1. An account of existential inertia
Because the literature in contemporary metaphysics and philosophy of religion on existential inertia (henceforth EIT)Footnote 1 is relatively new, it is difficult to pin down exactly what EIT is. To make things more difficult, the current literature on the topic seems to indicate that there are multiple mutually exclusive accounts of EITFootnote 2 and serious underdevelopment with respect to its (1) scope, (2) relation to time, and (3) modal quantification.Footnote 3 Despite this, it seems like a simple formulation of EIT can be put forth. Schmid says,
In simplest terms, EIT is the claim that at least some temporal concrete objects persist in the absence of both (i) sustenance or conservation from without and (ii) sufficiently destructive factors operative on the object(s). EIT does not aim to answer what it is in virtue of which objects persist; instead, EIT aims merely to describe the way at least some objects persist.Footnote 4
So, we can start from this account and plausibly say that EIT is a descriptive thesis about the continued existence (i.e., persistence) of concrete temporal objects, which claims that such objects persist in existence barring any sufficiently destructive factors. It is important to keep in mind that because EIT is a descriptive thesis, it needs to be supplemented with a metaphysics if one is to utilize it in any way other than a mere assertion against the metaphysics of Aquinas, e.g., supplementing the thesis with an atomistic, or Schmidian–Lindorff metaphysics.Footnote 5 More concretely, EIT can be stated formally as such:
Existential Inertia Thesis (EIT): For each member O of some (proper or improper) subset of temporal concrete objects and for each time t such that O exists at some time t* earlier than t, (i) at t, O does not concurrently ontologically depend on the existence or activity of some concrete object O*, where O* is not a (proper or improper) part of O, and (ii) if O is not positively destroyed within the temporal interval [t*, t], then O exists at t.Footnote 6
Take, for instance, a book in front of you. This book is a member of the subset of temporal and concrete objects and exists now at time t, and has existed prior to t, at what we will call t*. EIT makes two claims about the book. First, at t, the book depends on nothing outside of it for its continued existence, its continued existence is self-contained in all that it has. Second, the book will continue to exist barring any sufficiently destructive force.
2. The problem
Interestingly, such an account of persistence has been applied by both Schmid and others as an undercutting defeater in Thomistic natural theology. Specifically, it has been utilized to attack the First Way,Footnote 7 Second Way,Footnote 8 De Ente Proof,Footnote 9 and other various aspects of Aquinas’s system.Footnote 10
The basic intuition behind the family of objections can be grasped by thinking about causation. According to EIT, any existing thing x is created at some time t and continues to exist without any external influence (this would include any sustaining cause or participation in something external to x) or sufficiently destructive factors. In other words, there just is no need to appeal to any external influence to explain the continued existence of x. Broadly speaking then, EIT proponents pose an argument from Ockham’s Razor:
(1) There is no need to multiply explanatory entities beyond necessity.
(2) (Because of EIT) Adducing God’s causal power as an explanation of persistence is multiplying explanatory entities beyond necessity.
C: There is no need to adduce God’s causal power in an explanation of persistence.
There are various ways of spelling out EIT and putting various twists on the basic syllogism above, but for the purpose of this article, the above analysis is sufficient. It is clear how one can start to see that EIT, if true, poses a devastating objection to Thomistic metaphysics and the doctrine of God: without the need for a sustaining cause, God’s action in the world is much more difficult to prove, and as a result, creation becomes nothing more than God acting as some deistic prime mover that sets up the universe and leaves it alone to keep going. Hence Kerr’s apt summary of the issue, (if EIT is true)
At most one could say that there is a first cause that passes on existence, but that existence once possessed simply remains in the thing until the thing loses it. Existing things then do not participate in existence for any moment that they exist, in which case they are not members of per se series.Footnote 11
3. Aquinas’s response
I now turn to one of Aquinas’s responses to an account of persistence almost identical to EIT. In doing so, I will look briefly at a response to an objector in the De Potentia Dei. In the response, Aquinas provides a negative argument against EIT. In other words, he criticizes the thesis. But because criticizing opposing arguments is not sufficient to establish one’s own position, I then look at Aquinas’s remarks in his early Commentary on the Sentences and reconstruct a positive argument against EIT. (It is important to keep in mind this distinction between a negative and a positive argument in order to understand the various types of responses to EIT.)
3.1 The disputed questions on power
Surprisingly, Aquinas anticipates EIT and explicitly addresses it in at least one place. In the De Potentia Dei, Aquinas faces an objection very similar to those appearing in contemporary analytic philosophy. The objector states:
God is the efficient cause of things. But, the effect remains when the action of the efficient cause ceases. Thus, the builder ceases to act yet the house remains and the flame that generated the fire may cease to burn, yet the fire generated by it continues. Therefore, even if all of God’s actions cease, creatures can continue to remain in existence.Footnote 12
In response, Aquinas says:
These lower agents are the cause of a thing as to its becoming, but not as to its existence properly speaking. For God himself is the direct cause of existence; and thus the cases are not similar. Hence, Augustine says: when a man is building a house and goes away, the building remains after he has ceased to work and gone: whereas the world could not stand for a blink of an eye if God withdrew his support.Footnote 13
Aquinas’s response is a bit obscure. In response to the objector Aquinas seems to be pointing out that the objector is (1) giving an argument by comparison and (2) that the objector’s argument fails because it assumes a faulty comparison from the way things are generated to the way that God generates (creates). The dialectic can be mapped out in a syllogism to see each person’s moves more clearly. The objector seems to be reasoning along the lines of the following:
(1) The power of the efficient cause can be divorced from the effect after it is generated.
(2) God is the efficient cause.
C: Hence, His power can be divorced from the effect after it is generated.
Aquinas’s response to this argument is that premise one assumes that all generation is of the same kind. But this is false since Aquinas’s metaphysics of creation demonstrated the necessity for a mode of generation higher than mere change.Footnote 14 This higher mode of generation is creation. So, since premise one rests on a faulty assumption, the objector’s argument seems to fail. In short, Aquinas is pointing out that God’s way of generating differs from that of creatures, and because of that we cannot assume that the way that efficient causality works in the creaturely realm can be applied to how it works for God.
Taken in isolation, Aquinas’s response can seem a bit dissatisfying. At best, it seems that what he is doing is attempting to shift the onus of proof back to the objector to prove that efficient causality works the same for creatures and God. But this is not possible for the objector to do, since it seems that this would presuppose knowledge of the divine essence, which on Aquinas’s own grounds one cannot know. Even if the onus of proof is shifted to the objector, and the objector cannot prove that his position works, it still does not follow that Aquinas’s own position is correct. Without any positive argumentation, it seems that Aquinas’s position does not rise to the level of knowledge, but simply opinion. In other words, to establish that God is concurrently acting, and that EIT is false, it does not suffice to simply knock down the objectors. Aquinas must also give reasons for holding his own position. To that, I now turn.
3.2 Esse, essence, and EIT
It seems that Aquinas gives three positive arguments for God’s sustaining causal activity in various places throughout his corpus.Footnote 15 I will focus only on the argumentation from esse/essence composition.Footnote 16 For this, we turn to the commentary on the Sentences. Aquinas says,
… in a thing that is said to be created, non-being is prior to being, not by a priority of time or duration, as if it first was not and afterward was, but by a priority of nature such that the created thing if left to itself, would come to non-being, since it has being only from the influence of a higher cause. For in each thing, what is naturally in it that it does not have from another is prior to what it does have from another.Footnote 17
This argument is difficult to understand. In the immediate context, Aquinas is attempting to prove that creation and eternal movement are different. While interesting, I set this immediate dialectical context aside in order to concentrate on the essential insight that Thomas expresses here: because a thing does not have esse in virtue of what it is, it would come to nonbeing if left to itself. Before laying out the argument, I wish to stress that we must be very careful to read Aquinas’s argument in line with his metaphysics as a wholeFootnote 18 and resist the temptation to isolate the causal principles underlying the argument without recourse to his account of participation.Footnote 19
3.3 The argument reformulated
It seems that the argument can be reformulated with close attention paid to the causal principles and Aquinas’s broader metaphysics as a whole. I have formulated it as such and bracketed the justification for each premise for those unfamiliar with Thomas’s broader metaphysical commitments:
(1) Composite things do not have esse in virtue of what they are. (This is justified by the real distinction.)
(2) If composite things do not have esse in virtue of what they are, then they must have it from another. (This is justified by principle of sufficient reason [PSR] since self-causation and bruteness are ruled out.)
(3) A composite thing participates esse at all times. (This is justified by Aquinas’s account of participation.)
(4) A composite thing must have esse from another at all times. (This follows from (2) and (3) – if it cannot have it from anything but another, and it has it at all times, then it has it in terms of another at all times.)
(5) Only God can be the cause of esse. (This is justified in De Potentia Dei.)
C: At all times God causes the esse of things.Footnote 20
This formulation of the argument avoids the over-determination problem. In other words, the causal principles here do not over-determine the scope of the expected causality and restrict the causality only to esse and its causation. My reformulation of the causal principle to avoid the over-determination problem is prima facie plausible because the causation of esse is unlike any other type of causation that is experienced since it is the condition for the possibility of any causation at all.Footnote 21
Each premise is defensible from within the broader schema of Thomas’s metaphysics. Premise one seems to follow from the arguments for the real distinction between esse and essence. Premise two seems to follow from the PSR since that would rule out brute facts and self-causation. I take bruteness and self-causation to be the only other types of coming to be besides origination from something’s nature or ad extra. Premise three seems to be justified on account of Aquinas’s metaphysics of participation. Premise four is a deduction from premises two and three. Premise five is held on account of Aquinas’s independent argumentation that only God has power over esse.Footnote 22 It seems then, that at the very least, this argument is rationally defensible and provides good reason to reject EIT. Needless to say, three objections to the argument can be leveled. I will now lay out such objections and give a brief response to each of them, and I hope to be able to formulate a longer response in the future.
3.4 Objection one and counter-response
First, it might seem that the argument against EIT relies on the claim that some sort of causal disposition is added to things that do not exist, namely essences. That is to say, the word ‘thing’ in premise four refers to an essence, which receives esse from without. Essences without esse are nonexistent, however. In talking about essences throughout the argument, it seems that I am speaking of them as if they are things that have a causal disposition to not exist, or that they have some sort of tendency to go out of existence if left alone. And of course, since essences without esse do not exist, this way of talking would make no sense, as something that does not exist cannot have any causal dispositions or tendencies. There is both an ontological and a linguistic point to be made here. The ontological point is that the argument seems to attribute a disposition to a nonexisting thing, and the linguistic point is that speaking of essences without esse is extremely difficult to do, since doing so seems to require speaking about nonbeing.
How could the Thomist stave off this objection? Two routes are open to diffuse it. (1) The idea that a causal disposition is being adduced to an essence can be rejected. And (2), one may affirm that such an idea is plausible. I opt for the former since the attribution of a causal disposition would seem to require an underlying substrate in which the disposition inheres; but this cannot be the case, for essences without esse do not exist. Taking the first option, then, one is not adducing a causal disposition to essence. What is being said is not that there exists some x, such that it has a causal disposition to go out of existence if left to itself. This is because the essence does not exist apart from its esse, and as nonexistent, it cannot be the case that a causal disposition is added to it. The essence just is nothing sans being actualized by esse. Instead, since it has esse at all times from a principle ad extra, then at all times it requires such actualization to exist. At any time essences exist, they exist in tandem with esse, i.e., as being actualized by, esse,Footnote 23 and so the objections do not seem to get off the ground.Footnote 24
3.5 Objection two and counter-response
A second objection is that the argument commits some sort of equivocation fallacy by referring to two different things: essence1 and essence2. The former is used to designate essence sans actualization by esse, while the latter is used to designate essence simultaneous with, and posterior to its actualization by esse. To see why it seems that there are two types of essences being referred to, consider that essence is discussed in two ways in the argument: as actualized with esse and as not. It would seem that this would suffice to invoke Leibniz’s Law of the Indiscernibility of Identicals (IoI). IoI states that x = y → ∀F(Fx ↔ Fy). In other words, for the domain of two objects x and y, if x is identical to y, then for all properties F, x possesses F if and only if y possesses F. Since essence2 has the property F of esse, but essence1 does not have property F, the two are not identical with each other. Because the argument treats the two as identical to each other, it thus commits an equivocation rendering it invalid.
In other words, the argument seems to refer to two different things (essence1 and essence2) under the same term – essence – thus committing an equivocation fallacy and rendering it logically invalid.
This objection, however, can be responded to by (1) questioning the scope or formulation of IoI or (2) denying that essence is not being equivocated on here. Consider first, that it is questionable whether IoI would apply in this case. The objection from IoI seems to assume that essence1 and essence2 are being differentiated by a property. Esse is not a property of things but the actuality (actulitias) of all acts.Footnote 25 Because esse is not a property, it seems that it would not fall under the purview of IoI. I admit however, this is only a prima facie response, as much more work would be needed to spell out what this means. Needless to say, it is an open route.
With regard to (2), it would seem that the argument does not explicitly speak of essence without esse and with esse – that essence1 and essence2 are never explicitly mentioned. In spelling out how the argument refers to essence1 and essence2, the objector may point out that premises one and two refer to essence without esse, and premises three and four refer to essence with esse. But this seems to be untrue because it trades on a misapplication of what an essence is for the Thomist. Instead, all of the premises one through four refer to a substance, not an essence. Hence, there is no equivocation going on in the argument.
3.6 An important historical and exegetical note
Interestingly, this second objection has deep precedent in the 20th-century Thomistic commentarial tradition, though it is not formulated as an analytic-styled objection but an exegetical problem in Aquinas’s writings, which is perhaps the reason that it has been missed in the contemporary discussion of EIT. It is worth briefly summarizing the exegetical issue and solution since it could help to elucidate the avenue by which I push my response. Joseph Owens points out that a real issue facing Aquinas, and philosophy as a whole, is how to conceptualize existence and speak about it, since esse considered in itself does not have an essence and thus does not seem like it can be grasped.Footnote 26 And Wippel has pointed out the difficulty in thinking about essence sans esse, since there is no room in Aquinas’s thought for any preexisting essences prior to their actualization.Footnote 27 In short, 20th-century commentators on Aquinas have noted the difficulty in conceptualizing esse and essence.
A very brief summary of the exegetical solution will have to suffice. One must understand that esse and essence are never reified principles but co-principles in a thing. In other words, esse sans essence and vice versa do not exist.Footnote 28 Because the principles only exist in things as constituting their whole substance, and as the deepest level of composition in a thing, our knowledge of the principles comes through knowledge of things, but in a specific way, that is, first through the cognitive action of judgment and then secondly through the grasp of a thing’s essence. Owens says, ‘What things are is known through conceptualization. That they exist is known through a different activity technically called judgment’.Footnote 29 Esse, then, is known through the cognitive faculty of judgment, rather than intellection. Further, esse is grasped (through the intellectual activity of judgment) only in the thing that it constitutes and never as a reified principle.
The difficulty of objection three has its roots in the 20th-century exegetical debates of Aquinas and is tackled through a deepened inquiry into the Thomistic conception of human cognition.Footnote 30 We can see how my response in the preceding section was to deny that there are two types of essence and explain that premises one through four of the argument refer to substances and not reified principles. My response seems to parallel the exegetical solution of Owens and Gilson in which it is stressed that esse and essence are never grasped by the intellect alone, since they never exist alone.
3.7 Objection three and counter-response
A third objection comes from the nature of the real distinction itself. It would appear to be the case that esse and essence are either (1) logically distinct or (2) really distinct. The Thomist opts for the latter, while critics of Thomistic existentialism usually opt for the former. But, it seems that there may be a third option available. Perhaps it is the case that the justification for the real distinction has failed to rule out the alternative that the real distinction changes once a thing becomes actualized – that esse and essence are really distinct before (sans) creation of a substance but only logically distinct after the creation of a substance. Because esse and essence are not really distinct after creation, esse just is included within essence: what a thing is includes its existence (esse). This amounts to a denial of premise one in the argument. Intuitively, it can be summed up by saying that a thing receives existence and ‘holds it’ without any external aid.
It could seem that this just amounts to a denial of the real distinction, but it seems to me that the criticism cuts a bit deeper. Rather than flat-out denying the real distinction, the objection denies that it holds universally. The question here is whether or not the arguments from the real distinction prove that the distinction holds at all times and in all things – ruling out the possibility that esse could be subsumed into essence post-creation of the substance.
This is a bit abstract. Phrasing it differently could help. A denial of the real distinction is what enables one to get out of the argument against EIT, since premise one would fail. In doing so, one denies that essence and esse are really distinct at all times and instead says that once a thing is actualized, the esse comes under the essence of what it is, and they are no longer really distinct but only logically so. Because they are no longer distinct, they no longer need a cause ad extra, and thus no longer need God’s causality acting on them. This objection seeks to push the claim that the Thomistic real distinction is underdeveloped. It grants that there is a real distinction between esse and essence in the logical order and sans creation. But, once created, a thing’s esse is subsumed into the thing’s essence, and the real distinction no longer holds.
This objection is plausible at first glance, but what does it really amount to? Putting it in concrete terms is crucial. The objection claims that the real distinction does not hold in the real order (after the creation of a substance) since esse is brought under the concept of essence once a thing is actualized. For instance, Fido, once actualized, is no longer a composite of esse and essence, but just is essence with esse subsumed under it. But, under further analysis, this does not seem to make sense. For starters, esse just is what makes essence possible; and as being the condition for the possibility of essence, esse must be distinct from it at all times. At all times, esse is functioning at the condition for the possibility of essence, and thus as the very condition for an essence being able to be actualized at all. Since this is a relevant difference operative at all times, it seems to be sufficient to establish that esse and essence must be really distinct at all times.
This response can be further detailed. The objection seems to make some crucial assumptions that Aquinas would disagree with: it seems to assume (1) a ‘thick’ theory of essences, whereby essences without esse have some sort of ontological status, and (2) that essences and esse are separable. Aquinas’s metaphysics would not allow for these two assumptions.Footnote 31 For Aquinas, the components of a substance, e.g., esse and essence, are really distinct but not separable; they are co-principles or constitutive elements of a thing. To understand this point, it is helpful to consider the concept of a suppositum. A suppositum is an individual, which includes all of its own parts.Footnote 32 Within a suppositum, there are constituent elements that are really distinct, but not separable, and at the most fundamental level, the suppositum is a composite of esse and essence. It is important not to confuse essence here with an abstract nature or universal in the modern sense. As Aquinas makes explicit, an essence of a thing is that which is signified by the definition of a thing, i.e., all that a thing is is without esse.Footnote 33 When a suppositum is created, esse does not ‘fill in an essence’, as one would fill a preexistent mold, but simultaneously actualizes the entirety of the suppositum’s essence, thereby giving rise to all that the definition (essence) includes, and thus the suppositum itself. Esse’s actualization of the essence and thus the entire suppositum occurs at all times the suppositum exists. Since esse is the principle making the essence and the suppositum to be at all times, esse cannot simply be subsumed into the essence as the objection claims but must be distinct from essence. So, it would seem that the objection does not work.
4. Conclusion
I have sought to show that Aquinas’s metaphysical commitments – especially his account of esse – can diffuse the objections stemming from contemporary discourse on EIT. From the real distinction of esse and essence in created things, it follows that such things do not have esse in virtue of what they are but receive it from another. Since they have esse at all times, they must receive it from another at all times. Since the only ‘thing’ that can give esse is God, it follows that at all times God gives created reality esse, albeit it esse of a different kind than God himself (ipsum esse). If successful, this argument does not demonstrate how God’s causality works on creatures, only that it does, and specifically that God’s causality is active at every moment anything exists causing the thing to be.Footnote 34