What is Strong and Weak Simplicity?

Q. 59: Why “weak” simplicity is unacceptable?

In a relational-primitive framework, like the one I have defend here with 58 prior questions, any concession to a weak form of simplicity fatally disrupts the identification of God’s single act of being with the triadic self-giving of primitive relations. By allowing real distinctions, whether between essence and existence or between attributes and substance, weak simplicity reduces what should be constitutive relations to mere properties and splinters the divine act of existence into competing parts. True simplicity, by contrast, recognizes that the one actus essendi of God is nothing other than the perichoretic reciprocity of three metaphysical primitives, Father as begetting, Son as begotten, and Spirit as proceeding, and that no deeper explanation lies beyond their self-giving.

What is the relational primitive account? Key terms require definition. Primitive denotes what is basic and irreducible, requiring no deeper explanation. Relation names the way one thing stands to another; in God relation is the mode of existence of each Person. Essence signifies the fundamental whatness of a thing; in God it denotes the single simple reality identical with existence and self-giving. Together these definitions show that in a relational-primitive account, each divine Person is nothing other than a subsisting relation that coincides with the actus essendi and requires no explanatory closure beyond its own self-giving.

What is a weak and strong form of simplicity? A strong form of simplicity holds that in God there is absolutely no real composition or distinction of any kind: essence and existence are identical, attributes and relations are not additional features but simply names for one undivided divine reality, and all distinctions remain purely conceptual or analogical. By contrast, a weak form of simplicity concedes that there may be real distinctions in God, between essence and existence or between attributes and the divine substance, so long as these distinctions do not amount to metaphysical parts or potentiality. While weak simplicity tries to preserve God’s unity by denying any division into parts, it nevertheless treats essence and existence or relations and substance as ontologically distinct, whereas strong simplicity, and especially the relational-primitive account, insists that the one act of being is nothing other than the perichoretic self-gift of Father as begetting, Son as begotten, and Spirit as proceeding, leaving no room for any deeper distinctions in the divine life.

Central to this critique of a so-called weak form of simplicity lies the claim that essence and existence in God are identical. In classical metaphysics the actus essendi, or act of existing, names the very reality by which a being exists. In God, whose essence is identical with existence, the actus essendi is not an additional property but God’s undivided being. A weak simplicity that posits a real distinction between essence and existence thereby fragments God’s unity: relations become secondary “properties” presupposing an underlying substance, rather than constituting the substance itself.

Moreover, weak simplicity treats divine attributes such as goodness, wisdom, and power as real features standing alongside essence. This plurality of analogues implies multiple acts or modes that must somehow cohere in the divine unity. In the relational-primitive positive cast, however, every divine attribute is nothing other than an aspect of the one perichoretic exchange of begetting, begottenness, and procession. The term perichoretic, derived from perichoresis, describes the mutual indwelling of the three Persons, each interpenetrating the others without confusion. To allow any real attribute beyond those primitive relations risks introducing composition into the divine simplicity and fracturing the one act of being into multiple acts. Let’s explore three reasons why this risk is serious.

1. Goodness as a distinct divine attribute

On a weak simplicity account, one might say that God’s goodness is a real feature standing alongside His essence and relations. That implies God performs a separate act of “bestowing goodness” in addition to His triadic self-giving. In the relational-primitive view, however, goodness is nothing other than the one actus essendi lived out in perichoretic reciprocity. Treating goodness as a separate attribute introduces a second act alongside the relational gift, thereby fracturing the simple unity into multiple divine acts.

2. Omnipotence (divine power) as a separate potency

If omnipotence is treated as a real power distinct from God’s essence or relations, then God must possess and exercise that power in a separate divine act. But in a relational-primitive framework omnipotence is simply the efficacy of the one self-giving act of being. Positing a distinct omnipotence act amounts to a new component of God’s being, which contradicts the denial of any composition in the divine simplicity and splits the single actus essendi into two.

3. Omniscience (divine knowledge) as an independent cognition

A weak simplicity might hold that God’s omniscience is a real cognitive faculty apart from His essence and relations, implying a distinct knowledge act over and above the triadic self-gift. In relational-primitive theology, by contrast, God’s knowing is inseparable from His self-giving: to know is to give and receive relationally. Making knowledge a separate attribute erects an additional divine act, directly conflicting with the identification of all divine activity with the one perichoretic act of existence.

Conciliar definitions reinforce this strong simplicity. The Fourth Lateran Council declares that God is “one absolutely simple essence, substance, or nature : una essentia, substantia, seu natura simplex omnino” (Fourth Lateran Council 1215) and further teaches “Firmiter credimus et simpliciter confitemur quod unus solus est verus Deus, aeternus et immensurabilis, omnipotens, incommutabilis, incomprehensibilis et ineffabilis, Pater, et Filius, et Spiritus Sanctus : tres quidem personae, sed una essentia, substantia, seu natura simplex omnino; … consubstantiales et coaequales, et coomnipotentes, et coaeterni…” (Fourth Lateran Council 1215). Likewise, the Council of Florence proclaims that “These three persons are one God, and not three gods, because the three have one substance, one essence, one nature, one divinity, one immensity, one eternity” (Council of Florence, Cantate Domino 1441). Such definitions demand that any distinction in God be purely logical or conceptual, never metaphysical. A weak simplicity that counts essence and existence or relations and substance as real distinctions runs afoul of those definitions and conflicts with Thomas Aquinas’s teaching in the Summa Theologiae that there is no real distinction between essence and existence in God and that relations in God are not accidents but the divine essence itself. To preserve fidelity to the Magisterium and Tradition, one must reject weak simplicity.

Finally, from the standpoint of apophatic theology, weak simplicity undermines the negative safeguard that prevents us from projecting creaturely categories onto the divine life. Negative theology insists that God has no parts beyond the three subsisting relations and no potentiality or composition. If we admit real distinctions, we must endlessly qualify how they do not introduce parts, a task the via negativa sought to avoid. Instead, simplicity in the relational-primitive view is not merely an absence of parts but the positive reality of triadic self-gift. Unity and distinction coincide without tension because there is only one act of being, and that act wears a threefold relational face from eternity.

A father and doctor of the Church who took this apophatic approach to simplicity is none other than Gregory of Nazianzus. He illustrates that he’d rather have paradox than compromise God to a comprehensible coherent being among others. He writes on the Trinity in immanence and simplicity in Oration 23. First he writes,

“We, however, are a different sort. We concur and agree regarding the Godhead in no less a fashion than the Godhead is in internal agreement with itself, if it is not presumptuous to say this; and we have become one lip and one language, but in an opposite way from those who once built the tower. They were unanimous in their pursuit of an evil end, whereas our efforts toward harmony have as their object every highest good, the exalting of Father, Son, and Holy Spirit, with one heart and one voice that it may be said of us, and not only said, but also believed, that God is really “among us,” who unites those who unite him and exalts those who exalt him.” Oration 23:4.

And later Gregory of Nazianzus writes,

“…a nature that is in internal agreement with itself, is ever the same, ever perfect, without quality or quantity, independent of time, uncreated, incomprehensible, never self-deficient, nor ever so to be, lives and life, lights and light, goods and good, glories and glory, true and the truth, and the “Spirit of truth,” holies and holiness itself; each one God, if contemplated separately, because the mind can divide the indivisible; the three God, if contemplated collectively, because their activity and nature are the same; which neither rejected anything in the past as superfluous to itself nor asserted superiority over any other thing for there has been none; nor shall leave anything to survive it or will assert superiority over anything in the future, for there will be none such; nor admits to its presence anything of equal honor since no created or servile thing, nothing which participates or is circumscribed can attain to its nature, which is both uncreated and sovereign, participated in and infinite. For some things are remote from it in every respect; others come close to it with varying success and will continue to do so, and this not by nature, but as a result of participation, and precisely when, by serving the Trinity properly, they rise above servitude, unless in fact freedom and dominion consist of this very thing, attaining a proper knowledge of sovereignty and refusing to confound things that are distinct because of a poverty of intellect.” Oration 23:11.

Two of the most influential advocates of what we now call a weak form of simplicity are John Duns Scotus (c. 1266–1308) and Francisco Suárez (1548–1617).

Scotus famously held that divine attributes are really identical in God yet formally distinct. He wrote that “what Scotus calls the formal distinction … is less than a real distinction yet more than a conceptual distinction” between aspects of God’s being. By positing a formal distinction between, say, God’s essence and His existence or between His mercy and His justice, Scotus treats these as real features in God rather than reducing them to mere conceptual oppositions. That move, however, breaks the identification of God’s single actus essendi with the triadic self-giving of primitive relations.

Suárez likewise maintains that divine attributes can be distinct only in reason and not in reality. He allows distinctions of reason between attributes, goodness, wisdom, power, while insisting there is no real metaphysical composition. Although this sidesteps outright part-making, it still leaves room for multiple divine formalities that presuppose an underlying substance, rather than recognizing all attributes as facets of one perichoretic act.

Earlier patristic and medieval writers generally did not articulate a weak simplicity in these technical terms and, as we saw in Nazianzus, had their own strong spiritual and apophatic commitments. Duns Scotus represents the first major medieval figure to introduce a formal distinction within God, and Suárez to extend it in early modern scholasticism. Both thinkers thereby exemplify why any concession to real distinctions, even formal ones, undermines the strong, relational-primitive account of divine simplicity.

Because weak simplicity fractures this relational positive ontology, it cannot sustain a coherent relational-primitive theology. Only a strong simplicity, one that identifies God’s act of being with the perichoretic reciprocity of primitive relations (Father, Son, and Spirit) preserves both unity and distinction in the divine life.

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Argument

Let’s start with and stay within a relational metaphysics, such that the Father’s begetting, the Son’s begottenness, and the Spirit’s procession as the only irreducible metaphysical primitives. As such, this primitive approach exhaustively constitutes God’s being, such thay any concession to “weak” simplicity (real distinctions beyond those three relations) is logically impossible. Only a “strong” simplicity that admits no further distinctions remains coherent.

P1. By definition, a metaphysical primitive is a fundamental category requiring no deeper explanation. In God, the only such primitives are the three subsisting relations: Father as begetting, Son as begotten, Spirit as proceeding.

P2. An ontology built on primitives holds that these primitives exhaust the reality in question. No additional metaphysical primitives or categories may coherently be introduced without contradiction.

P3. God’s actus essendi (His very act of existing) is identical with the perichoretic reciprocity of these three relational primitives. There is no “substrate” behind them; they are God’s being.

P4. To posit a real distinction in God, whether between essence and existence, between attributes and substance, or between any other features, would require introducing a new primitive category or relation outside the triad.

P6. Weak simplicity admits one or more real distinctions beyond the triadic relations (for example, a formal distinction between essence and existence or between goodness and power).

P6. Premise 4 entails that any such extra distinction demands a new primitive. Premise 2 rules out any additional primitives. Hence weak simplicity contradicts the exhaustiveness of relational primitivity.

Conclusion: the only coherent form of divine simplicity within a relational-primitive ontology is one that refuses any real distinctions beyond the three subsisting relations. God’s unity and distinction coincide solely in the perichoretic self-gift of Father, Son, and Spirit, no weaker simplicity can withstand this metaphysical framework.