A new Thomistic view of the Trinity

I think the historical Aquinas’ solution to how God is one in three persons is a relative identity view that posits two kinds of identity:

1. Individual identity: the lack of a real distinction, where real distinction might come from a difference of matter (as in material substances), a difference of form (as in angels) or an opposition of real relations (as in the Trinity).

2. Sameness of essence: having the numerically same substantial form.

While this is a relative identity account, it has an advantage over more standard relative identity accounts in that it nicely explains our intuitions about absolute identity. For on Aquinas’ solution, as far as we know, except where God is involved, the two identities are co-extensive. For Aquinas (like perhaps Aristotle) believes in individual forms of creatures, so all creatures that are distinct by individual identity have numerically distinct substantial forms, and conversely there are no mere creatures with two substantial forms. Thus when we are not dealing with God, we can afford to be ambiguous between the two kinds of identity, and hence talk as if there was absolute identity. (As far as I know, Thomas never makes this point.)

The point of this post, however, is to offer an alternative version of Aquinas’ two-identities account. The alternative is thoroughly Thomistic, but it’s not what Thomas has. Here it is. We have two kinds of identity. The first is individual identity, as in the historical Aquinas’ solution. The second is:

3. Sameness of esse: having the numerically same esse or act of being.

Just as in the historical Aquinas’ solution, the alternate account has the feature that apart from theological cases, the two kinds of identity are co-extensive. Distinct individual creatures have distinct acts of being, and no creature has two acts of being.

A disadvantage of this view is that “sameness of esse” doesn’t fit quite as well as “sameness of essence” with the Nicene Creed’s “homoousion”. But some things are worth noting. The previous English translation of the Nicene Creed in the Catholic Church actually had “sameness of being”. The word ousia is the abstract form of einai, to be. And in God essence and act of being are the same by divine simplicity. So I think the disadvantage can perhaps be overcome.

An advantage, however, is that sameness of esse seems even more identity-like and unifying than sameness of form. If x and y have the very same act of being, it is hard to deny that there is a real unity between x and y. Here is one way to see the point. On Platonist metaphysics, unlike on Thomastic metaphysics, you and I have sameness of form: we each have the numerically same Form of Humanity. Granted, Platonist metaphysics may be false. But the fact that you and I count as having sameness of form on Platonist metaphysics should make a little less happy about using that as an account of the unity in the Trinity. On the other hand, once we supplement Platonist metaphysics with an act of being, it is clear that you and I will get different acts of being, since each of us can exist without the other doing so.

Moreover, this account may help cast a light on the thorny question of why Aquinas at one point posits a human esse in the incarnate Christ distinct from the divine esse (though elsewhere he denies it). For suppose that there is only one esse in Christ and we accept the sameness-of-being account. Then we would be able say that the Jesus Christ as human is God, since the one and only esse in Jesus Christ, whether as human or as God, is the divine esse, and this we shouldn’t say (and indeed Aquinas denies it). Thus if we accept the sameness of esse account, we get an argument for the two esse view of the Incarnation. Of course, we can turn this around. We might say that the two esse view is false, and hence the sameness of esse account is false.

Existence and causation

Start with these plausible claims:

1. If x causes y, the causal relation between x and y is not posterior to the existence of y.

2. A relation between two entities is never prior to the existence of either entity.

So, the causal relation between x and y is neither prior nor posterior to the existence of y.

But the causal relation is, obviously, intimately tied to the existence of y. What is this tie? The best answer I know is that the causal relation is the existence of y or an aspect of that existence: for y to exist is at least in part for y to have been caused by x.

Substances and their existences

I used to think that:

1. x is a substance just in case  <x exists> is not grounded in any fact about any other entity other than x.

But it is plausible that a finite creature’s existing is its being created. And that Alice is created seems to be grounded in God creating Alice, which seems to be a fact about God.

There is a nice response to this worry. On standard medieval views, creation is a one-way relation. When God creates Alice, there is a relation of being-created-by-God in Alice but no relation of creating-Alice in God. We can say, then, that in an important sense the fact that God creates Alice is not a fact about God, but about Alice, where we say that a fact is about x provided the fact is in part a fact of x’s existing or there being some property or relation in x.

It’s interesting that the very plausible account (1) of substance combined with a theistically plausible view that the esse of a finite thing is its being-created yields the rather abstruse one-way relation thesis.

This line of thought does not, however, fit well with the claim that I made in The Principle of Sufficient Reason that for a caused entity, its esse is its being caused. For Alice is also caused by her parents. And while divine causation may be a one-way relation, it seems unlikely that creaturely causation is.

There are three ways out of this worry. (i) We could say that creaturely causation is also a one-way relation. (ii) We could say that I was slightly wrong, and for a caused entity, its esse is its being primarily caused, i.e., caused by God. (iii) We could modify (1) to:

2. x is a substance just in case  < x exists> has a grounding in a fact that is neither about any entity other than x nor grounded in a fact about any entity other than x.

For we can then say that while Alice’s being-caused is grounded in her parents’ activity, which is a fact about her parents, it is also grounded in God’s causing Alice, which is not a fact about God in the sense of being grounded in a relation or property of God’s.

I like both (ii) and (iii). What is especially attractive about (ii) is that if the esse of Alice is her being caused, then the esse of Alice is highly disjunctive, being multiply grounded—in God’s causing Alice, in her parents causing her, in her parents’ gametes causing her, maybe even in her grandparents’ causing her, etc. But it doesn’t seem right to say that Alice’s esse is highly disjunctive. So a focus on primary causation seems attractive. And I think—but without a careful examination—that the arguments in Principle of Sufficient Reason work with that modification still.

An omnipotence principle from Aquinas

Aquinas believes that it follows from omnipotence that:

1. Any being that depends on creatures can be created by God without its depending on creatures.

But, plausibly:

2. If x and y are a couple z, then z depends on x and y.

3. If x and y are a couple z, then necessarily if z exists, z depends on x and y.

4. Jill and Joe Biden are a couple.

5. Jill and Joe Biden are creatures.

But this leads to a contradiction. By (4), we have a couple, call it “the Bidens”, consisting by Jill and Joe Biden, and by (2) that couple depends on Jill and Joe Biden. By (1) and (5), God can create the Bidens without either Jill or Joe Biden. But that contradicts (3).

So, Aquinas’ principle (1) implies that there are no couples. More generally, it implies that there are no beings that necessarily depend on other creatures. All our artifacts would be like that: they would depend on parts. Thus, Aquinas’ principle implies there are no artifacts.

Thomists are sometimes tempted to say that artifacts, heaps and the like are accidental beings. But the above argument shows that that won’t do. God’s power extends to all being, and whatever being creatures can bestow, God can bestow absent the creatures. If the accidental beings are beings, God can create them without their parts. But a universe with a heap and yet nothing heaped is absurd. So, I think, we need to deny the existence of accidental beings.

If we lean on (1) further, we get an argument for survivalism. Either Socrates depends on his body or not. If Socrates does not depend on his body, he can surely survive without his body after death. But if Socrates does depend on his body, then by (1) God can create Socrates disembodied, since Socrates’ body is a creature. But if God can create Socrates disembodied, surely God can sustain Socrates disembodied, and so Socrates can survive without his body. In fact, the argument does not apply merely to humans but to every embodied being: bacteria, trees and wolves can all survive death if God so pleases.

Things get even stranger once we get to the compositional structure of substances. Socrates presumably depends on his act of being. But Socrates’ act of being is itself a creature. Thus, by (1), God could create Socrates without creating Socrates’ act of being. Then Socrates would exist without having any existence.

I like the sound of (1), but the last conclusion seems disastrous. Perhaps, though, the lesson we get from this is that the esse of Socrates isn’t an entity? Or perhaps we need to reject (1)?

Existence

In his famous critique of the ontological argument, Kant said that existence is not a property. Frege and Russell gave a very influential response to Kant (though not framed as such): the existence of an object is not a property of the existent object, but it is a second-order property of an abstract object. Thus, the existence of Biden is the second-order property of being instantiated possessed not by Biden himself but by the abstract object Bidenness.

But now consider this very plausible principle:

1. The existence of an object is explanatorily prior to all the (other) properties of that object.

The parenthetical “other” is included to make (1) acceptable both to Frege-Russell and to “pre-Kantians” who think existence is a property of the existent object.

But combining (1) with the Frege-Russell account leads to an explanatory priority regress:

• Biden’s maleness is posterior to Biden’s existence.

• Biden’s existence is Bidenness’s being instantiated.

• Bidenness’s being instantiated is posterior to Bidenness’s existence.

• Bidenness’s existence is Bidennessness’s being instantiated.

• Bidennessness’s being instantiated is posterior to Bidennessness’s existence.

• Bidennessness’s existence is Bidennessnessness’s being instantiated.

• …

How can we arrest this regress? A natural move is to restrict the Frege-Russell view of existence to contingent entities. Thus, Biden’s existence is the instantiation of Bidenness, but Bidenness is a necessary entity, and its existence is not the instantiation of some further entity. Indeed, perhaps, the pre-Kantian view holds of Bidenness: Bidenness’s existence could just be a property of Bidenness.

Note that if the pre-Kantian view holds of necessary beings, then Kant’s critique of the ontological argument falls apart, since God is a necessary being.

But let’s think through the pre-Kantian view a little bit. Suppose that x is an object and e is its existence, and suppose e is a property of x. But how can x possess e without already existing prior to having e? (I.e., surely, (1) is true with the parenthetical “other” removed.) There seems to be one possible move here: perhaps x = e. That would be a view on which some objects are identical with their own existence—a view very much like St. Thomas’s, who held that God, and God alone, was identical with his own existence.

So, interestingly, thinking the Frege-Russell view through leads fairly naturally to a view like Thomas’s.

I am attracted to this variant of the Thomistic view:

2. Uncaused objects are identical with their existence.

3. The existence of a caused object is its being caused.

The worry that an object cannot possess a property without “already” existing does not appear pressing when the property in question is being caused.

Moreover, we might even more speculatively add:

4. An object’s being caused is its cause’s causing of it.

On this view, a contingent thing’s existence, like on the Frege-Russell view, is a property of something other than the thing: it is a property of the cause (perhaps an extrinsic property of the cause, when the cause is God, so as not to violate divine simplicity).

Haecceity and esse

I wonder if the haecceity of a thing isn't identical with its esse.

A Thomistic argument for essentiality of origins

Here is a suggestive Thomistic line of thought in favor of the essentiality of origins—i.e., the principle that the causes of things are essential to them.

Consider two possible cases where a seed is produced in the same apple tree T:

1. A seed is produced at t because of the tree’s exercise of seed-producing powers together with God’s cooperative exercise of primary causation.

2. A seed is created directly at t by God and not by the exercise of the tree’s powers.

And suppose that the seeds in the two cases are exactly alike, occur in the same place on the tree, etc.

I will argue that the Thomist should say that these will be numerically different seeds, and the best explanation of their difference is given by essentiality of origins.

For the Thomist is committed to there being a genuine difference between the two cases. Cooperative divine-creaturely causality is metaphysically different from divine primary causality. But where does the difference lie? Well, in (1) the tree’s causal powers are activated, while in (2) they are not. But it is a standard scholastic maxim that the effect is the actuality of the cause qua cause. Thus it seems that the difference between cases (1) and (2) should be found in the effect, namely the seed.

Furthermore, suppose that the difference between the cases is solely located in the cause, namely that in case (1) the tree’s causal powers are activated but not in (2), and that this activation is an accident A of the tree. The difference between cases (1) and (2) then is that in case (1), A occurs in the tree and in case (2) it does not. But for any accident of the tree, God could miraculously suppress any effects of that accident. Thus, there will be a case where A occurs in the tree and no seed results. And we could, further, imagine that:

3. Not only does God suppress the effects of A but he additionally directly miraculously produces an effect exactly like the one that A would have produced.

The difference between (3) and (1) can’t be in the activation of the tree’s causal power, since that is still there in (3). So we really should suppose a difference in the effects between (3) and (1). But a similar difference should exist between (2) and (1).

Note that the Thomist cannot say that there is a difference on the side of the causes lies in God, namely that in case (1), God’s causal power is unactivated but it is activated in (2) and (3). For an intrinsic difference in God between possible worlds would violate divine simplicity.

Thus, it is the effects, namely the seeds, that are numerically different, and they are different precisely because their causes are different. But the seeds are exactly alike. So the difference must be a metaphysical difference between the seeds. And this strongly suggests essentiality of origins. Indeed, it suggests that entities have encoded within them the identity of their cause.

Objection: The argument at most suggests that there has to be a numerical difference when something is produced by a finite cause (with God cooperating) and when something is produced directly by God. But why think there is also a difference when the effect is produced by one finite cause rather than another?

Response: The simplest metaphysical explanation of why it makes a difference whether God produces the effect or it is produced by finite causes is that the effect has metaphysically encoded in it what its cause was. In fact, my own view is that this may be found in the effect’s esse: perhaps an effect’s esse is to be caused by this-and-that.

Moreover, suppose that there need be no numerical difference between effects of different finite causes, but there is a numerical difference between direct effects of divine causation and the effects of finite causes. Then in principle scientists could have directly made the numerically same seed that the tree made in (1), but God couldn’t have directly made the numerically same seed. That seems unacceptable. (Of course, one might rejoin that essentiality of origins is unacceptable as it implies that God couldn’t directly make the numerically same seed that the tree could make. But when, as I suppose, an effect of necessity encodes in itself what its cause is, the impossibility of something’s being made by a different cause does not seem to be a limitation on that cause.)