Responding to Dale Tuggy
A Definitive Response to Dale Tuggy’s “When and How in the History of Theology Did the Triune God Replace the Father as the Only True God?”
1,950 words, 11 minutes read time.
Thesis
Dale Tuggy argues in TheoLogica 4.2 (2020) that belief in a triune God arose late and reflects a Western misunderstanding that displaced the original confession of the Father alone as the one true God. He rests his case on three points. First, he says that “there is no idea of a triune God in the Bible” (29). Second, he claims that “no tripersonal god is mentioned in the first three centuries of Christian history” (29). Third, he states that only after the Council of Constantinople in 381 did Christians “sometimes” use the word Trinity for the one God, thereby replacing the earlier monarchy of the Father (34). When Scripture, the Fathers, and the councils are read through the four-sided horizon of a deeply informed Catholicism and through my own analytic framework, each of these claims collapses.
My Model Divine Simplicity and the Trinity Explained – RobertDryer
In contrast I think my model of the Trinity is explanatory and helpful (at least axiomatically) for clarifying Tuggy’s errors. I start where the Fourth Lateran Council begins: God is one essence, substance, or nature absolutely simple. Four principles follow. First, divine simplicity means pure act, with no potency, layering, or substrate. Second, Aquinas remarks that “relation really existing in God is really the same as His essence” (Summa theologiae I, 28, 2 ad 3); therefore relation is the very subsistence of the essence. Third, three irreducible relations of origin can be identified: paternity, filiation, and spiration. Each relation is the whole divine act under a distinct vantage: originary giving, gift received and returned, and gift of gift. Fourth, every external work is one indivisible act, though Scripture appropriates that act to distinct Persons. The resurrection illustrates the point. Scripture ascribes the event to the Father who raises, to the Son who takes back his life, and to the Spirit who gives life. One and the same power of pure act appears under three relational vantages; no multiplication of causes is required.
Scriptural Evidence
Tuggy bases his first claim on lexical silence, yet the New Testament constantly presents one divine reality refracted through three personal bearings. I begin with the baptismal mandate, which instructs the Church to immerse “in the name of the Father and of the Son and of the Holy Spirit” (Matthew 28 19). The phrase “the name” is singular, marking a single essence, while the three coordinated genitives point to three distinct relational modes within that essence. John’s prologue supplies the same pattern: “the Word was with God, and the Word was God” (John 1 1). The preposition “with” secures relational distinction; the predicate “was God” secures essential identity. Paul’s trinitarian blessing, “the grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit” (2 Corinthians 13 13), unfolds one salvific act in three aspects. My ontology allows these texts to speak at face value. The single act of subsistent being is given, received and returned, and shared, all without multiplying gods.
A further strand of evidence appears when we recall how the Septuagint renders the divine name YHWH as Kyrios. That translation choice seeded Greek Scripture and synagogue liturgy with a term that already carried the full weight of Israel’s monotheistic confession. Against that backdrop Paul can re-shape the Shema in 1 Corinthians 8 6: “for us there is one God, the Father, from whom are all things, and one Lord, Jesus Christ, through whom are all things.” In the Septuagint the Shema reads, “The Lord our God is one Lord.” Paul retains the word heis but now distributes the titles: heis Theos for the Father and heis Kyrios for Jesus. Because Kyrios already functions as the surrogate for YHWH, inserting Jesus into that slot embeds him inside Israel’s unique-deity clause without abandoning monotheism. My relational model explains the theological logic at work. The Father remains the originary source, the Son receives and returns the same divine act, and the Spirit (named implicitly by the di’ clause “through whom are all things”) completes the triune structure of creative causality.
The early Church’s Christ-hymns confirm the point. Philippians 2 9–11 climaxes in the confession that “every tongue confess that Jesus Christ is Lord,” a direct citation of Isaiah’s YHWH oracle. Paul then adds “to the glory of God the Father,” preserving the monarchy of the Father while applying YHWH status to the Son. Once again the text assumes that one may invoke Kyrios with full divine force for Jesus and still worship the Father as the single source, precisely the balance my ontology secures. Taken together, these passages show that the New Testament does more than form a triad of honorifics. It re-deploys the language of Israel’s unique God, distributes that language across Father, Son, and Spirit, and thereby witnesses to one simple divine act manifest under three irreducible relational vantages.
Ante-Nicene Fathers
Tertullian insists that Father, Son, and Spirit possess “one power and one substance.” Substance here is numerically one divine reality communicated without division, matching my claim that the Father’s relational mode distributes the single divine act filially and pneumatically. Origen calls the Son “eternally generated light from light,” affirming derivation without conceding creaturehood. That formulation presupposes the same ontology: filiation is the divine act viewed from the vantage of reception and return.
Cappadocians and Councils
Basil of Caesarea can pray to “one God, the Father,” yet in the same treatise he insists that the Son “possesses the whole being of the Father in himself” (On the Holy Spirit 18). The grammatical switch is intentional. Basil keeps the title one God at the level of origin while securing full consubstantiality for the Son. Gregory of Nazianzus drives the point home in two complementary settings. In the heat of debate he tells Eunomius that if “unbegotten” were truly the definition of God, the word God would become a mere relation, for theos in ordinary Greek grammar is “God of …” (Oration 29, §11). Gregory uses that bit of syntax to expose Eunomius’ confusion, not to reduce divinity to a relation. When he steps back from polemic to teach the faithful he says, “The Three are one God because consubstantial, one God because of the monarchy” (Oration 40, 41) and elsewhere, “each one God if contemplated separately, the three God if contemplated collectively” (Oration 23, §11). He is perfectly comfortable treating God as the absolute name of the simple essence that Father, Son, and Spirit possess indivisibly. Gregory of Nyssa joins him: “One God in three, and these three are one” (Against Eunomius 1, 34). What looks like tension dissolves once my relational framework is applied. Paternity is the primal relational stance of the one act, and that same act subsists filially and pneumatically without division.
The councils confirm what the Cappadocians proclaim. Nicaea confesses the Son homoousios with the Father. Constantinople I reaffirms Nicaea, then Rome’s Tomus Damasi in 382 anathematizes anyone who excludes the Son or the Spirit from divine worship “because of their one and equal divinity.” Constantinople II in 553 adores “one deity to be worshipped in three persons.” Tripersonal monotheism is therefore a shared inheritance of East and West and it antedates Augustine by decades.
Logical Coherence
Tuggy’s formal objection appeals to the indiscernibility of identicals: if the Father is God and the Son is God, then by Leibniz’s Law the Father must be the Son, contradicting doctrine. He treats “is God” as a marker of numerical identity inside pure extensional logic. In my essay “Leibniz’s Law and Identity” I show why that treatment fails. Leibniz’s principle ranges over predicates describing what something is—nature and attributes—whereas the names Father, Son, and Spirit designate how the one essence subsists. They indicate modes of possession, not extra properties added to a shared substrate, so indiscernibility can hold at the level of essence without erasing hypostatic distinction.
I also point out that relations of origin are hyper-intensional. Extensional predicates apply by extension alone, but hyper-intensional terms depend on how the truth is expressed. Saying the Father is unbegotten and the Son is begotten does not assign divergent properties alongside the essence; it narrates the inner order in which the simple act exists. Because origin relations operate in this hyper-intensional register, they lie outside the scope of the extensional identity operator that Leibniz’s Law presupposes. Aquinas anticipated the same idea: “Nothing prevents numerically the same thing from being referred to different things according to different relations” (Summa theologiae I, 39, 1 ad 1). The numerically same thing is the divine essence; the different relations are paternity, filiation, and spiration. Relational origin is not an accidental attribute attached to deity but the very mode in which the one act of being subsists. Thus, the Father and the Son are numerically identical with the simple essence while remaining distinct in their incommunicable modes of origin. Indiscernibility at the level of nature coexists with real personal distinction, and Leibniz’s Law is preserved.
Inseparable Operations
Tuggy also objects that Trinitarians multiply causes. My principle of inseparable operations answers by noting that creation, redemption, and sanctification are one action of one efficient cause. Scripture distributes verbs among the Persons to reveal interior relations, but the Father creates through the Son in the Spirit, and the action is numerically one.
Singular Use of “Trinity”
With the identity dilemma settled, I address Tuggy’s concern that Trinitarianism implies three causal agents and undermines monotheism. Cause here has its classical metaphysical sense: one efficient cause, the unique divine principium that confers existence without temporal succession. The Father, the Son, and the Holy Spirit do not act as three parallel producers; the one simple essence exercises a single undivided causal power under three relational vantages. Patristic tradition captures this in the axiom opera Trinitatis ad extra sunt indivisa, while Aquinas writes that “the divine persons do not operate as three principles but as one principle” (Summa theologiae I, 45, 5 ad 1). My analytic restatement is that the pure act of being is numerically one and every external effect flows from that act, even though Scripture uses distinct personal names to unveil the inner order of origin. Because the causal power is single, naming the Trinity in the singular is not stylistic but ontological. Tuggy says singular reference to the Trinity appears only in Gregory of Nazianzus after 381 and may be a later interpolation. Yet Hilary of Poitiers in the early 360s already prays “Sancte Trinitas” in De Trinitate Book 12, and Gregory’s Orations 39, 40, and 41 address “O Trinity” with singular verbs in manuscripts independent of later editors. Singular “Trinity” thus predates Augustine and occurs in both Latin and Greek, confirming that the Church regarded the triune God as one efficient cause before later Western developments. Because the three self-standing relational modes share and are the single act of divine being, the term Trinity functions legitimately as a singular referring expression for the one God.
Conclusion
Scripture, the pre-Nicene Fathers, the Cappadocians, and the ecumenical councils all teach that the Father, the Son, and the Holy Spirit are each truly God while there is one God. My analytic account clarifies this pattern. The divine essence is pure act, differentiation is relational, each self-standing relational mode is the full divine act from a unique vantage, and every external work is one indivisible operation. Tuggy’s scriptural, historical, and logical objections fail. The classical confession remains intact: God is one simple essence eternally subsisting as Father, Son, and Holy Spirit, each wholly God by identity of essence, each distinct by relation of origin, inseparable in operation, and worthy of undivided adoration.
