I recently watched a dialogue between Timothy Flanders and Fr. Christiaan Kappes presenting an "Introduction to Gregory Palamas" and heard a proposition being offered for creedal unity (outlined in detail at 1:08-1:26) that I do not believe can possibly be right. My concern about this proposal is that it would, if adopted, essentially negate any practical possibility of reunion with the East on Thomist grounds. That is, if Fr. Kappes is correct, then the degree of Catholic latitude on metaphysical issues must necessarily be constrained in order for the East and West to be able to agree on the origin of the Holy Spirit, which even Fr. Kappes said will never happen regardless of how sincere the desire for unity is.
[Fr. Kappes responded to me thoroughly and thoughtfully; I have introduced some numbered notes throughout to briefly respond his criticism. I haven't convinced him on the acceptability of Thomism to the Eastern view, but I have provoked further consideration, and we both agree that the triumphalist Thomist position needs criticism and correction. I thank Fr. Kappes for his gracious donation of his time and consideration.]
I. The Context of the Discussion
In brief, Fr. Kappes maintains that doctrinal agreement is impossible in the absence of metaphysical agreement, and this agreement would be around what Fr. Kappes calls the "patristic" metaphysics as contrasted with the "classical" metaphysics espoused by St. Thomas Aquinas. I infer from the rest of what Fr. Kappes says that he groups the latter view into the "smorgasbord of filioquisms," which filioquisms were as numerous as there were religious orders. I would agree with him that there are certain erroneous positions that must be excluded on metaphysical grounds, notably including the Victorine analogy of the Father and the Son to the form and matter of the Holy Spirit, which would definitely entail two principles. But if we learned any lesson from the so-called "Neo-Thomist captivity of the Church," there is simply no good in confusing any metaphysical system with the dogma it is trying to articulate. On the contrary, if there were ever an example of Godel's incompleteness theory (or perhaps more aptly, Tarski's undefinability theorem) in action, it is in the Trinity, where logic can only be paraconsistent at best.
In terms of articulating his own metaphysical position, Fr. Kappes focuses on St. Gregory Palamas's acceptance that the Spirit proceeds from the Son "quod essentia," paralleling St. Cyril's statement that the Spirit proceeds "from the essence of the Son." Fr. Kappes posits a contrast between proceeding from the essence of the Son and from the person of the Son, maintaining that Latins can affirm according to Lyons that the Spirit proceeds from the Father alone as a person but only from the Son's essence. This he contrasts with the developed Thomist position, which is sometimes described as "strict Dominican" or "Anselmian" or "classical," to provide an idea of just how much ground this critique is intended to cover. Specifically, he argues that Thomists cannot say that the Spirit proceeds "from the essence of the Son" but must say that the Spirit proceeds from the Son "personally."
I'll start by saying that I don't have nearly the expertise Fr. Kappes does in this area. In addition to his own Byzantine scholarship, he has access to scholars like Jared Goff and Garrett Smith who are among the best medievalists alive. In terms of relevant qualifications, in discussing his opinion of Francis Meyronnes, Fr, Kappes suggested that it would require five to ten years of serious study in metaphysics to dispute his conclusions, and I'm not sure where my couple of decades as a hobbyist would compare. But unlike the issue of what exactly medievals meant by a real distinction, which is enormously complicated, this idea that "from the essence" means something distinct from what Thomists meant by "personally" is a narrow and distinct claim. Therefore, I don't have the same qualms about arguing that this distinction doesn't make any sense, and I would say that no matter who is making the claim, including (if it had been the case that they did) theologians like Bl. Duns Scotus and St. Gregory Palamas.
II. Dogmatic Considerations
As background, the Fourth Lateran Council's confession of faith makes a straightforward statement of the filioque: "The Father is from none, the Son from the Father alone, and the holy Spirit from both equally (pariter)." As logical statements go, there aren't many clearer ways to ways to state identity, and I can't see any other interpretation than "from the Father and the Son who are identical [in some respect]." (And despite the concerns Fr. Kappes raised about St. Anselm, this formulation seems to be consistent with his text against the Eastern view.) The council also explicitly vindicated Peter Lombard's view of the Trinity, saying "For the Father, in begetting the Son from eternity, gave him his substance, as he himself testifies : What the Father gave me is greater than all. It cannot be said that the Father gave him part of his substance and kept part for himself since the Father’s substance is indivisible, inasmuch as it is altogether simple. Nor can it be said that the Father transferred his substance to the Son, in the act of begetting, as if he gave it to the Son in such a way that he did not retain it for himself; for otherwise he would have ceased to be substance. It is therefore clear that in being begotten the Son received the Father’s substance without it being diminished in any way, and thus the Father and the Son have the same substance. Thus the Father and the Son and also the holy Spirit proceeding from both are the same reality." Especially the last quoted sentence should emphasize that this is an interpretation of the filioque, namely, that the Spirit receives His essence from both the Father and the Son in like manner to the way the Son receives His essence from the Father alone.
In my view, this is the fundamental dogmatic understanding to which Lyons and Florence were attempting to reconcile the East, especially given that Lombard's Sentences were the key source for both St. Thomas and St. Bonaventure. Fr. Kappes notes repeatedly that Lyons and Florence did not dogmatically define the metaphysical explanation of how the Spirit proceeds from the Son, whether personally or essentially, although at one point he does concede that the standard interpretation of Lyons is that the Spirit proceeds from the person of the Son. I disagree with the assertion if it were to be interpreted as saying that the Spirit in no sense comes from the person of the Son but the Father alone. The Fourth Lateran provides critical context that underlies the standard interpretation, and given the context of Canon 2, that canon says that the Spirit receives His essence from both the Father and the Son equally. I see no conflict between the Fourth Lateran and the formula of Lyons stating "We profess faithfully and devotedly that the holy Spirit proceeds eternally from the Father and the Son, not as from two principles, but as from one principle; not by two spirations, but by one single spiration." In that procession, as the Fourth Lateran explains, "proceeding from both" means the Spirit receives His undivided and indivisible essence from the Father and the Son, in like manner to how the Son receives His undivided and indivisible essence from the Father.
As to the later councils, it is fair to say that Florence was most specifically directed to East-West unity in a way conscious of the division. There could be an argument made that the confession of faith from the Fourth Lateran wasn't specifically directed to this distinction and Lyons gave only a simple statement because the level of disagreement was not perceived, so that only Florence confronts the issue squarely. But that cuts both ways; the fact that the focus was less polemical also means that it is likely to represent the straightforward belief without any political accommodations to water it down. In the case of the Fourth Lateran, Pope Innocent III was trying to bring the East back into the fold at the time of the Fourth Lateran Council and even invited the East to the council, until political issues related to the inability to appoint a Latin patriarch in Constantinople greatly offended the Orthodox. It seems unlikely that the council, in its defense of Lombard, would have gone out of the way to say something specifically directed toward the East. And obviously, Lyons was a sincere effort toward reunion on the understanding that there were not significant disagreements on doctrine. So there's simply no reason to think that the dogmatic statements of the Fourth Lateran Council and Lyons mean anything substantially different from Florence, even though they were definitely broad enough to allow interpretations (like those of the Victorines) that were erroneous. In short, one can accept Fr. Kappes's view that there might be different metaphysical explanations of how exactly the Spirit receives His essence from the Father and the Son, but I can see no real way that the object of this explanation can be completely different. What is being explained at the Fourth Lateran and Lyons is the same.
To that point, there doesn't even seem to be any relevant difference between the Fourth Lateran's qualifier pariter and the Florentine formulation tamquam ex uno principio. The Bull of Union with the Copts issued by Florence describes the Trinity as "unbegotten Father, Son begotten from the Father, holy Spirit proceeding from the Father and the Son," maintaining that "The Father alone from his substance begot the Son; the Son alone is begotten of the Father alone; the holy Spirit alone proceeds at once from the Father and the Son." It goes on to say "Whatever the Father is or has, he has not from another but from himself and is principle without principle. Whatever the Son is or has, he has from the Father and is principle from principle. Whatever the holy Spirit is or has, he has from the Father together with the Son. But the Father and the Son are not two principles of the holy Spirit, but one principle, just as the Father and the Son and the holy Spirit are not three principles of creation but one principle [emphasis added]." I highlight that last phrase in particular because I don't even perceive any metaphysical disagreement about what it means: the Spirit proceeds from both persons united by their consubstantial principle of unity, which is exactly what the Fourth Lateran says. That is what unites the Trinity with respect to creation; it is likewise what unites the Father and the Son with respect to being the principle of the Spirit.
 [Dr. Jared Goff is working on an article concerning the origins of Lyons, and Fr. Kappes has asked him to consider the points I've raised here about the background. I am looking forward to that article, even if it ends up correcting me.]
III. What Does "Quod Essentia" Mean?
So where is this idea coming from that "from His essence" means something other than "from Himself personally?" As best I can tell, it seems to be taken from Bl. Duns Scotus in Ordinatio I, 11, 36 et seq. There is an extended discussion on how the Father and the Son are not merely concordant actors in spiration but act as one by the one divine will that they both possess. His summary at 1.11.62 [emphasis added] is quite clear: "But as to what concerns the intended proposition, one should not understand that the Father inspirits before the Son inspirits, in the way that the Father generates first in origin before he inspirits, because then the Son would not inspirit (as the argument deduces), just as the Holy Spirit cannot generate a Son already understood to be generated. But the order that exists in the Father is as follows: first both fecundities are from himself; second, there is in the Father the act of first fecundity, and then in the Son there is the second fecundity; third there is the act of the second fecundity, from the Father and the Son together as then having that fecundity, – yet still in a certain order, because the act is of the Father from himself, but of the Son not from himself but from the Father, just as neither in the second moment is there that fecundity of the Son from himself, but it is of the Father from himself. There is not then an order of origin between the inspiriting of the Father and of the Son, as if the Father inspirited in some moment of origin in which the Son does not inspirit, but they inspirit together in the same moment of origin; there is however there an order of inspiritings in the act of inspiriting, because the Father in that moment of origin inspirits from himself, but the Son not from himself."
Aha! Scotus says that the Son does not inspirit from himself; the foul Dominicans are vanquished! If we only take St. Augustine's psychological analogy seriously, as the Subtle Doctor does, we can give the one true metaphysical interpretation of tamquam ex uno principio that everyone East and West can get behind (save those benighted Thomists!). But perhaps we should postpone the parade until we have a chance to examine that claim.
All that "not from himself" must mean in this context is that the Son's personal property (of filiation) does not add anything to the Father's action. We know that this phrase, whatever it means, must be understood in the context of activity; Fr. Kappes's explanation as to why the person or essence cannot be any sort of matter from which the Spirit is taken is dead on. For example, we cannot truly say that the Father's hypostasis or the divine essence are some kind of reservoir from which the Spirit is drawn, although that image is used metaphorically. Then once we understand spiration as action, "not from Himself" should not be taken to say that the Son is not personally acting, which is clearly untrue. On the contrary, "not from Himself" must be intended only this sense of distinguishing His personal property. In other words, the Son must be "inspiriting" with the Father according to their common essence, what He has received from the Father. That means that participating "quod essentia" in this context is a subset of personal participation, not a disjoint set. We can certainly then say that the Son is participating "quod essentia," that is, exactly and only with respect to His common essence with the Father, without denying that He is personally participating in the act of spirating. There is, as Scotus puts it, a "the act of the second fecundity," even though there is "an order of inspiritings in the act of inspiriting." Yet we say that they spirate as one spirator, not two, and one principle, not two, on account of acting out of the common essence.
 [Fr. Kappes notes that "participating" and "sharing" have baggage that makes the use of those terms inappropriate in the Trinitarian context, and he is entirely correct. "Co-acting" or "co-spirating" would be a better term in retrospect for the Son also acting.]
IV. The Position of St. Thomas
Fr. Kappes seems to believe that Dominicans are metaphysically committed to collapsing this distinction between "personally spirating" and "spirating from Himself" in the sense that Scotus articulates. That is presumably based on the maxim "In God, all is one where relative opposition does not prevent it." Because Aquinas, as is well known, takes this view, Fr. Kappes suggests that Thomists can have no basis for saying that that the Son inspirits "not from Himself."
In terms of the explanation for this assertion, Fr. Kappes says that St. Thomas did endorse procession from the essence in Part Two of Contra Errores Graecorum but later moved away from this position as being "too crude," which in Fr. Kappes's view was evidence of a shift from the patristic view to classical metaphysics. Yet already we see St. Thomas articulating the same distinction between "personally" and "not from himself" in CEG II, 16:
That the Son spirates he has from a personal property.
Lest anyone object that the Son does not spirate the Holy Spirit in the proper sense of the term, the Son is called by these Doctors the spirator of the Holy Spirit, having precisely from a personal property that he should spirate the Holy Spirit. For Athanasius says in his letter to Serapion: “The heretics blaspheme and deny the Son, the Spirator of the true Spirit, the Paraclete.” And again in the same letter: “He who blasphemes against the Spirit spirated also blasphemes his Spirator, that is, the Son, and through the Son he blasphemes his Father.” Against Eunomius Basil also says: “Without any doubt we believe the Son to be the Spirator and giver of the Holy Spirit.”
As Fr. Kappes correctly observes, St. Thomas seems to have no problem with the "from the essence" language, but Fr. Kappes doesn't seem to recognize that Aquinas also has no problem in saying that the Son's spiration is from a personal property (the essence He possesses as a result of filiation) without itself being a personal property, a critical distinction that leaves open grounding the power of spiration in possession of the divine essence. We can leave aside whether the cited authorities in question justify the position; Fr. Kappes has extensively documented St. Thomas's respectful corrections of Ps.-Basil in his article "The Filioque, Thomas de Aquino Byzantinus, and Ps.-Basil’s Contra Eunomium: Mark Eugenicus and John Montenero, OP, at the Council of Florence (1439)." Even with that understood, this passage still suffices to show that Aquinas recognized that the power of spiration did not need to identify a personal property. In other words, the Son has this power of spiration as a result of filiation, but the power itself in no way originates from the personal property itself but solely by virtue of possessing the same essence as the Father. That view should not be problematic from what is laid out before; does this position actually change?
I will have to attempt to infer what Fr. Kappes has in mind with this critique, because he doesn't provide any specific citations. But he does mention that it relates to the distinction between the Son and the Spirit by relations, and he also talks about St. Anselm's approach of distinguishing the Persons by "from" relations, as well as mentioning that a metaphysical distinction is required between points B and C to distinguish lines AB and AC. What he said also reminded me of a remark by Jared Goff that St. Thomas considered denial of the filioque inherently heretical, which Dr. Goff said was not the case for Scotus since there was an intervening metaphysical conclusion that would have to be drawn. Lastly, as mentioned, he suggested that it was a change from St. Thomas's prior position that "from the essence" was unproblematic. That suggests to me that he has in mind particularly the position fully articulated in ST I, 36, 2, ans., which includes both of the following statements:
If therefore in the Son and the Holy Ghost there were two relations only, whereby each of them were related to the Father, these relations would not be opposite to each other, as neither would be the two relations whereby the Father is related to them. Hence, as the person of the Father is one, it would follow that the person of the Son and of the Holy Ghost would be one, having two relations opposed to the two relations of the Father. But this is heretical since it destroys the Faith in the Trinity.
Hence also the Greeks themselves recognize that the procession of the Holy Ghost has some order to the Son. For they grant that the Holy Ghost is the Spirit "of the Son"; and that He is from the Father "through the Son." Some of them are said also to concede that "He is from the Son"; or that "He flows from the Son," but not that He proceeds; which seems to come from ignorance or obstinacy. For a just consideration of the truth will convince anyone that the word procession is the one most commonly applied to all that denotes origin of any kind. For we use the term to describe any kind of origin; as when we say that a line proceeds from a point, a ray from the sun, a stream from a source, and likewise in everything else. Hence, granted that the Holy Ghost originates in any way from the Son, we can conclude that the Holy Ghost proceeds from the Son.
I can start by asking a question: is St. Thomas here begging the question in favor of his metaphysics? Certainly, that must be the case. Fr. Kappes and Dr. Goff both point out that the Scotist metaphysics doesn't require these conclusions, so St. Thomas has surely brought some unshared metaphysical assumption to the table. It is critical to note this for the reason that Fr. Gilles Emery notes in Trinity in Aquinas (p. 267): "Evidently, Thomas knows that the doctrine professed by the Greeks is not in any way Sabellian. The problem lies with the fact that, in his opinion ... the negation of the procession a Filio, if it is followed through to its logical conclusion, leads necessarily to Sabellianism: And it is this which is heretical." I cite Fr. Emery here and in what follows both because he is well-known as a Thomist scholar and because he appears as a Thomist foil in Fr. Kappes's articles. And Fr. Emery's conclusion here is sound; Thomas concludes the denial of the filioque is heretical based on a metaphysical conclusion, but that assumes Thomas's metaphysical axiomata are held in common.
It is this comparison between the Thomist metaphysical system and other systems that seems wanting. In order to better inform that comparison, I will be relying on The Logic of the Trinity by Paul Thom, which covers the philosophical use of relations, simplicity, and identity in various Western authors including Augustine, Boethius, Lombard, Bonaventure, Aquinas, and Scotus. What Thom says about Scotus, following Richard Cross's explanation, lines up perfectly with what Fr. Kappes and Dr. Goff say about Scotist and Thomist metaphysics being fundamentally irreconcilable. In other words, that Scotus disagreed with Aquinas's metaphysics with respect to simplicity and relations should come as no surprise, and I take the beatification of Scotus as a clear indication that the Catholic Church has not ruled out either view as being permissible. We definitely have two completely different metaphysical systems in play. Even at that point, it is still not clear why the incompatibility between Thomism and Scotism, if it does not create any dogmatic incompatibility in the West, would nevertheless create dogmatic incompatibility with the East.
Moreover, Fr. Kappes's assertion is that it is only later Thomism that suffers from this problem, as if this distinct Thomist metaphysical system somehow arose in time over the course of St. Thomas's literary production. The idea that this "mature" view on relations represents a change in Aquinas from an earlier patristic view to a later classical/metaphysical view has no support in Thom or, as far as I can tell, anywhere else. Nor do I see any reason why a Thomist would not be able to consistently affirm the sense of "not from Himself" that Scotus affirms, which strikes me as the same distinction affirmed by the Fourth Lateran Council. So on the face of what St. Thomas himself says about relations, the objection remains cryptic, and it requires some work even to know what exactly Fr. Kappes is saying about St. Thomas.
V. Making the Argument Explicit
In trying to explicate the objection, I've dug through a number of Fr. Kappes's articles to tease out the basis for this claim, and there are a couple of citations that provided helpful suggestions. There is a hint in the aforementioned article on John Montenero, where he explains that Montenero was not following Aquinas at Florence, but he nonetheless sees some "tension" in Aquinas. The following excerpts seem particularly relevant:
Of course, one can immediately see a tension: The patristic-commentator Aquinas affirms something like Neo-Platonic noetic productions of persons, particularly the Spirit from the Son’s essence and from the Father as principle, while the Aristotelico-Anselmian Aquinas emphasizes that only divine esse and relations of origin and their opposition count for any distinction in the Trinity.
As if forestalling any development of what will become Montenero’s position, Aquinas actually exhausts this topic, approving citations of Greek Fathers whose fundamental point he emphasizes in his heading of the relevant chapter by his own words: “That the Holy Spirit is spirated from the essence of the Son (Quod de essentia filii spiratur Spiritus Sanctus)” (emphasis mine). He sometimes approvingly glosses their words as in the following example: “[Cyril of Alexandria:] ‘The very Spirit exists as fruit of the Son’s very essence’ […] [in the following sense, then he is] said to be eternally from the Son” (emphasis mine). If we compare Aquinas’s many select passages, often emphasizing the essence as the eternal source for the Father’s spirating through the Son, we could plausibly interpret at Lyon the virtual presence of Aquinas’s patristic sources in the definition: “The Holy Spirit eternally (aeternaliter) proceeds from the Father and the Son, not as if from two principles, but as if from one principle, not two spirations, but a unique spiration […]” “The word ‘principle’ signifies only that whence another proceeds: since anything whence something proceeds in any way is called a principle. As the Father then is one whence another proceeds, it follows that the Father is a principle.” Both the persons of the Father and the Son are included by Thomas under “one principle” but according to a certain qualification. The essence is the power possessed by Father and Son by which one immediately, and the other only mediately, spirates and thus they are both non-temporally the source of the Spirit in one eternal act of spiration. On one hand, Aquinas’s patristic reading of texts, similar to that of Lyon, suggests agreement with the Greeks at Florence, but on the other the overwhelming preference on the part of systematic theologians who follow Aquinas today is (rightly) to demand a strict emphasis on relations alone. For its part, the definition of Lyon lacks the clarity of distinction in Aquinas of attributing “immediate” spiration of the Spirit to the Father.
As it now stands, the definition of Florence can be read either in light of Montenero’s position, as attested in the Florentine Acta, or Aquinas’s plausible influence on the formula of the Second Council of Lyon, the very source of contention necessitating the debates at Florence. Of course, this does not resolve the tension present in Thomas’s own works, where Augustine’s psychological analogy of mind, intellect, and love are reducible to mere metaphors, on one hand, while, on the other hand, Aquinas turned to developing the notions of eternal subsistent relations out of Anselm’s De processione Spiritus Sancti that are said somehow to enjoy their fons and origo in the Father, though not in the sense of Augustinian productions out of the Father as mind. Thus, work remains to compare the authentically Thomistic subsistent relations of origin and opposition to Mark’s Palamite Greek tradition of productions by the Father of divine persons, for such a dialogue was entirely absent from the Council of Florence.
Fr. Kappes thus alleges a "tension" between Aquinas's "patristic sources" and the "authentically Thomistic subsistent relations," suggesting a possibility that these might be reconciled, although one senses that Fr. Kappes is pessimistic. These hints become more plain when he discusses Scholarios's reception of subsistent relations in his article "RECEPTION OF THE NOTION 'SUBSISTENT RELATIONS' AS PERSONS IN LATE BYZANTIUM." He refers specifically to Gennadios Scholarios's discussion with Mark Eugenicus before the Council of Florence and the Eastern scholastic's rejection of subsistent relations as a sufficient causal account for the purposes. Fr. Kappes explains:
Effectively, prior to Florence, Scholarios coincides with Bonaventure of Bagnoregio and John Duns Scotus (who took two different positions in his career) on the fact that the taxis or ordo of the Trinity demands a primus/protos who is undoubtedly the Father. In so many words, Scholarios agreed with Cabasilas but in a Franciscan mode of arguing for primus in the eternal ordo of persons. Aquinas had rarely, though verbally, conceded this point a few times in his multiple volumes of works but it is clear that the effect of Scholarios’s analysis of the issue accurately read Thomas Aquinas to reduce all distinction to a non-productive relation to another as the sole constitutive of a divine person, whereas subsistent relations are, like the Franciscan reading of Augustine’s De Trinitate, a corollary of internal, eternal, noetic production of a psychological nature that establishes a foundation for each relation in the Father’s production of Word and Love. For Aquinas, Anselm’s famous emphasis is sufficient: Everything in godhead is possessed equally by all persons, save what is opposed by relation.
So we seem to have finally arrived at the critique: mere subsistent relations. While this concept does appear to rank moderately higher in Fr. Kappes's estimation than the Victorine "Mommy and Daddy having a little baby" analogy to the Holy Spirit, it can't be by much. I therefore take Fr. Kappes's position to be as follows: (1) St. Thomas initially held the allegedly Augustinian view of internal processions, which was compatible with the Neoplatonic concept of productions as outlined by St. Bonaventure, Bl. Duns Scotus, Gennadios Scholarios, and Mark of Ephesus. (2) But Aquinas then turned away from this view, demoting the psychological model from what it was in Augustine to a mere metaphor in favor of a purely classical metaphysical model based on Aristotle and Anselm.
VI. The Psychological Analogy in St. Augustine
Fr. Kappes has pointed out that no one really understands (or, in most cases, has even read) Augustine, and I can't disagree with that or claim to have done much better. Michel Rene Barnes cites a statement by Gerald Bonner (as quoted by John Rist in Augustine) as follows: "More than most authors Augustine has been the object of unjustified denunciation by those who have not read him." So I must rely on my betters in that regard. On the psychological analogy, I will rely on two scholars who have done comprehensive and thorough studies of Augustine's pro-Nicene doctrine of the Trinity: Barnes and Lewis Ayres. In particular, I have found the following works particularly useful: by Ayres, Augustine and the Trinity, and "Remember That You Are Catholic" (serm. 52.2): Augustine on the Unity of the Triune God; and by Barnes, "Rereading Augustine's Theology of the Trinity" in The Trinity, David, Kendall, and O'Collins, eds., and "The Visible Christ and the Invisible Trinity: Mt. 5:8 in Augustine's Trinitarian Theology of 400."
Based on their work, I think this idea that Augustine had a Neoplatonic metaphysical view in mind for the psychological analogy is very unlikely. That's not to say that Augustine did not use Platonic metaphysical concepts; most assuredly, he did. But the driving thought behind the triadic analogies is to show an example of the unity of operation to support the pro-Nicene principle that one operation is one nature, with no particular relationship to Neoplatonic triads. Ayres and Barnes both date Augustine's approach on this subject to early works including Epistles 11 and 14 to Nebridius, which deal with how the Trinity is one but the Son alone is Incarnate. Ayres in "Remember..." sets out Augustine's program for how we can speak about inseparable operation using triadic analogies yet also speak of the Son alone being Incarnate as follows: "Once he has set out this terminology, Augustine’s argument continues thus: if we understand that all things show these three aspects inseparably, then we should be able to at least imagine the idea of three distinct things being inseparable in their activity. So far the analogy does not work by aligning the three persons with individual terms in the analogy: the point to be illustrated is much more formal and concerns only the inseparability of the three things that are also a unity [emphasis added]." The logical structure is consistent with Latin pro-Nicene theology, as opposed to Neoplatonic triads. Ayers further observes that, once this triadic analogy is used to establish unity, Augustine next turns to the existence of the Son particularly and the Father as principium of the Trinity, which explanation does not appeal to the triadic analogy.
That same formal approach is later applied in a mature way to the use of the psychological analogy as follows: "Within Augustine’s Trinitarian logic because the Triune God is truly simple each person must be their own memory, understanding, and will. And yet, at the same time, the memory, understanding, and will that each irreducibly is is also simply that of the one God. If the three terms were applied each to a person directly then, as Augustine says both here and earlier in Book 6, the Father would not be a full person but would, for instance, have will only in the Spirit. The problems of this position are overcome in Book 6 of trin. by the exegesis of 1 Cor 1.24 that there is only one power and wisdom of God, in which all three persons irreducibly share, and which is appropriated by Scripture to the Son. In Book 15 the full power of Augustine’s solution is seen: the simplicity of God guarantees the irreducibility and yet inseparable nature of the persons and allows Augustine to maintain the logical order of Trinitarian procession." What is absolutely critical to see, and what is often missed in the Neoplatonic interpretation, is that the "analogy" to the terms is intended to show only unity of operation and not distinction of the persons by way of relation. Citing Ayres, Barnes concludes as follows: "These replacements are not properly called analogies and indeed Augustine declines to call them such." That there are persons, and how there are persons, is taken up elsewhere. The conclusion is merely used to show that, if there are persons, there is no conflict in appropriating to those persons particular actions even in the unified operation.
It is striking how consistent this is with St. Thomas's argument for why the attribution of processions to intellect and will is not adequate to distinguish the persons. In Summa Contra Gentiles IV, 24, he says: "But, again, if one says that the processions differ in principle, in that the Father produces the Son by way of intellect as Word, and the Holy Spirit by way of will as Love, it will be necessary to say that in accord with a difference of intellect and will in God the Father the two processions and the two proceeding are to be distinguished. Will and intellect in God the Father are not distinguished really, but only rationally, as was shown in Book I. It follows, then, that the two processions and the two proceeding differ only rationally. Now, things which differ only rationally are predicated of each other: it will be truly said that the divine intellect is the divine will, and conversely. Therefore, it will be true to say that the Holy Spirit is the Son, and conversely. This is the Sabellian impiety. Therefore, it does not suffice for the distinction of the Holy Spirit and the Son to say that the Son proceeds by way of intellect and the Holy Spirit by way of will, unless along with this one says the Holy Spirit is from the Son." The logic here is identical to Augustine's; will and love show common operation but not personal distinction.
In terms of what that next metaphysical step is and how Augustine takes it, there is no entirely satisfying answer, because it isn't clear that Augustine himself intended to answer this question. Augustine clearly uses the term principium
in his Trinitarian account. Ayres's book covers Augustine's passage in De Ordine
2.5.16 that uses the term principium sine principio
in a sense alleged by Olivier Du Roy to be a Neoplatonic account of emanation, an assertion which Ayres follows Nello Cipriani in rejecting. The relevant chapter
of Ayres's book concerning the use of principium
with respect to the Holy Spirit is currently online, and the analogies concerning principium
appear to be entirely situated within the pro-Nicene concept of inseparable operations as opposed to explaining how the principium
operates. In terms of providing a metaphysical explanation, Augustine does not seem to go beyond what Florence says: "But the Father and the Son are not two principles of the holy Spirit, but one principle, just as the Father and the Son and the holy Spirit are not three principles of creation but one principle
." I think Ayres is entirely fair in concluding that Augustine's theological view is therefore compatible with the Thomist view without actually espousing it, and I will say the same about Scotus's interpretation of the psychological analogy. Either of the later positions is a consistent metaphysical explanation of Augustine's position, and neither was actually taught by him. We are at the point that I mentioned earlier: that of having multiple incommensurate explanations with different axiomata.
 [Fr. Kappes notes that the varied literature on Augustine makes this a wash, but Ayres is certainly worth considering. Fr. Kappes's analysis of Augustine is based on detailed philological comparison with Neoplatonic sources, which is why he finds it persuasive.]
VII. The Logic of Relations
Given that there will not be any obvious resolution for the metaphysical quandary, we can at least try to see if there is a logical framework that allows for some common conceptual ground. For that, we can turn to Thom's work mentioned above. Thom explains that Augustine has modified the Aristotelian categories to make all of them ad se (to God) with the exception of relatives, which is ad aliud (to another). If the concept of substance is then suitably modified to say that there are no accidents in God, which is a significant change from Aristotle, then God can be a single substance with three relatives. But as Thom points out, this analysis "leaves one important question unanswered: Is the distinction between the three relatives grounded on anything further?" Thom (p. 40) concludes that Augustine hasn't provided any answer, which is consistent with what we've said above about Augustine's use of the psychological analogy not providing a reason for personal distinction. Ayres, Barnes, and Thom have thus all come to the conclusion that Augustine has not used the psychological analogy to ground the inner-Trinitarian relations.
While Augustine seems to deliberately avoid this grounding question, possibly because he simply doesn't have an answer to it, Boethius later takes up the question directly. Thom (p. 60) summarizes Boethius's position on the grounding of the relations (namely, that there is no grounding other than the divine essence) as follows: "The answer -- a mysterious one -- is that they are differentiated by the Personal properties [Paternity, Filiation, Spiration], which are all identical with divinity." Peter Lombard follows the path blazed by Boethius (p. 98-102), and he concludes that the Personal properties are "in the Persons and are the Persons and are the divine essence," while echoing St. Hilary's demurral ("I do not know and do not ask") with respect to any further explanation. That would be the status quaestionis as of the Fourth Lateran Council, providing the context of Canon 2 on the filioque.
The consideration of this issue in the thirteen century develops what is called the "common opinion," which is essentially Peter Lombard's position established as a mean between two other positions, (1) the position of Gilbert of Poitiers that the relations differ from the Persons in an unqualified way and (2) the position of Praepostinius that the relations do not differ at all from the Persons except by manner of speaking. (This is something of an oversimplification of the situation offered by Bonaventure, as Thom outlines in more detail, but for our purposes, it will do.) It is at this point where two different metaphysical approaches emerge. The first, Bonaventure's approach, is one that I would call "eclectic Platonic," which is similar to the one that Augustine and Boethius followed. It is not strictly Neoplatonic in terms of following the triadic structure or other characteristic features of Neoplatonism, but it borrows certain philosophical concepts about the nature of entities implicitly to help in the explanation. The second, courtesy of Albert the Great and followed by Aquinas, is a position I think of as "systematic Aristotelian," which attempts to take the Categories as modified by Augustine and Boethius and to apply them in a more systematic way. I will say in advance that the difference in this respect makes absolutely no difference for the metaphysical conclusions on relations, but it does augur the divergence of metaphysical systems between Franciscans and Dominicans.
Among the three authors (Bonaventure, Albert, and Aquinas), there is general agreement on one new principle articulated by Bonaventure (Thom, p. 111): that the Personal properties inhere "in" the persons in the respect that they are the same as the divine essence but that they really distinguish the Persons to the extent that they are "towards" another. It might be useful to think of relatives in this context like vectors, mathematical entities with a magnitude and a direction, so that the relatives are identified with the divine essence in respect of their "magnitude" and identified with the Persons with respect to their "direction." St. Bonaventure, St. Albert the Great, and St. Thomas all agree that this distinction is the right way to explain how the relatives are the essence (in one sense) while remaining a basis of distinction, and they also agree that the "towardness" of the Personal properties establishes a real distinction of origin between the Persons. Where all three of these authors will differ is in exactly how the Personal properties, as relatives, inhere in the divine essence and how they are predicated of the Persons and the divine essence.
The reason that I call Bonaventure more "Platonic" is that his rules of predication seem to be more in line with how they are understood in Platonic metaphysics, which seems to be more in line with Augustine's generally Platonic epistemology. Specifically, Aristotelianism epistemology has a more strict definition of what abstraction by way of intellect can be, and Bonaventure describes it in a way that Albert and Thomas cannot accept. As Thom explains at p. 107 et seq., Bonaventure does accept the Aristotelian distinction between quo est and quod est in God, but he modifies it to make sure that there is no conception of diversity or distinction that is typically implied in abstracting from (ab). To do so, he distinguishes abstraction from the nature of the thing, as with universal/particular or form/matter, from abstraction in which our understanding must grasp something according to multiple concepts because of our relation to it. Our understanding of quo est and quod est in God operates in the latter way, and thus we can distinguish the Personal properties with respect to the essence and the Person according to mode without a real distinction between the two. Then there is also the distinction between the Persons, which relates to a mode in which something stands (or relation towards), which is a real distinction. This leaves Bonaventure with a tripartite scheme of our intellectual distinctions concerning God: (1) purely notional distinctions, which do not correspond to any real distinction (as with God's goodnesses and greatness), (2) attributed distinctions according to our concepts, which correspond to a modal distinction (as with essence and person), and (3) distinction of plurality which do not introduce a diversity of essence or nature but which are real (as with the persons among one another). Because the Personal properties are both in the essence and the Person but closer to the Person than the essence, Bonaventure concludes that there is only a "small difference" between the properties and the Persons and that they are only "in" the divine essence "speaking generally and loosely" on account of the Persons being in the divine essence. (What I found interesting was that Scotus rejects this account of abstraction (Thom, p. 146), presumably based on further developing the formal distinction as a basis for the distinctions that Bonaventure makes here.) In any case, the Seraphic Doctor's conclusion on relative opposition, based on relations being "toward," seems to be exactly what we expect in the Latin tradition.
As I mentioned, Albert disagrees with Bonaventure specifically on this idea of "abstracting from," in which Albert follows Boethius in saying that the rules of predication must instead follow the categories the the extent that the subjects allow (Thom, p. 118 et seq.). Albert therefore doesn't believe that there can be any such "from" relationships in divinity. Instead, there are predicates that are substantial and those that are not, the latter of which specifically include the relativity (pointing-towards) of the Personal properties. This allows the inherence of the relatives in the divine essence not to exclude real distinctions by way of their objects. But Thom (p. 127) aptly states the degree of agreement as follows: "Apart from the divergences we have noted in the way the two theologians construed inherence and abstraction, their accounts of the Persons are identical."
St. Thomas, for his part, ends up moving a bit back toward Bonaventure from the position that Albert has staked out (Thom, p. 129 et seq.). Notably, he says that, since the essence and the Persons themselves differ conceptually as abstract to concrete, there is no reason that we should have any more concern about "abstracting from" with respect to the relative Personal properties than we do with respect to (abstract) simplicity and (concrete) perfection (Thom, pp. 138-39). This leads to an understanding of the conceptual distinctions (rationes) in our statements about God, which is not drastically different from Bonaventure's tripartite division presented above. Aquinas outlines a "greater rational distinction" between essence and properties as compared to the Persons and their properties, a distinction that falls nicely in line with Bonaventure's "small difference" between Persons and properties. (Emery explains in detail how St. Thomas thinks about relations at pp. 194-98.)
Note that all three conclude identically on a real distinction between the Persons and the nature of the relational opposition between the Persons based on "towardness." In St. Thomas's case, this distinction is aligned with the distinction of abstract to concrete, activity to perfection, which seems to be the same distinction between the unity of inseparable operations and the persons that Augustine first considered in his pro-Nicene theology. At this point, the thirteenth-century authors all believe the same thing about relative opposition: the relations are in (and identical with) the divine essence and the Persons to the extent that they are "in" the Persons, and they are identified with the Persons and establish real distinctions to the extent they are "towards." Note also that even the definition of relative opposition is identical: the Father is "toward" the Son, the Son is "toward" the Father, and the Holy Spirit is "toward" the Father and the Son as one principle, exactly as the Fourth Lateran Council teaches. This directly answers the first part of Fr. Kappes's assertion that St. Thomas's later position requires a personal property of the Son to distinguish the Son from the Spirit. Rather, since the distinction only needs to be in the manner that the Holy Spirit is toward the Father and the Son as object, in which respect they are not distinguished by personal property, this logical condition that is satisfied by the relations of opposition as outlined.
VIII. Seraphic and Angelic
Nonetheless, there is a subtle difference here about how we know the relations, even though they all agree that the "toward" aspects of the relations establish a real plurality. As I suggested above, that epistemological difference on intellection between Platonic and Aristotelian metaphysics is a sign of underlying axiomata. That hints at a larger metaphysical difference, which doesn't actually exhibit itself in the context of relations discussed above or the filioque, but it does serve as a useful illustration of how different metaphysical systems can explain the same dogmatic facts. That difference resonates with the different titles given to Bonaventure and Aquinas, the Seraphic Doctor and the Angelic Doctor, two different ways of venerating these souls who seem superhuman in their grasp of God.
I raise this point here to answer the second part of Fr. Kappes's assertion -- that St. Thomas has changed from an earlier patristic position. Contrary to what Fr. Kappes says about Aquinas's development, this metaphysical difference I have in mind stretches all the way back to Bonaventure's and Aquinas's respective commentaries on the Sentences, which unquestionably predate CEG and SCG, much less the ST. (In fact, it probably dates to their immediate predecessors, the Franciscan Alexander of Hales and the Dominican Richard Fishacre.) This difference relates to the technical use of the term "infinite" to refer to God.
Leo Sweeney, in Divine Infinity in Greek and Medieval Thought, has identified two distinct technical senses in which this term is used for God's very being. The first sense is defined with respect to creation (extrinsic denomination) and is associated with power, to wit, God's infinite array of possible effects with respect to creation. To the extent that God's infinite power is identified with His being, this is associated with how God contains all being in Himself and perfects all being and is contained or perfected by none of creation, including with respect to properties like immensity (non-spatiality), omnipotence, and incomprehensibility. Since it is associated with God's relation to creation, it is typically associated with God as triune being infinite, as opposed to directly predicating infinity of the divine essence. The second sense is one pertaining to God's being in itself as actus purus (intrinsic denomination), referring to God's absolute freedom from matter and potency as unlimited act. This second sense is St. Thomas's concept of divine infinity. There is also a parallel form of this second sense in St. Gregory of Nyssa and St. John Damascene concerning God's absolute freedom from all determination, which serves a similar conceptual function and which is later connected to the Dionysian hyperousios in the Neoplatonic metaphysics. (N.B., on the Greek view, in addition to Divine Infinity, see Fr. Sweeney's article "Augustine and Gregory of Nyssa: Is the Triune God Infinite in Being?" in Augustine: Presbyter Factus Sum).
Lombard in the Sentences appears to be limited to the first sense, and it is even possible that he limits himself further to the earlier classical view that does not truly attribute infinity to the essence in any sense, which would be even more constrained than his source in Augustine (Sweeney, p. 365-83). Bonaventure's own source, Alexander of Hales, endorses the first sense of divine infinity, equating the essence with the power of God (Sweeney, p. 423). According to Sweeney, Bonaventure himself appears to go a bit beyond that in terms of considering God incapable of determination of matter and potency, but he never actually uses the concept of being unlimited act explicitly, and seems to find creaturely finitude as composition (lack of simplicity) rather than determination by matter or potency (Sweeney, pp. 426-32). Sweeney (p. 432) concludes that Bonaventure's own view is consistent with Alexander's. But I believe Jared Goff has shown Sweeney wrong here, because his book Caritas in Primo identifies the source of Bonaventure's doctrine of divine infinity to be John Damascene's, which would actually be the parallel Greek version of divine infinity in God's very being. That version of infinity would view God as free from determination in the Neoplatonic, rather than the Aristotelian, sense.
By contrast, Aquinas applies infinity to the divine essence in the Aristotelian sense of being unlimited by matter or potency. Sweeney cites his conclusion (p. 435) that the divine essence is "infinite through negation of whatever would determine and restrict it [namely, matter and potency], for form as form is infinite." Aquinas's concept follows on Richard Fishacre's statement (p. 422) that God is properly infinite when removed from all limitation of matter and potency: "Quia ergo Deus in se simplex est et carens compositione cum alio, ut sit pars compositi, patet quod est infinitus virtualiter, non propter additiones virtutis factas in infinitum, sed potius quia in infinitum elongatus est ab impedimentis et materia, cum sit substantia omnino separata." The identity of the essence with its act of existence, utterly simple and without determination by anything else, makes the divine essence absolutely infinite in being. This seems like a perfect anticipation of Aquinas's own doctrine, down even to the use of the term virtualiter to describe the infinite number of modes in which esse can be finitely imitated by created things, anticipating the use of the virtual distinction by later Thomists.
Fr. Sweeney (p. 436) summarizes the endorsement of the first and second views of divine infinity by Bonaventure and Aquinas respectively as follows: "Manifestly, Aquinas' theory of the infinity of divine being differs deeply from Bonaventure's. The former concentrates on essence, whence he moves to power; the latter concentrates on power and thence moves to essence. The former grounds the infinity of God's essence in its freedom from potency and matter: it is subsistent, God is existence. The latter (with the exception of two brief texts) identifies the infinity of the divine essence with its immensity: it is preset in all creatures, however many and varied they may be." Subject to the correction that Bonaventure has likely followed John Damascene's expansion of the concept of divine infinity, the difference is correctly stated. Again, this difference emerges from the beginning in their commentaries on the Sentences, not as an extended development.
As I suggested, Fr. Kappes and his colleagues Jared Goff and Alexander Giltner give a sophisticated account of Bonaventure's notion of divine infinity in their article "Palamas among the Scholastics," including statements such as the following (with citations omitted) that "Augustine likely uses Porphyry, who unified Plotinus’ threefold Hen univocally, so that Proclus and Damascius fiercely criticized him. Bonaventure’s reception of Augustine’s divine ideas (c. 1254–7) cedes (implicit) priority to Maximus Confessor and Ps.Dionysius, explicitly prioritizing Damascene on divine infinity. Hence, Bonaventure situates Augustine’s understanding of infinity of the divine ideas within the prior and conceptually broader affirmation of the actually intensive infinite of the divine essence itself." I see nothing in Fr. Kappes's assertions that acknowledges this equally profound and completely different concept of divine infinity on the Thomist side, even though the three authors concede that "the Franciscan school was built on utterly different metaphysical foundations from those of Albert the Great (d. 1280) and Thomas Aquinas (d. 1274)." Where is the acknowledgment that St. Thomas had a drastically different understanding of divine infinity, one that likewise maintains that God is free from all determination but not in the same sense as Damascene does?
Although this difference seems subtle, it is nothing short of a radical metaphysical paradigm shift to the Aristotelico-Thomist (A-T) metaphysical system. I suspect that the full implications of Fr. Sweeney's conclusion have not been realized simply because the dominant view of the philosophia perennis (one that Fr. Sweeney himself held) requires a narrative of progressive development. Aquinas is permitted to have systematized what came before, but he certainly could not be viewed as a creative and novel systematizer. In service of that dominant narrative, there have many attempts to explain exactly what Aquinas "discovered" or "made explicit" in the tradition; perhaps it was the essence-existence distinction (Sweeney's own view), the idea of actus purus, the concept of divine ideas, the analogia entis, the strong account of divine simplicity, the virtual distinction, God as Aristotelian prime mover, or the concept of subsistent act of being (ipsum esse subsistens). But by Fr. Sweeney's own argument, Fishacre's concept of infinity is a philosophical novum not found in any of his antecedents, and it is not in any sense a necessary logical development from what came before. It seems to me that the deployment of this concept unlocks everything that comes after, and it is unfortunate that St. Thomas is not given credit for being as inventive as he was in deploying it.
The antecedents for the A-T system are Boethian. In Boethius's own commentary on the Categories
, which shows the significant influence of Porphyry, Boethius continues Augustine's modifications to the Categories
for the divine substance, modifications which includes the removal of the notion of substances as subject of changeable (accidental) being to permit God to be identical with His own perfections like goodness and greatness (Thom, pp. 47-50). The Porphyrian context for Boethius's interpretation is important; Boethius's thinking about universals
is Aristotelian and not Platonic, meaning his metaphysics is not fundamentally Platonic either. This becomes specifically important in the idea of God as suprasubstantial. Thom (p. 48) follows Douglas Hall in seeing a Proclan influence in Boethius's principles that God is "good without quality, great without quantity," but Boethius's interpretation is in the context of his Augustinian Aristotelianism, which he expressly applies to divine simplicity. This sets the stage for St. Thomas's interpretation of divine infinity not in the Neoplatonic way but in the Aristotelian sense given by Fishacre. In addition, as McInerny (p. 250) notes, Boethius distinguishes between essence and existence (diversum est esse et id quod est
), which is unquestionably necessary for St. Thomas's doctrine of subsistent act.
Aquinas, for his part, certainly would not have seen his synthesis as radically changing the foundation of metaphysics. He simply connected Fishacre's concept of infinite being to the suprasubstantial divine essence of Boethius and gave a systematic account of that combination. But that opened up a concept that had, as far as I can tell, never been seen before, not even in Fishacre: participation in the act of existence of an intrinsically infinite being. That concept was the basis for a metaphysical reinterpretation of everything that had gone before. It is unclear what Platonic or Neoplatonic origin this doctrine might have, despite Enrico Berti's suggestion that there must be one (it is clearly not from Aristotle!). That origin remains unclear despite the efforts of Wayne Hankey and other scholars to pin it down, and the fact that it was genuinely unanticipated would explain why. What remains undeniable, though, is Stephen Brock's conclusion in "Harmonizing Plato and Aristotle on Esse: Thomas Aquinas and the De hebdomadius," "What I think we should be struck by is simply the degree to which it is, or at least wants to be, Boethian."
Because Aquinas has been viewed as an expositor of the philosophia perennis and because Aquinas did not view himself as an innovator, Aquinas's development on Boethius is not seen as upending the existing metaphysical paradigm in the way that Scotus's formal distinction, which was anticipated to some degree by Bonaventure in much the way that Aquinas was anticipated by Boethius, shook up the existing metaphysics. Ironically, no one really doubts that Scotus's notion of infinity in the context of the divine perfections is essential for his account of divine transcendence and univocal being, yet Aquinas's novel construal of divine infinity, which is likely not anticipated by anyone before Fishacre, is not similarly seen as a critical step in his analogical account of being. That is unfortunate, because it has resulted in needless strife between Dominicans, who believed that they were simply defending the unvarnished philosophia perennis, and the perceived "innovators" of the Franciscan school, a conflict that persisted through the twentieth century and even today.
In any case, regardless of whether one accepts my position that Aquinas has inaugurated a completely new paradigm or that it instead has a basis in the Neoplatonic roots, it is not realistically possible to say that Aquinas undergoes some drastic metaphysical change away from Platonic exemplarism. The Boethian lens that Aquinas applied to Platonism never had traditional Platonic or Neoplatonic participation in its field of view. Whatever Aquinas's position was on being and participation, it began early and was held durably.
In summary, we have seen that Bonaventure and Aquinas had different ontological paradigms from essentially the beginning of their respective works. But that difference did not prevent them from reaching identical logical and ontological conclusions with respect to the relational properties and the relative opposition of the Persons. In that respect, both of those positions are Augustinian in terms of originating in Augustine's modification of the metaphysical category of relation, despite significant differences in other areas. This suffices to answer both parts of Fr. Kappes's argument.
 [Fr. Kappes notes that he and his co-authors, Goff and Giltner, were generally aware of this difference in the infinities in the background, which I should have picked up from Goff's treatment of Sweeney in Caritas in Primo. He also notes that they have not addressed potential implications for the discussion to date, so this merits further discussion.]
 [Fr. Kappes questions my connection of St. Thomas to Boethius based on McInerny, who is a known outlier and who was criticized pretty ruthlessly on philological grounds. I was actually convinced by Stephen Brock, who admits that McInerny is the lone outlier but who points out that the philosophical concepts are used for the same purpose even when they weren't using the same language. If I am wrong on this point, however, it would most likely mean that St. Thomas was even more of an innovator in his concept of infinite being (although some Neo-Thomists would no doubt call this a "discovery of timeless truth" as opposed to an innovation). In any case, being wrong about Aquinas's source in Boethius would not modify my defense.]
IX. "Mere" Subsistent Relations
As I have suggested, Thomists often seen to view it as unnecessary to explain themselves, as if Thomism were simply an inevitable metaphysical development. This is why I suspect that Fr. Kappes views "mere subsistent relations," as a straightforward appropriation of the existing metaphysical concept, which Fr. Kappes describes as "non-productive." That could be true but for the modifications that are made in view of the Thomist idea of infinite act. Unfortunately, Fr. Emery is among the Thomists who lays out the conclusions of St. Thomas without acknowledging the metaphysical innovations that he has made, so while I cite his descriptions of St. Thomas's doctrines below, the explanations of the reasons must be based on what I have laid out previously and some additional background on St. Thomas's doctrine of creation that I provide below.
Subsistent relations, including their associated emanations/productions, are one of the fundamental metaphysical categories rewritten in Aquinas's metaphysics. As a prelude, his view of creation as a finite participation in God as existence itself leads to taking the notion of the creator-creature relation in a new metaphysical sense. This change in turn leads to the complete metaphysical revision of Dionysius's concept of the good as self-diffusive (bonum est diffusivum sui) and Arisotle's notion of the first mover based on final causality. The connection between God as "the good" and final causality of creation has been remarked for many years; see, e.g., Lawrence Dewan, "St. Thomas and the Causality of God's Goodness"; Bernhard Blankenhorn, "The Good as Self-Diffusive in Thomas Aquinas"; Stephen Brock, "The Causality of the Unmoved Mover in Thomas Aquinas's Commentary on Metaphysics XII." The critical step that Aquinas makes is identifying the creative act, the procession (or emanation) of creation from God, with the activity of the internal processions. Emery (p. 172) specifies Thomas's principle as follows: "the procession of the divine persons is the cause and the reason of the procession of creatures." Thus, he translates emanation from a Neoplatonic understanding to the A-T paradigm. Importantly, there is nothing inactive in the actus purus; as principium for creation, God is both efficient cause (imparting motion) and final cause (drawing that motion to Himself). What this illustrates is that the category of relation applied the infinite act of being, as with the cause-effect relation in creation, can be productive in the A-T metaphysics.
Because efficient and final causality has no analogue in divinity, this modification cannot be directly translated into the production of the divine Persons, but it turns out that the principle still holds. In the causal relations, the effect only as a certain resemblance to the cause, but that is not true with all relations to the infinite divine act. Here, Aquinas deploys the psychological analogy in a way similar to Augustine's own use: as a metaphor for activity rather than as a strict analogy to the terms. Specifically, Aquinas sees the ability of the intellect in its "notional acts" to image its own content as a model of the immanent activity of the infinite act to produce its own perfect image. Aquinas sees the license to use this metaphor in the Biblical terms "Word" and "Image." Emery (p. 184-98) describes Aquinas's use of the psychological analogy in detail, and when this use is situated in the context of the Thomist principle that the processions are the cause of creation's procession, it is easy to see how this notional act of self-imaging is productive. But it is the direct connection between the relations and notional acts of personal subjects, rather than the essence, that characterizes this innovative use of relations in A-T metaphysics.
Fr. Kappes has asserted Aquinas was following Anselm in his concept of relations, but in fact, Aquinas uses his novel system to correct Anselm. Based on his distinctive use of the category of relations, Thomas has moved productivity away from the essence into the category of relation, going so far as to dispute St. Anselm's efforts to localize production of the persons in the essence (Emery, p. 186). The correction of Anselm is the best indication of just how significantly the A-T metaphysical system has revised its historical antecedents, including authorities like Anselm. Importantly, this is a foundation for why the Trinitarian relations cannot be proved by argument as against Bonaventure (Emery, pp. 125-27)
Aquinas has definitely transformed the category of relations in terms of metaphysical explanation, and this manifests itself in a dispute that he has with Bonaventure on the nature of processions (Emery, pp. 147-48). This dispute follows the same differences between the great Doctors on the nature of divine infinity. Bonaventure reasons from powers to essence in divine infinity, so he sees a hierarchy of powers in the essence that necessarily begins with a first, characterized by fecundity in his innascibility, who acts in the mode of nature (intellect) and then in the mode of will to produce Persons. Aquinas starts from the infinite and utterly simple act that characterizes the divine essence with the relations at the level of Person and the notional acts expressing this infinite act in processions. For that reason, Aquinas entirely rejects Bonaventure's notion of fontal plenitude as a property of the Father, instead attributing it entirely to the relations of paternity and spiration themselves. Locating the reason for the Trinity in the relations themselves, as opposed to the underlying essence, is also the reason that Aquinas absolutely rejects the idea of demonstrating the existence of the Trinity. This is because the Persons, unlike the essence, can never be the result of reasoning about effects, which distinguishes him from Bonaventure and Anselm as well. For Aquinas, the personal aspects of God must be revealed personally.
 [Fr. Kappes actually found specific cases of Aquinas using the Neoplatonic concept of divine ideas in his earlier writing, so my thesis here is overboard: Aquinas definitely must have at least partially (and perhaps inconsistently) relied on Neoplatonic metaphysics in a way that was corrected by his later thinking. I believe I was simply wrong on this, and my position requires revision to be more narrow. As to the general idea that St. Thomas had an innovative metaphysical system based on his concept of infinite being, I would still say that there is a core metaphysical concept of infinite being here that is consistent from the beginning and by which these incompatible ideas are eventually revised, which would still support my defense here.]
 [Fr. Kappes asked for further support re: Emery's position on Aquinas, which I found discussed in Emery's Trinity in Aquinas (2003) at p. 185 et seq. That being said, I am deferring to Fr. Emery on this point; I am not aware of other scholarship on this specific point. It just seemed accurate, and it is consistent with Aquinas's distinction of notional acts being at the level of person and not essence.]
X. Going Back to Fr. Kappes
With the foregoing explanation, we can also respond to some of Fr. Kappes's arguments concerning Gregory Palamas's response to St. Thomas. Fr. Kappes reiterates his position that Aquinas originally held a Platonic exemplarist position but later moved to an "Anselmian" or "classical" position in the article linked with the interview, titled "Prochoros Kydones’s Translation of Hervaeus Natalis against Gregorios Palamas, Barlaam the Calabrian, and Neilos Kabasilas." This position is evident in the following excerpts:
Once upon a time, Aquinas had youthfully embraced Augustinian exemplarism in his Scriptum, but he then switched to rejecting Augustinian exemplars produced in the divine mind in SCG, I 54. 205 This marked the literary death of Augustinian exemplarity in divinis and his transition toward Aristotelian actus purus excluding the exemplarism of Lombardus (and, by implication, Palamas).
[FN 205] In actuality, the story of exemplarism and divine ideas in Aquinas is somewhat complex due to his shifting viewpoints. However, granted his mature position in the 1260s reduced divine ideas to an internal relation of the divine mind, parallel to a second intention, it does not seem to me to be hyperbolic to claim that Aquinas rejected the Neoplatonic tradition undergirding Lombardus and Bonaventura.
A great irony in Thomistic theology occurs (allegedly Augustinian on this score) in its ultimate rejection of Augustine’s mind, intellect, and love as a strict analogy of the psychological model of the Trinity, with the result that it is but a metaphorical topos. The publication of the SCG marked the point of departure for effective denial of any meaningful distinction between intellect and will in divinis. Therein, Aquinas claimed the necessity of positing the Spirit’s relation to the Son, qua person, to account for the existence of a Spirit. Otherwise, claimed Thomas, no metaphysical distinction between Son and Spirit can exist, as the deity is describable in purely Aristotelian terms of actus purus, reducing the psychological model to pure metaphor.
After the Franciscan school culminated in Scotus’s conviction that the human psychological model was in exact structural parallel of the Trinitarian structure of production, Franciscans often took up Scotus’s counterfactual hypothesis (or what Palamas took to be doctrinally necessary); namely, the Father can be justified, metaphysically, to produce two persons immediately, without recourse to the theological dogma of “ex filio”. While Franciscans were tenaciously committed to Latin dogma, they nonetheless argued that nothing prevented the psychological activities of the Father from producing the eternal Spirit without reference to the Son as a co-spirator thereof. Since Scotus’s critique of Aquinas’s metaphysics has the advantage of a posthumous rebuttal to Thomistic metaphysics, Hervaeus would have better served Prochoros than Aquinas for mining arguments to overcome the Scotist counterfactual argument. Scotus’s thought experiment was argued by Hervaeus to be implicitly absurd. In effect, Hervaeus argued that Aquinas’s simplicity criterion, logically and metaphysically, reveals a requirement for the Spirit to be directly related to the Son in order to distinguish its relation from the Son’s relation to the Father.
Perhaps the most surprising facet of this study lies in the fact that Palamas may have read a translation or summary or detailed account of Aquinas’s Summa Contra Gentiles and even recognized the Latin origin of several positions and modes of expression of Barlaam in his earliest works no longer extant. Granted the plausibility of the evidence, this allows us to suggest Palamas to be the earliest ex professo opponent of Thomas Aquinas’s theology of the filioque and grace in whatever way these doctrines were made available to him in the Greek language in 1334.
The far greater irony is that Fr. Kappes has fallen into the philosophia perennis trap that has plagued Dominican-Franciscan debates for years, and here he shows how it has tarnished East-West relations as well. Fr. Kappes sees a philosophia perennis, one on which Palamas and Scotus agree, so that wherever Aquinas agreed with it, he must likewise have had the same belief. But then (according to Fr. Kappes) Aquinas regrettably moved away from the philosophia perennis, and so fell into perdition, or perhaps just the inherently penitential activity of laboring on bad metaphysical theories. In theoretical terms, I see no difference between what Fr. Kappes has done here and what Martin Jugie and the Neo-Thomists did to Scotus and Palamas, and I do not think he is any more right than they are. History does not support that Bonaventure simply developed the Western theological tradition without innovation any more than it supports that Aquinas did so. Unlike the Schoolmen, we live in a time when we can respect Galileo and Einstein for having broken new intellectual ground; perhaps it is time that we give the Seraphic Doctor and the Angelic Doctor the same respect.
We must also acknowledge that the Western theological tradition that they were explaining was simply not the same as the Eastern theological tradition, even if the faith was the same. Each side had its respective philosophical expositors, such as Boethius and Peter Lombard in the West and Maximus and John Damascene in the East. In the thirteenth century, two drastically different metaphysical paradigms emerged, each with a respective notion of divine infinity built on a completely different metaphysical foundation. Neither was the philosophia perennis; both were deployed to explain a theological tradition. Then Gregory Palamas in the East reinterpreted both Augustine and Aquinas according to his own metaphysical paradigm, which was similar (or perhaps identical) to the Franciscan reimagination of the Western tradition but which poorly translated the concepts of the Thomist paradigm. At any rate, I see no awareness in Palamas of anything like the history or metaphysical roots for the A-T system that I have outlined previously.
And by the way, it is equally ridiculous for Thomists to do the same thing and to try to read every metaphysical system as if it could only have been their own. Fr. Kappes with his co-authors of "Palamas among the Scholastics" makes this response to Thomist efforts at ecumenism:
Too often modern ecumenical approaches to a Palamitico-Thomasian semantic equivalence implicitly negate the entire philosophico-theological tradition of saints and doctors, respectively, as “medievals” having “misunderstood” the real Aquinas. Were pertinacious Thomists and unadulterated Palamites so mistaken for more than a century? Is it only now that moderns have understood something beyond the borders of univocity, analogy, and equivocity? If we reject the irreconcilability of Palamism according to (1) fourteenth-fifteenth century medieval and Renaissance Thomists, (2) seventeenth-eighteenth century Thomasian theologians, and (3) nineteenth-twentieth century neo-Thomists, then contemporary late-twentieth and early-twenty-first century Thomists alone understand thomistico-Palamite questions. Tenacious Thomists and pledged Palamites are unlikely to surrender their academico-historical traditions for good-natured hearty appeals to reconciliation. Either toleration or continued division must reign.
I agree with them in one respect: this idea that we can simply say that there is some philosophia perennis with which we can all agree is hopeless. But that is exactly why this myth is dangerous. If we can instead turn back to the logical and the theological conclusions, recognizing as we do today that all three of these metaphysical paradigms speak in their own idiom and offer their own respective explanations, then there is hope for not only tolerance but also understanding. In short, I plead with Fr. Kappes for the same understanding and charity for St. Thomas that he requested for Meyronnes. Maybe if we can first understand that St. Bonaventure, St. Thomas, and St. Gregory Palamas did each create something never seen before, at least in terms of intellectual understanding, and try to understand exactly what they did, we can come together around the object of all of their devotion: the Holy Trinity.
 [As a pleasant conclusion to the discussion, Fr. Kappes will give consideration to the background of Lyons, to Aquinas's difference with Anselm, to Ayres's interpretation of Augustine, to the Thomist idea of notional acts, and to the Thomist scholars on these points. Since that was my best hope for writing this piece, I could really not have asked for more.]