Why the Aristotelian proof of God from motion does not work (everything you need for criticism)

I criticize here, with the help of many critical quotations from intelligent thinkers, an important theses of Catholic Thomistic philosophy, the proof of God from motion, based on the book "The Last Superstition" by the Thomism popularizer Edward Feser.

The point I'm trying to make is not the following:

"Aquinas' "First Way", IMO, is just vacuous scholastic twaddle without justifying this anachronistic Aristotlean assumption." (opinion from the internet)

There may be a grain of truth in this opinion if one also considers the following quote:

"What at first seemed to be a simple proof is in fact a world view in miniature, an image of the world projected onto half a page. Is it a proof of God's existence which, taken by itself, compels assent, quite independent of what we may think of Thomas' metaphysics or the remainder of his System? Definitely not." (Walter Kaufmann - Critique of Religion and Philosophy)

However, my criticism of the proof of God consists, at least in part, in allowing certain Aristotelian views to hold and yet declaring the proof invalid.

So here is a summary of the alleged proof:

"In Chapter 3 Feser discusses three of St. Thomas's magnificent five ways, describing the first way with customary clarity and succinctness. Noting that "no potential can make itself actual" (p. 91), Feser points to St. Thomas's well known example of a man pushing a stone with a stick. The stone's potency to move is actualized by the stick, whose potency to move is actualized by the hand, whose potency to move is in turn actualized by the firing of certain motor neurons, and so forth. In this, an essentially subordinated series, each actualized potency is simultaneously actualized by a superior. Feser notes that such a series "of its nature, must have a first member" because "it is only the first member which is in the strictest sense really doing or actualizing anything" (p. 95). Without a first Pure Act free from all admixture of potency, there are no other actualities, nor can there be, since all others "exist at all only insofar as yet earlier ones do" (p. 95)." (an official review of Edward Feser's Last Superstition by Michael O'Halloran)

By "and so forth" Feser means the existence of molecules, atoms and quarks and whatever else may be smaller. Aquinas would add:

"[T]his cannot go on to infinity, because then there would be no first mover, and, consequently, no other mover, seeing that subsequent movers move only inasmuch as they are moved by the first mover." (Aquinas)

And he concludes:

"Therefore it is necessary to arrive at a first mover, moved by no other; and this everyone understands to be God." (Aquinas)

However, one does not arrive at an in every respect actual unmoved mover:

"Assuming that Aquinas can block a regress in the case of movers and things moved, why must the primary mover be not just unmoved, but unmovable? Aquinas thinks that if the mover of some moved thing is not itself moved, it is an unmovable mover [...]. What justification does he have for supposing that an unmoved mover is unmovable? The sort of causal series he has in mind in the proof from motion has as a member something, M, that is being moved. M’s going from being in potentiality with respect to some state S to being in actuality with respect to S needs to be explained by some primary mover, P. All that is required of P is that it be in actuality with respect to S; P’s being in actuality with respect to S is what makes P the primary mover in this causal series ordered per se. So in order to count as a primary mover, as the stopping point in a causal series ordered per se, P must be unmoved (because it is in actuality) in the relevant respect. But it does not follow from this that P must be unmoved (and hence in actuality) in all respects. If P were in actuality in all respects, P would be absolutely unmoved and unmovable, but the fact that P is unmoved with respect to some state S does not entail that P is unmovable. Given that Aquinas’s argument so far has shown only that there must be some primary mover that is in actuality in the respect relevant to the particular case of motion at hand, it seems likely that there will be very many relatively uninteresting primary movers. The fire in our paradigm case seems to be a suitable primary mover, animals (or their souls) might be unmoved movers, and some of Aquinas’s own examples of causal series ordered per se apparently have human beings filling the role of primary mover, at least as Aquinas describes them. We might call fire, animals, human beings, and other natural unmoved movers (if there are any) mundane primary movers. The problem, then, is that the proof from motion gives us no reason to suppose there are any primary movers other than mundane primary movers." (Scott Macdonald - Aquinas’s Parasitic Cosmological Argument)

Mundane primary movers may result from accidentally ordered series (non-instrumental, non-simultaneous):

"An alternative strategy is to argue that every essentially ordered causal series has a first member, where a causal series is essentially ordered if no effects within the series can exist without their causes also existing (e.g., the movement of a stone depending upon the pressure of a stick). The thought is that even if some causal series can be infinite, no essentially ordered can be. A proponent of this strategy faces the challenge of explaining why a first cause in an essentially ordered series could not have been caused by things within a non-essentially ordered causal series." (Joshua Rasmussen - Cosmological Arguments from Contingency)

Aristotle himself gives an example for an accidentally (non-essentially) ordered causal series:

"As, when something has caused motion in water or air, this moves another and, though the cause has ceased to operate, such motion propagates itself to a certain point, though there the prime mover is not present[.] [464a1] [5]" (ARISTOTLE - ON DIVINATION IN SLEEP)

Here is an alternative translation:

"When something has moved a portion of water or air, and this in turn has moved another, then even when the initial impulse has ceased, it results in a similar sort of movement continuing up to a certain point, although the original mover is not present." (Filip Radovic - Aristotle on Prevision through Dreams)

In such an order, not all members need to coexist (e.g. the father and his begotten son).

Feser's example of the proof of God originally comes from Aristotle:

"The example [Aristotle] most often gives—a man using his hands to push a spade to turn a stone—suggests a series of simultaneous movers and moved. We may agree that there must be a first term of any such series if motion is ever to take place: but it is hard to see why this should lead us to a single cosmic unmoved mover, rather than to a multitude of human shakers and movers. […] Aristotle himself at one point seems to agree with this objection, and to treat a human digger as a self-mover (256a8)[:]" (Anthony Kenny – A New History of Western Philosophy)

"e.g. the stick moves the stone and is moved by the hand, which again is moved by the man; in the man, however, we have reached a mover that is not so in virtue of being moved by something else." (Aristotle – Physics)

Elsewhere Aristotle wants to rule out self-movers:

"The basic principle of Aristotle’s argument is that everything that is in motion is moved by something else. At the beginning of book 7 of the Physics he presents a reductio ad absurdum of the idea of self-movement. A selfmoving object must (a) have parts, in order to be in motion at all; (b) be in motion as a whole, and not just in one of its parts; and (c) originate its own motion. But this is impossible. From (b) it follows that if any part of the body is at rest, the whole of it is at rest. But if the whole body’s being at rest depends upon a part’s being at rest, then the motion of the whole body depends upon the motion of the part; and thus it does not originate its own motion. So that which was supposed to be moved by itself is not moved by itself [...]. This argument contains two fallacies." (Anthony Kenny – A New History of Western Philosophy)

These are the fallacies:

"First, it equivocates between logical and causal dependence, as Sir David Ross points out in his commentary on Physics 242a 38: ‘the motion of the whole logically implies the motion of the part, but is not necessarily causally dependent on it’. (Ross, p. 669). Secondly, it equivocates between being a necessary condition and being a sufficient condition. The part’s being at rest is a sufficient condition for the whole’s being at rest; from this it follows only that the motion of the part is a necessary condition for the motion of the whole, and not that it is a sufficient condition for it. Hence the argument in no way proves that something else, namely the motion of the part, is a causally sufficient condition for the motion of the alleged self-mover. So the reductio ad absurdum fails: it has not been shown that there cannot be a body which can initiate its own movement without external causal concurrence." (Kenny, Anthony - Five Ways)

Self-motion could be explained in the following way:

"In fact, the First Way cannot deny that there are non-processes that are active, because it argues to one. But in point of fact, both Aristotle and St. Thomas held that there are acts that seem to be processes and are not, and yet are not the First Mover. These are transitions of a sort, but not transitions from potency to act. The most common example they give of such a transition is that of not seeing to seeing. […] This type of pseudo-process, then, is a transition from act to act, and the being does not acquire something that it does not already have. Another example would be actively thinking about some fact that one already knows, but was not thinking of before. One is no greater for thinking about it, because one already knows it. One could say that there is a change in some sense going on here, but it is a peculiar one, one that could be called, in modern terms, a change of phase rather than a change of state. Now such transitions are most obvious in the operations of living things, but are not confined to them. […] And this leads us back to the First Way in the light of St. Thomas’ own philosophy. Since he admits, as was said earlier, that there are transitions that are not processes, then all the First Way really argues to in Thomism is to a living being, which is defined as one which can set up its own process. (Summa Contra Gentiles, IV, c. 20.) Of course, the living being does not "move itself" (movere se) in the respect in which it is in process, but processes like growth or movement of the limbs are initiated from the soul, or the “first act” within the being, and so have as their cause one of those transitions from act to act." (George A. Blair – Another Look at St. Thomas' "First Way")

Here, as an example, is a consideration where the mind moves the body:

"The [mind] is an entity and yet not a “res . . . ,” because it is the complete dynamism of [a] substrate-less absolute change [keyword: stream of consciousness as inner motion].“ […] As an entity of time [the mind or subject] would then be precisely the form of motion of a body. For as the subject in a form of one, namely, its own body, the subject would be exactly that which through itself as that completely special type of constant motion would place its body in motion or at rest: already as a cognizing, and thus first and truly as an acting subject." (Gerold Prauss - The Problem of Time in Kant)

The mind would appear on the basis of a highly complex organized body. One would also have to say that it would emerge from the body in an entirely natural way.

Natural motions, according to current theoretical physics, generally do not require continuous causation:

"Most important for our purposes, the whole structure of Aristotle’s argument for an unmoved mover rests on his idea that motions require causes. Once we know about conservation of momentum, that idea loses its steam. [...] There is conservation of momentum: the universe doesn’t need a mover; constant motion is natural and expected. [...] The universe doesn’t need a push; it can just keep going." (Carroll, Sean - The big picture)

There are philosophical explanations for this:

"Some Thomists claim that the crucial fact which the First Way seeks to explain is not the tendency which a heavy body has to fall — this, they admit, is something which was given to the heavy body by whatever it was in the past which made it heavy — but rather the current exercise of that tendency in actual motion. Every such potentiality of a creature, they say, needs to be actualized by the immediate action of the Creator. This seems to be a piece of nonsense. To say that something has a tendency to move is precisely to say that unless something interferes, it will move; if it moves therefore, when interference is removed, no further explanation of its motion is called for apart from the tendency and the removal of the interference." (Kenny, Anthony - Five Ways)

And:

"But it seems that at least things in perpetual motion could be self-movers. It seems, in Aquinas’s Aristotelian terms, that they could be at every moment things actually in motion and potentially in motion in the immediate future, their changing potentialities being continuously actualized by the action of their immediately antecedent actualities." (Jordan Howard Sobel - Logic and Theism Arguments: For and Against Beliefs in God)

The effect of gravity ends with large masses, which themselves would be nothing but mundane primary movers:

"Einstein had the brilliant observation that gravitational attraction was actually an illusion. Objects moved not because they are pulled by gravity or the centrifugal force but because they are pushed by the curvature of space around it. That’s worth repeating: gravity does not pull; space pushes. […] For example, you might be sitting in a chair right now, reading this book. Normally, you would say that gravity is pulling you down into your chair, and that is why you don’t fly off into space. But Einstein would say that you are sitting in your chair because the Earth’s mass warps the space above your head, and this warping pushes you into your chair." (Kaku, Michio - The God Equation)

Thus, large masses move (curve) the space and the space moves smaller masses in the direction of the larger masses.

One could identify two kinds of potential in Aristotle:

"My proposed interpretation will be based upon introducing [a] double feature of potentiality as a basic tenet of Aristotle's physics. I'll argue that there are two distinct kinds of potentials, the one consisting of potentials that are marked by their being logically entailed by the given existence of the actual, and the other, of potentials that are merely suggested by similarity or inductive considerations. The ontological difference between them is that whereas the entailed potential is fully effectual [...], the analogical or inductive potential is merely a necessary condition and thus necessarily ineffectual. [...] I'll use the terms "genuine" and "nongenuine" respectively to refer to these two modes of potentiality." (Zev Bechler - Aristotle's Theory of Actuality)

Nongenuine potentials

"are nonreal things." (Zev Bechler)

Genuine potentials, on the other hand,

"can be movers[.]" (Bechler)

This follows from all:

"[T]he proof of the necessity of a first unmoved mover is destroyed: No such mover is needed, nor de facto exists in the natural motion of the elements, where only the genuine potential is the mover. Hence the cosmic chain of mover-moved breaks down at each case of continuous natural motion, that is, of both living things and the five elements." (Bechler)

"For what is natural motion in Aristotle's theory if not exactly such motion that is externally uncaused, and so self-caused if all motion is caused? What is it to have "an arche of motion in the thing itself (en auto(i))" (DC 301b17, Phys 192b20) if not to have the cause"nature"within the thing? And what is a motion caused by such an internal nature if not self-caused? Even allowing that something else must act as a starter of some kind (the progenitor, or the obstacle remover) what is it that causes natural motion while already in existence, if not exclusively the internal arche, the nature?" (Bechler)

"[T]he genuinity of any potentiality entails its immediate actualization" (Bechler)

"[T]hat what becomes actual is what was potential, and, more importantly, [...] it became actual because it was potential before." (Bechler)

The German philosopher Friedrich Adolf Trendelenburg (1802 - 1872) criticized the Aristotelian definition of change as the actualization of potentiality:

“Trendelenburg took issue with [Aristotle's] definition in the Logische Untersuchungen on the grounds that the concepts of actuality and potentiality are less primitive than motion itself, and indeed need to be defined through it (I, 153).”

“[…] Trendelenburg points out, change, i.e., the concept of something becoming different than it was, already involves that of movement, for we understand change as the result of movement (I, 152).”

For Trendelenburg, movement “is the most fundamental and prevalent fact of all being. As such it is common to thinking and being, and indeed omnipresent in them. Whatever exists moves, or at least strives to move; and it will move whenever opposing movements are removed. Trendelenburg’s universe is much like that of Heraclitus: everything is in motion, and what appears to be at rest is really in motion. All rest in nature is really nothing more than an equipoise of motion (I,141–142). We can explain rest by motion, as retarded or balanced motion, but we cannot explain motion by rest, because motion comes only from motion (I, 141–142).” (Frederick C. Beiser - Late German Idealism)

Leibniz even offers an intermediate between act and potency, the vis activa, which constitutes his concept of force:

"Leibnizian force is a power amplified by a striving so that it can transfer itself into actualization. It is always active as an invisible internal motion and manifests itself in an outward development as soon as all hindrances are removed. So, its status is located between potency and act." (From the official English abstact of the German paper: Liske, Michael-Thomas - Nach Verwirklichung strebende Aktivkräfte versus schlummernde Potenzen: Kann Leibniz’ Vermögensbegriff die Konzeption eines Potentials erhellen? In: Studia Leibnitiana Band 41, Dezember 2009)

In the face of all these counterarguments, Feser turns the First Way into a composition argument as a way to save it. However, Feser is not the first to do so:

"In an attempt to vindicate the celebrated "Five Ways," John Lamont tries to show that Aquinas's arguments for an uncaused cause are successful provided they are understood as resting on an argument from composition.' Lamont further seeks to show that an uncaused cause must be immaterial and unique. In this paper, however, I shall argue that even if we accept the translation of Thomas's various proofs into an argument from composition, such an argument need in no way be thought of as implying the existence of an uncaused cause. Further, I shall show that Lamont's argument for the immateriality of the uncaused cause is problematic and his argument for its uniqueness unconvincing. [...] To sum up: Lamont, following Peter Geach, tries to show that Aquinas's proofs for the existence of God can be construed as a valid composition argument. I have argued that insofar as we can reduce the Five Ways to a composition argument, such an argument in no way yields the desired conclusion. The failure of Lamont's attempt is explained by the fact that he makes the proof of God's existence into a deductively valid composition argument only by begging the question with respect to the fundamental issue, namely, that the sum of all effects is really a group in need of a singular cause different from the causes of any of the effects of which it is the aggregate. Finally, inspection of Lamont's reasons for arguing in favor of God's immateriality and uniqueness reveals that such attributes could be seen to be validly predicated of God only by excluding alternative hypotheses which Lamont does not even envisage." (ANTOINE COTE - THE FIVE WAYS AND THE ARGUMENT FROM COMPOSITION)

The big problem is that Feser basically does not believe in the ontologically prior efficacy of parts at all:

"For example, if a stone is a true substance, then while the innumerable atoms that make it up are real, they exist within it virtually or potentially rather than actually. What actually exists is just the one thing, the stone itself." (Edward Feser – Aristotle's Revenge)

To this must be added the following:

"[S]ince (per one of Feser’s premises) only actual things can actualize something’s potential for existence, it follows that the parts Feser adduces cannot causally actualize the existence of the substances they compose." (Joseph C. Schmid - Existential inertia and the Aristotelian proof)

Hence, Feser thinks holistically, and that amounts to:

"According to holism, the table in front of you does not derive its existence from the sub-atomic particles that compose it; rather, those sub-atomic particles derive their existence from the table." (Philip Goff - Is the Universe a conscious mind?; the example of the table is probably meant only illustratively, because artifacts are usually real reductionist composites)

"For the neo-Aristotelian, the denizens of spacetime belong to fundamental ontological and natural kinds as expressed by their existence, identity, and persistence conditions. Some of these spacetime occupants are metaphysically elite, fundamental, or basic in that their natures are such that they fail to depend on any distinct entity for their existence and identity. Hence the category of substance as a basic particular lies at the heart of a neo-Aristotelian ontology. Properties, whether particular or universal, are metaphysically posterior to their substantial bearers. Causation [...] is best understood in light of the manifestation of the powers and liabilities of individual substances. […] At bottom, the neo- Aristotelian considers the causal motor and cement of the universe to ultimately derive from propertied particulars that are metaphysically fundamental— that is, Aristotelian substances." (Ross D. Inman - Substance and the Fundamentality of the Familiar. A Neo-Aristotelian Mereology)

"Substantial Priority [...] employs the classical Aristotelian insight that substances ["some intermediate, composite objects, living organisms and human persons"] are metaphysically fundamental in the sense that they are not only metaphysically prior to each of their parts, but also ground the existence and identity of each of their parts." (Ross D. Inman - Substance and the Fundamentality of the Familiar. A Neo-Aristotelian Mereology)

This means that parts cannot cause the whole, which is contrary to the point the composition argument is trying to make.

It is true that every chemical substance is divisible. But the substance does not consist of parts before a division, it is not an aggregate of parts, because the parts become actual only in the division itself. When the parts thus obtained are brought together under very specific conditions, the original whole in which the parts are "dissolved" is again created. An illustrative example would be a larger drop of water floating in a space station. One can divide the drop into two partial drops and put these parts together again into a single drop without being able to say of this one that it is now composed of two parts, which is obviously nonsensical. It has no parts, holistically speaking, only aspects and properties. Water can also be split chemically into oxygen and hydrogen. But both were only potentially in the water. And through the process of electrolysis or water splitting, they are actualized. Conversely, water can be made from oxygen and hydrogen (in a risky and expensive way). The holism is in these cases in no way harmed.

Here, the holism of an animal is presented taking a leopard as an example:

"A leopard is self-moving because the action of one part of it, the brain, which is an action of the leopard, moves another part of it, the legs, which is a movement of the leopard. […] I mean we think of the leopard as the natural unit of which the legs and brain are essentially parts; being a part-of-the-leopard is what it is for the leg to be what it is; it has its existence as what it now is by being a part of the leopard. The whole leopard, so to say, comes first. The parts are secondary. If the leg ceases to be part of the leopard it will turn into something completely different, as mutton is something completely different from a sheep. So a leopard is alive because it has organs which exist as what they are precisely by being organs, being functioning parts of a prior whole." (Herbert McCabe - On Aquinas)

Here is a summary of Aristotelian holism, which says that substances, i.e. substantial wholes, are (ontologically) prior to their "parts," since, according to Aristotelians, the parts of a substance get their identity and existence from their functions within the substance:

"[...] [A] natural object (e.g., a piece of the element earth, or water, or a plant, or a living organism) is absolutely whole, absolutely a unity. Not even what we would normally call the parts of such a natural substance (e.g., the legs of the cow) are actual parts. They are merely potential parts (i.e., the cow is not composed of them), and the moment they become actual parts they stop being really the same things. A separate leg is no leg at all, Aristotle would say." (Zev Bechler - Aristotle's Theory of Actuality)

"Aristotle's forms are not parts or components within the object because, being aspects, they are not the kind of thing that can compose their object." (Zev Bechler - Aristotle's Theory of Actuality)

Intuitively, one rightly assumes that once holistic things begin to exist, they will persist for some time:

"I say that [a] chair’s existence at t + ε is fully explained by the actualization of the potential, possessed by the chair at t, to continue to exist through t + ε, and the absence of anything that intervenes to prevent the realization of this potential." (GRAHAM OPPY - On stage one of Feser’s ‘Aristotelian proof’)

One can add that

"most things naturally tend to remain in existence." (Anthony Kenny - Medieval Philosophy)

And:

"[O]nce [things] are GIVEN existence there is no reason to assume that they could lose that existence if something wasn’t preserving their existence. After all, even in the Scholastic model, in order for at least physical things to have existence they have to have substance, and once granted substance there’s no reason to assume that they could lose that without there being some other force or cause to do that." (The blogger Verbose Stoic)

What Feser does not realise is that he also has to do more argumentation. After all, we are talking about the actual existence of a substance which, according to Feser, needs a per se sustaining cause. But the substance only needs such a cause if there is an internal or external force directed towards the destruction of the substance, otherwise not:

"[A] per se, sustaining cause C is required for S’s actual existence only if (i) there is some F (either intrinsic or extrinsic to S) acting on S to bring S toward non-existence; (ii) F is a net factor or force in the absence of C’s existential sustenance; and (iii) S actually exists such that actual existence is distinct from the condition or outcome of S’s non-existence.

But here’s the rub: on the basis of the Aristotelian proof [...], conditions (i) and (ii) have simply not been adequately justified as holding. Because these are necessary conditions [...] for the requirement of a sustaining cause, it follows that, on the basis of the Aristotelian proof, the need for a per se, sustaining cause of S’s actual existence [...] has not been adequately justified." (Joseph Schmid - Stage One of the Aristotelian Proof)

Feser is at least a reductionist in his God-proof reconstruction and therefore must assume simples that God generates and moves so that they can move everything else in the world. If the transcendent God is the first member of the causal series, then something physically indivisible must stand in the second place (but in the first place within the immanence), because otherwise it would not be at exactly that second position. Doesn't God then seem completely superfluous and can't we save ourselves the incredible leap to the transcendent?

For to

"[j]ump from a first immanent cause to a first transcendent cause appears [it doesn't only appear so] to be one of the most questionable moves in the Thomistic program." (Edward N. Martin – Infinite Causal Regress and the Secunda Via)

Yet even more baffling, Feser

"offers us the explanation that God is the first transcendent cause, which, given God’s eternality and immutability, is prima facie [but not only prima facie] very hard to accept." (Edward N. Martin)

Immanent (fundamental or elementary) particles would thus suffice to account for everything under the plausible assumption of naturalism. If one sees a barely surmountable difficulty regarding the hard problem of consciousness, then naturalistic panpsychism (Philip Goff) or naturalistic dualism (David Chalmers) could be helpful additional presuppositions.

A further remark shall be made here to the particles which would be indivisible atoms of matter without further substructure (all of a piece), having absolute cohesion of their homogeneous minimum extension, which could only be misunderstood by mathematical minds as a sum of discrete parts:

"[E]ven though [the particles] have spatial extent, the question of their composition is without any content." (Brian Greene - The Elegant Universe; Greene has spoken here of strings as fundamental particles)

Aquinas also seems to agree with this in some way:

"For example, in his commentary on Aristotle's Physics, Aquinas writes of natural minima that, “although a body, considered mathematically, is divisible to infinity, the natural body is not divisible to infinity.”"
(https://en.wikipedia.org/wiki/Minima_naturalia)

One can also grant the Thomists a certain version of a hylemorphism, if it absolutely must be.

It would be a concrete, naturalistic hylemorphism. Form and matter of a particle would not be like two heterogeneous, abstract things, which would have to be put together awkwardly by a god. There would be a natural duality of two aspects, form and matter, within the absolute unity of the particle. The aspects would be similar in nature in a certain sense (both forms of energy), whereby the matter would be something like dammed up, potential energy of a rest mass and the form would be something like an electromagnetic field energy, which arises from the matter, constantly originates and passes away and therefore can "move" the matter smoothly and continuously and produce complex stuff.

Here is a similar description:

"The form, or nature, or essence, is some definite component sitting inside the matter but distinct from it in a simple, physical sense, like the balloon from the helium it contains. (Zev Bechler - Aristotle's Theory of Actuality)

Form and matter would necessarily always go hand in hand, and they would have always existed and will always exist, at all times constituting the indissoluble unity of a particle, all without loss of energy. Nothing supernatural at play. And perhaps only in our mind, that is, only conceptually, the particle has a dual aspect nature, but extramentally, that is, in reality, it is probably one in a strict sense.

A physical field is, in principle, a modern equivalent of the Aristotelian form. The fields can move matter, i.e. account for the motion of particles in a certain direction.

Moreover, they are perhaps not essentially different from matter, which should deeply satisfy every naturalist:

"[F]ields have energy. They therefore are a form of matter; they can be regarded as the fifth state of matter (solid, liquid, gas, and plasma are the other four states of matter)." (Marc Lange - An Introduction to the Philosophy of Physics)

Physical fields could also help to understand the mind:

"Standard neuroscience investigates how neuronal processing works. But it has problems explaining the mind’s qualia, unity, privacy, and causality this way. For example, it isn’t clear about why colours and other qualia are processed so similarly yet experienced so differently, how colour and shape information unite in visual processing, and how abstract information, concrete brain activities, and private experiences are causally and ontologically related given their radical differences.
Field theories of mind try to avoid such problems by turning from neurons to their fields. Here minds typically get their unity from the continuous nature of the fields generated by discrete neurons, while different qualia arise from different structures in the fields. These qualia are private (not publicly accessible) either because they’re non-physical or because they’re the underlying nature of fields (hidden behind what instruments and reflected light show). Mind–brain causality is (in the simplest field theories) just field–brain causality. Field theories offer new ontological approaches to dualism’s problematic causality and reductionism’s explanatory gap. Field theories face their own problems, but they’re progressively improving upon each other (see Table 1). These theories can’t be easily dismissed, for they’re based on considerable evidence and they offer powerful ways of dealing with standard neuroscience’s deepest problems." (Mostyn W. Jones – Electromagnetic-Field Theories of Mind)

Back to the particles. A subject would distinguish them purely spatially, making the spatial properties less attached to the particles than to the observing or conscious subject. Kant gives a good example of mere extrinsic distinctiveness:

"Take two drops of water, and set aside any intrinsic differences (of quality and quantity) between them; the mere fact that they have been intuited simultaneously in different locations justifies us in holding that they are numerically different, i.e. that they really are two drops. (Immanuel Kant - Critique of Pure Reason up to the end of the Analytic)"

I have described extended particles, but there are also point-like particles in physics which have similarities with Leibnizian monads:

"A point particle (ideal particle or point-like particle, often spelled pointlike particle) is an idealization of particles heavily used in physics. Its defining feature is that it lacks spatial extension; being dimensionless, it does not take up space." (https://en.wikipedia.org/wiki/Point_particle)

And:

"In summary, extended particles have a fixed size, although they may have a fuzzy edge; point-like particles are mathematical abstractions with zero size. But even zero-size particles have an extended effect, due to the effect of the field surrounding them." (https://www.fnal.gov/pub/today/archive/archive_2013/today13-02-15_NutshellReadMore.html)

The attempt to save Aquinas' proof by making it a composition argument fails. The supposed saviors want to say: parts compose (move) the whole and these parts are composed by further parts and this cannot go to infinity and must end with God. I say that this is refuted by holistic wholes or fundamental particles or even point-like particles. Feser's reconstruction of the First Way to God is therefore not convincing.

If he would say that it is not only about the local movement (locomotion), when the Thomists speak about motion, then this would strike me as problematic. After all, Feser wants to talk to non-Thomists and convince them. Therefore, for a successful discussion, he should assume only two kinds of movement, locomotion and mental inner change (stream of consciousness in terms of successive intentions, thoughts, feelings and moods), which the non-Thomist has no problem to accept. As far as the locomotion is concerned, which Feser himself has given as an example, he has not succeeded, as I hope to have shown, in giving a proof of God.

Finally, it should be noted that the Thomists, when they talk about wholes and parts, in a very one-sided and narrow-minded way, know only complete independence of a thing (God) or only complete dependence (creation) on a thing (God). There is nothing in between. But it is not difficult to envisage a semi-independence of the things of the world. And to think of the stuff of the world (or some of it) as being independent, perhaps only dependent on quantum stuff, doesn't seem too hard either.

The quantum stuff would be the most fundamental building block or component of all things:

"It's beginning to look as if everything is made of one substance-call it "quantumstuff"-which combines particle and wave at once in a peculiar quantum style all its own. By dissolving the matter/field distinction, quantum physicists realized a dream of the ancient Greeks who speculated that beneath its varied appearances the world was ultimately composed of a single substance. Some philosophers said it was All Fire; some All Water. We now believe the world to be All Quantumstuff. The world is one substance." (Nick Herbert - Quantum Reality: BEYOND THE NEW PHYSICS) 

Alternative fundamentals: The Wave Function of The Universe; The Spacetime; The Initial Singularity et al. 

Thomistic hylomorphism cannot save the Aristotelian proof. The alleged proof that God must maintain the world by constantly reassembling form and matter, since both individually and in themselves are only abstract or nothing and reveal no continuity, does not work:

"Even if matter and form have no intrinsic tendency to persist, they might once joined. […] We can allow that matter without form and form without matter are nothing, but go on to say that the matter-form union is perfectly stable. The stability doesn’t have to be completely foreign from the intrinsic natures of matter and form. It’s just that it takes the combination of those natures to sum to inertia. Compare an appropriate pair of right triangles. Neither is square intrinsically, but put them together and they form a square. They give what they didn’t have by pooling their resources." (Paul Audi - Existential Inertia)

On top of that:

"The first 14 parts of Feser's arguments, if they work, lead to the conclusion that there IS a purely Actual Actualizer (I will use AA to refer to this term).

…

The biggest problems, for me, are that:

The conclusion doesn’t definitively lead to an AA who IS. It could also lead to an AA who WAS. Isn’t it possible that the AA is what went BANG in the Big Bang. That is, he gave his last full measure of devotion -- or in Feser’s terms, he fully actualized his potential -- in the act of creation -- by blowing himself up. Thus, he no longer exists." (Susan Humphreys - An alternative view of Edward Feser's Aristotle's Case for God in his book: "Five Proofs of the Existence of God. religioustolerance.org)

It should be added that when God was alone before creation, He could not be called an actualizer. He was only pure actuality in the sense of pure fulfilled reality as subsisting creative potency.

On an infinite series of essentially ordered causes:

For the Thomists, a triadic structure is indispensable for understanding an essentially ordered causal series. This structure, according to the Thomists, would consist of a first cause, at least one intermediate, and the effect.

My point is that such a triadic structure is also conceivable in the case of an infinite series of essentially ordered causes. The triadic structure and infinity do not necessarily create a conceptual tension.

In a sense, we can conceive of an infinite series in our mind's eye, possibly consisting only of instrumental causes. And the more abstractly one thinks about the series, the less implausible its infinity appears. 

An advocate of the impossibility of an infinitely long essentially ordered causal series will first remark the following: “Essentially ordered series must obviously be finite – unless one wants to claim that causes derive their causal power from nothingness.”

However, so I think, the causes do not derive their causal force from nothingness, but from their antecedent causes (non-temporal earlier causes) or, even more generally, from infinity. 

I agree at least that the infinity of the series seems strange at first sight. Especially such a series that expands more and more spatially because spatially expanded bodies in motion are strung together until they form an infinitely big composition.

However, Edward Feser's version (without hylemorphism) of the infinite series guarantees a certain plausibility in comparison, since it always goes into the smaller.

The opponent of infinity would nevertheless say: “Infinity destroys the intermediality of the series. And the intermediality is the fundamental element of such a series. In an infinite series, the links taken together appear as a single cause so that there can be no first, no intermediate cause, and no last effect. But the triad: (1) first cause; (2) intermediate cause; and (3) ultimate cause or last effect is essential.”

Perhaps a defender of infinity would point out that the concept of infinity is barely comprehensible, but can override the problems mentioned. This would be an appeal to the mysterious nature of infinity. After all, the first mover is also absolutely mysterious.

Moreover, the same defender might say: “The causes need not be taken together because the concept of infinity does not regard this as necessary. The infinite is always unfinished. Therefore, intermediate causes are very well conceivable up to the very last effect. We would have an infinity closed with the last cause/effect, but infinitely open in the other direction.”

In an infinite series, the status of an intermediate or first cause would be only relative, to be seen only in relation to another member or other members.

So, we require only a relative first cause or quasi-first cause (sort-of-first cause) and a relative intermediate cause or quasi-intermediate cause. Thus, for the aforementioned triad of first cause, intermediate cause, last cause, in the case of infinity (or adapted to infinity) we only need a corresponding counterpart, which can in a certain sense replace the Thomist triad, something comparatively equivalent to it.

But that is not a problem to manage. We have the series: A (Quasi-First Cause) → B (Quasi-Intermediate Cause) → C (Last Cause/Effect).

Here's the explanation:

C is conceivable because an infinite series need only be open at one end. It cannot be completed at both ends, but it can be completed at one end.

B is simply regarded as the penultimate cause.

And A is simply the remaining series running to infinity.

If one wants to object that this seems arbitrary, then one has to say: “That is not relevant. Infinity makes this division possible, and alone the fact of this possibility refutes the opposing position. Another possible objection would only presuppose what had to be proved first.”

An infinity is quite possible:

"Nonetheless, Kerr concludes from this point that, if there is no primary cause, no member of the series has causal efficacy. He says, “to deny a primary cause to the one-many series, i.e., to affirm the possibility of an infinite series, is precisely to remove the causal efficacy of the causes within the series…”. But this is precisely what Kerr has not demonstrated. Kerr is assuming that affirming that the series is infinite is equivalent to claiming that we can remove the mind from Aquinas’ stick/stone example while still maintaining that the rest of the series has causal activity. But these are entirely different claims. I agree with Kerr that if an essentially ordered series terminates in a primary cause, as in the stick/stone example, and we then remove the primary cause from the series—the mind—then everything that is causally down stream of that primary cause will lack causal efficacy. Tracing the series backwards from the stone, we will arrive at the stick, which itself has no causal efficacy either in a derived or underived manner, and so can impart no causal efficacy to all the rest. This would be problematic.

But if an essentially ordered series is infinite, then no matter how far back in the series we go, so to speak, we will never arrive at a member whose causal efficacy is neither derived nor underived as we do with the stick/stone example whose primary cause, i.e., the mind, has been removed. But this is the very reason the Thomist rejects infinite essentially ordered series. When we remove the primary cause from an essentially ordered series, we are forced to maintain that a series of causes ultimately depends upon a member that has neither derived nor underived causal efficacy, which is problematic. But if the series is infinite, there is no such problem and, thus, no pressure to conclude that such infinite series are impossible. Kerr is certainly correct that claiming that the series is infinite amounts to a denial of a primary cause, but it is not a denial via removal of a primary cause from an essentially ordered series. What Kerr needs to show is that removing a primary cause from an essentially ordered series and affirming that the series is infinite are equivalent claims. Until Kerr shows this, the proponent of an infinite essentially series is left with no good reason to think an infinite essentially ordered series lacks causal efficacy entirely. And I don’t take myself to have the burden of showing that there exists an essentially orders series where no member has its causal power non-derivatively because I am arguing merely for its possibility in this paper, not its actuality.

Cohoe also appeals to two common analogies to motivate premise 3 of his argument, namely, an endless series of rings and an endless series of train cars. He writes,

Knowing that a ring is held up by the previous ring or that a train car is pulled by the previous one does not on its own establish whether the ring can be held up or whether the train car is moving, because the previous members in these cases are intermediate members. An infinite series of intermediate members gets one no closer to resolution than a finite series does: both need a first, nonderivative member.

I take it Cohoe is suggesting that if we came upon a moving train and were told it lacked an engine but that, nevertheless, each train car being pulled by the previous one was sufficient to account for the motion of the whole, we would think this impossible. Edward Feser makes the same point. He writes,

The point is that secondary [instrumental or derivative] causes would lack efficacy without a primary cause. For example, a railroad boxcar cannot move on its own and without an engine, and neither can a finite series of boxcars, nor an infinite series of boxcars, nor a series of boxcars that loops around on itself to form a circle.

And the fierce critic J.L Mackie admitted that there is an apparent coherent thought or intuitive general principle behind these sorts of cases that are intended to motivate the Thomistic argument, though I disagree with him. Mackie says,

If we were told that there was a watch without a mainspring we would hardly be reassured by the further information that it had, however, an infinite train of gear-wheels. Nor would we expect a railway train consisting of an infinite number of carriages, the last pulled along by the second last, the second last pulled by the third last, and so on, to get along without an engine… There is here an implicit appeal to the following general principle: Where items are ordered by a relation of dependence, the regress must end somewhere; it cannot be either infinite or circular.

However, it is important to note here that these examples and analogies offered by Cohoe, Feser, and Mackie, at most, function as intuition pumps that are meant to motivate accepting the crucial premise of the Thomistic argument. But it seems to me the analogies provided are just too disanalogous with the case of infinite causal chains and too disputable to do any serious work in motivating the Thomistic argument. As such, these sorts of intuition pumps are unlikely to be persuasive to anyone who is not already convinced of the conclusion they are meant to support. To see why, let’s briefly look at the train analogy in a little more detail.

In Mackie’s quote above, the infinite train seems to already be in motion, and we are told that it lacks an engine. We find this absurd primarily because we already have a prior knowledge that trains cannot move without an engine and so must, in fact have an engine. But this analogy doesn’t do much work to motivate the crucial premise of the Thomistic argument. For in the case of a causal series, we do not have a prior knowledge that the series of causes “must have an engine”, i.e., must have a first member. To assume so would beg the question. And to base the assumption that we do have such prior knowledge in the case of the causal series upon the further assumption that an engine-less train and an infinite causal series are sufficiently similar seems unmotivated to me. So, it is unclear to me how Mackie’s suggestion is supposed to help the Thomist.

We might read Feser’s example as suggesting that the train is infinite in length and lacking an engine but not presently in motion. Of course, the train will never be set in motion without an engine. But what is this supposed to show regarding an infinite essentially ordered series? This example is simply too disanalogous with an infinite series of causes because when we go out into the world and observe it, we find a world in which things are already “in motion”, so to speak, and subject to causation, not one that is at rest. Perhaps Feser’s point is more like Mackie’s, that given the train cannot move without an engine, if we were to find a moving train and were told it was infinite in length and had no engine, we would know that this could not be the case and would have to infer that there was, in fact, a “first member”, an engine moving the train. But, again, this would just be question-begging for the reason given in the previous paragraph. Therefore, it seems to me that the infinite train analogy does little work in supporting Cohoe’s argument.

At this point, the Thomist might respond by highlighting the difference between an essentially and accidentally ordered series, or what Edward Feser terms a linear and hierarchical series, respectively. Feser says, “Because the later members of a linear series do not depend on the earlier members in the way the secondary members of a hierarchical series depend on its primary member, a linear series need not trace back to a ‘first’ cause in the relevant sense”. This strategy in responding to critics has merit if the objector fails to understand Aquinas’ distinction between an accidentally and essentially ordered series and his claim that only that latter cannot be infinite. For example, Feser accuses Graham Oppy (2006) of making this mistake. However, I want to emphasize that Feser’s strategy of highlighting the sort of dependence operative in an essentially ordered causal series does nothing to answer my objection because my objection takes this into account. I acknowledge the distinction between an essentially and accidentally ordered series and, again, grant that a finite essentially ordered series must have a first member or cause. My objection is that the Thomist has not shown that affirming that an essentially ordered series is infinite is equivalent to removing the primary cause of a finite essentially ordered series whilst maintaining that very series still has causal efficacy." (Thomas Oberle - Grounding, infinite regress, and the thomistic cosmological argument)

Addendum:

The Thomists seem to be approaching a Far Eastern view. Like: There is no spoon (The Matrix), there are only its conditions of existence (the spoon would be identical with the sum of its conditions), and these actually don't exist either, only their conditions of existence do and so on. And some meta-language won't be able to talk the spoon into reality. I mean, I can only pretend that the spoon really exists, as if it existed (in and of itself).

With this whole topic it comes to mind that in the Thomistic world view potentials in the strict sense possibly exist only in our heads idealiter, thus are there only in relation to our mind.
For the Thomistic God does not create the world by actualizing a potential situated in front of him (or in him), but by creating substances directly ex nihilo (which is again logically questionable, if we have not hypostasized and reified nothingness). However, every substance as a whole may very well be, at every instant in which it is created, completely in actuality.

We limited humans infer only a potentiality within the substance, because we cannot grasp the continuous process of God's re-creation. At the deepest ontological bottom, the world possibly always transitions from act to act.

Besides, if there should be a real difference between actuality and potentiality within a thing, then it is not enough for God to only "hold" them very close or next to each other. He must unite them (elimination of their heterogeneity to each other), by which, however, only the actuality can remain in the unification, otherwise there would be no world with true identity. And with no identity there would be no entity.

These thoughts of mine fit better to the Aristotelian principle that a cause can only give what it has itself. God as pure actuality can give only actuality.

But if we keep all these thoughts in mind when looking back at the Aristotelian proof, then this proof seems very questionable all at once. I argue with potentiality, although in retrospect it might not really exist. It would be an argumentative collapse.

I would like to explain what I have just said in a slightly different way. The following is assumed:

"[U]nder classical theism, creation cannot be the causing of something to reduce from potency to act. Creation does not consist in making substances go from potency to act. For ontologically prior to God’s creative act, the only thing in existence (under classical theism) is God. Moreover, God is purely actual. Hence, no potencies exist prior to creation. And if no potencies exist prior to creation, then they only exist posterior to creation." (Joseph C. Schmid - Stage One of the Aristotelian Proof A Critical Appraisal)

My contention is that they do not exist posterior to or after creation, either. This results when God creates all things completely anew from moment to moment. It seems superfluous to me if God attaches extra potentiality to a created or actualized thing.

For the potentiality would be replaced by a completely new one in the immediately following moment anyway. So, ultimately, it is irrelevant whether it was there at the previous moment or not.

This does not apply to the actuality of the thing being in a very specific absolute moment. This thing must be in actuality to be able to pass as a thing. Why not being in actuality in its entirety? It would be fully actual only in those respects which make it a specific, unique thing, thus, of course, not in all conceivable respects what is only due to God.

An ontologically heterogeneous potentiality, which "sticks" to the thing, would also not contribute to the thing's identity, since for this it would have to be unified with the thing's actuality, in which unification, however, it is annulled, since only actuality is relevant for existence.

So things progress from God's perspective from moment to moment, meaning then, from actuality to actuality. This also makes sense, because God as cause of the things can give only that to the effect according to the Aristotelian principle, what he has himself. And potentiality he simply does not have. If creation means actualization, how can potentiality arise from this actualization? It is not called actualization for nothing. Actualization renders only actuality.

One could perhaps object that things can change other things. Therefore, the changed things had to have corresponding potentiality. God had to have created potentiality. However, if things change, new properties and features emerge in them, i.e. they come into existence. When a property comes into existence, God alone has brought it about, and he has not made it out of a pre-given potentiality.

That is, things ultimately never really actualize a potential in another thing. This calculation does not work out, if one considers God's activity. God alone does everything in total actuality on both sides, his and that of creation.

The problem is then that God possibly forms an absolute Eleatic unity with his creation.

Here is a possible ontological structure of individual things in an atheistic world. The individuality or existence of a thing, strictly considered as such, would be a static potency, seemingly timeless, yet active in some sense (physically, perhaps the particle). From this existence so considered, the essential form-structure of the thing may arise in spontaneity, which is constantly emerging in a transition from act to act (physically perhaps the field of the particle or the wave of the same).
A completely passive potentiality of the whole thing would perhaps not exist. For either the thing already has an inherent tendency towards something, or it can be forced towards something, but not without resistance, not without giving up its own activity. A Thomistic description of a transition from potentiality to actuality would only be a conceptual matter and would have to be interpreted ontologically by means of the concepts of coercion, tendency and spontaneity.
It is of course very easy, much too easy, to explain the subject just described by reference to God, who then simply does everything as a metaphysical "stopgap". Either way, the influxus physicus is a difficult matter.

Alternative approach to the Aristotelian argument:

Start from a worldly substance, which is best conceived of as a finite line from A to B. In the mind's eye, this line exists. So we can say without difficulties, the line (substance) really exists (a closed continuous individual magnitude).

We will now always stick to the line because it simplifies the argumentation a lot without losing philosophical relevance.

I can only look at the line in two ways. On the one hand as a holist, on the other hand as a reductionist.

The holistic thinker would say that this line is continuous from A to B and is actual as a whole.

If you asked him how he explains this line, he would say: Maybe it has always existed in this length. Maybe it was "drawn" once in the past. Or perhaps it was once joined together by many small lines to the present form. Or it is a splinter of a division of a still much bigger line. These answers would deeply satisfy the holist.

The reductionist would say this line is a set of finitely many discrete points. And he would explain it by the fact that the points have found each other due to their adhesive power. The points could be real points without extension, but with an energy field surrounding them. Or they could be minimally extended (as dots), but all in one piece and with absolute cohesion.

Now the Thomist Feser would come and say to both of them: No, no, it doesn't work that way.
He would explain to the holist that the line is made up of constituents (small lines). Because you could make an intersection in the middle of the line, so that we have two parts that cause the whole. These two parts also each have a middle and so we could make intersections again so that we get even more parts that would cause the first two.
This could be carried on and on, but nothing should go to infinity, otherwise the line would never come into existence. For the parts stand in a certain causal relation to the so to speak "whole" whole, like the parts to the "whole" parts and so on.
The concept of hierarchical causality (simultaneous and instrumental) requires that there is a beginning and that this beginning can only be accomplished by an external God.

The holist would answer: You cut the line only retrospectively and retroactively, that is, after the line has been recognized naturally as a holistic substance, and thus artificially arrive at your result. But you don't have to do that. I am not forced to see it that way. Here at least assertion would stand against assertion, namely mine against yours. One can by all means justifiably ask: Why can't an immanent and holistic principle, intrinsic to the substance, make a unity out of the complexity (Feser's line), whereby God becomes superfluous?
Moreover, your approach is very reductionist. The line would end up depending on its parts (e.g. the whole human being would be at the mercy of the behavior of its smallest parts). But as I said, you don't have to see it that way. Your dividing of the line is also no real dividing in the sense of cutting. Because your midpoint between the two partial lines is a zero, an extensionlessness, a true ideal point, that means the two partial lines have a seamless transition to each other and that means again, they are not real parts. There are no extended "sticking" boundaries between the parts, nor any vacuum, void or empty space in between. So, you are still dealing with a holistic whole line in which parts are neither conceivable as discretely actual (because the seamless whole is in fact actual) nor as potential (because a potential part is not a part at all. It can be anything but just not a part and there is no set of potential parts that would be oddly and ineffectually dependent on each other). So strictly speaking, there are no parts, they exist only in thought.

The reductionist would say either my points are indivisible because they are without extension, or they are extended but divisible only in thought and not in reality. With the reductionist, the division finds an ungodly end with many points or dots.

Feser would now refer to the theory of Thomistic hylemorphism. Such a theory can be strictly rejected. There are many alternatives to this kind of hylemorphism, for example also a neo-Aristotelian hylemorphism, which does completely without God. Or something that has nothing to do with hylemorphism.

In Thomistic hylemorphism, for example, properties are regarded as real parts, but even Aristotle thought that properties were not parts of a thing, but aspects, e.g. the form itself being an aspect of a thing. For Aristotelian hylemorphism there is no need of a third (god), of a connecting principle or, more banally, of a kind of glue or putty making the form and matter stick together. In general, matter and form are at most conceptually distinguishable ontological instances, aspects, or modes of (or in, on, at) the ontically one existing thing. Matter and form exist in reality unseparated.

Now there could also come a fourth thinker who is monistic and in some sense pantheistic. He would now say that a line can only start from a point. But this point is God Himself or Nature Herself. God (or Nature) as a point cannot take another god as a starting point for "drawing" the line. Therefore, the one divine or natural punctiform simplicity must spontaneously extend itself into a line. God (or Nature) as a point forms with the line as extension a continuum without actual parts.
It is then so that this point cannot appear on such extended line, since it is everywhere and nowhere on it, i.e.: nowhere as an intersection point in it, everywhere, however, as the point in it extending to it, hiding itself in such extension.
Only therefore, at every place of the line, a mystical sense can make the "everywhere and nowhere" point become a "point of intersection", that is, visible or experienceable (unio mystica). God would be in the world, he would stand internally to it and not externally as with Feser's God.