The Natural Path to Saving the Old River Forest “Tree”

Fr. Philip-Neri Reese, O.P., has recently written “Losing the Forest for the Tree: Why All Thomists Should (Not) Be River Forest Thomists,” an open-access article in the journal Religions. Here is the abstract:

One of the most influential and controversial schools of 20th century Thomism—especially in North America—is the “River Forest School” or “River Forest Thomism”. And one of the most influential and controversial theses associated with that school is the thesis that metaphysics cannot be established as a distinct and autonomous science unless one has already proven the existence of a positively immaterial being. The purpose of this paper is to show that River Forest Thomism cannot and should not be reduced to that controversial thesis. As such, rejection of the thesis cannot and should not constitute a rejection of the school. Indeed, as soon as we understand what River Forest Thomism was really about, it will become clear that all Thomists should be River Forest Thomists.

In what follows, I consider and criticize his arguments against the “tree” of River Forest Thomism. I conclude with some reflections on the distinction between River Forest Thomism and Laval Thomism and attempt to deepen Fr. Reese’s argument about the “forest” of River Forest Thomism by noting certain strengths of Laval Thomism.

For those uninitiated, Ed Feser notes the close connection of these two schools in one of his posts on the Thomistic tradition (here):

3. Laval or River Forest Thomism: This approach emphasizes the Aristotelian foundations of Aquinas’s philosophy, and in particular the idea that the construction of a sound metaphysics must be preceded by a sound understanding of natural science, as interpreted in light of an Aristotelian philosophy of nature. Accordingly, it is keen to show that modern physical science can and should be given such an interpretation. Charles De Koninck (1906–1965), James A. Weisheipl (1923–1984), William A. Wallace, and Benedict Ashley are among its representatives. It is sometimes called “Laval Thomism” after the University of Laval in Quebec, where De Koninck was a professor. The alternative label “River Forest Thomism” derives from a suburb of Chicago, the location of the Albertus Magnus Lyceum for Natural Science, whose members are associated with this approach. It is also sometimes called “Aristotelian Thomism” (to highlight its contrast with Gilson’s brand of existential Thomism) though since Neo-Scholastic Thomism also emphasizes Aquinas’s continuity with Aristotle, this label seems a bit too proprietary. (There are writers, like the contemporary Thomist Ralph McInerny, who exhibit both Neo-Scholastic and Laval/River Forest influences, and the approaches are not necessarily incompatible.)

The “Forest” vs. the “Tree” of River Forest Thomism

Reese first distinguishes between the “forest” of River Forest Thomism and its “tree.”

The “forest” I have in mind is what is really at issue, what really matters for the larger project of River Forest Thomism. The “tree” is a single thesis to which River Forest Thomism is all-too-often reduced, both by those who identify as River Forest Thomists and by those who do not. The single thesis is this: the existence of a positively immaterial being must be demonstrated in order to establish metaphysics as a ‘scientia’ distinct from natural philosophy. (Reese 2024: 1)

In the main argument of second section of the article, Reese provides a most helpful articulation of the origins and historical development of the River Forest school of thought, from its “ur-source” in Fr. Aniceto Fernández-Alonso, O.P., through its five founding fathers: Fr. Humbert Kane, O.P., Fr. James A. Weisheipl, O.P., Fr. William A. Wallace, O.P., Fr. Raymond J. Nogar, O.P., and Fr. Benedict Ashley, O.P.

The development of River Forest Thomism is divided into three stages by Fr. Reese; the first stage is associated with three theses held by Fr. Fernández-Alonso in 1936, the second stage by four theses articulated by Fr. Weisheipl in 1961, and the third by eight theses expounded by Fr. Ashley in 1991. (Since Reese observes [2024: 15n2] that Glen Coughlin’s 2020 article in The Thomist is “the most recent defense” of the “tree” of River Forest Thomism, and as Coughlin—a student of De Koninck’s students at Laval—makes clear from his own work in natural philosophy, one could consider the River Forest / Laval connection partly joined here, and the entire twin-headed school spanning nearly 100 years yet. To my knowledge, the most recent elaborate defense of the River Forest / Laval approach is the February 2024 master’s thesis by Rev. Br. Columban Hall, O.P., “Finding Wisdom: Why Metaphysics Depends on a Proof for Immaterial Being.”)

The harmonization of the differences between Fr. Fernández-Alonso’s, Fr. Weisheipl’s, and Fr. Ashley’s theses is completed by arguing—very plausibly, to my mind—that there are core theses to River Forest Thomism vs. certain ancillary theses. These are arranged in Table 1 (Reese 2024: 6).

On the one hand, Reese argues that all Thomists should hold (1–4), and thus all Thomists should be River Forest Thomists in the core sense of the term. On the other hand, Reese argues that it is especially thesis (9) to which the River Forest school is often reduced (Reese terms this reduction to be “‘River Forest Thomism’” in scare quotes; I will just call it reduced River Forest). This is correct, but demands further discussion, for it is the purportedly necessary connection between thesis (3) and thesis (9) that is the subject of this debate. (For instance, recall Prof. McInerny’s article “The Prime Mover and the Order of Learning,” reprinted in the collection Being and Predication: Thomistic Interpretations.)

The reason why (3) is linked to (9) is because learning and discovery are so closely linked: “In one way, natural reason by itself reaches knowledge of unknown things, and this way is called discovery [inventio]; in the other way, when someone else aids the learner’s natural reason, and this is called learning by instruction [disciplina].” (De Veritate, q. 11, a. 1, c.) As Reese notes later, “to establish metaphysics as a distinct science, we must establish that there is something that needs matter and motion neither in order to be nor in order to be understood” (2024: 7). That is, one must either learn or discover that there exists some being that needs neither matter nor motion to be (and, thus, to be understood), thereby establishing the existence of the subject of metaphysics (as to that it is).

Reese argues that the “tree” of ancillary thesis (9) “needs to be dismissed summarily” as an unhelpful ancilla-ry thesis (2024: 7). The “forest” of theses (1–4) must be saved because, he maintains, thesis (9) is not true. In total, he provides four arguments for this.

Before summarizing those arguments, I wish to make a certain distinction in method. In an excellent talk on the metaphysical status of the separated soul, Fr. Reese proposes a tripartite distinction among exegetical questions. (I make use of this distinction in a post on the same subject.) One might compare this distinction to the littera, sensus, and sententia of scriptural exegesis.

Exegetical Question	Did a particular historical Thinker X, in point of fact, hold position Y?
Coherence Question	Ought Thinker X to have held position Y, given the other views that Thinker X holds?
The Truth Question	Should we hold position Y? In other words, is position Y true?

These questions might be applied to St. Thomas and thesis (9). Did St. Thomas himself hold thesis (9)? Ought he have held thesis (9)? Should we hold thesis (9) because it is true? Now, as even a little experience of this debate among Thomists makes clear, first, there is no obvious answer to the exegetical question. Second, most of the debate operates at the level of the coherence question. However, in what follows, I examine Fr. Philip-Neri’s arguments about thesis (9) as to the final exegetical question.

Summary of Arguments Against Thesis (9)

The “zeroeth” argument is a combination of two typical arguments in the literature against reduced River Forest Thomism. The first (the premise argument) is the objection is that nothing can appear in the argument that is not contained in the premises of the argument. So, any argument used by natural philosophy to establish the notion of being studied by metaphysics must contain the metaphysical notion of being already. Thus, natural philosophy does not establish metaphysics. The second (the equivocation argument) is an objection that builds on an attempted escape to the first: if the premises do not already contain a metaphysical notion of being, then what notion they do contain equivocates on the sense of being and results in a fallacy of four terms.

Reese merges these into the Standard Objections, Refined and Combined (2024: 8).

(1) The notion of “being” employed in natural philosophy is either (a) compatible with immaterial existence or (b) incompatible with immaterial existence.
(2) If (b), then natural philosophy cannot—in principle—prove the existence of an immaterial being.
(3) If (a), then natural philosophy’s proofs for the existence of an immaterial being presuppose, rather than establish, the fact that being can be immaterial.
(4) Natural philosophy can—in principle—prove the existence of an immaterial being.
(5) Ergo, natural philosophy’s proofs for the existence of an immaterial being presuppose,
rather than establish, the fact that being can be immaterial.

As Reese notes, the equivocation argument supports step (2), while the premise argument supports step (3). However, Reese himself objects to this argument, noting that a reduced River Forest Thomist might maintain that

yes, the notion of “being” employed in the premises of natural philosophical demonstrations for the existence of an immaterial being is (as a matter of fact) compatible with immaterial existence, but this does not mean that we are presupposing such compatibility when engaged in such proofs. Until the conclusion is drawn, it remains epistemically possible that the notion of “being” employed in the premises will turn out to be incompatible with existing immaterially. And it is only when that epistemic possibility is closed off that metaphysics has been established as a science. (Reese 2024: 9)

So much for the argument(s) in the literature.

The first of the arguments which Reese claims are novel is the following, the Insufficiency Argument (2024: 9), against reduced River Forest Thomists (i.e., “River Forest Thomists” in scare quotes):

(1) If most “River Forest Thomists” are right, then demonstrating the existence of God is sufficient to establish the science of metaphysics.
(2) Demonstrating the existence of God is not sufficient to establish the science of metaphysics.
(3) Therefore, most “River Forest Thomists” are wrong.

The key premise of the argument is the second one, since the first is simply a formally necessary consequence of thesis (9). Reese defends it by noting that God is outside the subject-matter of metaphysics (true), and that demonstrating the existence of some X outside of subject-matter Y cannot demonstrate the existence of subject-matter Y. In other words, to establish—i.e., learn or discover the truth regarding the existence of—the subject-matter of metaphysics, one must establish the existence of ens commune. Since God is outside of ens commune, proving His existence cannot establish metaphysics.

The second of Reese’s arguments is the Counterfactual Materialism Argument (2024: 12):

(1) If most “River Forest Thomists” are right, then, on the supposition of materialism, physics would be indistinguishable from metaphysics.
(2) But on the supposition of materialism, metaphysics would be indistinguishable from mathematics.
(3) Thus, if most “River Forest Thomists” were right, then, on the supposition of materialism, physics would be indistinguishable from mathematics.
(4) But on the supposition of materialism, physics would not be indistinguishable from mathematics.
(5) Therefore, most “River Forest Thomists” are wrong.

The first premise of this argument is drawn from the well-known textual basis for reduced River Forest Thomism, namely, the idea that if there were no separate substances (“positively immaterial beings” as distinct from the purported possibility of “neutrally” immaterial beings), then natural philosophy would be first philosophy, because natural philosophy would study the first principles of all being, simply because “being” and “mobile, material being” would be different rationes for exactly the same res. Based upon such a state of counterfactual materialism that follows upon the denial of thesis (9), Reese argues reductione ad absurdam that, for similar reasons, reduced River Forest Thomists must maintain the indistinguishability of natural philosophy (or, physics) from mathematics. The crux of this argument, then, lies in premise (2), to which I return below.

Finally, the third argument is the Cumulative Argument (2024: 13):

(1) To be a “River Forest Thomist” (at least consistently), one must hold that (a) were there no actual immaterial beings, metaphysics would be indistinguishable from mathematics, (b) natural philosophical demonstrations of God are not sufficient to distinguish metaphysics from mathematics, and (c) natural philosophical demonstrations of created immaterial realities only establish the science of metaphysics vis-à-vis precisely what has been concluded by the demonstration in question (e.g., vis-à-vis form, if an immaterial form has been demonstrated, vis-à-vis substance, if an immaterial substance has been demonstrated, etc.).
(2) But no Thomist should hold (a), (b), and (c).
(3) Therefore, no Thomist should be a “River Forest Thomist.” [viz., a reduced River Forest Thomist]

Clearly, parts (a) and (b) of this argument simply accumulate the results of the first and second of Fr. Reese’s arguments. Part (c) was added in Reese’s explanation of the Insufficiency Argument (2024: 11). There, he states that “The insufficiency argument aims to show that the [reduced] ‘River Forest Thomist’s’ epistemic/modal requirement—i.e., the requirement that we ground our knowledge of the possible immateriality of being in a demonstration of the actual immateriality of being—is simply too demanding a requirement.” This epistemic/modal requirement is sometimes phrased in a general way that ab esse ad posse valet illatio, sed ab posse ad esse non valet illatio. For example, if one demonstrates the existence of the separability of the soul, then only those concepts or principles directly involved in such a demonstration are now known to be part of the subject-matter of metaphysics. In other words, this requirement leads to a very restrictive possibility for discovery of ens commune.

A crucial claim is made, in this regard, by Fr. Philip-Neri:

[T]he only reason one could have for holding (b) and (c) together [in the Cumulative argument] is antecedent commitment to what we have been calling the “epistemic/modal requirement” (i.e., the requirement that our knowledge of the possibility of something immaterial must be grounded in a demonstration of the actuality of something immaterial). But that requirement seems wrong. For if it were true, it would either be true because it is a particular instance of a more generally true principle that “our knowledge of the possibility of some x must be grounded in a demonstration of the actuality of some x”, or it would be true because there is something special about immateriality that makes this not-generally-true principle true in this case. But there does not seem to be anything special about immateriality, and the general principle seems to be false.

The astonishing claim that this “general principle” is false will be discussed below.

Clearly, the Cumulative Argument will only be convincing on the merits of the Insufficiency and Counterfactual Materialism Arguments as well as Fr. Reese’s use of the axiom about arguing from actuality to possibility.

Criticism of Fr. Reese’s Arguments

I consider the above four arguments in order. As to the “zeroeth” argument, the Standard Objections, Refined and Combined, I agree with Fr. Reese’s own response. Indeed, Coughlin (see his 2020: 428–30) responds along similar lines after raising an objection very much like the “Standard” one, which I wish to quote at length:

Yet the truth of the matter, however odd, is that we do argue from the material to the immaterial (and from the created to the uncreated). Saint Thomas, as we saw, goes so far as to say that we can know nothing about the immaterial except by argument from the material. He, at least, must think it is possible so to argue. Exactly how we pull it off is a little more difficult to say. It seems that we first prove the existence of immaterial things, and when we do so, we are not yet aware that “being” must be equivocal. We prove, for example, that there is a first mover or we recognize that we have an intellectual power. Only later do we realize that such things must be unbodily. To do so, we must use demonstrations that have negative conclusions. For example, we might argue that the first mover must have infinite power, but no body has infinite power, and conclude that the first mover is not a body. The major premise is seen by noting that every body has finite power, so that what has infinite power cannot be a body (i.e., no body has infinite power). But we see that in order to explain motion, there must be something of infinite power. Once we see all this, we can see that the first mover is immaterial. We have proven, starting from notions that include matter, that there is a transcendent, nonmaterial being. The negative premises are seen by way of the negations of the predicates of affirmative claims. We see what turns out to be immaterial at first only as a cause, then we later see that many of the predicates said of material things are to be denied of it. This most of all brings home the fact that nothing is said univocally of the immaterial and the material. Every positive predicate must be hedged round with negation: yes, God exists, but he does not have an existence which actuates a material essence; yes, God is one, but not by the unity of continuous magnitude; and so on. We arrive at negative judgments or separations. These separations permit us to distinguish the subject whose existence we have just proven from the subjects of natural philosophy—to see, in fact, that there must be some more universal science because being turns out to be more universal than we had thought, that being as such and mobile being are not coterminous and that there must be a new mode of definition for our newly expanded subject. (2020: 429–30)

The passage from St. Thomas to which Coughlin refers near the beginning of the quotation is In I Sent., d. 3, q. 1, a. 2, ad 2: “[Our intellect] it cannot come to purely intelligible things except through argumentation [in intelligibilia pura devenire non potest nisi arguendo].” This path of argumentation discovers a “being” (a first mover, say), but we do not yet realize the systematic equivocation (by reason) involved in that use of the term “being.” Purifying negations are required for this. We gradually recognize the analogous character of the name “being” used to name that cause whose existence is discovered by argument. Indeed, what the argument is that thesis (9) assumes need not as such use the term “being” as a minor or major term, even though such an argument helps to constitute via the order of discovery the expanded analogical range of the ratio entis. The argument quia for the existence of such a thing as a first mover does not of itself establish the ratio of ens commune but is a necessary condition for it.

In other words, the notion of “being” employed in natural philosophy bears a ratio that is potentially compatible with immaterial existence (for “being” can exist in material or immaterial substances), but, antecedent to the discovery of the analogical expansion of that ratio, is qua ratio incompatible with that immaterial existence (for no material substance is an immaterial substance).

Against the Insufficiency Argument

The insufficiency in the Insufficiency argument lies in an equivocation. That is, thesis (9) need not be taken to maintain that such an argument proves the existence of God under the same ratio in which God is the principle of the subject of metaphysics. Thus, to demonstrate the existence of some X outside of subject-matter Y cannot demonstrate the existence of subject-matter Y precisely as such, but if X necessarily entails subject-matter Y in order to be adequately grasped, then a demonstration of X is a sufficient condition for knowing the existence of subject-matter Y.

Such a reply is latent in Coughlin’s passage, quoted above. He makes this explicit when he notes “To discover that there is an immaterial first mover is to discover God or some inferior immaterial substance as the principle of motion, not as the principle of being.” (2020: 430) In other words, the defense of premise (2) of the Insufficiency Argument equivocates on the ratio of God in question.

One might note, furthermore, that “to establish” the subject of metaphysics, ens commune, can be taken in various senses. In a first sense, the subject-matter of a science is established by being known in light of its principles while grasping scientific objects of that science. Thus, continuous quantity is established via the habitus of geometry through the demonstrations of that science. But, in a second sense, the subject matter of geometry is established by understanding the truth of the basic definitions laid down, say, at the beginning of Euclid’s Elements, the recognition of which is through a process of formal abstraction based upon sense experience. Even the very young, geometric neophyte can thus establish the subject-matter of geometry. Lastly, one might “establish” the subject-matter of a science hypothetically, as a dialectical construct or for the sake of argument. Indeed, it seems to me that ens mobile is taken in this last way prior to the insights gained by the end of Physics, Book I (on which, more below).

Since it is only the first two senses which as such grasp the truth of things in rerum natura (for the last is only on the way to doing so, as dialectics is used to establish first principles), and since the first of these is clearly too strong, it is in the second sense in which, I take it, thesis (9) maintains that a natural philosophical argument establishes the subject of metaphysics (subject to the elaborations given by Coughlin, above). However, as noted below, this “establishment” is incomplete without logic.*

Against the Counterfactual Materialism Argument

Recall that this argument depends upon a crucial premise, namely (2), which Reese defends as follows:

(1) If most “River Forest Thomists” were right, then, on the supposition of materialism, all the items ordinarily identified as metaphysical would need matter and motion in order to be.
(2) But, on the supposition of materialism, all of the items ordinarily identified as metaphysical would not need matter and motion in order to be understood.
(3) Thus, on the supposition of materialism, all the items ordinarily identified as metaphysical would need matter and motion in order to be but not in order to be understood.
(4) Mathematics is the science of what needs matter and motion in order to be but not in order to be understood.
(5) Therefore, if most “River Forest Thomists” were right, then metaphysics would be indistinguishable from mathematics.

Premise (4) is the standard Thomistic account of mathematical abstraction and is not at issue in this debate. In my view, among other problems with this argument, it is premise (2) of the above supporting argument to the Counterfactual Materialism Argument which causes the whole to fail.

First, it does so because it begs the question. What are those things ordinarily identified as metaphysical? The very contention of thesis (9) is that no such things exist until they are identified in the first place. As Rev. Br. Hall notes in his thesis, “There are no metaphysical terms—there are just terms, and these are applied analogically in the different sciences depending on the precise formality under which the science operates.” (2024: 18)

Second, as a result of begging the question, premise (2) becomes ambiguous. On the one hand, it fails to convince by neglecting the point that physical things do need matter and motion in order to be understood. So, any putatively “metaphysical” things would need matter and motion in order to be understood. Yet, on the other hand, if the point here is the dialectical one that putatively metaphysical things do not need matter and motion for there intelligibility and are thus in the same intelligible boat as mathematical objects, this fails to convince because the abstraction from matter and motion which enables the conceptualization of mathematical objects is of a different character than the abstraction that enables the conceptualization of physical objects.

Third, and following upon this last point, premise (2)—in its hopes to reach conclusion (5)—misses the ability of the natural philosopher to distinguish his science from mathematics (as is done, say, in Physics, II.2). That is, a reduced River Forest Thomist can simply deny that (5) is true on independent grounds. This is because an intellectual habitus enables the recognition of what is not within its purview. A natural philosophical habitus enables this with respect to mathematics because one can readily see that arguments in the latter make no use of what those in the former require, namely, matter and motion (and, by the way, finality).

Fourth, a reduced River Forest Thomist might be non-plussed by conclusion (5). Isn’t it precisely the problem that, without defeating materialism or naturalism, one might fall into a platonic or pythagorean trap of thinking that mathematics is a sort of metaphysics? Isn’t this the very sort of trap into which much modern analytic philosophy has fallen, via a hypostatization of logical intentions, the very danger which Thomists face if thesis (9) fails?

Finally, and apart from the premises in the arguments, I would like to note that the counterfactuality here seems not so counterfactual to many philosophers. That is, as Fr. Philip-Neri notes in his conclusion, “many of the themes considered central to contemporary metaphysics are actually topics proper to natural philosophy.” (2024: 14) Is this not a predicament that a reduced River Forest Thomist would predict? As Coughlin notes, “The fundamental problem for us as humans is that we are animals, and so the proper objects of our minds are the whatnesses of material things.” (2020: 433) We are born in a cave, a cosmos at the bottom rung of a universe of being, and mere mathematical abstraction might awaken us to the conceptual possibility that there is an outside to the cave, but such thought does not get us outside. (Perhaps Aristotle’s famous image in Metaphysics II, of nocturnal creatures, may have had bats and caves in mind.)

Against the Cumulative Argument

As I indicated above, the Cumulative Argument is convincing, in part, only if the above two arguments are convincing. However, they are not. The remaining part of this final argument lies in Fr. Reese’s claim that reduced River Forest Thomism’s reliance upon the axiom that ab esse ad posse valet illatio is too restrictive.

Imagine a “River Forest Thomist” who establishes the science of metaphysics by demonstrating the immortality of the rational soul. Since the soul thus demonstrated is a being and a form, he will be entitled (at least by his own lights) to claim that being, form, and soul can be numbered among the things that need matter and motion neither in order to be nor in order to be understood. But the separated soul that has just been demonstrated to exist is neither a substance, nor a potency, nor an accident, nor a whole, nor a perfectum, nor a multiplicity, etc. Thus, the “River Forest Thomist” will have to wait until he has further demonstrations of the actual immateriality of each of these things before he can number them among the things that need matter and motion neither in order to be nor in order to be understood. This epistemic/modal requirement is simply too strong. (2024: 11)

I presume Fr. Reese really means immortality here, which makes such an argument a very strong one, insofar as demonstrating the immateriality of the soul is relatively easier. However, I will argue as if the term were “immateriality” in the first sentence, for my reply holds a fortiori of immortality.

My reply: the example restriction to being, form, and soul is not true. (I grant that the separated soul is not a substance simpliciter; this way of sustaining thesis (9) is limited in this respect.) However, soul does have potencies (the possible intellect and the agent intellect); it has various accidents (such as concepts and the relations of which they are principles); the soul is a type of whole with respect to its parts (powers); as form, it is a sort of perfectum; finally, as Aquinas makes clear in many places, there are many such souls. In other words, the demonstration of the immateriality of the soul immediately raises questions about all the terms linked to it that are also linked to the discussion of souls that do not exist after the corruption of a living thing. This is the “dialectical spade work” of logica utens that must happen after such a demonstration and while one is on the hunt for that “science which we are seeking,” as Aristotle calls first philosophy and theology.

However, a second reply is that I think Reese is wrong to cast doubt upon the general principle that ab esse ad posse valet illatio. For this principle is true simply speaking, for potency is knowable only through its act. Nor do the examples he offers as counterexamples work:

• “After all, we know that some organisms (e.g., methanogens) could live on Mars, even though we do not know whether any organisms actually live on Mars” (2024: 14). — This equivocates on a logical could (it is conceptually possible, it is conceivable that) with a real possibility. Even Wikipedia is not so sanguine: “Some scientists have proposed that the presence of methane in the Martian atmosphere may be indicative of native methanogens on that planet. In June 2019, NASA’s Curiosity rover detected methane, commonly generated by underground microbes such as methanogens, which signals possibility of life on Mars.” (emphasis added) But to be a sign of the possibility of something is not to prove its real possibility. Ab posse ad esse non valet illatio. To know the real possibility of such life on Mars by analogy to conditions on Earth is, furthermore, to know possibility through actuality.*
• “[W]e know that the world could have been without [sic] a beginning in time, even though we know that it is not actually without a beginning in time.” (Reese 2024: 14) — Perhaps this example would be clearer if the “without” were a “with.” Nonetheless, it fails due to a transgression of genera. Granting (as I do) the (controversial) Thomistic philosophical thesis that God is able to create a temporally beginningless world (and thus such a world is able to be), our knowledge of the actual condition of the world or what God actually did is due to faith, as Aquinas argues. So, this is not a valid counterexample to the axiom ab esse ad posse valet illatio because it does not treat the axiom in the same respect at each instance. (If Fr. Reese means both the possibility statement and the actuality statement to be taken within theology, then I would respond the example is no counterexample, because we know theologically the possibility of a temporally beginningless universe from the actuality of eternal processes; see De Potentia, q. 3, a. 13, c.)
• “[W]e know that God could make himself sacramentally present under the species of rice, even though we have good reason to think that he never has and never will actually do so.” (2024: 14) — This is not a sufficiently strong counterexample because “having good reason to think” something is clearly a statement of probable knowledge, which is not strong enough to defeat a principle such as the one in question. This is because the principle is per se nota, given that potentia is only intelligible through actus; act is, indeed, prior to potency in all senses of “prior” (Metaphysics, IX.8).

A final criticism I have to Fr. Reese’s paper is that he mentions Coughlin’s argument in his endnotes, but never takes it up. Reese ably summarizes Coughlin’s argument as follows:

The larger structure of Coughlin’s argument is by way of elimination: either we know this through the first operation of the intellect, or we know this through the second operation of the intellect, or we know this through the third operation of the intellect. Not the first, because that only delivers the truth that matter and motion are not required in order to be understood. Not the second, because such a judgment of separation will either be known per se or it will be known on the basis of other truths; but it is not per se nota. Therefore, it must be known on the basis of other truths—i.e., it must be known through the third operation of the intellect. But this discursive process of reasoning must belong to some scientia, and it cannot belong to metaphysics without vicious circularity. Thus, it must belong to natural philosophy. (Reese 2024: 15)

It is a corollary to Coughlin’s argument that thinking out the necessary consequences of River Forest thesis (3) leads us to hold thesis (9). One might consider the alternative, namely that some first or second act of the intellect might suffice. However, such conceptualizations and judgments are possible to the mind (I can conceive of “being” without attending to whether it is material or not, and then am able to make judgments about that concept), but whether those judgments are true is the very point at issue. Without determining the truth of thesis (9), Thomistic metaphysics runs the risk of falling by the sword of the Kantian critique and more. A reified logic would take the place of metaphysics.

The Natural Path through the Forests of Thomistic Schools

River Forest and Laval are often joined at the hip. This is not inaccurate. However, there are distinctions to be made, and one can do so using the lists which Fr. Reese’s article helpfully constructs. Indeed, he notes (2024: 15n6) one such difference, namely that Charles De Koninck was much less sanguine than a William Wallace about the ability of the natural science, qua extensions of natural philosophy, to attain demonstrations propter quid following the canons of Aristotelian science.

Another point of distinction is the emphasis which the Laval School places upon logic as the tool of philosophy. This emphasis upon logic is found, for instance, in the works of Msgr. Maurice Dionne or Yvan Pelletier. A story I have heard is that Msgr. Dionne once said that, had he ten years in which to study all of philosophy, he would spend the first nine studying logic and then turn to the rest. (N.b., emphasis; I do not thereby assert other schools of Thomism are poor logicians.) The Rev. Br. Columban Hall’s thesis astutely and rightly begins by noting the overlap between the domains of logic and metaphysics and how this leads to problems in regard to this very debate.

In the debated topic at hand, it seems to me that “to establish” the subject of a science is done in various ways (as noted above). The strong sense is to establish the subject of a science through demonstrations within that science. In this way, a subject is established with respect to the scientific objects in that science through the principles of that science. The middle sense is to establish the subject of a science as the necessary condition (foundation for) the strong sense; this is done by grasping or understanding something of the existence and quiddity of that subject—for instance, the graps of ens mobile at the end of Physics, Book I. The weakest sense is to establish a subject of a science as a sort of dialectical field.

This Socratic playground or the dialectical “field” of a science is not yet its disciplined “subject,” in either of the first two senses. For instance, there is a field of inquiry in Physics, Book I that is ens mobile. The field of that dialectic is bordered on the one hand by Parmenides and on the other hand by Heraclitus, with many others in between. It is still natural philosophy, in its pre-scientific, dialectical work-and-contemplative-play that is attempting to take the field. After all, a science, in proceeding rationabiliter, can do so demonstratively or dialectically, but both are the proper acts of a scientific habitus (see SBdT, q. 6, a. 1, 1a, c.: “In this sense, rational method is opposed to demonstrative method. We can proceed by this rational method in all the sciences, preparing the way for necessary, proofs by probable arguments.”). Logica utens is required for this, for logic is that art of the mind for discussing all of reality, even if, quoad nos, it is realities as a beings of reason which we use as tools to sift the being of beings.

This leads to a third point of distinction, the Laval School emphasis upon the “natural path” in our knowledge. This natural path is discussed by Aristotle in Physics, I.1, and seems to be nearly always on the mind of Charles De Koninck when he writes. De Koninck’s ACPA Aquinas Medal address, “Three Sources of Philosophy,” discusses the logic of this path. (One might also consider the lecture “Common Conceptions and Proper Conceptions in the Study of Nature,” by Mr. Marcus Berquist, reprinted in Learning and Discipleship: The Collected Papers of Marcus R. Berquist, 243–67.)

Along this natural path, we proceed from what is better known to us at first to what is better known (and more knowable) in itself. We proceed from the phenomena or effects to their “principles, causes, and elements.” (Physics, I.1) This is because our minds proceed from knowing something potentially to knowing something actually, and thus from thoughts that are comparatively more full of potency (vaguely grasped) to more full of act (distinctly grasped). This is to proceed, intellectually, from thoughts that are more general to those that are more specific. Children at first conceive that all adults are parents, but later distinguish between those which are and those which are not. The import of defending thesis (9) is to defend this natural order in our learning given our natural condition, that the connatural object of the human mind is ens concretized in the quiddities of sensible substances. We are connaturally prone to materialism or naturalism, and from this cave that would trap philosophy forever we must find some escape. As St. Thomas states in In I Sent., d. 3, q. 1, a. 2, ad 2: “[Our intellect] it cannot come to purely intelligible things except through argumentation [in intelligibilia pura devenire non potest nisi arguendo].”

Conclusion

In conclusion, I think that the corollary drawn by Fr. Reese about (non-reduced) River Forest Thomism, the need to return to natural philosophy “as an integral and autonomous discipline” is well made. At least in this part, I would not miss the forest here.

Fr. Philip-Neri’s talk about “schools” of Thomism lead my thoughts elsewhere.** There is a distinction between a school of thought (which possesses conditions of formal unity, such as principles necessary to Thomism generally or to River Forest Thomism, as Fr. Reese argues) and a tradition of inquiry (along the lines of what MacIntyre thinks of a tradition). A school has a formal unity due to the central and architectonic functions of certain philosophical principles (thus, what are non-contingent, non-historical), while a tradition is the contingent, historical community of teachers and learners of such a school. (The school is the regime-form, politeia, the tradition is the polis, as it were.)

This, in turn, is connected to how one could consider a field of inquiry versus a discipline. The former (say, in the case of natural philosophy) includes materialists, rationalists, Parmenides, Aristotle, etc., but natural philosophy as a discipline both excludes that rambunctious range but only by including (1) an Aristotelian dialectic (or, Aristotelian doxographical “array”) preparatory to the scientific form proper to a discipline that establishes the subject of the discipline (transitions from the weak sense of subject to the middle sense), and (2) that scientific form itself (subject, principles, objects as conclusions, etc.).

Thesis (9) of River Forest Thomism depends upon the discipline of natural philosophy to aid in preparing the field of metaphysical inquiry and, along with logica utens, plant that “tree” which, with proper attention, becomes first philosophy with fruits of natural theology.

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* This paragraph clarified after publication.

** In what follows, I draw upon some thoughts due to conversations with and reading the work of Fr. Cajetan Cuddy, O.P.; see his essay in The Oxford Handbook of the Reception of Aquinas, as well as a forthcoming essay, “Thomism and the Question of History: A Theory of Unity and Plurality in Authentic Schools of Catholic Theology.”