Disputatio VI: On Participation and the Ontology of Theosis

Thesis

The believer’s participation in divine being is constituted through the Spirit’s causal mediation, whereby the finite is reconstituted in relation to God’s own properties (D_G) through participated correlates (D), thus realizing the ontology of theosis.

Explicatio

“It is no longer I who live, but Christ who lives in me.”
— Galatians 2:20

Having established that theological felicity is grounded in the Spirit’s causality, we now inquire into the ontological form of that causality as participation—the creature’s share in divine being without confusion of natures. For theology to be true, its language must correspond to an order of reality in which divine and creaturely existences are related not by common genus but by causal participation: the Infinite present in and through the finite.

Modeling T demands a two-sorted ontology. Let S represent the creaturely individual, D_G a divine property or perfection, and D the participated correlate induced by God’s act of self-communication.  D is not identical with D_G(lest Creator and creature collapse), yet it is causally constituted by D_G and reconstitutes S ecstatically (extra nos). This cross-sort relation is the metaphysical structure of participation.

To participate in divine properties is to have what one might not otherwise have—to exist by grace rather than by nature. The creature’s present disposition is thus caused by the presence of D within its being. In Lutheran terms, this is the Infinite in the finite, the divine gift that reconstitutes the believer from without. Human existence is thereby lived ecstatically, for to be S is to be S-in-D, and to be S-in-D is to be S-in-Christ.

This participation is causal but non-competitive. It does not add parallel finite causes to the causal network of the world but alters the modal profile of the agent. The believer becomes a new kind of cause—one whose being and agency are constitutively open to God. This is formalized in the no finite overdetermination lemma: holding fixed the finite causal graph G, S⁺ (S-with-D) differs from S* (S-without-D) not by additional finite causes but by a change in dispositional constitution. Causal closure of the finite is preserved, yet divine efficacy operates in et per finitum.

Theologically, this means that the believer’s transformation in Christ is not metaphorical but ontological. The Spirit causes participation; the Son is the form of participation; and the Father is its source. Theosis thus names the creature’s being taken up into divine life through causal participation, not by nature’s elevation but by grace’s reconstitution.

Objectiones

• Obiectio I. Participation seems to imply mixture of essences; if divine properties cause finite being, then divine and human natures are confused.

• Obiectio II. A two-sorted ontology suggests two orders of being with no real communication; participation then becomes only metaphorical.

• Obiectio III. If participation alters the creature’s modal profile, it introduces new causes into the finite domain and thus violates causal closure.

• Obiectio IV. To describe participation in causal terms risks transforming grace into a natural process, thereby undermining its gratuity.

Responsiones

• Ad I. Participation does not imply mixture but relation.  D is the correlate of D_G, not its fragment or duplication. The creature remains finite, but its being is constituted in reference to the divine. Theosis is not fusion but asymmetrical communion—the Creator communicates being without ceasing to be transcendent.

• Ad II. The two-sorted ontology of Creator and creature is bridged by the act of divine self-communication. There is no common genus, but there is real relation. The divine gives rise to its own correlate within the finite, thereby grounding communication without abolishing difference. This relation is incarnational and pneumatological: the Son mediates; the Spirit constitutes.

• Ad III. The no finite overdetermination lemma ensures that participation introduces no duplicate finite causes. The Spirit’s causality reconfigures the finite constitution of agents without adding parallel forces. Divine causality is therefore constitutive, not interventionist. The finite retains causal integrity even as it is ontologically transformed.

• Ad IV. To call grace causal is not to naturalize it but to affirm its real efficacy. Grace would be unreal if it produced no change in being. The Spirit’s causal act is not one finite process among others but the metaphysical condition of creaturely transformation. In this sense, grace is both free and necessary: free as divine gift, necessary as the ground of any creature’s new being in Christ.

Nota

The ontology of participation described here moves theology from an anthropology of intrinsicality to one of extrinsicality. The believer’s life is not self-contained but lived extra nos, constituted by what lies beyond the self. As meaning is not “in the head,” so virtue, faith, and agency are not “in us,” but in Christ who lives within us. To be human in grace is to be human-from-without, defined by relation to God rather than by self-possession.

This external constitution mirrors theological realism: we speak truly of God only because our speech and being are grounded in God’s act. Theologies that begin from the self—whether epistemologically or existentially—reverse the order of dependence and reduce participation to projection. By contrast, the participatory model begins from divine causality: we are spoken before we speak, and our being is a word within the Word.

Here theology attains its nova lingua, its “new language.” The old language of philosophy—closed under finite causality—cannot express the Infinite-in-the-finite. The new language arises from the incarnation itself, in which divine communication reconstitutes the grammar of creation. This nova lingua does not abolish reason but transforms it, granting new predicates and new inferences to name what was once unsayable: that God acts in us and we live in God.

Determinatio

From the foregoing it is determined that:

1. The believer’s participation in divine being is causally constituted through the Spirit’s mediation. The relation between Creator and creature is two-sorted, without common genus yet bridged by divine self-communication.

2. Let D_G denote a divine property and D its participated correlate. Then for every believer S,

   $$S\leftrightarrow D_G\text{ via }D,$$

   where D reconstitutes S ecstatically (extra nos).

3. This participation is causal but non-interventionist. Holding fixed the finite causal network G, S⁺ (S-with-D) differs from S* (S-without-D) by a change in dispositional constitution, not by addition of new finite causes. Thus, divine efficacy operates in et per finitum.

4. The anthropology of intrinsicality gives way to that of extrinsicality: human being and agency are defined by relation to God in Christ. To live coram Deo is to exist extra nos.

5. The nova lingua of theology arises from this participatory ontology. It is a language incarnational in form—finite yet filled with infinite meaning.

Therefore, theosis is not metaphor but metaphysics: the Spirit’s act of constituting creaturely being as participation in divine life. Through this causal participation, theology itself becomes part of the event it names: the Word of God dwelling within human words, and human words transfigured into instruments of divine truth.