowledge, for instance, can be potential instead of actual. I normally know the square of 15 only potentially. I wasn’t thinking of it until I wrote that sentence, but now I’m thinking of it, because I always have the potential to think of it. All of God’s knowledge, on the other hand, is always actual.
Some ancient Greek philosophers pondered abstracts such as Unity and Being, and tried to decide which was logically first: what is it on which every other existing thing depends? It seems that Being is the first thing since everything else that exists has Being. But Being is one thing, so maybe Unity is the first existence. But then how can Unity have existence without Being? Thomas cuts through this Gordian knot by showing that all these abstractions are qualities of the simple God: they are all equally first, because they are all inseparable from God, who is inseparable from his essence. After the question on perfection, Thomas adds Goodness to this list. Goodness is the same as Being. Evil is only a lack of Being. God’s Goodness is inseparable from his Being, and all things that are, are good insofar as they exist.
After then discussing the infinity, immutability, and eternity of God, Aquinas turns to the question of how God can be known by us. We can be sure, he says, that the created intellect can know God in his essence because Paul’s inspired words tell us that we shall one day see Him as He is. But seeing God can come only by grace, which grants the spiritual light that makes God visible. We cannot see God, i.e. know Him in his essence, in this lifetime, but through grace God gives us some knowledge of Himself through Scripture, inner understanding, and in some cases visions.
Now all this doctrine about the need for grace and the limited usefulness of reason differs significantly from what a devotee of a certain Protestant sect once told me about Aquinas’s views. I don’t know if Aquinas sounds either particularly Protestant or particularly Catholic in this section. But he sounds Biblical to me, and he sounds wise with a wisdom that has come through grace.