Joseph C. Schmid and Daniel J. Linford on the Neo-Platonic Proof vs. the Trinity, part 2

  

NPCP, the Trinity, and the Incarnation

 

Consider again NPCP’s primary motivation: explicability. More specifically, the compresence of distinct elements together in a unified being demands some explanation—and because the explanation cannot be in terms of the being itself or one of its parts, an extrinsic cause (so the argument goes) is required.

 

But the exact same modification for demanding an extrinsic cause unifying composite objects seems equally to apply to the multiplicity of divine persons united in a single Godhead. In other words, there seems to be no justification for NPCP that doesn’t also justify demanding an extrinsic unifying cause in the case of things that are composites of (say) distinct attributes, or of essence and accident, or that you have but not in the case of things within which there is a multiplicity of distinct persons and/or processions.

 

Indeed, the fact of distinct x’s being a being—i.e., a multiplicity or differentiation among numerically distinct realities—is precisely what requires an extrinsic cause in Plotinus’s view. For Plotinus, the One’s simplicity is utterly unqualified (Gavrilyuk [Plotinus on divine simplicity, Modern Theology 35:442-51] 2010, pp. 442). At Enn. 6.9.4. Plotinus says that “the One transcends all differentiations characteristic of being . . . Plotinian simplicity excludes any multiplicity” (Gavriluk 2019, pp. 447-448). Anything apart from the One requires a unifying cause of its multiplicity of distinct divine persons would demand a unifying cause.

 

Clearly the trinitarian God cannot have a unifying cause. But what, then, could explain the unity of the distinct persons in God? If the answer is that there’s no explanation, then that seems to be a perfectly legitimate move for the detractor of the Neo-Platonic proof in explaining the most fundamental composite thing(s). If the answer is that it’s simply metaphysically necessary that there be three distinct persons in one God, then that also seems to be a perfectly legitimate move for the detractor of the Neo-Platonic proof.

 

Perhaps the explanation is in terms of one of those very divine persons (the Father, say)? But once again this will undercut the Neo-Platonic proof. For this explanation amounts to the proposal that one of the x₁, x₂, . . . x_n explains the unity of those very x’s. However, if this type of explanation is granted, then the unity of the fundamental composite object(s). If one of those very x’s can explain the unity of them all, then this should equally be the case when the ontological items in question (the x’s) are parts (again, in the very broad classical theistic understanding of parts). And hence it would not necessarily be the case that any composite object must be explained in terms of some extrinsic sustaining cause.

 

Perhaps there is some fourth thing—some fundamental aspect of God, say—that explains or accounts for their unity? But (i) this is plausibly incompatible with DDS (since this thing would be some positive ontological item within but distinct from God), and (ii) this reduces to the answer in the previous paragraph, since there’s the further question of what explains the unity or connectedness or compresence of {Father, Son, Holy Spirit, this fourth fundamental aspect of God}. And any explanation in terms of the final element in the set amounts to citing one of the very x’s among the x₁, x₂, . . . x_n to account for their unity.

 

Fundamentally, then, our challenge for the trinitarian proposal of the Neo-Platonic proof is as follows. In explaining the unity (togetherness, compresence) of the numerically distinct divine persons in one being (the Godhead or G), the explanation is either (i) internal to G, (ii) external to G, (iii) G itself, or else (iv) there is no explanation. But if the explanation is internal to G, then something within a unified plurality can explain the unity of said plurality—in which case, the same could apply to the objects within NPCP’s domain of quantification, thereby undermining NPCP’s demand for an outside explanation of such objects. If the explanation is external to G, then there is something outside of or external to God which explains something about God, which is obviously incompatible with classical theism. If the explanation is G itself, then an object within which there is a unified plurality can explain the unity of said plurality without recourse to any external entity—n which case, the same could apply to the objects within NPCP’s domain of quantification, thereby undermining NPCP’s demand for an outside explanation of such objects. Finally, if there is no explanation, then once again, the same could apply to the domain of NPCP, thereby undermining NPCP. Thus, either classical theism is false, or else NPCP (and hence the neo-Platonic proof itself) is undermined.

 

In general, then, any proposal for explaining the unity of the trinitarian persons will undercut NPCP and a fortiori the Neo-Platonic proof. Trinitarianism is therefore inimical to the Neo-Platonic proof in yet another way.

 

Interestingly, the same problem arises with the incarnation. According to the doctrine of the incarnation, God the Son assumed a human nature, such that Christ was truly God and truly man, possessing two natures (one divine, one human). There is thus some kind of unity, togetherness, or compresence of distinct items in the incarnation. But in explaining the unity (togetherness, conjoined-ness, compresence) of the distinct natures within one person (Christ or C), the explanation is either (i) internal to C, (ii) external to C, (iii) C itself, or else (iv) there is no explanation.

 

If the explanation is internal to C, then something within a unified plurality can explain the unity of said plurality—in which case, the same could apply to the objects within NPCP’s domain of quantification, thereby undermining NPCP’s demands for an outside explanation of such objects.

 

If the explanation is internal to C—i.e., of the explanation is not in terms of either of the united natures—then the divine nature is not the explanation for C’s unity. But this contradicts classical theism’s commitment to universal divine causality (Grant [Free will and God’s universal causality: the dual sources account] 2019), according to which everything distinct from God is ultimately explained by god’s causal activity. And since God is identical to the divine nature, it follows that there cannot be anything distinct from the divine nature that isn’t ultimately causally explained by the divine nature. And, hence, C’s unity must ultimately be explained by  the divine nature. And so the proposal on which the explanation is external to C (which again, is equivalent to the explanation not being in terms of either of the united natures) is incompatible with classical theism.

 

If the explanation is C itself, then a being in which there is a unified plurality can explain the unity of said plurality without recourse to anything external—in which case, the same could apply to the objects within NPCP’s domain of quantification, thereby undermining NPCP’s demand for an outside explanation of such objects.

 

Finally, if there is no explanation, then once again the same could apply to the domain of NPCP, thereby undermining the NPCP. Thus, either classical theism is false, or else NPCP (and hence the Neo-Platonic proof itself) is undermined.

 

We conclude, then, that the Neo-Platonic proof faces a serious challenge with respect to the incarnation. (Joseph C. Schmid and Daniel J. Linford, Existential Inertia and Classical Theistic Proofs [Cham, Switzerland: Springer, 2023], 315-18, emphasis in original)