29. Trin. 1.2.4–3.5 (CCL 50:31–32); trans. McKenna, FOTC 45:7–8 (modified). (continued)
On the Trinity
commentators have often divided the work in half, treating it as if it were two separate works: the first half (Books 1–7), often described as a systematic treatise on the dogma of the Trinity; the second half (Books 8–15), described as a speculative exploration of the Trinitarian structures of human consciousness. The second half represents Augustine's most original contribution. Modern philosophers and psychologists have fruitfully explored these later books for insights on Augustine's philosophy of mind. Still, it is vital not to detach the overall work from its historical, literary, and theological contexts. The first half bears little resemblance to later medieval or modern dogmatic treatises on Trinity; nor is the second half merely a personal speculative enterprise. It has been argued recently that the work needs to be read as a unified whole, as a sort of spiritual exercise, an exercitatio mentis, not unlike those Neoplatonic-inspired ascents of mind described in Confessions and elsewhere.30 The work can thus be read as a progressively deeper and interior probing of what within us makes it possible for us to encounter, and thereby come to know and love, the God who is Trinity. Augustine, at the opening of Book 15, offers an intriguing overview of the first fourteen books. While this is no substitute or shortcut for working through the entire treatise, it helps us see what Augustine saw himself trying to do. From On the Trinity, Book 15:
(3.4) The necessity of our argumentation and reasoning, therefore, compelled us to say many things in the course of these fourteen books which we were unable to view in their entirety at one and the same time. In order that we may, therefore, refer them quickly in thought to what we wish to grasp, I shall, with the help of the Lord, have everything that I have made known and discussed in each of the books brought together briefly and without discussion, and shall place it, as it were, under a single gaze of the mind, not how each thing led to certain convictions, but the convictions themselves, in order that what follows may not be so far away from what precedes that the study of what follows may bring about the forgetfulness of what precedes, or, if this has already happened, then in order that what has escaped from one's memory may be quickly recalled by reading them once again.
(3.5) In the first book the unity and equality of that highest Trinity is shown according to the sacred Scriptures, and the same subject is continued in the second, third, and fourth. But in these three later books, the question about the sending of the Son and the Holy Spirit is carefully studied. And it is shown that He who was sent is not, therefore, less than He who sends just because the latter sends and the former is sent, since the Trinity—which is equal in all things and is also, in its nature, equally unchangeable, invisible, and present everywhere—works inseparably.
30. On this, see John Cavadini, "The Structure and Intention of Augustine's De trinitate," Augustinian Studies 23 (1992): 103–23.
The fifth is concerned with those to whom it seems, therefore, that the substance of the Father and of the Son is not the same. For they thought everything said of God to be said according to the substance, and, therefore, claimed that, since "to beget" and "to be begotten," or "begotten" and "unbegotten" are different terms, therefore the substances [of the Father and the Son] are different. Consequently, it was shown here that not everything said of God is said according to substance, as according to substance He is said to be good and great, or whatever else is said of Him in respect to Himself; but that some things are also said of Him relatively, that is, not in respect to Himself, but to something that He Himself is not, as He is called "the Father" in relation to the Son, or "the Lord" in relation to the creature who serves Him; and that in the realm of creation, where anything thus predicated, that is, in relation to something which He Himself is not, also includes the idea of time, as when it is said: "O Lord, you have become a refuge for us" (Ps 89:1), nothing takes place in Him whereby He is changed, but He Himself continues altogether unchangeable in His own nature or essence.
In the sixth, how Christ was called by the mouth of the Apostle the "Power of God" and the "Wisdom of God" (1 Cor 1:24) was discussed in such a way that a more careful study of the same question was put off until later: whether He, by whom Christ was begotten, is not Himself wisdom, but only the Father of His own wisdom, or whether wisdom begot wisdom. But whichever of these it might be, the equality of the Trinity (as well as the fact that God is not threefold but a Trinity) also appeared in this book. Nor are the Father and the Son, as it were, something double in relation to the single Holy Spirit, where the three are not something more than one of them. We also discussed how the words of Bishop Hilary31 can be understood: "Eternity in the Father, the form in the Image, and the use in the Gift."
In the seventh, the question that was deferred is explained in such a way that the God who begot the Son is not only the Father of His own power and wisdom but is Himself also power and wisdom, and so, too, the Holy Spirit; but yet that they are not together three powers or three wisdoms, but one power and one wisdom as one God and one essence. Then we inquired how they may be called "one essence, three persons," or by some Greek au-
31. "Bishop Hilary": Hilary of Poitiers (c. 315–c. 367), one of the leading Latin-speaking pro-Nicenes of the 4th century. He unsuccessfully tried to organize resistance to the anti-Nicene drift that took place under the Emperor Constantius in the 350s, an effort which cost him a lengthy exile in the Greek East. Hilary's De trinitate (SC 443, 448, 462) was one of Augustine's major sources. On this, see Mark Weedman, The Trinitarian Theology of Hilary of Poitiers, Supplements to Vigiliae Christianae 89 (Leiden: Brill, 2007). Augustine's quotation here does not match Hilary's De trinitate 2.1: "infinite in eternity" (infinitas in aeternitate, PL 10:51); the phrase, "Eternity in the Father" (Aeternitas in Patre), is found in a Pseudo-Ambrosian commentary on the Apostle's Creed (PL 17:538A).
thors, "one essence, three subsistences." And we found that we are compelled by necessity to speak in this manner so that we might be able to answer in one word when anyone asks what the three are, whom we truly confess to be three, namely, the Father, the Son, and the Holy Spirit.
In the eighth, it also became clear, from the reasons which we gave for those capable of understanding, that not only is the Father not greater than the Son in the substance of truth, but neither are both together something greater than the Holy Spirit alone, nor are any two something greater than one in the same Trinity, nor are all three together something greater than each other. After this, I reminded [readers] that the incorporeal and also unchangeable nature that God is might be understood (insofar as it can be understood) by the truth which is beheld by the understanding, by the highest good from which comes every good, by the justice on account of which the just soul is also loved by a soul that is not yet just, and by the love which in the sacred Scriptures is called God—by which those who have understanding also begin to discern, however it may be, the Trinity, namely, the lover, what is loved, and love.
Our discussion in the ninth book brought us to the image of God, which the human being is in terms of mind, and we found a kind of trinity in it, namely, the mind, and the knowledge by which it knows itself, and the love by which it loves itself and its knowledge. And we pointed out that these three are equal among themselves and are of the same essence. We treated this subject more carefully and more precisely in the tenth book, and this brought us to an even more evident trinity in the mind, that is, in the memory, the understanding, and the will. But we also made this discovery: that the mind could never be such that it would not always remember itself, understand itself, and love itself, even though it would not be always thinking of itself, and that even when it did think of itself, it did not always separate itself in the same thought from corporeal things; hence, we put off the discussion about the Trinity of which this is the image, in order that a trinity might also be found in corporeal things themselves, where the reader's mind could be more suitably exercised.
For this reason we chose the sense of sight in the eleventh book, since what we found in it could also be recognized in the other four senses of the body, even though we did not mention them. And so the trinity of the outer person appeared, first of all, in those things that are perceived on the outside, that is, from the body that is seen, from the form imprinted thereby in the gaze of the beholder, and from the attention of the will which combines both. But these three, as is obvious, are not equal among themselves, nor are they of the same substance. Next we discussed another trinity in the mind it-