If one had to choose a teaching of Christianity that caused more confusion than any other, the leading candidate would likely be the doctrine of the Trinity. Who has not been told at some point that God is both one and three, and that, though contradictory, such Christians must acquiesce for the sake of faith? Critics—both popularizers and sometimes academics—often hold up the Trinity as an exemplar of Christian irrationalism, proof that Christians cannot be both reasonable and faithful.

But the dogma of the Trinity, as disclosed in the life of the Church, revealed in the Scriptures, developed by the pre-Nicene Church Fathers, formulated at the councils of Nicaea and Constantinople, and interpreted by the likes of Boethius and Augustine in the West and the Cappadocians in the East, does not demand acceptance of either contradiction or blind faith. As traditionally formulated, the doctrine is not contradictory at all.

Whence, then, the confusion? For both misguided believers and ill-informed critics, the answer tends to be that they have mistaken the elements of Trinitarian doctrine. Many criticisms raised in academia compound the error with a sort of malpractice of the philosophy of language, or by simply ignoring the traditional fundamental tenets about the nature of God

As Aquinas observes, language signifies a conceptual content generally and is directed toward a specific reality. Sometimes what we say may not signify much in the conceptual order (as when one asks of an unknown animal wandering through the back yard: “what is that?”). At other times language can be rich with content but not designate any real object, as with fairy tales.

This distinction between language’s ability to signify and to designate makes the difference between the mystery of the Trinity and its caricature, “mysterianism.” The Trinity is indeed mysterious. But in acknowledging mystery, we nonetheless grasp our language own about that mystery. We need not entirely comprehend something to understand what it is that we might say about that thing. When dogma concerns the mysteries of God, it may not exhaustively disclose divine things, but we should not conclude that dogma itself is beyond understanding. As Philip Cary pithily put it: “Although God is incomprehensible, the doctrine that God is incomprehensible is not.”

Take, for instance, Dale Tuggy’s criticisms of Trinitarian doctrine. Tuggy is a philosopher and a Christian at CUNY Fredonia. Tuggy’s work is instructive, because it exemplifies common assumptions about the Trinity which—though usually thoughtful and lucid—render the traditional doctrine unintelligible. Explaining what goes awry in Tuggy’s critique helps to identify those unspoken presumptions that can occlude what Trinitarian doctrine actually says. And by clearing away misunderstandings about the Trinity, we can easily see that Trinitarian doctrine does not pose any contradictions.

History, Analyzed

Analytic philosophy has a reputation for Procrustean treatments of intellectual history. There is some truth to this prejudice—Bertrand Russell did author A History of Western Philosophy, after all—but at present many analytically trained philosophers do excellent work on historical figures, either in the form of intellectual history or by bringing older sources into contemporary debate. These treatments succeed because they buttress their concern for argumentative rigor with an understanding of the broader historical and metaphysical frameworks in which those arguments can be intelligible.

Tuggy’s treatment of the Trinity too often borrows from the Russell’s school. Certain mistakes result from an inadequate survey of the Patristic tradition. For instance, Tuggy claims that Christians before Origen’s authorship of On First Principles (c.216-32) thought of the Word as coming into being at a particular time.1 Beyond the obvious Scriptural ground for the eternity of the Son (Ephesians 7:2, Hebrew 7:24, Revelation 1:8), even a quick skim of the early post-apostolic fathers shows the Word’s eternity confirmed, for instance in St. Ignatius (b. 50 AD),2 and by the first major Christian systematic theologian—St. Irenaeus (b. 125 AD).3

Similarly, Tuggy claims that catholic theologians first insisted on the full divinity of Christ in the fourth century, and he has in mind the Cappadocian Fathers and Constantinopolitan council. Yet, again, the New Testament attributes the proper names of God from the Old Testament—Lord, I am—to Jesus,4 and the apostles preached the same message. St. Irenaeus in the second century declared that “The Father is Lord, and the Son is the Lord, and the Father Is God, and the Son is God.” Tertullian (b. 155) remarks that “thus does He [i.e., the Father] make Him [the Son] equal to Him [i.e., the Father]: for by proceeding from Himself He became His first-begotten Son, because begotten before all things.”5 And it was Origen of Alexandria who pioneered not just the language of hypostases to distinguish the Father, Son, and Spirit, but likely also the term “homoousios”.6 And, of course, the Nicene’s council’s declaration of the Father and Son possessing the same being, and the description of the Son’s being “true God from true God” is unmistakable.

Aside from simply overlooking textual evidence, Tuggy pays scant attention to the close relationship between dogma and practice. Tuggy claims that “Early on, Christians did not call the Holy Spirit ‘God,’ nor did they worship or pray to the Holy Spirit.” Not only does the Scripture regard the Holy Spirit as the inner source of Christian worship (e.g., I Cor. 12:3), the means by which believers receive Christ and have access to the Father (Eph. 2:18),—but even at the first generation of Christians, Christians were baptized in the name of the Father, Son, and Spirit. If baptism does not count as an act of worship, needless to say, nothing does. Indeed, in the controversies about the status of the Holy Spirit, those who regarded the Spirit as divine were able to appeal precisely to the prayers and practices of the Church.

At other times, Tuggy does engage with the primary sources but misconstrues their meaning. For instance, he argues that St. Augustine means by the term person “basically … nothing.” In support of this rather surprising view—given the sheer quantity of pages in which Augustine talks about what he does mean by the persons of the Trinity—Tuggy appeals to De Trinitate VII.11, where Augustine says that

“the only reason, it seems, why we do not call these three together ‘one person’, as we call them ‘one being’ and ‘one god,’ but say ‘three persons’ while we never say ‘three gods’ or ‘three beings,’ is that we want to keep at least one word for signifying what we mean by ‘trinity,’ so that we are not simply reduced to silence when we are asked three what, after we have confessed that there are three.”7

Applying the distinction between signification and designation, Tuggy interprets Augustine to mean that the term “person” is used without signifying anything, while (presumably) designating the Father, Son, and Spirit. Yet this is clearly not what Augustine is saying. Augustine is explicitly talking about the difficulty of selecting a Latin term to signify what is meant by the three “hypostases” (a Greek term) of the Trinity. The difficulty is that the Latin terms that typically render ousia and hypostasis, namely essence and substance, do not express a distinction. They mean more or less the same thing. The Latin term persona was chosen, as Augustine notes, not because it already includes the connotations Trinitarian doctrine expresses, but simply because, as Latin lacks any term readymade to express the distinctions central to the Trinitarian formula, some term must be chosen lest Christians are “simply reduced to silence when we are asked three what.” This is simply how terms of art are coined.

Augustine makes the context of his remarks—namely, the difficulty of capturing the Greek in Latin—hard to miss: prior to the passage Tuggy quotes, one finds Augustine saying “our Greek friends have spoken of one essence, three substances; but the Latins of one essence or substance, three persons; because, as we have already said, essence usually means nothing else than substance in our language, that is, in Latin.” And the entirety of the passage cited by Tuggy concerns the question of how best to render the Greek into Latin. Tuggy neglected the linguistic difficulties that Augustine painstakingly addresses, with the result that the position he criticizes turns out to be his own misinterpretation.

Trinitarian Doctrine

Tuggy summarizes the traditional Trinitarian view as “The Father, Son, and Holy Spirit are just one thing and they are not.”8 More precisely, Tuggy summarized the doctrine of the Trinity as holding that “The Father is identical to God, the Son is identical to God, and the Holy Spirit is identical to God, but the Father is not identical to the Son, the Son is not identical to the Holy Spirit, and the Holy Spirit is not identical to the Father.”9

Tuggy maintains that the “is” in this formula is an “is” of identity, and “God” is used in precisely the same way in each instance. Moreover, Tuggy thinks the term God designates a particular entity, and that either the terms “Father”, “Son”, and “Holy Spirit” likewise designate particular entities (resulting in tritheism), or aspects of a single instance (modalism). Tuggy’s objection is both logical and metaphysical. It cannot be the case that a=Z, b= Z, and c= Z without a, b, c, and Z being identical. If Tuggy has accurately captured the doctrine of the Trinity, then he has demonstrated a logical contradiction and an incoherent metaphysics.

Although the summary Tuggy provides does not express the classical Trinitarian dogma, it does state with remarkable clarity some of the most common misconceptions of Trinitarian doctrine. The misunderstanding concerns both the language used to articulate the doctrine of the Trinity (specifically the way in which the term “God” is predicated), as well as the metaphysical frameworks native to the Patristic period. Let us consider both of these in turn.

Language: Predicating Divinity

Orthodox believers call the Father, the Son, the Holy Spirit, and the Trinity “God”. To employ the distinction we set forth earlier, “God” can be used to designate the Trinity as a whole, or any person of the Trinity. “God” signifies the possession of the divine essence in the subject of which “God” is predicated. Thus, when we predicate “God” of the Trinity as a whole, or one of the persons, our designation differs while the conceptual content remains the same.

For this reason, believers do not call the Father “God” in the way that this author is called “Thomas,” but more in the way that this author is called human (though with an important difference we will discuss shortly). The Father is God because he enjoys the fullness of the divine essence. Likewise, the Son is called God because he too has the fullness of the divine essence. So too the Holy Spirit. When Christians speak of “God” in each instance, they mean to signify the same conceptual content, but designate a distinct reality.

“God”, then signifies one essence, though it can designate any one of the Persons of the Trinity, or the Trinity itself. So Gilles Emery observes that in “the credo … the Son is ‘God from God.’ Here, the first name God distinctly designates the Son, while the second clearly designates the Father.”10 Without accounting carefully for the way in which theological language is actually used, one easily misses what is going on when Christians use the word “God.” An elementary understanding of the philosophy of language should be sufficient to dispel this misconception of the Trinity.


However, when any investigation heads down too far down the path of linguistic questions, we quickly find ourselves in a thicket of metaphysical questions. Does the traditional doctrine of the Trinity mean that the persons of the Trinity share an essence in the way that the author and readers of this article share a certain essence? If we wish to understand the way the Church Fathers would answer this question, we must be attuned to the ways in which theologians of the Patristic era conceived individuation and metaphysical constitution.

For instance: many in the Platonic schools would hold that two human beings share an identical essence, while the more Aristotelian answer is perhaps that each man has a similar essence–formally identical but numerically distinct.

I was once told with the utmost seriousness that I was ridiculous for buying almond milk, because “everyone knows you cannot milk an almond.” Missing the background assumptions of a belief or practice makes even reasonable things seem absurd. One can see a similar confusion when Tuggy attributes to the Fathers the following difficulty: if Father, Son, and Spirit share the same essence in the way that humans or dogs share an essence then “they [i.e., the persons of the Trinity] are not numerically identical to one another, [and] the Father and Son are two different Gods.”

But, of course, in the Patristic era with the welter of scriptural hermeneutics, middle and neo-Platonism, revived Aristotelianism (etc.), this is no more a metaphysical problem than almond milk is a scam. If two physical beings share in the same essence, they are individuated (at least in part) by their material. Thus, two dogs can equally share the canine essence while being different dogs because the canine form is instantiated in different matter.11 While it follows for physical beings that universal essence is instantiated in discrete entities, matter is necessary to constitute these beings as individuals. Yet God (qua God) is not a material being. The analogy that humans are to human nature as the Trinitarian persons are to the divine nature obviously cannot hold, because material beings relate to their nature in a fundamentally different way than immaterial beings. Given the insistence on divine simplicity, there is no distinction between God and divine nature. The doctrine of divine simplicity is an essential constituent of Trinitarian theology, not a philosophical roadblock that must be surmounted. The problem Tuggy attributes to the Church Fathers is no more a problem than is the proper way to milk an almond.

Which leads to a second, more fundamental metaphysical issue. Tuggy clearly regards God as a discrete being, a being among other beings.12 While this assumption is normal in the context of analytic philosophy of religion, it is quite foreign to early Christianity, both in the theoretical sphere of theology and the practical spheres of liturgy, prayer, and worship. When Moses asks God for his name, the answer is given in terms of being: I AM. At least by the time of Isaiah, the Hebrew Scriptures had secured a firm view of God’s transcendence, and had firmly distinguished his way of being from that of the gods. The strong apophaticism of the Old Testament and the consequent prohibition against idolatry attest that even prior to the Christian era, God cannot be reduced to a mere being among other beings. Thus, while theologians may speak of God as a being, they do not predicate “being” in the same sense of God as they do particular beings in the word. (The analogy of being is not simply a special exception made for God; as Aquinas argues, we do not even refer to all worldly beings as beings in the same sense.13)

As David Bentley Hart has vigorously argued, the difference between polytheists and monotheists has never been how many individuals fall into a genus of deities. The difference is, rather, that the gods are beings in the world, usually immortal, that exceed human beings by degree in their power, beauty, intelligence, and (perhaps) goodness. God, on the other hand, is not individual of a kind or a being in the world at all. God’s powers do not exceed those of worldly beings simply by degree. Whereas gods—if there be any—might share in some common essence—or might instantiate a specifically identical essence—in God himself there is no prior essence on which God depends, or which constitutes him as a kind of entity. This is why the early Christians can speak of men becoming “gods”—not as joining the Trinity as another hypostasis, but simply as becoming immortal. Compared to the monotheistic way, Tuggy’s view regards God not as the eternal Creator who exceeds all limits, but as a particularly powerful spirit, a glorified angel—much more a Mormon view of God than a Christian one.

The One God

Classical monotheism (Christian or otherwise) does not regard God to be one in the numerical sense. There is not one God in the way there is one quarter in my pocket or one sitting president of the USA. Numerical unity is an effect of finitude. Counting presupposes limits. A human being differs from a dog because the latter is subject to limits the former is not. Even in the case of one person who is entirely comparable to the other not only in nature, but also by possessing to the maximal extent possible the same accidental features, these persons will still differ because each is limited at a particular time to this material rather than that of the other. For this reason we can count human beings. But God is not a physical being and does not have a limited way of being. It is limitation that enables us to count distinct entities arithmetically. God’s limitlessness makes arithmetical numbering inapplicable.14

An atheist might deny the existence of an infinite source of worldly being, and an analytic philosopher of religion might deny its coherence. But our objective is to determine what traditional Trinitarians say, and this requires us to be able to entertain and evaluate the metaphysical frameworks they employ.

The sense in which God is one is, for the generations that developed orthodox Trinitiarianism, primarily in terms of metaphysical simplicity. Or, to put it another way, God is perfectly one, while we—that is, finite, composite things, are only imperfectly one. Our unity is that of an individual being, individuated precisely by virtue of the diversity of our metaphysical constituents.

God, on the other hand, lacks metaphysical composition. There is, in God, no distinct principle of substance or accident, form or matter, essence or existence—in short, no potency distinct from act. God cannot, then, be distinguished from creatures as creatures are distinct from each other—as one limited thing is distinct from another by virtue of the distinct limits of each, their finite way of being, their place within the cosmic order—but as the infinite differs from the finite. This is, more or less, what the Western Fathers meant when they called God “being itself” and what the Eastern Fathers meant when they said that God was “beyond being.”

Christians have articulated this “ontological difference” variously: the author of Genesis portrays places God above the generation of the world (unlike, say, the Greek gods), Isaiah declares that the Lord’s thoughts and ways transcend those of created beings,15 God names himself in terms of Being in the first person in Exodus, St. Paul identifies the triadic dependence of creatures on God as being from, in, and through God, St. Irenaeus depicts God as an infinite surplus of being in which all created things partake as finite participants, St. Augustine identifies God as ipsum esse (being itself),16 Dionysius the Areopagite places God beyond being,17 Aquinas declared God to be the pure, unrestricted act of existence, and so on. And the notion of God’s transcendence does not originate with “elite” theologians, but with God’s revelation of himself in the Old Testament, especially the prohibition on identifying God with any finite being, any being who occupies a particular place in the cosmos, as well the necessary logic of a Creator who is independently of the cosmos, to say nothing of the liturgical and spiritual practices of the New Testament Church.

Tuggy has little patience for this central aspect of early Christian thought. In fact, he claims that to deny that God is a being, is to be an atheist—an accusation, not coincidently, that simply repeats—for more or less the same reason—the common pagan claims that Christians were atheists. Both believe in a multiplicity of discrete, humanoid entities called gods, and both regard the traditional Christian view that places God outside the order of finite existents as atheism. But if Tuggy (or his pagan forebears) is correct on this point, then the great theologians of the Christian tradition—from Moses to Isaiah to Paul, Irenaeus to Augustine to Aquinas—were atheists. Some theologize in monastic garb, others in tweed suits, and still others sporting tinfoil hats.

Transcendence and Immanence

The specifically Scriptural notion of transcendence is, as Phillip Cary has pointed out,18 essential to understanding the Trinity. In much of the pagan philosophical traditions (especially the neo-Platonist stream) and the early Christian heresies (especially the Gnostics and the Arians), God’s transcendence was modelled on a spatial paradigm: distance. As the heavens overarch the earth and its denizens, so God stands above and apart from lower realities—immediately below him stand the immaterial intellects, then man, then animals and plants, and finally inanimate matter. Human salvation was often thought of in terms of ascent, closing the distance from below by freeing the soul from its bodily boundaries so that it may rise through the aeons; or else in terms of descent, either through a series of cosmic mediators or by supplementing philosophical reflection with religious practices (as one can see in Iamblichus’ defense of theurgy.)

Arius’ insistence that the Son’s role as mediator made him something less than God but more than a creature can be understood in terms of this logic of distance. God is—as all other beings in the order of the world—securely fastened to his place in the cosmic hierarchy. His transcendence, then, remains a relative transcendence, not differing in kind from the way one entity transcends another. This sort of transcendence cannot be reconciled with immanence, and so God stands in need of intermediary beings that transit the great chain of being on his behalf.

The Scriptural model of transcendence is, of course, quite different. God’s transcendence is not that of one entity related to another within a common world. God creates the world from nothing—and therefore is not a being in or of the world—and yet “in him we live and move and have our being.” The act of creation renders God both transcendent to and imminent within the world. God is not in the world—he is not a discrete being that is here rather than there, now rather than then, of this sort rather than that—and yet, as the absolute source of being, all beings have being by participation in him. God is more interior to things than they are to themselves. There simply is no distance we need to bridge to “get to” God.

In salvation history, God does not come into the world from without, as in Gnostic mythology. Instead, God creates a distance by meeting us in creaturely form. As in ordinary vision, we do not see the causes of our seeing, so God escapes notice precisely by virtue of his imminence. Jesus’ humanity is strange precisely because God now can be differentiated by the disciples by being over there rather than over here (on the shore rather than a fishing vessel, for instance).

This Scriptural account resonates both with the philosophical arguments for God’s existence and nature. God’s transcendence may be gestured at by the metaphor of transcendence, but it is most usefully articulated for philosophical discourse in terms of metaphysical simplicity. The dependence of individuals, which are necessarily composed of act and potency, on a source that lacks metaphysical composition is subject to metaphysical demonstration.19 If, per impossibile, certain theistic personalists are correct insist that the Scriptures regard God as a mutable, finite entity, then it follows that the Scriptural God is not really a creator, but only a demiurge; that god, like the rest of us, depends for his being on the absolute; and that we might best leave the Scriptures for the deeper truths of the philosophers.

Hypostasis and Ousia

Supposing that God is one in the sense understood in the Patristic era—not one in the sense of a discrete being, but the One—how did the orthodox believe that God is also three? The debates that led up to the Nicene and Constantinopolitan Councils were fueled largely by the claims the Scriptures make about who Christ was—God, Lord, Logos, the revealer of the Father, one can declare his identity as “I am” and proclaim that “I and the Father are one.” The author of the Gospel of John begins with a declaration of the Logos who was in the beginning with God, and indeed was God, and then reveals Jesus’ identity in dramatic fashion with the apostle Thomas say to Jesus “my Lord and my God.”

Yet in applying the names of God—Lord, I am—to Jesus, the Scriptures also maintained a distinction between the Son and Father. Jesus is portrayed as having been sent from God (indeed, conceived by the Holy Spirit), attributed a filial relationship with the Father, and regarded as the visible revelation of the invisible Father.

Christians in the post-apostolic era inherited this peculiar dialectic of unity and difference, and—especially once the Church began to free itself from the threat of persecution and had the space to establish its doctrines in a more precise fashion—felt compelled to explore these truths in more depth.

The predominate two trends that emerged were conceiving the unity of the Godhead as merely one in will—as business partners in a joint venture—or, more radically, as one in being.20 The first council of Nicaea (325 AD) considered various proposals about the Father and Son, including some intermediate positions—such as Eusebius’ suggestion that the Father and Son do not possess the same being, but rather, like a human father and son, possess similar essences (homoiousios). But the Nicene council rejected the Eusebian option in favor of the doctrine that the Father and Son are of one being, consubstantial, homoousios.

What, then, of the diversity of persons? For the Fathers, it cannot be the case that the Father and Son participate in a separate, subsistent essence, as some Platonists believed human beings participate in a subsistent human nature. For all the differences among the contending parties, no-one thought that the Father was dependent on a higher cause; and, as we have seen, positing a distinct essence would entail metaphysical composition. Nor did the orthodox party think that the Father and Son were but masks of the same individual playing different roles (as the term persona suggested). They regarded as heresy the denial of a real and permanent difference between the divine persons, which they denominated modalism or Sabellianism.

The formula that was settled upon was that there are three hypostases in one ousia, which was translated, awkwardly, into Latin as one substance in three persons. Even at the time the language was proposed, it was understood that the term “persons” was used as a term of art, and that its ordinary senses—including the notion of a mask or a mere role—would, taken out of context, be quite misleading. (Tuggy does not take into account the evolution of the notion of person, and simply anachronistically attributes a modern notion to the early Christian period.) This is even more true in the modern era, when—following Descartes—we tend to think of a person as an individual center of discursive consciousness, possessed of an independent intellect and will. Whatever the orthodox formula means, it is most certainly not that.

But the question remains: how can we maintain that the persons are one in being and yet really distinct? The answer was given in Scriptural terms. The Son is begotten of the Father; the Spirit proceeds from the Father with the Son. The Persons of the Trinity differ—contra Sabellius, really and eternally differ—from one another. And yet, because the Father gives the whole of his being save what is proper to his person (namely, being the Source) to the Son, and with the Son the Spirit, all three persons possess the fullness of divinity. The Son, on the other hand, is really the full expression of the Father. A contrast between the Aristotelian notion of relations in substances, on the one hand, and the Christian notion of divine relations, on the other, is useful here. A substance for the Aristotelian has its being in itself, while relations have the status of an accident (that is, a way that a substance can be, but one that is always a subsequent expression of a substance, not a constitutive principle). A subsistent relation could not be more different: the divine persons’ relations constitute their personhood. An Aristotelian substance is not what it is by virtue of its relations. The Father is who he is in the eternal act of begetting the Son and spirating the Spirit, for instance; whereas I would be who I am regardless of whether or not I penned this article.

There is, then, an element of truth in the subordinationist position, and we are now in a position to see where they went awry. While it was perhaps natural to see the processions of the Trinity in terms of a priority of origination, the subordinationists also asserted a diminution of divine “content”, similarly to the descent of Plotinus’ hypostases. In the order of origin, the Father is prior to the Son and the Spirit, in the sense that he is their source.21 The mistake lies in inferring that, because the Son and Spirit have their origin the Father, that they therefore possess only a lesser share of the divine essence. Yet the Son is who he is by virtue of being the perfect expression of the Father, and the Holy Spirit likewise subsists as the perfect love of the Father and Son.

This further contrasts human and divine persons. The difference between the two is much greater than merely the materiality and finitude of human beings. “Person” is not predicated univocally of man and God. In begetting a child, a father and mother do not share the fullness of their being to their offspring. Being individuated by their respective material composition, each is a distinct being. On the “Platonic” interpretation, each is a different participant in a human essence, and on the Aristotelian view, each possesses a distinct essence. Their difference is always a distance, and this distance reflects the imperfection of even the most ardent love. The Trinitarian persons, on the other hand, share the fullness of divine being; all that the Father has, he gives the Son and Spirit. Whereas love is for human beings an accident (that is, an addition to human being, an act or a habit), the act of love constitutes the essence of the Trinity. The complete and infinite gift of divine being constitutes the persons as persons; love is not merely something they may or may not do or have.

The notion of subsistent relations—which is almost entirely absent from Tuggy’s analysis of classical Trinitarianism—makes clear why the Godhead may be said to be both diverse (as to persons) and one without composition. God’s unity—that is, his absolute simplicity—is what makes the notion of subsistent relations intelligible. There is, in God, no real distinction between act and potency—and thus no real distinction between substance and accident—and therefore the action of generation and spiriting cannot be adventitious to the divine essence, but must be identified with God’s essence. God’s essence is the infinite Trinitarian life. God’s essence is action, and is therefore relational—not in spite of simplicity, but because of it.


The orthodox formulation does justice to the dynamic of Scriptural language about God: the unity of the Son and Spirit with the Father, the Son’s claims of divinity, the diversity implied in the Son being sent from the Father and the Spirit breathed forth, the baptismal rite, and the insistence of the Shema: the Lord is one.

These arguments, I expect, will not convince the atheist or the analytic theologian equipped with impoverished philosophies of language and being that the Trinity in fact exists. But our aim has been more modest: to discern whether the doctrine of the Trinity, as expounded by the Church Fathers, asserts contradictory propositions. The only answer that can be given once a cursory examination of the original doctrine has been undertaken is negative.

Though I have not attempted to argue that one should believe in the Trinity, a few words on the Christians grounds for belief in the Trinity are not entirely out of place. Most theologians regard the Trinity as something revealed, or something for which merely probable arguments can be given, rather than something that can be philosophically demonstrated in the strict sense. That is to say that Christians believe that God has, in history, revealed the Trinity to us in a Trinitarian way: the Church is moved by the Holy Spirit to the Christ, in whom we are incorporated and through whom we see the Father. The Trinity stands, then, on both sides of revelation: as both–the revealing and what is revealed. The Holy Spirit is given by the Son after the ascension to the Church, to form the heart of worship and to guide the Church into truth.

The Father, Son, and Holy Spirit are found primarily and concretely in the life and experience of the Church. This can be articulated by theologians (including the authors of Scripture) through second order reflection. But the grounds for the Christian doctrine of the Trinity are—thankfully—not so sterile as Tuggy seems to imagine: extracting propositional content from the Scriptures (without much use for the living context from which Scripture arises and in which it is understood) and seeing what can and cannot be deducted therefrom.

The Scriptures, as read by Christians, are rooted in the life of the Church, a life animated and guided by the Holy Spirit, just as the progression of the seed to the tree is guided by a vital principle. The Scriptures themselves proclaim the living church to be the pillar and ground of truth. It is under this guidance and in this form of life that the truths intimated in Scripture are unfolded. One might not believe the Church to be actually animated by the Spirit of God (if one is an atheist), or else one might prefer to think of Christianity as a set of beliefs—as mental microbes or memes—that can be severed from their place in the concrete, organic life of Christ’s living body. Revelation—and the revelation of the Trinity in particular—is not primarily understood by Christians (traditionally and for the most part) to be the divine dispensation of propositions that reason could not provide, and which Christians should accept axiomatically; rather, revelation is given in the life of the Church—the ongoing experience of the gift and guidance of the Holy Spirit animating its structures of church authority, scriptures, rituals, intellectual life, and political history (as messy as that might be).

  1. Dale Tuggy, “Ten Steps Towards Getting Less Confused About the Trinity #6 Get a Date, Part 2”, www.trinities.org/blog. 

  2. St. Ignatius, Letter to Polycarp 3:2. 

  3. St. Irenaeus, Against Heresies II.13:8. 

  4. For an accessible (and sometimes needlessly skeptical) scholarly survey of the uses of the Old Testament designation of God in the New Testament, see Raymond Brown’s Introduction to New Testament Christology

  5. Tertullian, Against Praxeas ch.7. 

  6. See M.J. Edwards, “Did Origen Apply the Word homoousios to the Son?”, Journal of Theological Studies 49,578-590 (summarizing the historical evidence). 

  7. St. Augustine, De Trinitate VII.11, quoted in Dale Tuggy, “10 Steps toward getting less confused about the Trinity - #5 “Persons” – Part 1,” www.trinities.org/blog

  8. “The Unfinished Business of Trinitarian Theorizing”, p. 172. 

  9. “Unfinished Business”, p. 172. 

  10. Gilles Emery, The Trinity 48. 

  11. The precise role of matter in the constitution of physical objects differs, of course, both across the great philosophical traditions of the time and within them. Yet matter would almost always have played individuating forms, even if the precise relationship of matter to form could differ widely. 

  12. To put it more precisely, Tuggy regards “being” as univocally predicated of God and creature. 

  13. See John Wippel, The Metaphysical Thought of Aquinas , p. 91. 

  14. See Aquinas’ lucid discussion at Summa Theologiae I, q. 30, art. 2 and I, q 42, art 1. 

  15. Isaiah 55:8, 9 

  16. City of God, XII, 2. 

  17. Divine Names XIII.3 

  18. Phillip Cary, “On Behalf of Classical Trinitarianism: A Critique of Rahner on the Trinity”, Thomist (56:3) 365. 

  19. See, e.g., Joseph Owens, An Elementary Christian Metaphysics; Robert Spitzer, New Proofs for the Existence of God; St. Thomas Aquinas, On Being and Essence for examples. For my reformulation of certain of these arguments, see http://www.thomasmcothran.com/argument-for-existence-of-god/

  20. Khaled Anatolios has a lucid account in his Retrieving Nicaea

  21. It is, of course, important not to understand causation here on the model of causation in creatures, whereby causes are greater than effects. Causation in the Trinity refers to the Father as the principle and ungenerated source of the Son and Spirit. For this reason, Latin theologians often tend to prefer speaking of a principle rather than a cause.