On "On the Trinity"

This is the result of an interesting exercise, in which we summarize big theology books in two pages. Ah, the things we do for coursework -- but it's still good practice. And I'm sure it needs correcting!  The quick-and-dirty always does.

Augustine's de Trinitate, written in the early 400's, is clearly intended to emphasize the unity of God. Coming out of the contests of the late 300's, and the aftermath of the production of the Nicene-Constantinopolitan creed, the text has the air of a preemptive dispute. Augustine remains concerned to describe God in ways that rule out the errors of separation and subordination of persons in the godhead. And yet it is not primarily a polemical text, written to counter opponents. In several places, Augustine does engage in refutation of opinions, and at length. However, the book proceeds under the constantly repeated declaration that he writes in order to explain his best understanding, and invites charitable correction while he warns the reader of misunderstandings along the way.

Augustine introduces “Trinity” as a way of referring to the unity of the persons of God — not as a fourth being in relation to three other beings, but as a name for God representing the unity of Father, Son and Spirit. (Robert Jenson's insistence upon the name of God as “Father, Son and Holy Spirit,” likewise attempting to express God as the unity of persons, is a modern parallel — though it lacks the singular impact of “Trinity.”) Doctrinally, this is as important a move today as in the wake of the Arian controversies. Augustine moves from a conversation that is principally about three personal beings and their interrelationships — begetting, proceeding, sending — to a conversation about the one God who acts.

One of the problems this approach solves is the question of which person of God is witnessed as acting in the scriptures of the Old Testament. And the answer follows what the Latin church said after Augustine: opera trinitatis ad extra indivisa sunt — the economic actions of God are actions of God, so when we see God through the persons of the Trinity, we must be able to suggest that any and all of the persons are involved in any and all actions. Speaking of God as Trinity allows Augustine to speak of the appearances and works of God in the Old Testament as actions of the one God. God is the Creator, God speaks to the prophets, God is the agent of change and the Lord of creatures, God is the one in whom the people hope — not the Father alone, as though the Father were God without, as Augustine says, Reason and Wisdom. This allows him to deal with the Old Testament witness in ways that acknowledge the absence of the incarnate Son in the text, while not following Arius in separating and subordinating the logos of God. Instead, he speaks plainly of God.

And yet, in order to keep the argument from sticking at the level of philosophical distinctions between persons and substances, Augustine moves very quickly from the discussion of the personal being and unity of God into the reason for it: the faith of the church. God needs to be this way, because this is the God in whom we trust. We trust in the Son and the Spirit as God acting for us, in the full historic reality of the incarnation and the ongoing advocacy of the Spirit. At this point, Augustine makes the connection between the denial of full consubstantial deity, and the sin of pride because of knowledge. He connects denial of the improbable events of this history, on the strength of human reason, with the denial of the equality and full deity of the Son and Spirit with the Father. Because of the faith, even if we make the verbal distinctions between Father, Son and Spirit, Augustine teaches us to say that God is one in the important ways that relate to purpose and action.

In spite of the contentious nature of the topic, Augustine asserts throughout de Trinitate that God is rationally accessible, that God is understandable because God gives Godself to be understood, especially as Word. And yet words are exactly the problem when we come to explaining the God whom we understand mentally. And so, to make the intellectually difficult arguments about the Trinity more easy to believe, Augustine makes a series of trinitarian analogies. As early as book four, Augustine makes a first trinitarian analogy of mind, understanding and will: three names for three deeply interrelated things, aspects of one being. And after a detailed exposition through three further books, covering the ground of the trinitarian controversies and following out the line of the councils, he sets out these analogies as valid ways of talking about the unity and diversity of the persons.

The love, the lover, and the loved form the first analogy, on the basis of the internal relations of the persons within the Trinity. The mind, the understanding and the will form the second analogy, because of the necessities of love in a rational being. The mind loves, and the mind has knowledge, and so the mind, love and knowledge begin this second analogy in the self. And the self that loves and knows also understands itself as the lover, and wills love toward the loved. And though the mind is fallible and human love is imperfect, yet in the mind memory, understanding and will are one life and so one substance. And so Augustine works his reader upward from the lesser to the greater through the analogy from human life to the life of God. And after a few more books of corrections to historic opinions and contentions over these analogies, the analogy returns to the human subject who remembers, understands, and loves God. This lets Augustine keep the creaturely analogy, precisely because the human subject is created in the image of God.

Finally, for Augustine, the image of God in the human subject is the pedagogical key to talking about the trinity and unity of God. These analogies of the triune God in human creatures form what is called the vestigium trinitatis, the trace of the triune being of God, seen in us as the lingering image of God in which we have been created. This expression will become problematic in its own right in later theology, as the vestigia become a source of natural knowledge of God and a way of reading God from creation without the aid of revelation. But Augustine intends the vestigium trinitatis as a corrective grammar — as much a way of speaking about human beings as creatures before the Creator as it is a way of speaking of God in the integrity of divine being and action.