Perfection and the Necessity of the Trinity in Aquinas

Abstract

For Aquinas, the very meaning of perfection demands that there could be no absolute perfection that was not shared by three Persons. My first aim in this paper is to establish this point, which has been acknowledged only rarely by readers of Thomas, yet which follows unavoidably from Thomas's theology of the Word. I show as much by engaging with scholars who, rightfully attentive to Thomas's teaching on faith and reason, and to his rejection of “necessary reasons” for the Trinity, deny or fail to recognize this link between the meaning of perfection and the necessity of the Trinity. Such scholars, however, all end up running aground on claims that Thomas consistently registers. I hope to show, therefore, that new approaches to this area of Thomas's Trinitarian thought are needed: approaches that can acknowledge his presentation of perfection as necessarily Triune without violating the limits he places on natural reason.

Introduction

For St. Thomas Aquinas, the very meaning of perfection demands that absolute perfection could not exist at all if it were not shared by three Persons.

That's a big claim. And there's good reason to think it can't be true. For, all through his career, Thomas is clear that it is only through faith that we can discover the truth of the Trinity.¹ Once the Trinity is accepted, theologians can offer probable arguments for the Trinity; and these arguments can show a certain congruence or fittingness between belief in the Trinity and truths accessible to natural reason.² But no such argument can prove the Trinity, and Thomas's Trinitarian theology as a whole is normed by the limits he places on natural reason.³ Yet it seems just as basic to Thomas's thought that natural reason can discover the meaning of absolute perfection.⁴ But if natural reason can discover the meaning of absolute perfection, and if the meaning of absolute perfection intrinsically requires that an absolutely perfect God be a Triune God, then it would seem that natural reason can discover the Trinity. And, by the same logic, because Thomas is clear that natural reason cannot discover the Trinity, and because he is just as clear that natural reason can discover the meaning of absolute perfection, we would seem forced to conclude that Thomas does not—and cannot—bind the meaning of absolute perfection to the necessity of the Trinity.

Yet things are perhaps not so simple.

For, all through his mature corpus, Thomas consistently lays out a series of principles which seem to lead seamlessly and inexorably from the meaning of perfection to the necessity of the Trinity. We will work through all of these principles at some length in what follows. For now, we can just sketch them in the barest of terms. In brief: because God is absolutely perfect, He must understand, for understanding is a pure perfection; because God is intelligent, there must be a Word in God, for a word belongs to the ratio of understanding; because there is a Word in God, there must be procession in God, for procession belongs to the ratio of a word; because there is procession in God, there must be real relation in God, for real relation follows on any procession within any unity of nature; because there is real relation in God, there must be real distinction in God, for real distinction belongs to the ratio of real relation; because God is simple, each of these really distinct entities must be the self-subsistent divine nature, and so each must subsist in God; and because a person is defined as that which subsists in a rational nature, each of these really distinct subsistent things in the intelligent divine nature must be a distinct divine Person.

Elsewhere, I have walked systematically through a number of Thomas's works in which he lays out these principles.⁵ And, in so doing, I have attempted to show that the logic at work here is, in fact, airtight and ironclad: Thomas begins with the intrinsic requirements of absolute perfection; he ends with personal plurality in God; and every step he takes follows unavoidably from the previous step and leads unavoidably to the subsequent step.

In our reflections here, we will reach the same conclusion. Yet we will do so to a particular purpose: for we hope to defend it from those who would deny it—or from those who, at the very least, come short of embracing it. For it is true—and it is important, and it is encouraging—that a small band of prominent scholars have acknowledged that Thomas, through the principles we just outlined, binds the meaning of perfection to the necessity of the Trinity.⁶ Yet these scholars are dwarfed by others who act as through these principles did not exist, and who confidently register claims which, if these principles were accounted for, would need to be heavily qualified if not altogether scrapped.⁷ And, finally, and most importantly for us, there is still another cluster of scholars who actively engage these principles, but who either argue or assume that there is something less than strict necessity at work here. This final set of scholars do not always actively deny that Thomas binds the logic of perfection to the necessity of the Trinity; yet they all read the above principles without embracing—or so much as acknowledging—this conclusion. And they thereby give the impression that these principles can be engaged without this conclusion's being reached.

I hope to show here, however, that they can only avoid this conclusion by failing to reckon with the plain meaning of the principles in question. I hope to show, that is, that these attempts to scale back the collective force of these principles ultimately fail to acknowledge the actual force of these principles, and that they thereby end up running aground on the plain meaning of these principles—and on the plentiful texts in which Thomas articulates them. And, in showing as much, I hope to establish that the conclusion is unavoidable: for Thomas, the very meaning of absolute perfection, on its own terms, demands that it must exist as shared and as Triune, or it could not exist at all.

To see as much, we will begin, in Section I, by laying out the assorted ways in which these scholars—out of an entirely appropriate and praiseworthy desire to uphold the limits that Thomas places on natural reason—uncouple the meaning of perfection from the necessity of the Trinity. As we will see, these scholars can, at least for our purposes, be roughly divided into two closely related “camps”: the first camp holds that natural reason cannot discover that a word belongs to the ratio of understanding, or that such a Word is necessary present in God; and the second camp holds that, while natural reason can discover that an inner word is present in God, it cannot conclude that this word is a distinct divine Person. After presenting these two positions, we will see that neither can do justice to—and that neither can be sustained in the face of—principles that Thomas presents all through his mature Trinitarian theology. Specifically, Section II will show the shortcomings of our first camp, and Section III will draw out those of our second camp. Section IV, finally, will hone in on a basic difficulty common to both camps: for, as we will see, neither of these positions can be coherently maintained unless one holds, at least implicitly, that natural reason cannot, under any circumstance, discover some facet of a reality that we encounter among sensible creatures. This point will be central to our argument here, so we can repeat it: the particular strategies by which each of our two camps shroud the Trinity from natural reason end up—usually inadvertently—shrouding a reality we encounter among sensible creatures from natural reason.⁸

Before beginning, however, I should make absolutely clear what I do not hope to accomplish here: I do not in any way hope to conclude that, for Thomas, natural reason can discover the Trinity, or that Thomas ultimately violates his own prohibition of “necessary reasons.” This may come as something of a surprise. For it should be abundantly clear by now—and it will become clearer and clearer as we continue—that I do hope to establish, beyond any room for any real doubt, that, for Thomas, the very logic of absolute perfection requires that it be Triune perfection. And I have no plans of calling into question Thomas's teaching that natural reason can discover the meaning of absolute perfection. Yet my aim is not to conclude that, therefore, Thomas opens up the possibility of our discovering the Trinity apart from faith and apart from Revelation.

Instead, my aim here will be a bit more modest. Most immediately, it will be to expose the inadequacies that plague all of the currently available explanations as to how Thomas can avoid laying bare the Trinity to natural reason given what he says about the ratio of understanding, the ratio of a word, and so on. And, in showing as much, I hope to achieve a second, and deeper, goal. For I hope to show that there is a question here that has yet to be answered. Indeed, I hope to show that there is a question that has yet to be even asked with the requisite seriousness, and whose difficulty has yet to be acknowledged. This question comes overwhelmingly to the fore when one admits both that Thomas binds the meaning of perfection to the necessity of the Trinity, and that Thomas denies the possibility of the Trinity's ever being discovered by natural reason. For, when one acknowledges both these points, and when one refuses to let one of them crowd out the other, one is faced with a very difficult question: how Thomas can hold them both without merely contradicting himself?⁹ In what follows, I hope to show that this question needs to be asked. And I hope thereby to open up space for, and perhaps even to inspire, new attempts to grapple with this question.¹⁰ In order to do so, however, we must spend the bulk of our time here establishing the most contested point: for Thomas, the very meaning of perfection requires that it be Triune perfection, and readings of Thomas that refuse to acknowledge as much ultimately run into serious difficulties.¹¹

I. The Two Camps

a) The First Camp

Bernard Lonergan articulates the position of our first camp clearly enough when he writes that

though our intelligere is always a dicere, this cannot be demonstrated of God's. Though we can demonstrate that God understands, for understanding is a pure perfection, still we can no more than conjecture the mode of divine understanding and so cannot prove that there is a divine Word…Aquinas regularly writes as a theologian and not as a philosopher; hence regularly he simply states what is simply true, that in all intellects there is a procession of inner word.¹²

Thus, Thomas may well hold that God's intelligere is, in fact, a dicere; and he may well tell us that “in all intellects there is a procession of inner word.” Yet, in registering these claims, he speaks not as a “philosopher,” but as a “theologian.” These truths, therefore, cannot be proven through philosophical reflection; they can only be received through Revelation, and so it is only with Revelation that we can know with certainty “that there is a divine Word.”

This first approach can also boast the adherence of the figure who has offered by far the most sustained and sophisticated engagement with the question of “necessary reasons” in Aquinas: R. L. Richard.¹³ And Richard puts the matter even more strongly than Lonergan had: he writes that “the principle calling for universal procession of an inner word in intellectual activity was not a philosophical law, but rather a strictly theological generalization dependent for its ultimate formulation on knowledge of the first trinitarian procession precisely as revealed.”¹⁴ Thus, the fact that a word belongs to the ratio of understanding—from which it follows that there must be a divine Word in the divine understanding—is available to us only through theological reflection on Revelation.¹⁵

More briefly, and more recently, David B. Burrell seems to have thrown in his lot with this camp: he affirms that Thomas's teaching on the word “in no way contradicts his previous strictures against knowing what divinity is like,” and he treats a reference to Lonergan as sufficient in order to justify this claim.¹⁶ With similar brevity, Matthew Levering writes that “Aquinas's knowledge of God's knowledge and will…does not make the Trinity rationally necessary”; and the only support Levering offers is a reference to the passage from Lonergan we gave above.¹⁷ And, finally, Timothy L. Smith, again with reference to Lonergan, writes, “The fact that Thomas states ‘that in all intellects there is a procession of an inner word’ is not a datum of rational reflection but the truth as made known by revelation.”¹⁸

b) The Second Camp

According to the second camp, in contrast, natural reason can discover that the presence of a divine Word follows necessarily on the meaning of understanding, but it cannot discover that this Word is really a distinct divine Person. Gilles Emery puts the matter quite clearly: he reminds us that “faith…alone causes us to know the divine Person of the Word”;¹⁹ and he justifies this claim by writing, “Philosophical thought can discover the presence of a word within the divine mind (see SCG I, ch. 53), but it cannot reach the personal distinctiveness and hypostatic subsistence of this Word (see ST I, q. 32, a. 1, ad 2).”²⁰ Emery elaborates his position further elsewhere:

St. Thomas certainly does not claim that the real distinction between divine Word and the Father who utters it can be proved by reason (that would mean proving something which only faith can teach us), but the reasoning showing the existence of a Word in God (irrespective of the form which its reality in God takes, that is, of the problem of its personality and of its real relationship with the entity from which it proceeds) would however seem to include all the rigor of mature Thomist thinking.²¹

Thus, Emery once more contrasts “the real distinction between the divine Word and the Father,” which cannot “be proved by reason,” to the “existence of a Word in God,” which Thomas establishes with all desirable rigor.

We see something similar in Hyacinthe Paissac's classic study on the inner word, where Paissac claims that Thomas “demonstrates simply…that, in God, because there is intellection, there is necessarily a principle and a term [i.e., a word] of this intellection; but the principle and the term (or word) are not really distinct, or at least one cannot know it, and there is still no allusion to a personal word.”²² Paissac continues that Thomas does not make “‘manifest’…that the Word in God is really distinguished from its principle; but simply that, in God, there is the presence of a Word.”²³ Thus, for Paissac as for Emery, a clear line runs between the presence of a Word in God and the distinct personal subsistence of that Word. Even more briefly, Emmanuel Durand seems to join his francophone confreres when he writes, “Even if the word belongs to the perfection of human knowledge, there is no rational necessity that it be personal in God.”²⁴ Finally, John McDermott offers a somewhat different, and far more sustained, iteration of this position, arguing that “Thomas considers the divine processions and relations naturally knowable; supernatural revelation is required only to identify these relations as persons.”²⁵

Having presented these positions, we can now begin showing their shortcomings. And we can do so by tracing out in detail the path by which Thomas links the meaning of absolute perfection to the necessity of personal plurality in God.

II. Necessarily Present

No one contests that natural reason has access to the first step of this path: an absolutely perfect nature must be an intelligent nature. For God, as absolutely perfect, must enjoy all perfections found in creatures; understanding is such a perfection; God, therefore, must understand.²⁶

Things begin to get interesting, however, with the next step: that a word belongs to the ratio of understanding, which means that a word must be present in all acts of understanding everywhere, no matter what—including, analogously, in God. Thomas puts this point most strongly in two passages, both of which we can run through in some detail. The most relevant chunk of the first passage, which comes from the DP, begins as Thomas writes that

we must attribute to God every perfection that is in creatures, as regards the ratio of the perfection absolutely, but not as regards the way in which this perfection exists in this one or that one…Now in creatures nothing is more excellent or more perfect than to understand…It follows then that understanding is in God as well as whatsoever belongs to the ratio of understanding, although it belongs to God in one way and to creatures in another.²⁷

With these points in the background, Thomas introduces “the concept of the intellect”; he identifies this concept with “the interior word”; and he continues: “Therefore, because there is understanding in God, and because He understands all other things in understanding Himself, there must be in Him the conception of the intellect, which belongs absolutely to the ratio of understanding.”²⁸

This claim, which is presented in the strongest of terms, is of the greatest importance for us: if a Word is present in God, then it is because such a word “belongs absolutely to the ratio of understanding.” It is not merely that the structure of human or creaturely understanding requires the presence of such a word; and so the necessity entailed here does not arise from any features unique to human or creaturely intellects which might distinguish them from the divine intellect. Thomas is absolutely clear on this point: he begins by distinguishing “the ratio” of a given perfection from “the way in which this perfection exists in this one or that one,” and he goes on immediately to again distinguish “whatsoever belongs to the ratio of understanding” from anything that might follow on the “way” in which understanding exists in God or in creatures. And, after drawing these two rapid-fire distinctions between the ratio of understanding and the different ways in which understanding exists in different natures, Thomas plants the inner word squarely within the ratio of understanding: the necessity of such a word is not limited to any of the ways in which understanding exists, and it is certainly not limited to human or creaturely understanding. Instead, a word “belongs absolutely to the ratio of understanding.” The very ratio of understanding, then, requires that there could be no understanding anywhere, or of any sort, without some sort of word being somehow present. And so the very meaning of understanding demands that if a word were simply absent from God, then God could not understand at all.

And we see much the same point at the end of Thomas's career: in his Commentary on John, he writes that “it is necessary to have a word in any intellectual nature, for it is of the very ratio of understanding that intellect, in understanding, should form something. Now what is formed is called a word, and so it follows that in all who understand there must be a word.”²⁹ Again, Thomas does not limit this necessity to acts of understanding in a human or a created nature; instead, he extends it, analogously, to “any intellectual nature” and to “all who understand.” Indeed, the very next sentence finds Thomas writing, “Now, intellectual natures are of three kinds: human, angelic and divine.”³⁰ Thus, immediately after writing that “it is necessary to have a word in any intellectual nature,” Thomas explicitly includes the divine nature within the “intellectual natures” in which such a word is “necessary.”³¹ Again, Thomas could not be any clearer: a word belongs to the ratio of understanding simply. Were God to lack such a Word, therefore, there would be no analogy, but equivocity, between our understanding and His. Simply because of what it means to understand, an act of understanding—including, analogously, the divine act of understanding—would necessarily cease to be an act of understanding were it to lack such a word.³²

Thus, we take our most basic point to be established: according to Thomas, a word belongs absolutely to the ratio of understanding, and so merely from the fact that God understands—and regardless of the unknowable mode of divine understanding—it follows unavoidably that a Word must necessarily be present in God.³³ The members of our first camp, for their part, hold that natural reason could never, under any circumstances, conclude that a word belongs to the ratio of understanding, or that such a word is necessarily present in God. As we will see in detail in Section IV, however, they can only do so by holding—either explicitly or implicitly—that some dimension of what it means to understand—and so some dimension of a reality that we encounter among sensible creatures—must be absolutely inaccessible to natural reason. Before pursuing this point, however, we will lay the groundwork for seeing that those in our second camp ultimately end up in a similar spot. For, as we will argue presently, Thomas proceeds as inexorably from the presence of a divine Word to its distinct personhood as he does from the meaning of understanding to the presence of that Word. And we will also see that the path he lays out demands that this second position can only be sustained if natural reason cannot, under any circumstances, know something belonging to the inner meaning of a word, of procession, of relation, of simplicity, or of personhood—all of which, like understanding, we can discover through reflection on sensible creatures.

III. Necessarily Personal

a) From a Word to Procession

The path Thomas lays out from the presence of a divine Word to the distinct personhood of that Word is a bit longer and more involved than the one leading from the meaning of perfection to the presence of a divine Word. Tracing it out, therefore, will take more time. Yet, though there are more steps involved here, we will see that each such step follows unavoidably from the one immediately before it in order to form an inescapable chain of reasoning.

We can begin where our engagement with the first position left off: because a word belongs to the ratio of understanding, a Word must necessarily be present in God. Again, all members of the second camp happily accept that we can know as much by natural reason. Yet their position begins to falter as Thomas thinks through the nature of an inner word. For Thomas tells us quite plainly that “it belongs to the ratio of an inner word, which is the intention understood, that it proceed from the one understanding.”³⁴ And again, “the very concept of the heart has of its ratio that it proceed from another.”³⁵ Thus, just as a word belongs to the ratio of understanding, so too procession belongs to the ratio of a word. Were a word to cease to proceed, therefore, it would cease to be a word. Indeed, Thomas even applies this claim directly to the divine Word, writing of “the divine Word” that, “from the very fact that it is a word, it has the ratio of proceeding from another,” and that “the Word of God…[has] the ratio of proceeding from another.”³⁶ Thus, if there is a word in God—and if, as Thomas makes clear with some frequency, “word” is predicated analogously, and not equivocally, of us and of God—then there must necessarily be procession in God.

And this note of procession within God takes on added heft in light of Thomas's teaching that, because of divine simplicity, the divine Word that proceeds in the divine essence must be identical to the divine essence. As Thomas puts it, “in God, to understand and to be are the same; and so the Word of the divine intellect is not an accident but belongs to its nature, because whatever is in the nature of God is God.”³⁷ Because of divine simplicity, “whatever is in the nature of God is God.” If, therefore, there is a Word in the divine nature, then divine simplicity demands that this Word must be the divine nature.

b) From Procession to Real Relation

The next step Thomas takes follows just as naturally and inevitably from the intrinsic demands of procession within a single nature: he writes that

when something proceeds from a principle of the same nature, it is necessary that both the one proceeding and the source of procession agree in the same order, and in this way it must be that they have real relations to each other. Therefore, because the divine processions are in the identity of the same nature, as above explained, it is necessary that these relations, according to the divine processions, are real relations.³⁸

Thus, we saw above that understanding follows on the very meaning of perfection; that a word follows on the very ratio of understanding; that procession follows on the very ratio of a word; and that the identity of the divine Word and the divine nature follows on the very meaning of divine simplicity. And we see now that reciprocally real relations follow necessarily on any procession within “the identity of the same nature.” It is true that Thomas does not use the language of “ratio” in drawing out this note of reciprocally real relation: he does not, that is, claim that real relation belongs to the ratio of procession. Yet, he does use the language of “necessary”; he uses it twice in two sentences; and he presents this necessity as following directly and exclusively from the fact that the divine Word proceeds within the one divine nature.³⁹

Indeed, the specifics of Thomas's claim here should already be enough to establish the necessity with which real relation in God follows on procession in God. Yet, because Thomas does not use ratio-language to secure this point, we can reinforce it by showing that it follows from a number of angles.⁴⁰ First of all, Thomas elsewhere—while asking whether there is real relation in God—make an even more basic point. For he makes clear that if only some processions require a reciprocally real relation, then any procession of any kind at all intrinsically requires at least a real relation. He tells us that

whenever one thing originates from another there must be a real relation—either only on the part of that which originates, when it receives not the same nature as its principle, as in the creature's origination from God—or on the part of both, when that which originates attains to the nature of its principle, as when a man is begotten, and a real relation results between father and son.⁴¹

As we saw above, when the one proceeding shares in “the nature of its principle,” there is a reciprocally real relation between the one proceeding and its principle. Indeed, Thomas is even clear here that such reciprocal real relation follows not only from procession within a numerical unity of nature—which is found only in God—but also from any procession within the same specific nature, which can be found “when a man is begotten”—or, indeed, in any univocal generation. And, even more importantly, he is explicit that even when there is no such unity of nature, any procession of any sort requires at least one real relation, even if it is not reciprocated. That is, even procession outside of a unity of nature requires that the one proceeding be really related to its principle, even if that principle is only rationally related to that which proceeds from it.⁴²

This point is most significant because, as we will see in a moment, the very ratio of real relation—even when it is not reciprocal—includes a real distinction between the things related. Yet we can conclude these points on intra-divine procession by noting that Thomas not only presents such real distinction as following from real relation; instead, he even presents it as following from any procession of any kind. Thomas puts this point most strongly when he writes that “procession, insofar as it is procession, means a real distinction with respect to the principle from which it proceeds.”⁴³ Just so, coming from the other direction, he writes that “a principle implies distinction from that of which it is the principle,”⁴⁴ and he does so after having tied “principle” directly to “procession” earlier in the same work: “The word ‘principle’ signifies only that from which another proceeds; since anything whence something proceeds in any way we call a principle.”⁴⁵ Thus, anything that proceeds is from a principle, and the very word “principle” implies a “distinction” between this principle and that which proceeds from it. Finally, Thomas puts this point most plainly when he writes that “the same thing does not proceed from itself.”⁴⁶ And, indeed, this point may be obvious. Yet it will prove crucial for our purposes, and so we can reiterate it: Thomas explicitly presents this note of distinction—and he even makes explicit, in one case, that the distinction in question is real—as following on the very meaning of procession.⁴⁷

c) From Real Relation to Distinct Persons

The most basic point regarding procession, however, had already been secured by Thomas's explicit claim that, “because the divine processions are in the identity of the same nature, as above explained, it is necessary that these relations, according to the divine processions, are real relations.”⁴⁸ For, later in the same question, Thomas goes on to bind real relation indissolubly to real distinction:

From the very fact that something is attributed to anything, everything that is of the ratio of the former must be attributed to the latter…Belonging to the ratio of relation is the regard of one to another, according as one is relatively opposed to another. Therefore, because there is in God real relation, there must also be real opposition. And relative opposition, in its ratio, includes distinction. Hence, there must be real distinction in God…according to what is relative.⁴⁹

Thus, Thomas is explicit that opposition belongs to the ratio of relation, and that distinction belongs to the ratio of opposition. Thus, if there is real relation in God—and, again, there must be reciprocally real relation in God if there is procession within the identity of the divine nature—then there must be real distinction in God. The very ratio of real relation makes this conclusion unavoidable.⁵⁰

Yet if the ratio of real relation demands that the divine Word must exist as really distinct from His Speaker, then the meaning of divine simplicity demands that this same divine Word must subsist as really distinct from His Speaker. For Thomas is clear that, because God is simple, the divine nature must be self-subsistent,⁵¹ and he regularly argues that

in God existence and understanding are the same: hence the Word of God is not an accident in Him, or an effect of His, but belongs to His very nature. And therefore it must be something subsistent, for all that is in the divine nature subsists; and therefore Damascene says that ‘the Word of God is substantial and has hypostatic being.’⁵²

As we saw above, divine simplicity demands that the Word cannot be in the divine nature without being the divine nature;⁵³ we see now that the self-subsistence of the divine nature demands that the Word cannot be the divine nature without subsisting in and as that nature. To be in God is to subsist as God, and so if the divine Word is really distinct from His Speaker, then the divine Word must subsist as really distinct from His Speaker.

And, finally, because Speaker and Word each subsist in the supremely intelligent divine nature, and because Thomas defines a “person” as a “subsisting thing in a rational nature,”⁵⁴ it follows that Speaker and Word must, by definition, be distinct Persons in God. Thomas puts the matter plainly: “there are multiple real relations in God; hence it follows that there are also multiple realities subsisting in the divine nature; which means that there are multiple Persons in God.”⁵⁵ Personal plurality in God follows necessarily from a plurality of really distinct subsisting things in God; and a plurality of really distinct subsisting things in God follows necessarily from the existence of multiple real relations in God. Yet, as we saw above, the existence of these multiple real relations in God follows directly and necessarily from the procession of a divine Word within the one divine nature; and the procession of a divine Word within the one divine nature follows directly and necessarily from the ratio of a word and from the meaning of simplicity. Thomas, therefore, builds up patiently and ineluctably from the mere existence of the divine Word—through the ratio of a word, the demands of procession, the ratio of relation, the demands of simplicity, and the meaning of personhood—to arrive inevitably to, as Emery puts it, “the personal distinctiveness and hypostatic subsistence” of the divine Word.⁵⁶

IV. Common Difficulties

Casting our gaze over Thomas's argument as a whole, we can stress the most basic point: the path Thomas lays out from the meaning of perfection to the multiplicity of divine Persons holds with the strictest necessity, and it does so because of the intrinsic meaning of the terms involved. This link between perfection and personal plurality, that is, holds because of the intrinsic meaning of perfection, understanding, a word, procession, relation, simplicity, and personhood.

We can linger with this point for a moment, for establishing it is at the heart of our concern here. Thus, to take the example of the Word's procession, Thomas does not write that all of our words proceed from us, and that we can therefore conjecture—or we can conclude that it would be fitting, or at least not impossible—that the divine Word should proceed within God. Nor, from the other direction, does Thomas say that, in Revelation, we see that the divine Word does, in fact, proceed from Another, but that He does so for some reason owing to His unique status as the divine Word, which separates Him from our own Words, and so which is not rooted in anything we might learn about the nature of a word as such. Instead, Thomas teaches explicitly and consistently that procession belongs to the ratio of a word. This procession does not follow on the way in which a given word—either human, angelic, or divine—exists; it follows on the ratio of a word, which holds analogously in all words everywhere, no matter how a given word might exist. If, therefore, we can know the ratio of a word—and if “word” is predicated analogously, and not merely equivocally, of God and of creatures—then it seems to follow that to know a divine Word as present in God is to know that Word as necessarily proceeding in God.

In Section I, we saw a similar point regarding the ratio of understanding and the presence of a divine Word. We can stress now that similar points could be made regarding all of the steps by which Thomas reasons from the meaning of perfection to the plurality of divine Persons. For Thomas never teaches that, because of the shape that understanding, processions, relations, and personhood take among creatures, we can conjecture that the divine understanding might possibly require a word, that intra-divine procession might possibly yield a real relation, that intra-divine relation might possibly entail real distinction, or that distinct subsisting realities in God might possibly be Persons in God. Nor does he present any of these conclusions as following simply from some revealed datum, or from some incomprehensible feature unique to divine understanding, processions, relations, or Persons. Instead, he presents these conclusions as following with the strictest necessity from the very meaning of understanding, procession, relation, and personhood, he makes clear that these conclusions must hold anywhere those terms are predicated properly or analogously.

Seeing as much, finally, should be enough to allow us to draw our final conclusion, and thereby to call the positions of both our camps here fundamentally into question. For we suggested at the close of Section I that our first position can only be sustained if there is some facet of the ratio of understanding that natural reason cannot, under any circumstances, discover. And we can see now that our second position is ultimately beholden to a similar commitment, if only implicitly, and if perhaps unbeknownst to any of its proponents. For we have seen at great length that the combined force of the ratio of a word, the demands of procession within a single nature, the ratio of relation, the demands of divine simplicity, and the meaning of personhood is enough to make unavoidable the conclusion that no word could possibly be present in God without subsisting as a distinct Person in God. And so it seems to follow straightforwardly that, just as to espouse the first position is to hold that natural reason cannot discover some facet of the ratio of understanding, so to espouse the second position is to hold that natural reason cannot discover some facet of a word, procession, relation, simplicity, or personhood.

Things become difficult for both of our positions, however, when we recall that natural reason can encounter or discover all of these realities among sensible creatures. It follows, therefore, that to espouse the either of our two positions is to hold, at least implicitly, that natural reason cannot know some facet of a reality that it encounters in the normal course of its affairs among sensible creatures. For it is true that neither an act of understanding nor an inner word nor procession nor relation nor simplicity nor personhood are themselves sensible creatures. Yet it seems plain enough that, for Thomas, we regularly encounter processions and real relations and persons in our dealings with sensible creatures; that we encounter acts of understanding and inner words within ourselves, who are sensible creatures;⁵⁷ and that reflection on sensible creatures by natural reason is enough, at least in principle, for us to conclude with certainty that the world must be caused by a simple Creator.⁵⁸ Thus, even if these realities are not themselves sensible creatures, it seems plain enough that our encounters with sensible creatures are enough to introduce us to them. Again, natural reason can discover all of these realities through its routine dealings with sensible creatures; yet neither the position of our first camp nor that of our second camp can be sustained unless natural reason cannot under any circumstances discover some facet of at least one of these realities. Our second position may tend in this direction less obviously than does the first. Yet it tends there just the same, and, like the first, it does so inescapably.⁵⁹

Conclusion

We cannot here ask the obvious question: can one claim—as both of our camps require that one claim—that natural reason cannot discover some facet of a reality that we encounter among sensible creatures without thereby running afoul of Thomas's basic epistemological commitments? Again, we cannot ask this question here.⁶⁰ Instead, we can conclude with three points. First, and most briefly, we can note that none of the members of either of our camps has addressed—or so much as acknowledged—this cluster of epistemological questions which their solutions open up.⁶¹ Secondly, the challenge that both of our camps face seems daunting enough to warrant new approaches to this question: approaches that differ fundamentally from both of the positions we have engaged here; approaches that can do justice both to the plain meaning of the texts we have explored here and to Thomas's rejection of “necessary reasons” for the Trinity; and approaches that can avoid barring natural reason from realities that seem to lie within its ambit.

The third and final point is perhaps the deepest. For, so far as our purposes go, we can leave open the possibility that, on Thomas's terms, some facet of a reality we encounter among sensible creatures might well be inaccessible to natural reason. And so we can leave open the possibility that one of our two positions here might be sustained. Yet we can stress that, were this the case, then our main burden here—that is, the conclusion that none of the members of either of our camps have explicitly acknowledged—would still stand. For it would still be the case that, in fact, the very meaning of perfection requires that absolute perfection could not exist at all unless it were shared by multiple Persons. On such a reading, we could not know of this truth apart from Revelation, precisely because we could not know the meaning of understanding, of a word, of procession, of relation, of simplicity, or of personhood apart from Revelation. Yet, with Revelation, we would see that, in reality, the meaning of absolute perfection is such that it must necessarily be shared by multiple Persons.

And, again, this is the most basic point we hope to have shown here: for Thomas, the very meaning of perfection demands that one can only be absolutely perfect if one is perfect with another Person. The texts on which we have focused here demand this conclusion; they defy any reading that comes short of embracing it; and they cannot be dismissed—and the conclusion they demand cannot be evaded—on the grounds that Thomas denies natural reason access to the Trinity. Of course, these texts do demand that we take on the very difficult task of reconciling Thomas's Trinitarian reading of absolute perfection with the limits he places on natural reason. And so, having shown that Thomas binds the meaning of perfection indissolubly to the necessity of the Trinity, I hope to have shown something of the urgency of asking how he can do so given the limits he places on natural reason.