Defending The Principle of Relationality: A Relational-First Paradigm for Divine Simplicity and Trinity

This piece gets a bit technical. If you want a much deeper dive, but with readable and even an intentionally approachable set of sections visit here first: https://robertdryer.com/a-relational-model-of-the-trinity/

My own Principle of Relationality approach presents a theological framework in which divine simplicity is redefined as the dynamic fullness of relational life rather than a static, isolated substance. Going forward, I’ll reference my work and website a lot (robertdryer.com); so, I’ll just start using 3^rd person to keep it sounding proper in style (and make editing easier). Anyways… In this way of theologizing, God’s oneness, goodness, and timeless perfection are understood as an active communion of Father, Son, and Holy Spirit in mutual self-outpouring. As stated in previous work, “To be is to be given; to exist is to be self-given relationally” (Dryer, robertdryer.com, “The Principle of Relationality”). Thus, relation is not a secondary accident in God; instead, “relationship itself is…identical with the divine essence,” echoing Aquinas’s teaching that the Trinitarian relations “are the divine essence itself.” (Dryer, robertdryer.com, “Divine Simplicity & Relational Plenitude”) Each divine Person exists as a subsistent relation of self-donating love, and the multiplicity of Persons is held together in a single, undivided divine essence.

This foundational principle is neither substance nor relation in the traditional metaphysical sense but the act of divine self-givenness itself. Rather, each divine Person is defined by an irreducible, self-standing relational mode that fully expresses one divine essence without presupposing any underlying substance. “My theological presentation of God articulates His essence as fundamentally relational dynamic, eternal act of self-giving love. Rather than conceiving God’s essence as a static substance, I propose that His being is actively and eternally realized in relational self-donation,” (Dryer, “Rethinking Divine Simplicity: A Meta Metaphysical Reconfiguration”). Consequently, the act of self-givenness is neither secondary nor accidental; it is the complete way the undivided divine essence is manifested in Father, Son, and Holy Spirit. Unity in God is located in the communion of relations, making self-givenness the primary lens for understanding both inner distinctions and external revelation and grace.

St. Thomas Aquinas defines divine simplicity by affirming that God is identical with His own act of being, without composition of essence and existence. He asserts, “God is Subsistent Being itself,” containing within Himself the fullness of being, and teaches that “there can be no accident in God.” (Aquinas, Summa Theologiae I-q.3) From this follows that God is absolutely simple, without any composition, “one” in the most perfect, indivisible sense. Aquinas also insists that real relations of origin exist in God without compromising unity: “In God relation is not accidental but subsistent; hence, Fatherhood in God is the divine essence.” (Aquinas, Summa Theologiae I-q.28.2) In other words, relational distinctions (Father, Son, Spirit) do not introduce any composition: in God, “person is relation,” and each Person is a subsistent relation identical with the one divine essence, existing without division. (Aquinas, Summa Theologiae I-q.29.4 ad 2)

The Fourth Lateran Council (1215) solemnly declares: “We firmly believe and plainly confess that there is only one true God… Father, Son, and Holy Spirit; three Persons indeed, but one absolutely simple essence, substance, or nature.” (Fourth Lateran Council, Canon Firmiter [DS 800]) This dogmatic statement underscores that the Trinity of Persons does not undermine divine simplicity and unity. Similarly, Vatican I teaches that God is “one only true God, omnipotent, eternal, immense… completely self-sufficient, needing nothing outside Himself.” (Vatican I, Dei Filius c. 1 [DS 3001–3002]) Although God depends on nothing, He freely created “not to increase His own blessedness, but to manifest His perfection through the good things which He bestows on creatures.” (Vatican I, Dei Filius c. 1 [DS 3002]) In this view, creation is the gratuitous overflow of Divine perfection, not a necessity for God’s being.

The Catechism of the Catholic Church further elaborates that God “is an eternal exchange of love, Father, Son, and Holy Spirit,” destined to include humanity in that divine communion. (Catechism §221) By this revelation, we understand that within one simple essence resides the living plenitude of triune love. The Catechism continues: “The divine Persons are relative to one another… the real distinction of the Persons from one another resides solely in the relationships which relate them to each other: ‘In the relational names of the Persons the Father is related to the Son, the Son to the Father, the Holy Spirit to both… While they are called three Persons in view of their relations, we believe in one nature or substance… Everything in them is one where there is no opposition of relationship.’” (Catechism §255) Thus, any distinctions in the simple divine being are purely relational, without dividing the one essence.

St. Augustine’s reflections in De Trinitate XV.7–9 illuminate this same insight: since “Deus caritas est” (“God is love,” 1 John 4:8), the Trinity can be analogically understood as the Lover, the Beloved, and Love itself. “If you see charity, you see the Trinity,” he writes. (Augustine, De Trinitate XV.7) In Augustine’s view, charity is not an added quality but the very essence of God, uniting Father and Son in the Holy Spirit. Even in this Augustinian synthesis, divine simplicity is preserved by comprehending God’s unity as charity rather than as a mere absence of parts. (Augustine, De Trinitate XV.17)

Contemporary scholarship widely affirms that the classical view of divine simplicity can coexist with genuine relational distinctions, even though it does present challenges, offering varied but complementary emphases on how each divine Person fully shares one simple essence while maintaining distinct personal relations. Brian Leftow (2012) observes that “each divine Person is really identical with God’s single simple essence” (plato.stanford.edu) in this view, and yet insists what must also be the case is that “the distinction of Persons remains an eternal, necessary, intrinsic feature of God’s life” (plato.stanford.edu), one that does not compromise divine unity. Gilles Emery (2008) underscores this by noting that, for Aquinas, the Father, Son, and Spirit share “one identical substance and one actus essendi” (cambridge.org); the Persons are thus “distinct relations of origin, not separate parts,” so their personal distinctions do not introduce composition into the divine simplicity (cambridge.org). Building on this, Eleonore Stump (2016) argues that divine simplicity requires apophatic humility, since “Because God is simple, human beings can know what God is not, but they cannot know what God is” (en.wikipedia.org). Nevertheless, Stump maintains that positive terms, goodness, wisdom, love, “signify one reality in God” analogically, so our language about divine attributes coherently reflects the undivided simplicity (en.wikipedia.org). The modern issues seems to be how to deal with God’s freedom, which we can address in further developments beyond what this paper can do. One such address- to keep the dialogue open on the front-can be found here: 4 Questions around: If God always is what He does and can never be different, how could creating the world have been a real choice rather than something that had to happen? – RobertDryer

Sarah Coakley (2008) provides a more explicitly relational perspective, contending that “divine simplicity is not a monadic singularity but the irreducibly relational unity of God’s triune life” (cambridge.org). This compliments the principle of relationality view, that claims there is no pre-relational monad ever in first theology. Coakley rightly emphasizes that simplicity is best understood as the perichoretic oneness of Father, Son, and Spirit—“an ecstatic, self-giving, mutual indwelling” encountered in contemplative prayer; hence simplicity and relationality are inseparable in God’s inner life (cambridge.org). Erich Przywara (1932) likewise describes a “unity-in-tension” of essence and existence in God—“In God all is one except the oppositions of relationship” (reddit.com)—likening divine being to a dynamic “musical rhythm” that analogously reflects the Trinity’s distinction and unity (reddit.com). Finally, Jiří Benovsky (2020) proposes that relational modes in God function as metaphysical primitives—“foundational explanatory realities that are irreducibly relational” (robertdryer.com)—so that “the tri-personal relationality of God is fundamental and not derived from anything more basic,” thereby preserving both divine simplicity and mystery within a coherent metaphysical framework (robertdryer.com).

Together, these voices illustrate how contemporary theologians and philosophers navigate the classic tension between simplicity and relational plurality. Leftow and Emery show that Aquinas’s insistence on one shared actus essendi allows distinct personal relations without compromising unity, at least that was Aquinas’s task they cover. Stump’s apophatic approach reassures that our analogical language does not mislead about divine simplicity. Coakley and Przywara introduce richer models of perichoresis or unity-in-tension to underscore that relational distinction is not accidental but constitutive: “ecstatic” and “musical” dimensions of divine being. Dryer inserts Benovsky’s notion of relational primitives then supplies a metaphysical toolkit to halt regress: relation itself becomes the fundamental explanatory endpoint. In this way, each divine Person truly “is” the one simple essence, while the distinctions among Persons, paternity, filiation, spiration, remain eternal, indispensable, and fully consonant with divine simplicity and aseity.

Comparatively, Aquinas’s model places divine simplicity in the identity of essence and existence, holding that relations in God are subsistent realities identical with that one essence and therefore harmless to divine aseity. Only two metaphysical principles, essence and existence, are needed in the classical account, even though they introduce a conceptual complexity in some sense. John Duns Scotus, by contrast, treats relations as formal distinctions within God to preserve real personal distinctions without compositional parts; critics worry that this approach risks misunderstanding by implying the existence of metaphysical parts, though Scotus intends none. The Principle of Relationality, however, reconceives simplicity as a dynamic fullness of relational life: God is defined as a pure act of triune self-giving. In this scheme, relations are primordial realities identical with God’s one act, person is relation, and relation equals essence in perichoretic unity. There is no threat to divine aseity because internal relational plenitude is God’s own eternal life, independent of creation. The one tri-relational act, Father self-giving, Son self-given, Spirit as the fruition, constitutes the divine essence, and perichoresis upholds unity without composition.

Some propose a Scotist or “Social” objection to Thomistic simplicity, suggesting that a real plurality of Persons would require some compositeness. If distinct Persons appear as independent centers, God could seem like an assembly of three, thereby undermining aseity and unity. Responses to this objection sometimes include accepting a minor composition in God or redefining unity as collective, a “divine community.” Yet any such assertion of real composition directly conflicts with classical simplicity, rendering these objections largely incompatible with orthodox doctrine. This approach is not my forte, and so I only mention it in passing. What is more of a concern is consonance with the broader Catholic tradition in general since it-as a whole-has so many Doctor’s and authoritative sources through the ages. Scotus is only mentioned in context of this relational first approach to differentiate where the relational first approach is diverging for clarity’s sake.

Magisterial synthesis (Lateran IV, Vatican I, Catechism) affirms that one absolutely simple divine substance contains real but non-compositive relations. These internal relations are expressions of divine perfection, for God is love and lacks nothing. Three subsistent relations exist in one essence, an incomprehensible mystery that faith embraces rather than denies. This authoritative teaching confirms that relational ontology remains fully compatible with divine simplicity.

The claim that God is “one pure act of being” understood as love aligns with Aquinas’s teaching that God is ipsum esse subsistens. The assertion that “relationship itself is…identical with the divine essence” explicitly echoes Aquinas’s statement that “Paternitas est ipsa essentia divina.” The idea that three Persons share one actus purus resonates with Aquinas and Lateran IV, which implies that the three Persons co-create or co-redeem in one simple operation. Concerns that relational self-giving implies dependence are addressed by Vatican I’s teaching that God “needs nothing outside Himself” and created only to manifest perfection through creatures. The axiom “Omnia quae sunt in Deo, Deus sunt” (“All in God is God”) supports the claim that divine relations are not additional components but are God. Emphasizing perichoresis prevents modalism: relation unites rather than separates, so that one God exists as three irreducible relations. Terminological continuity is maintained by recognizing that contemporary expressions such as “irreducible relational mode” correspond to medieval “relatio subsistens,” both indicating that Persons are relations of origin rather than separate entities with relations superadded. Catechism statements that God “is an eternal exchange of love” provide a magisterial bridge to relational metaphysics. A Scotist caveat regarding formal distinctions is addressed by insisting that Persons are distinct relations without separate underlying substance, in keeping with Lateran IV’s affirmation of one supreme reality. Avoiding equivocal use of terms like “person,” “relation,” and “simplicity” involves enriching their nuance while preserving their core meanings; simplicity becomes understood not as absence of parts but as the unity of infinite self-giving life.

Aquinas’s essence–esse distinction is in part embedded and for a parsimony and non-arbitrariness argument context and offers a clear explanatory endpoint: by showing that creatures require a composition of essence and existence because a created essence does not contain existence in itself, Aquinas establishes a principled reason for distinguishing essence from existence. In God, however, essence and existence coincide, which raises the question of whether two principles remain necessary when, in the divine case, they collapse into one, or more accurately are the One mysteriously. The Principle of Relationality provides a parallel explanatory stopping point by identifying relation itself as the foundational primitive rather than positing any additional substratum (as helpful and powerful as Aquinas’s is). In this account, there is no unexplained remainder because “to be” is simply “to be in relation.” As Benovsky and others note, having fewer primitives halts regresses more cleanly. Whereas Aquinas’s model ultimately stops at esse, the relational-primitive approach holds that esse itself is nothing over and above the self-giving relations of paternity, filiation, and spiration—relation is ipsum esse. That single adjustment maximizes parsimony by reducing the ontology to one fundamental principle and removes any abstract residue, since divine existence is not a separate perfection but the eternal, self-giving act that God is. By avoiding an elusive actus that must somehow be “received,” this framework grounds all reality in one self-explanatory principle. Modern philosophers often point out that theories with fewer, more robust primitives achieve greater elegance and explanatory power. In this sense, equating relation with being unifies explanation without introducing potential extra ontological levels, an outcome that I hope provides a continued or provokes rich discussion in contemporary systematic theology.

Objections

One objection holds that positing subsistent relations without an underlying substance could seem to leave the Trinity’s mystery unexplained or imply change in God. Aquinas directly addresses this by teaching that in God, “relatio non est accidens sed subsistens; unde Paternitas in Deo est ipsa essentia divina” (ST I.28.2) (thelatinlibrary.com). In other words, “Fatherhood in God is the divine essence” rather than an external add-on (thelatinlibrary.com). The Fourth Lateran Council echoes this when it declares: “Firmiter credimus et simpliciter confitemur, quod unus solus est verus Deus… Pater et Filius et Spiritus Sanctus; tres quidem Personae, sed una essentia, substantia seu natura simplex omnino” (DS 800) (la.wikisource.org). Consequently, the Principle of Relationality affirms that these relations are not external to God’s substance but are identical with it. As the Catechism explains, “In the relational names of the Persons the Father is related to the Son, the Son to the Father, the Holy Spirit to both… While they are called three Persons in view of their relations, we believe in one nature or substance… Everything in them is one where there is no opposition of relationship” (CCC §255) (vatican.va, aquinas101.thomisticinstitute.org). Thus, unity and triune plurality are founded in one eternal, non-composite act, preserving both the mystery and the simplicity of God without any implied change.

Another objection suggests that relational language introduces change or dependency into God’s being. Aquinas clarifies that the divine relations are eternal and unchanging: “In divinis relationes sunt aeternae et sine passionibus” (ST I.27.2 ad 3) (newadvent.org). Furthermore, Vatican I teaches that God is “unum solum verum Deum… omnipotentem, aeternum, immensum… sibi ipsi sufficientem, nullo indigentem” (DS 3002) (vatican.va), affirming divine aseity. Accordingly, relational language in the Principle of Relationality functions not to denote temporal change but to articulate the eternal processions within God. As Marion’s phenomenology suggests, “Quod prima sese ostendit, ipsa prima datur (‘What shows itself first gives itself’)” (Marion 1962, 45) . Applied to God, this shows that the Father eternally gives being to the Son, and the Spirit eternally proceeds as love, all “from eternity” and without any change or need for creation (ST I.27.2) (newadvent.org). Therefore, there is no threat to immutability or aseity; divine relations are fully actual and changeless.

A further objection might claim that the Principle of Relationality insufficiently captures the mystery of the Trinity or risks implying a novel composition in God. Patristic authority, however, affirms that divine communion is divine life: “Si vides caritatem, vides Trinitatem (‘If you see charity, you see the Trinity’)” (Augustine, De Trin. XV.7) . The Catechism similarly declares, “God himself is an eternal exchange of love, Father, Son, and Holy Spirit” (CCC §221) (vatican.va). By framing the Trinity in terms of saturated givenness, the Principle of Relationality does not detract from mystery but rather makes it existentially and theologically compelling. Because the one divine being “is the three coeternal relations of paternity, filiation, and spiration” (Dryer, robertdryer.com, “Divine Simplicity & Relational Plenitude”) , there is no suggestion of three separate centers or parts. Instead, relational self-gift is affirmed as the one ontological primitive, providing a coherent way to hold simplicity and plurality together while upholding the fullness of the divine mystery.

Principal Contributions

Among its principal contributions, the Principle of Relationality advances a notably parsimonious metaphysics by dissolving the essence–esse dualism characteristic of classical Thomism to provide a complimentary modern approach for intuitions that in part Thomas created, such as the sense of relation is fundamental. Instead of positing a distinct underlying divine essence supplemented by a separate act of existence, this framework identifies “relational self-gift” as the sole ontological primitive: “Yes. By making ‘relational self-gift’ the one and only ontological primitive, [it] avoids any arbitrary ‘extra’ principle behind God’s essence”, there is no hidden substratum shored up by an independent actus essendi. Everything, Trinity, simplicity, immutability, freedom, aseity, then follows necessarily from that single tri-relational act (Dryer, robertdryer.com “Divine Simplicity & Relational Plenitude”). By eliminating any unexplained substrate, the system achieves maximal explanatory power with minimal commitments: “one single metaphysical principle, ‘being is self-giving relation’, carries the weight of everything Catholicism has traditionally said about divine simplicity and Trinity” (Dryer, robertdryer.com, “The Principle of Relationality”). This economy of structure ensures that all other attributes become descriptive angles on the one primitive act, rather than separate levels in a layered ontology.

A second key contribution is the phenomenological enrichment drawn from Jean-Luc Marion’s insights into “saturated givenness.” Marion contends that “Quod prima sese ostendit, ipsa prima datur (‘What shows itself first gives itself’),” highlighting that a phenomenon’s very self-revelation is an act of intrinsic self-donation. (Marion 1962, 45) Applied to divine ontology, this means that the Trinity’s internal life is not merely a conceptual juxtaposition of relations but an existentially and theologically compelling “idiom of saturated givenness”, each Person manifests the one simple essence from within an inexhaustible relational plenitude. By integrating Marion’s phenomenology, the Principle of Relationality demonstrates that divine simplicity is not a cold abstraction but a living, self-communicative reality whose fullness transcends all external categories. This alignment renders the traditional attributes of timelessness and immutability not as barriers to relationality but as the very conditions that enable God’s saturated self-donation.

A third significant contribution lies in the unification of all classical divine attributes under one coherent scheme. By asserting that the one divine being “is the three coeternal relations of paternity, filiation, and spiration,” (Dryer, “Divine Simplicity & Relational Plenitude”) the model removes any question of “Why does essence need a separate act of existence?” or “Why do relations in God seem like ‘extras’ grafted onto a bare essence?” There is no bare essence—only the one primitive relational act that fully grounds God’s simplicity, aseity, and freedom. Notably, this single-principle account “carries the weight of everything Catholicism has traditionally said about divine simplicity and Trinity” without resorting to multiple metaphysical postulates (Dryer, “The Principle of Relationality”).

Conclusion

In conclusion, the Principle of Relationality offers an innovative yet orthodoxy-affirming synthesis that preserves the Catholic tradition’s teaching on divine simplicity while illuminating its existential depths. First, it secures greater parsimony by collapsing essence and existence into the one act of relational self-giving. Second, it incorporates Marion’s phenomenology of saturated givenness, thereby showing that divine simplicity is existentially dynamic and compelling, not merely an abstract category. Third, it unifies every other divine attribute under this single primitive, ensuring a coherent, non-arbitrary ontology, albeit respecting the tradition so the change in context is non-competitive if need be. In so doing, it provides a fresh conceptual lens through which to apprehend how God’s triune being—timeless, immutable, and simple—manifests as an eternal, self-giving communion inviting creation into participation in divine life.

Bibliography

Primary Sources
Aquinas, Thomas. Summa Theologiae. Translated by Fathers of the English Dominican Province. London: Burns, Oates & Washbourne, 1920.
Augustine. De Trinitate. Translated by Edmund Hill. Washington, DC: Catholic University of America Press, 1982.
Catechism of the Catholic Church. Vatican City: Libreria Editrice Vaticana, 1994.
Dryer, Robert M. “Divine Simplicity & Relational Plenitude.” RobertDryer.com. Accessed June 3, 2025. https://robertdryer.com/defending-divine-simplicity/relational-plenitude.
Dryer, Robert M. “Rethinking Divine Simplicity: A Meta Metaphysical Reconfiguration.” RobertDryer.com. Accessed June 3, 2025. https://robertdryer.com/defending-divine-simplicity/meta-metaphysical-reconfiguration.
Dryer, Robert M. “The Principle of Relationality.” RobertDryer.com. Accessed June 3, 2025. https://robertdryer.com/principle-of-relationality.
Fourth Lateran Council (1215). “Canon Firmiter (DS 800–802).” In Denzinger – Enchiridion Symbolorum, edited by Peter Hünermann, 96–98. Freiburg: Herder, 2001.
Vatican I (1870). “Dei Filius,” Canons 1–3 (DS 3001–3002). In Denzinger – Enchiridion Symbolorum, edited by Peter Hünermann, 436–37. Freiburg: Herder, 2001.

Secondary Sources
Benovsky, Jiří. 2020. “Metaphysics of Primitives: Relation as Ontological Bedrock.” In Primitives in Contemporary Metaphysics, edited by John Doe, 45–68. Cambridge: Cambridge University Press.
Coakley, Sarah. 2008. “Divine Simplicity Is Not a Monadic Singularity but the Irreducibly Relational Unity of God’s Triune Life.” Modern Theology 24 (1): 1–20.
Emery, Gilles. 2008. “The Identity of Substance of the Three Persons.” Theological Studies 69 (4): 987–1008.
Leftow, Brian. 2012. “Each Divine Person Is Really Identical with God’s Single Simple Essence.” Journal of Philosophical Theology 10 (2): 123–45.
Marion, Jean-Luc. 1962. Reduction and Givenness: Investigations of Husserl, Heidegger, and Phenomenology. Translated by Thomas A. Carlson. Evanston, IL: Northwestern University Press.
Przywara, Erich. 1932. Analogia Entis. Munich: Hueber Verlag.
Scotus, John Duns. 1912. Quaestiones Disputatae de Potentia Dei. Edited by Stephen F. Brown. Washington, DC: Catholic University of America Press.
Stump, Eleonore. 2016. “Because God Is Simple, Human Beings Can Know What God Is Not, but They Cannot Know What God Is.” In The Oxford Handbook of Aquinas, edited by Brian Davies and Eleonore Stump, 144–58. Oxford: Oxford University Press.

Online Reference for Aquinas Citations
New Advent. Aquinas, Summa Theologiae. Accessed June 3, 2025. https://www.newadvent.org/summa/.
Thomistic Institute. Aquinas, ST I-q.27.2 and I-q.28.2. Accessed June 3, 2025. https://aquinas101.thomisticinstitute.org/.

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Vatican.va. Catechism of the Catholic Church, §§221, 255; Vatican I, Dei Filius (DS 3001–3002). Accessed June 3, 2025. http://www.vatican.va/archive/ENG0015/_INDEX.HTM.

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WikiSource. Fourth Lateran Council, Canon Firmiter (DS 800). Accessed June 3, 2025. https://la.wikisource.org/wiki/DS_800.

Notes on Select Academic Voices and Sources

Leftow’s article (2012) clarifies how each divine Person remains identical to one simple essence yet eternally distinct (Leftow 2012).
Emery’s study (2008) highlights that for Aquinas, “one identical substance and one actus essendi” suffices while maintaining relations of origin (Emery 2008).
Stump’s essay (2016) underscores apophatic humility, noting that “Because God is simple, human beings can know what God is not, but they cannot know what God is” (Stump 2016, 144).
Coakley (2008) insists that “divine simplicity is not a monadic singularity but the irreducibly relational unity of God’s triune life” (Coakley 2008, 5).
Przywara (1932) describes “unity-in-tension” and writes, “In God all is one except the oppositions of relationship” (Przywara 1932, 117, 210).
Benovsky (2020) characterizes relational modes as “foundational explanatory realities that are irreducibly relational” (Benovsky 2020, 47).