The Trinity

I had the priviledge of journeying with 9 other students today through three hours of a discussion on the Trinity via Thomas Aquinas. It was one of the most enjoyable sessions that I had for a long time. I was able to grasp a vision of what a unified trinity might look like for the first time in my life. Thomas' view may not be completely correct, but it works well enough to guide one's thoughts in contemplation of God. So here's a summary of what we talked about, likely mostly for my own benefit in posterity.

His arguments begin with procession. There are, in a human soul, two kinds of inward processions. If our soul is created in the image of God, then these two kinds of processions will be present in God. These processions might be understood as conception in the intellect and love, which is any movement of the will. Concepts are words: thus the Word is the Concept of God within God. God being God, any concept He had would be perfect. This is the Word. God's internal movement (He is pure act, after all) towards Himself (and us, in God's conception of us) is a movement of His whole self, and thus the procession of the Holy Spirit is fully God.

To distinguish between the three persons whose essences are identical, St. Thomas relies on relations. Based on the processions, we can understand 4 relationships in God: Filiation, the relationship of a son to a father; Paternity, the relationship of a father to a son; Spiration, the relationship of the Father and the Son to the Spirit (a special kind of relationship used to describe God's will's procession); Procession, the relation of the Spirit to the Son and the Father.

There is an important, but difficult to understand distinction in what kind of relationships exist upon which his arguments rest. That is, there are relative relationships: the relationship of one thing to another. This kind of relationship does not inhere as an accident in the thing related. That is, if I move about my keyboard in front of or behind my monitor, it won't change the keyboard at all. It will be relating to the monitor in a different manner, however. The other kind of relation is the relation of something in which there is an inherence of accidents. An example of this is the black coloring of a Bible's cover. The Bible isn't defined by the black, so the black must be relating to the book in some way.

Aquinas takes this distinction to say that this second kind of relation in God will not be accidental, but essential. This is based on his simplicity doctrine, which I won't argue for here. Those relations I described earlier are all essential in God, then.

From this discussion, Aquinas is free to move on to the discussion of Persons. Personhood is defined as distinct substance of a rational nature. But, wait, isn't substance essence? How can there be three persons of distinct substances if there's only one essence? This problem is solved by a proper understanding of what substance is. Substance can be understood either as essence (or ousia) or it can be understood as the genus of things that are. St. Thomas eliminates the first definition and clings to the second, which has three properties. One part of this is the important term "hypostasis." This is understood as that which accepts accidents. That is, what underlies all of my blond hair, blue eyes, etc. When people refer to me, they don't refer to my accidents, but tomy substance or hypostasis. It can also mean the "natural thing," in which part I am in substance a human. My substance is the human substance. In another way I am "subsistence," or an individualized something.

The last article we worked on in session was the most difficult but most rewarding part of our journey. It is Question 29, Article 4 of the Summa. In this section he explains his vision of the Trinity in more detail than he had yet done (I suppose he's been doing this all along, but this article is a kind of culmination). There is a lot of work done in a few sentences of the last paragraph in the responsio of this article, but it's worth looking at.

Here's the text:

Now distinction in God is only by relation of origin, as stated above (28, 2, 3), while relation in God is not as an accident in a subject, but is
the divine essence itself; and so it is subsistent, for the divine essence
subsists. Therefore, as the Godhead is God so the divine paternity is God the Father, Who is a divine person. Therefore a divine person signifies a relation as subsisting. And this is to signify relation by way of substance, and such a relation is a hypostasis subsisting in the divine nature, although in truth that which subsists in the divine nature is the divine nature itself.

He says this:

1. Distinction in God based on relation.
2. Relations in God are essence of God.
3. The Divine Essence is self subsisting.
C1: Therefore the Relations in God are subsistent.
C2: Therefore the Godhead is to God as Paternity is to God the Father.
4. God the Father is a Person.
C3: Therefore Divine Person signifies a relation that's subsisting.
C4: This signifies relation by way of substance, and this is a hypostasis subsisting in the Divine Nature!

This explains the Trinity. It lays out a relationship between the Persons and Essence that makes sense with a simplicity of God doctrine. It's pretty beautiful, if you see it. It's probably easiest to see when talking about with someone, though. Then the image is shared and it's pretty exciting. It comes together and makes sense. You can see how each person is God, truly, and how God has distinctions that are Persons, truly. It's a great beginning to two more sessions on the Trinity. I'll be leading the next one.