In Defense of the Proof of God in De Ente et Essentia: A Response to Existential Inertia

        I wrote this article a couple of years ago in the hopes of having it published in an undergrad journal, but I was unable to do so. I am now uploading this to the blog because I do not have plans on publishing it, and if I decide to try and publish it again, I will edit and expand the current version since this paper does not engage all of Joe's work on existential inertia, but I think it's a good starting point for my engagement of his work. I hope whoever reads this finds it helpful.

 Introduction

In an early work called De Ente et Essentia, St. Thomas Aquinas makes an argument for the existence of God, whom Aquinas takes to be pure existence itself. Critical to his argument is the notion that substances do not have existence in themselves, but rather are granted existence from another, namely God, who has existence in itself and is, therefore, pure existence itself. Since this is the case, if substances do actually have existence and persist in existence without the help of a sustaining cause of their existence, then Aquinas’ proof would be completely undermined. This view is known as existential inertia, or the thesis that: 

Necessarily, concrete objects (i) persist in existence (once in existence) without requiring a continuously concurrent sustaining cause of their existence and (ii) cease to exist only if caused to do so. (Schmid 2020)

In his 2020 paper, Schmid gives two accounts of existential inertia and these are the two accounts which I will address in this article. In this paper, I will begin with an explication of Aquinas’ proof of God in De Ente et Essentia and, in the process, explain the Thomistic account of existence. I will then present the Fregean model of existence as an alternative to the Thomistic account and then undermine it using Thomistic reasoning as well as research from Bill Vallicella. I will then move onto a presentation of the transtemporal and the propositional necessity accounts of existential inertia. I will then attempt to show the issues with these views using the Thomistic metaphysics of existence and the Principle of Sufficient Reason recently formulated by Robert Koons and Alexander Pruss. Fundamentally, I will argue that existential inertia is not a viable alternative to the Thomistic account of existential persistence.

Aquinas’ Proof of God

When St. Thomas Aquinas was a 30 year-old Dominican friar, he wrote De Ente et Essentia as a little metaphysical textbook for younger friars who were in earlier stages of formation. The topic of the treatise was on how angels possess a principle of potency in them, even though they are immaterial. A popular solution known as universal hylomorphism was put forward by the Franciscans, and this position stated that angels were composites of matter and form just like material creatures, but that unlike material creatures, angels possessed an incorporeal matter. St. Thomas, however, thought that this was an ad hoc solution to the issue, which led him to seek other, more promising solutions. This led him to one of his most famous and insightful metaphysical theses: the real distinction between essence and existence. St. Thomas argued that the principle of potency in angels was not matter, but rather essence, what they are, which stands in potency to esse. This did not just apply to angels, for St. Thomas, but also to all other beings with definite definitional content, and this point becomes clear in his argument for the real distinction:

Whatever is not included in the understanding of an essence or quiddity is coming to it from outside, entering into composition with the essence; for no essence can be understood without its parts. But every essence can be understood without even thinking about its existence, for I can understand what a man or a phoenix is, and not know whether it actually exists in the nature of things. Therefore, it is clear that existence is distinct from essence, unless, perhaps, there is a thing whose quiddity is its own existence. And this thing would have to be unique and the first [being]. For something can only be multiplied either by the addition of some difference, as the nature of the genus is multiplied in the species, or on account of the reception of a form in diverse pieces of matter, as the nature of the species is multiplied in several individuals, or on account of one of the things multiplied being separate and the other received in something; for example, if there were some separate warmth, then it would be separate from a non-separate warmth [i.e., the warmth of a warm body] on account of its separation itself. However, if there were a thing that is existence only, so that it would be subsistent existence itself [ipsum esse subsistens], then this existence would not receive the addition of a difference, for then it would no longer be existence only, but existence and some form besides; and even less would it be receptive of the addition of matter, for then it would already be not subsistent, but material existence. Therefore, it remains that there can only be one thing that is its own existence. And so, in any other thing, the existence of the thing has to be other than its quiddity or nature or form. Therefore, the intelligences have to have existence besides their form, which is why it was said that an intelligence is form and existence. (Aquinas 240)

The way that St. Thomas establishes the real distinction between essence and existence, esse, is by first showing that there is at least a conceptual distinction between essence and existence, and does this with the example of a man or phoenix. From this he argues for the conceptual distinction between essence and esse by pointing out that it is at least conceptually possible that there be a thing with no distinction between its essence and existence, and then lists some of the properties that this being would have. The primary property of this being is that it would be impossible to multiply this being, as it has an essence, and essence can be thought of as bounds or limits on a thing’s esse: a being which has no limits cannot be multiplied for there is nothing to multiply or replicate. Given that a being whose essence and esse are identical would have no bounds, all beings that do have bounds must have a real distinction between their essence and existence. This follows from the fact that, since it is impossible for something that is pure esse to be multiplied, if there were such a thing, all other things which could be multiplied have a distinction between their essence and existence (Kerr 29).

From this, a key tenet of St. Thomas’ metaphysics becomes illuminated, and the most important one is the way in which St. Thomas conceives of essence as the limiting principle of esse. For St. Thomas, essence is to existence, esse, as potency is to act, and potency is always a limiting principle of actuality. From this analogy, one can see that St. Thomas views essence as nothing more than limits on existence, esse, and these limits are what defines esse and gives rise to definite definitional content, which is just essence. Essence, for St. Thomas, “is that through which” “a thing has esse;” essence is nothing more than the limits on existence that become actualized by esse (Kerr 37). 

With this backdrop in place, St. Thomas’ argument for God becomes quite clear:

1. There are some things that have a distinction between their essence, what they are, and their existence, esse, that they are.

2. No thing which has a distinction between its essence and existence can have existence in itself, but only from another.

3. There are some things which have a distinction between their essence and existence and they receive their existence, their esse, from another (from 1 and 2).

4. There cannot be an infinite causal regress of things which have a distinction between their essence and existence, for things which have a distinction between their essence and existence don’t have existence through themselves, but only through another.

5. The only thing which can grant existence to others is something which has existence in itself (from 2 and 4).

6. Therefore, all things which have a distinction between their essence and existence receive their existence from something which has existence in itself (from 3 and 4).

7. If there is something which has existence in itself, that thing is God.

8. Therefore, God exists (from 5 and 6).

Given all of this, it becomes clear why existential inertia is a non-starter for St. Thomas. It would require that existence, esse, is in some sense internal to essence, for in order for a thing to have something inertially it must have it through itself, but this is impossible on the Thomistic view as the Thomistic view entails that things only “have” existence through another. The only other way for existential inertia to be a real rival to the Thomistic view is if it rejected the Thomistic metaphysics of existence and argued for some other model of existence, and this seems to be where the real debate over existential inertia is. It seems that existential inertia could function under a Fregean model of existence, but this needs to be argued for and the superiority of this model, or any other alternative to the Thomistic model, has not been demonstrated in the literature. On the contrary, if anything, alternatives to the Thomistic account, especially the Fregean account, have been subjected to incredibly harsh criticisms, while Thomistic models have been explicated and been powerfully motivated (Miller, 2012; Novotný & Novák 56; Vallicella, 2010). 

In the following section, I will provide some of Vallicella’s insights regarding the Fregean model of existence and then show how the Thomistic model is free from the same worries.

Undermining the Fregean Model of Existence and Arguing for the Thomistic Model as an Alternative Model

The Fregean model of existence, which can also be referred to as the thin model of existence, holds that “the concept of being is closely allied with the concept of number: to say that there are x’s is to say that the number of x’s is 1 or more—and to say nothing more profound, nothing more interesting, nothing more” (Van Inwagen 4). This, however, leads to some serious metaphysical issues, as people like Vallicella have argued:

On the thin theory, existence is a property of concepts only and cannot be sensibly predicated of individuals. The theory says that existence is the property of being instantiated, the property of having one or more instances. An affirmative general existential such as “Horses exist” does not predicate existence of individual horses; it predicates instantiation of the concept horse. Equivalently, it says that the number of horses is one or more. And a negative general existential such as “Mermaids do not exist” does not predicate anything of individual mermaids—after all, there aren’t any—it denies that the concept mermaid has any instances. Equivalently, it says that the number of mermaids is zero.The theory handles the semantics of general existentials very nicely, and this is a point in its favour. But our main concern is with the ontology of the thin theory. It is important to distinguish between the instantiation theory as a semantic theory about existential sentences and an ontological theory about existence. Let us suppose for the moment that every general existential can be expressed salva significatione as an instantiation claim. This is false, as I will show later. But even if it were true, it would not follow that the thin theory is adequate ontologically. To see what is wrong with the ontology of the theory, note first that instantiation is a relation, a dyadic asymmetrical relation. We can of course speak of the property of being instantiated but only so long as it is understood that this is a relational property, one parasitic upon the relation of instantiation. Therefore, if a first-level concept C is instantiated, then there is some individual x such that x instantiates C. It would be nonsense to say that C is instantiated while adding that there is nothing that instantiates it. That would be like saying that Tom is married but there is no one to whom he is married. Just as “Tom is married” is elliptical for “Tom is married to someone”, “C is instantiated” is elliptical for “C is instantiated by some individual x”. Now either x exists or it does not. Suppose it does not. Then we have instan- tiation without existence. If so, existence cannot be instantiation. For example, let C be the concept winged horse and let x be Pegasus. Assuming for the moment that there are non-existent objects, the latter instantiates the former since Pegasus is a winged horse. But Pegasus does not exist. So existence cannot be the second-level property of instantiation if we allow non-existent objects to serve as instances of concepts. The instantiation theory of existence is false if there are non-existent objects. Now suppose that x exists as we must suppose if we deny that there are non-existent objects. Then the theory is circular: It presupposes first-level existence. If the concept American philosopher is instantiated, then there is at least one individual that instantiates it, an individual that possesses first-level existence. No first-level concept or property or propositional function or cognate item can be instantiated unless it is instantiated by some individual that exists, where “exists” obviously cannot have the sense of “is instantiated”. Because of this circularity, the thin or quantificational theory in all its variants is unten- able. It fails as an answer to the question, What is existence? (Novotný & Novák 52-53)

Vallicella’s argument seems quite powerful and provides good reason for rejecting the Fregean model of existence. How then, though, are we supposed to account for the existence and instantiation of concepts? The Thomistic model offers a solution.

As mentioned earlier, the Thomistic model of existence holds that existence, esse, is the most fundamental principle of actuality in things. It also maintains that existence, esse, in itself is conceptually indefinite and it is only essence, which are ultimately the limits on esse that give rise to definite conceptual content in things. This seems to be a plausible model since, in order to avoid the vicious circularity of the Fregean model, we must posit that existence is not a second-order property of things. However, existence can also not be like other first-order properties as this falls prey to Kant’s criticism that existence is not a real predicate, as it does not add any definitional content to things (Kant 566). Therefore, existence must be more fundamental than all first-order properties and act as a sort of ground for all first-order properties, which means that existence must be inherently conceptual as existence cannot be the ground of something conceptual if it is not itself conceptual in some sense. Again, though, existence does not add conceptual content to a thing, as Kant points out, but it must be absolutely fundamental in the thing so it seems that there must be some other principle in the thing which limits existence’s conceptual content and this is the Thomistic conception of essence (Kant 566). Thus, it seems that there is at least some reason to accept the Thomistic model of existence.

With this in place, I will move on to argue against two of Schmid’s accounts of existential inertia: the transtemporal account and the propositional necessity account.

Explicating and Responding to Existential Inertia

As stated earlier, existential inertia is the thesis that temporal concrete objects will persist in existence without the help of a sustaining cause of their existence (Schmid, 2020). While there have been other accounts of existential inertia explicated elsewhere in the literature or other in other spaces of metaphysical discussion, I will only explicate and deal with the two novel accounts that Schmid presents in his 2020 paper, leaving aside his brief exposition of Beaudoin’s account, and I will respond to each account respectively (Schmid, 2020 & Beaudoin, 2007). 

This is Schmid’s first account of existential inertia: 

For concrete object O and times t-1 and t (where t-1 is immediately temporally prior to t), the existence of O-at-t is explained by the conjunction of (i) the state and existence of O-at-t-1 and (ii) the absence of any sufficiently causally destructive factors acting on O-at-t-1 and through t. (Schmid, 2020) 

At first glance, this account of the persistence of O does not seem to be in conflict with Aquinas’ proof for Schmid does explain where exactly the existence of O-at-t-1 is located; by this I mean, Schmid has not yet said whether O-at-t-1 has existence through itself or through another. If O-at-t-1 has existence internally as if it were a property of O-at-t-1, then there seems to be a sort of vicious circularity where O-at-t-1 depends on existence in order to exist, but existence is now a property of O-at-t-1 and so existence depends on O. Ed Feser has made a similar objection to accounts of existential inertia where existence or persistence is a power or property of substances that persist in existence (Feser, 2021). One may respond by appealing to nominalism and saying that the reason O-at-t-1 has the property of existence is because it exists at t1, O’s character of existing at t1 is why it has the property of existence at t1; but if one were to make this appeal, then they would be ridding the property of existence that O-at-t-1 has of any explanatory power and we must then look elsewhere for an explanation of why O-at-t-1 exists.

Schmid goes on to explicate a variation on this vicious circularity objection, but I think there are key differences between his version and mine that shows he misunderstands the objector’s concerns. 

One may worry that (1) falls prey to a sort of vicious circularity. For how could the immediately temporally prior state and existence of O explain the present existence of O if O itself had no ability to persist through time from the prior state to the present state? After all, if O had no such ability to persist from the prior state to the present state, then clearly O-at-t-1 won’t be able to explain O-at-t. But that means that (1) cannot explain persistence through time since it presupposes such persistence. In short, (1) cannot explain O’s persistence from t-1 to t, since the account needs to presuppose O’s persistence from t-1 to t in order to allow O-at-t-1 to explain O-at-t. (Schmid, 2020)

I believe Schmid’s mistake here to be that the objector to existential inertia is saying that nothing in his account gives O the ability to persist, which entails a vicious circularity, but this is not what I or others have objected to in the existential inertia thesis (Feser, 2021). Rather, objectors simply argue that once existence or persistence is made internal to O, and this property is what explains O’s existence at anytime t or persistence in existence at anytime t, then there is a vicious circularity, and Schmid seems to even concede this point in his more recent popular level work, as long as we grant realism rather than nominalism (Schmid, 2021). 

In contrast, Aquinas’ account of the persistence of temporal concrete objects does not entail any vicious circularity. For St. Thomas, substances do not have existence in a possessive way, but rather have it in a wholly derivative way and can only be said to “have” existence in a participatory way and this participation in pure esse is what accounts for their continued existence. Since, on this account, substances don’t have existence in themselves, but “have” it from another, or in a merely participatory way, there is no vicious circularity for a certain substance O depends on existence for its existence and in persistence in existence, but existence does not depend on O. Given this, it seems clear that Aquinas’ view is far superior to this first account of existential inertia. 

I should also point out that casting this account in metaphysically lightweight terms to avoid the vicious circularity objection seems to require a Fegean model of existence where existence is not a kind of first-order property, although a peculiar one at that, as St. Thomas would argue, but rather it is a second order property. The Fregean view, however, is extremely problematic, and entails a vicious circularity, but going into the details of this view goes beyond the scope of this paper.

Given that this account entails a vicious circularity if a Thomistic conception of existence is granted or relies on problematic theories of existence in order to avoid this circularity, we have good reason to reject this account of inertial persistence and reason to accept the Thomistic, participatory model of persistence.

Let’s now move onto Schmid’s second account of existential inertia: “Existential inertia is a basic, primitive, foundational feature of reality” (Schmid, 2020). By this, Schmid means that the fact that temporal concrete objects persist in existence without the help of a sustaining cause of their existence obtains of metaphysical necessity. Schmid goes on to write that this entails that existential inertia is “neither analyzable . . . nor,” obtains “in virtue of more fundamental/basic facts” (Schmid, 2020). 

This account seems rather problematic, but I would first like to show how there is an asymmetry between the metaphysical necessity of existential inertia and the metaphysical necessity of God, on the Thomisitic conception of God. The reason that Thomists say that God is metaphysically necessary is because He is pure existence itself, which makes the question “why does God exist,” seem silly; it would be very odd to behold pure existence itself and then ask: “why does pure existence itself exist?” The situation is quite different for existential inertia. It seems perfectly reasonable, even expected, that the fact that temporal concrete objects persist in existence without the help of a sustaining cause of their existence has a deeper explanation and it is not at all self-evident that existential inertia is metaphysically necessary, unlike the case of God where it seems self-evident that pure existent itself, if it exists, must exist of metaphysical necessity.

An even stronger argument, though, can be made against this thesis from a recent formulation of the Principle of Sufficient Reason by Alexander Pruss and Rob Koons (Pruss-Koons PSR from now on). On this formulation of the PSR, all natural facts, which are really just bounded facts or facts that have limits to their conceptual content, have explanations and they provide powerful arguments that a denial of this PSR entails global and perhaps even self-defeating skepticism (Koons and Pruss, 2020). Relating this to the second account, on this view the persistence in existence of temporal concrete objects without the help of a sustaining cause of their existence is a metaphysically necessary fact. However, given this PSR only unbounded facts, or facts that report the existence of wholly unbounded beings, can be metaphysically necessary, but this supposed necessary fact is clearly not wholly unbounded, for this fact clearly has definite, and therefore bounded, definitional content, and, therefore, it can't be metaphysically necessary. If one tries to argue that such a fact can be necessary, then it can be shown that an acceptance of this fact as metaphysically necessary entails a self-defeating skepticism. If one says that a bounded fact can be necessary, then one opens a door to skepticism, namely that bounded facts can be necessary; the problem is that there is no relevant difference between bounded facts in the relevant respect of boundedness. Since this is the case, there is no reason to suppose that some bounded facts are necessary while others aren't. So if one says that existential inertia is necessary, then they open the door for their current solipsistic experiences being necessary because these experiences are also bounded and there is no relevant difference between the existential inertia and one’s solipsistic experiences with regard to the relevant respect of boundedness. This leads one to a radical skepticism, for if one's solipsistic experiences are possibly necessary, then there's always a chance that they could be necessary which can never be ruled out and such a possibility provides a defeater for all empirical knowledge. The self-defeat comes in when one realizes that to be conscious is to be conscious of something, even if that is your self, but that something is always bounded and so one will have no reason to believe in the existence of oneself, which is self-defeating. 

I will address two possible ways to avoid this skeptical scenario without recourse to the Pruss-Koons PSR, and show why both routes fail.

The first response would be to say that one need not have a PSR restricted to bounded facts in order to avoid skepticism, but one only needs a PSR restricted to contingent facts to avoid such a scenario. The problem with this objection is that it misses the point of Pruss-Koons PSR. Proponents of this PSR do not disagree with the objector that all contingent facts have explanations, rather they are trying to find a measure to determine which facts are necessary and which facts are contingent, and boundedness seems to be a primitive measure of contingency. After all, most definitions of contingency say something to the effect that a fact is contingent if and only if it could have been different, or that a fact is contingent if and only if it could have failed to exist; boundedness seems to be the ground of both of these definitions for a fact could only be different if it possess some bound which could have been different, and it seems quite plausible to suppose that facts could only have failed to exist if they have bounds for bounds demarcate the being of a certain thing and since bounds can change, the thing could change and fail to be that thing, fail to exist, once those bounds are changed. Moreover, there is primitiveness to boundedness which contingency lacks. It seems very reasonable to ask why a certain fact is contingent, but it seems a bit strange to ask why a certain fact is bounded, assuming it is bounded, because the reason it is bounded is because it has bounds, which is tautologous. In sum, this objection fails because it misses the point of the Pruss-Koons PSR and fails to ground the contingency of certain facts, while the Pruss-Koons PSR does.

A second possible response could be that there is a relevant difference between bounded facts in this case, for the reason that existential inertia is metaphysically necessary while one’s solipsistic experiences are not is because existential inertia is a foundational fact, while one’s solipsistic experiences are not. This objection fails, for it begs the question and assumes knowledge of the foundations of reality, which is precisely the topic of discussion. Again, the purpose of the Pruss-Koons PSR is not to disagree with the person who says that some facts are foundational or necessary, while others are contingent, but rather to have a ground for the contingency and necessity of facts. When one asserts that a certain bounded fact is necessary because it is foundational, then one has begged the question for they have failed to give an explanation of the fundamentality of this fact. Furthermore, this objection would simply assume a knowledge of what the foundations of reality are, but this is the question at hand and so to assert such knowledge without any argument against the Pruss-Koons PSR would be question-begging.

An important thing to note here is that the Thomistic account does not violate the Pruss-Koons PSR, for, on this view, God is pure esse and would be, as Pruss and Koons would say, a “supernatural fact,” or an unbounded fact. The fact that the Thomistic view does fall into the same skeptical worry as existential inertia is reason to favor the Thomistic account over existential inertia.

Conclusion

In this paper, I have explicated St. Thomas Aquinas’ argument for the existence of God, provided some motivation for accepting his view of existence, and then defended his proof against existential inertia. I have provided some reason for rejecting two accounts of inertial persistence that have been offered in the literature, while also motivating the Thomistic account of existential persistence. Moreover, I think that I have provided reason to accept Aquinas’ proof of God in De Ente et Essentia. The debate over inertial persistence is a new area in the literature, and I hope that this article fruitfully contributes to that debate.

Works Cited

Aquinas, Thomas. Thomas Aquinas On Being and Essence - Fordham University. 23 Nov. 2006, https://faculty.fordham.edu/klima/Blackwell-proofs/MP_C30.pdf.

Beaudoin, John. “The World’s Continuance: Divine Conservation or Existential Inertia?” International Journal for Philosophy of Religion, vol. 61, no. 2, 2007, pp. 83–98., https://doi.org/10.1007/s11153-007-9113-1. 

Feser, Edward. “Oppy on Thomistic Cosmological Arguments.” Religious Studies, vol. 57, no. 3, 2021, pp. 503–522., https://doi.org/10.1017/s0034412520000384. 

Inwagen, Peter Van. Ontology, Identity, and Modality: Essays in Metaphysics. Cambridge Univ. Press, 2006. 

Kant, Immanuel. The Cambridge Edition of the Works of Immanuel Kant. Edited by Paul Guyer and Allen W Wood, Cambridge Univ. Press, 1998. 

Kerr, Gaven. Aquinas’s Way to God: The Proof in "De Ente Et Essentia". Oxford University Press, 2015. 

Koons, Robert C., and Alexander R. Pruss. “Skepticism and the Principle of Sufficient Reason.” Philosophical Studies, vol. 178, no. 4, 2020, pp. 1079–1099., https://doi.org/10.1007/s11098-020-01482-3. 

Miller, Barry. The Fullness of Being: A New Paradigm for Existence. University of Notre Dame Press, 2012. 

Nevitt, Turner C. “How to Be an Analytic Existential Thomist.” The Thomist: A Speculative Quarterly Review, vol. 82, no. 3, 2018, pp. 321–352., https://doi.org/10.1353/tho.2018.0024. 

Novotny, Daniel, and Novák Lukáš. Neo-Aristotelian Perspectives in Metaphysics. Routledge, Taylor & Francis Group, 2016. 

Schmid, Joseph C. “So You Think You Understand Existential Inertia?” Majesty of Reason, 31 Oct. 2021, https://majestyofreason.wordpress.com/2021/07/31/so-you-think-you-understand-existential-inertia/. 

Schmid, Joseph C. “Existential Inertia and the Aristotelian Proof.” International Journal for Philosophy of Religion, vol. 89, no. 3, 2020, pp. 201–220., https://doi.org/10.1007/s11153-020-09773-9. 

Vallicella, William F. A Paradigm Theory of Existence: Onto-Theology Vindicated. Kluwer Academic, 2010.