“One Long Argument”—The Thomistic Account of Biological Evolution

Books reviewed:

Tabaczek, O.P., Mariusz. Theistic Evolution: A Contemporary Aristotelian-Thomistic Perspective. Cambridge University Press, 2024. 300 pages; $76 (hardback), $45 (electronic).

Carreño Pavez, Juan Eduardo. Thomistic Philosophy in the Face of Evolutionary Fact: Methodological and Conceptual Insights for an Integration. Editiones Scholasticae, 2024. 760 pages; $116 (hardback).

By John G. Brungardt

‍INTRODUCTION

‍Any treatment of biological evolution that is sufficiently robust in theological and philosophical registers is Catholic as well as catholic. The very nature of the task demands it, especially in view of what the theory shows or fails to show about human origins. This focal point in anthropogenic questions is clear and should not be avoided: “You ask whether I shall discuss Man” wrote Darwin to Wallace about the drafting of On the Origin of Species, “I think I shall avoid the whole subject, as so surrounded with prejudices, though I fully admit that it is the highest and most interesting problem for the naturalist.” (quoted in Carreño, 156n118) While Darwin did not avoid the problem in later work, his Descent of Man fails to meet the requirement of theological and philosophical robustness—unlike the two books under review here.

Fr. Mariusz Tabaczek, O.P. is the author of many other books and articles, including Emergence: Towards a New Metaphysics and Philosophy of Science as well as Divine Action and Emergence: An Alternative to Panentheism. These works feature deep engagements with contemporary philosophy of science and religion, offering to the contemporary academy a better look at the resources of Thomistic philosophy and its relevance to pressing and perennial questions. His 2024 work Theistic Evolution is no exception.

Juan Eduardo Carreño’s book originally appeared in Spanish in 2017 (RIL Editores, Chile). This English translation, as Carreño notes, is reworked and expanded; it is essentially a second edition. Carreño’s other work includes Vivere viventibus est esse: El vivir como perfección del ser en la obra de Tomás de Aquino (Vivere viventibus est esse: Life as a Perfection of Being in the Work of Thomas Aquinas). His book on evolution displays an encyclopedic erudition and a living engagement with historical and philosophical sources. It was one of the recipients of the 2025 Expanded Reason Award.

Both books deserve careful study and should serve as resources for the field in years to come. In what follows, I review the highlights from each work, noting some of their most salient contributions. I then turn to consider two debated points that these books include or highlight and which I found most helpful for focusing my own thought.

THE POLISH THOMIST AND EVOLUTION

In Tabaczek’s Theistic Evolution, a brief introduction perfunctorily sets the stage. (Each chapter introduction does the same, helpfully but dryly; e.g., need we be told that the chapter will conclude with a short conclusion?) The essential proposal is that the work-in-progress status of modern evolutionary biology can find a dialogue partner in “the philosophy of biology and metaphysics” (8). Key mention is made of the philosophy of nature, however, a welcome change from reducing it to a simple function of Aristotelian-Thomistic metaphysics. (This does not prevent him from using “metaphysics” in that looser sense throughout.)

While his book on emergence treats of the material in much greater depth, the first chapter on the “Metaphysics of Evolutionary Transitions” reviews the key principles of that philosophy of nature as regards change. Tabaczek does not shy away from prime matter or substantial form, or the dispositions of matter or its “striving for perfection” or of the virtual presence of parts in substantial wholes, all key principles employed by Thomists treating of this topic in the past. This recapitulation of principles from the governing habitus of natural philosophy is direct and at times too rushed. (For instance, prime matter is defined “as pure, unactualized possibility of there being anything at all” [21], which is clearly too broad.) Tabaczek also adopts needless abbreviations and quasi-symbols; the algebraic air this gives to the presentation might assist some parts of his audience, however. The heart of Tabaczek’s account of evolutionary transitions resolves to a cosmic context of causality into which he builds updated accounts of the disposition of matter via accidental changes as well as instrumental, secondary causality. This “total cause” or “causal matrix” or “causal polygeny” (48; see 47–52) is a welcome use of a host of Thomistic principles as well as a development of suggestions made by Fr. Benedict Ashley, O.P. While its details are diffuse, this causal matrix is at least well disposed towards empirical determinations. It is also a theme to which I return below.

Chapter 2 (“Essentialist and Hylomorphic Notion of Species and Species Transformation”) and Chapter 3 (“Natural Selection, Teleology, and Chance in Evolution) build upon the first chapter by adding further detail to accounts of form and finality in evolution. Chapter 2 argues, quite effectively, that a hylomorphic notion of species (a realist and essentialist notion) is able to provide a metaphysical grounding for more empirical or pragmatic concepts of species used in biology that tend towards relational or property-cluster types. This leads Tabaczek to defend a divide between real essences and what we can practically know about them (87); in other words, the more philosophically knowable are found higher in the Porphyrian classification, while empirical methods and categories operate at lower levels (90). This proposal will seem like a sort of dualism to some who would wish nature to come in neat, easily categorizable species and a philosophical irrelevance to others who enjoy nature’s nigh-Heraclitean variety; it strikes me as much closer to the realism of Aristotle, the first biologist, and the pragmatic suggestions of Charles De Koninck in The Cosmos.

Chapter 3 features a treatment of the reality of chance in the cosmos, developing a typical reading of Aristotle that likens him in a certain way Stoicism while correcting this with Aquinas’s own view, namely, that chance is not a mere epistemic effect due to the unforeseeable interference of accidentally-crossed causal series and due to extrinsic causal factors, but resolves to how things exist intrinsically and not how they are known (103–105). While this stops short of the details one finds in Cajetan’s treatment of chance in his commentary on ST, Ia, q. 115, a. 6 (the article cited by Tabaczek) or the extensive developments made by Charles De Koninck, it is not necessarily in disagreement with them. The reality of chance events in the cosmos is a crucial complement to teleology. Speciation can employ both goal-directed processes and chance interplay. Of course, this means that evolution becomes principled internally by the natures of things, since chance resolves ultimately to natures and since finality is the cause of those natures. This emphasis upon natures as intrinsic principles of evolution deserves more emphasis. One finds it, for instance, in the treatment of Augros and Stanciu in The New Biology. Tabaczek finds it as well in St. George Jackson Mivart (123).

The first three chapters complete a philosophical treatment of evolution more at home in the philosophy of nature (as Thomists usually understand the term); Chapter 4 begins the metaphysical and theological treatment of evolution, which is sustained through the remaining five chapters.

Chapter 4, “Aquinas’s Account of Creation,” actually begins with an examination of St. Augustine’s treatment of creation and rationes seminales. Tabaczek properly deflates the suggestion, made since the late 19th century, that rationes seminales anticipate evolution. The chapter instead focuses on the standard Thomistic account of creation ex nihilo and the opera distinctionis et ornati. The standard metaphysical toolkit is employed in the remaining chapters, along with an evolutionary redefinition of rationes seminales in terms of primary and secondary matter. Tabaczek properly notes that this allows for genuine novelty in the innovation of form in the cosmos.

Chapter 5, “Aquinas and Evolution,” considers how, according to St. Thomas, the universe’s formal parts are its species, not individuals; this demands a certain perfection of the universe. Nonetheless, the universe, according to Aquinas, can increase in perfection. Tabaczek relies upon an important text in the Sentences commentary about the possibility of the increase of species in the universe. Tabaczek mutes, however, the fact that the text in question concerns what is within the power of God in making universes as such. Be that as it may, Tabaczek does show how Aquinas argues against instrumental creation and has potential space among secondary causes for the innovation of new species. This requires him to expound a Thomistic version of theistic evolution (167–69), one which attends to the results of the natural science, uses a hylomorphic approach to understand them, along with the metaphysical model of evolutionary transitions proposed in the first three chapters. It places this account within a Thomistic doctrine of creation in which micro- and macro-evolution is part of the work of adornment, entailing that the perfection of the universe includes its natural historical increase in perfection from potentialities (rationes seminales) within it, and requiring no special, direct divine intervention for speciation (with the exception of anthropogenesis). The chapter closes with a rebuttal to Tabaczek’s Polish Dominican confrère, Michael Chaberek, who contends that Aquinas’s principles support only progressive creationism. (See also their published debate in Nova et Vetera [English Edition], vol. 22, no. 1, 2024.) The fruitful contribution in this response, however, is the recapitulation of the various sorts of species concepts (e.g., metaphysical species, biological species, natural kinds, biblical kinds). Tabaczek’s position requires a measure of humility, insofar as reducing these distinct approaches to species or kinds to a monistic one is not humanly feasible. However, it also rebuts NOMA-type thinking (Stephen Jay Gould’s “non-overlapping magisteria” of the domains of science and religion), insofar as the distinct accounts can be sapientially interrelated.

After the more preparatory fourth and fifth chapters, Chapters 6–8 constitute the heart of his theological account of evolution (in both philosophical and revealed senses). Chapter 6 proposes a Thomistic account of creation making use of evolution in the history of the cosmos; Chapter 7 examines speciation events within this history in general; Chapter 8 considers anthropogenesis.

‍Chapter 6, “Evolution and Creation,” aims to avoid the extremes of theistic evolutionisms that essentially adopt some version of creatio continua or instrumental creation. Instead, he defends a Thomistic version where creation in the strict sense (“the production of the whole being” ex nihilo) is distinguished from production or formation, and how the divine act of creation includes secondary causes able, via creaturely participation in the governance of the cosmos, to bring about the innovation of new species: “In the course of the complex matrix of the processes effecting particular cases of speciation, God does act as the first and primary cause of novelty, working through secondary and instrumental causation of contingent creatures.” (198–99) The language of “evolutionary creation” from the Aristotelian-Thomistic perspective is problematic.

‍This clarification having been established, Chapter 7 (“Concurrence of Divine and Created Causes in Evolutionary Transitions”) specifies how God and created causes are agents in a speciation event. Tabaczek approaches this by comparing and contrasting that event with divine and creaturely concurrence in begetting offspring in ordinary or non-speciating generative activity (212–13). This point alone is worth emphasizing, but it helps to show the power of the Thomistic account when transferred to evolutionary transformations (216–17). As I will discuss at greater length below, Tabaczek crucially characterizes both the secondary as well as instrumental causality at work at the level of creatures. In particular, he correctly emphasizes that, even in ordinary generation, the progenitor(s) are only the “instrumental causes of the essence as such” of the offspring (213, 217), a feature that is a fortiori retained in speciation events. Much like other Thomists before him (one thinks of Maritain or De Koninck), the cosmos itself becomes an ordered and unified array of secondary and instrumental causes, teleologically inclined towards its own further perfection at the hands of its Creator: “God indeed brings the unity of the evolutionary causal matrix, but he does that through the secondary quasi-causality of chance. . . . Grounded in numerous particular per se causes contributing to this evolutionary causal matrix, it comes about as a chance occurrence that remains, nonetheless, within God’s providence.” (219–20)

Chapter 8, “Theological Anthropogenesis and Evolution,” applies the causal model elaborated in Chapter 7 to the specific case of human evolution and then reviews the debate about the mystery of human origins in a properly theological register. Interested readers can see the latter at greater length in a forthcoming issue of Lux Veritatis (vol. 1, no. 3), where Tabaczek extends his engagement with the work of Kenneth W. Kemp. Tabaczek finds Kemp’s defense of an updated version of Mivartism (i.e., that anthropogenesis was the infusion of a human soul into an adult hominid that was biologically but not philosophically human) too dualistic, voluntaristic, and metaphysically dubious. Tabaczek’s review of the debate surrounding monogenism and polygenism is also very helpful, where he finds occasions to agree with Kemp’s careful work on the subject.

Tabaczek’s account of anthropogenesis itself is nuanced and, to my mind, one of the two best applications of Thomistic principles to the question I have read to date in terms of depth, detail, and philosophical adequacy (the other one is Carreño’s). Here, he argues that the progenitors of the first true human are not instrumental causes of the human essence, but only secondary causes of the dispositions of primary matter necessary qua material dispositions for the infusion of the human soul by God. He writes that he is “skeptical about considering parents as instrumental causes of the souls (in themselves) of their children” (232). This is undeniable insofar as the human soul as a subsistent form must be created. However, it does not follow that human parents or non-hominid progenitors of the first true human(s) are instrumental causes in no way of the essence as such of human individuals. For what it means to be an instrument is precisely to be a secondary cause that is ordered to an effect outside its power and yet used to bring about that effect by a higher power. One must distinguish between proximate and remote senses of instrumentality.

‍THE CHILEAN THOMIST AND EVOLUTION

We now turn to the book that, by word count, is just about twice as long as Tabaczek’s. Indeed, if one might offer a criticism of the text at an editorial level, Carreño’s tome might have begun with its third chapter, insofar as the first two chapters respectively review the overarching Thomistic framework of corporeal living beings and the modern, scientific conceptions of corporeal living beings in the long history and many strands of evolutionary biology. (If one might offer a critique of the literal physical text, it is that the length of the book outdoes the strength of the binding during reading—at least, that was the case with my copy!)

However, if one might defend these initial chapters, it would be in view of offering a self-contained text that treats of all the necessary materials required for the conceptual integration of very diverse intellectual traditions, while at the same time developing the Thomistic account of scientific knowledge in regard to how it can properly incorporate natural-historical data. After these first two essentially introductory chapters, the third and fourth chapters review the disagreements and difficulties between Thomism and evolutionary biology and sketch the proposals for integration made by other Thomists. The fifth chapter establishes the Thomistic account of knowledge in some detail while proposing a place for natural-historical data in its registry of possible demonstrations. The heart of the book lies in its final three chapters: a Thomistic defense of what it means to call evolution a fact (Chapter 6), a proposed causal model for evolutionary changes in general (Chapter 7), and the application of that model to the evolution of life in the cosmos (Chapter 8).

As stated, Chapter 1 treats of the metaphysical and natural philosophical contours of the Thomistic philosophy of corporeal living things. For Thomists, the material could have been assumed or largely condensed. For non-Thomist readers, however, the material is essential and a highly effective condensation (despite its length!) of many more loca in St. Thomas and the Thomistic tradition. The chapter also effectively brings to bear academic work that could help the North American Thomistic academy better understand the Spanish-language contributions of their South American colleagues. The point of the chapter, however, in view of the larger project is to begin to raise questions to be addressed: How should the genesis of new species be accounted for? How should we understand how the more perfect can come from the less perfect? Can we still contend that the human species completes the cosmos? Another key point of the chapter is its defense of the irreducible character of life via its treatment of the vegetative soul, a theme to which I return below.

Chapter 2 is a review of the history of taxonomy and modern evolutionary theories, including Darwinism, its historical alternatives, the neo-Darwinian synthesis, and variant or sub-parts of that synthesis. Part of the point of the sometimes exhaustive levels of detail can be seen only later: unless one is familiar with the actual natural history (or, aware of the amount of work required to gain that familiarity), one will not be willing to countenance evolution as a fact. The devil is in the details. The chapter also introduces further key questions: What is a species? How can natural-historical data be incorporated into an overarching philosophical account?

Chapter 3, “Disagreements and Difficulties,” recapitulates and focuses the prior two chapters. On the side of scientists reacting to philosophy, Carreño rightly emphasizes the distinctiveness of the living and is irreducibility to biochemical mechanics. On the side of Catholic philosophers reacting to the history of evolutionary theory, he sketches various instances of the lack of mutual comprehension, especially concerning the most key question of his own text, namely the evolution of the human person, especially in respect of “the ontological structure of the living body” (236). The real difficulties to be dealt with by the Thomistic approach Carreño highlights as follows: How is the opposition between mechanism and vitalism to be overcome? What exactly is a species, and can more philosophical approaches be joined with biological ones? How is one to account philosophically for evolutionary transitions? How is the human difference to be articulated and defended? And, how to explain the finality and perfection of the cosmos in light of evolution?

Carreño sketches here three options for evolutionary transitions: (1) the substantial transformation of one kind of substance into another kind via substantial change; (2) substantial supraformation, a change in which a new substantial form is drawn from primary material potency that subsumes the prior substance; (3) transgenerational substantial transformation, a change in which a new species is educed in the process of generative activity.

Chapter 4 explores prior attempts at receiving evolution into Thomistic philosophy, especially in view of the questions Carreño elaborates in prior chapters, by a select group of Thomists or those writing in dialogue with Aquinas: Edith Stein, Manuel Cuervo, Jacques Maritain, and various others, including Mariusz Tabaczek. Carreño’s purpose is not to provide a complete survey but an illustrative one that begins to advance points of resolution and response to the questions he has raised. Thus, Edith Stein discusses the real heterogeneity of species as well as supraformation (300); Cuervo articulates various aspects of causal agency and the human difference (308). With Maritain, Carreño is able to indicate other resolutions, such as the Thomistic quasi-analogy of hominization and embryogenesis (312–13), the role of the cosmos as a total cause (316), the place of divine likeness and the appetite of matter as principles (e.g., 318–320), and Maritain’s critique of views of transformation or supraformation (akin to Mivartism) and defense of transgenerational transformation (332). I comment below on Carreño’s engagement with Tabaczek; his interpretation of some (e.g., Austriaco) seems too hasty. However, the chapter concludes (361–66) with a helpful summation of this Thomistic survey, and adds the question about how to reconcile the conservative principle of Thomistic cosmology, the role given to a principle of perfection, with the innovative tendency seen in this history of evolution?

The fifth chapter is essentially preparation for Chapter 6. It presents an overview of the Thomistic account of science and integrates natural-historical knowledge into that account. On the whole, Chapter 5 is much indebted to Maritain’s vision, one with which I disagree in view of Charles De Koninck’s criticisms. (I pass over this disagreement here, only noting that Carreño misreads entirely De Koninck’s account of history; see 412n135). Nonetheless, I find Carreño’s core proposal sound, that is, that historical-natural knowledge, whose material object is being, finds a certain formal object and mode of definition in the concrete historical intelligibility (which he locates within the “empiriological” category of Maritain by reduction). This proposal is crucial, since it recognizes that the essential materials of the philosophy of evolution are infra-scientific (in the Aristotelian sense) but for all that not incapable of incorporation in a sapiential mode into natural philosophy and metaphysics.

Chapter 6 (“Evolution: From Natural Historical to Philosophical Fact”) carries out what Chapter 5 had proposed in general epistemological categories. The notion of a “scientific fact” or “philosophical fact” is, again, one with roots in Maritain’s Degrees of Knowledge. The “facts” in question here are achieved by quia or propter quid demonstrations or the interpretation of natural-historical data (431, 437). This latter is much more at home in a narrative register (as De Koninck would note of historical accounts), and, I might add, the type of judgment one must make about it much more in need of what St. John Henry Cardinal Newman called the illative sense. That is, Carreño concedes that evolutionary biology cannot meet the standards of Aristotelian scientific demonstration (it is not a fact in that sense), and he even concedes that it cannot be called a scientific fact in the sense that an empiriologically sound quia demonstration has been achieved (453). Yet this does not prevent it from being able to be judged true upon the proper interpretation of natural-historical data and in that judgment related to and incorporated into higher modes of scientific and philosophical discourse.

Chapters 7 and 8 continue the integration of the fact of evolution into Thomistic philosophy. After the sixth chapter proposed an “epistemological typification of the fact itself,” Chapter 7 begins the work of “the reformulation of the fact according to the categories and at the level of intelligibility from which the integration is proposed,” namely, a Thomistic philosophical one, and “the articulation of the fact with the principles, concepts, judgments, and knowledge that comprise philosophical knowledge.” (470) This requires Carreño to make distinctions about God’s act of creation (in this, much along the same lines as Tabaczek), arguing that evolution is not to be included in creation taken in a strict or theological sense (production of all being ex nihilo with a beginning in time), but is compatible with a formal sense of creation, namely, that all being is created by God but how a specific being is generated in the order of secondary causality is open to investigation. Carreño then discusses the case of microevolution, or intraspecific change and diversification, the subject of which is a genetically related population and the finality of which is some further perfection of the universe via the realization of the appetite of matter: “The very fact of evolution denies that the universe realizes in act all the possibilities contained in the divine mind, for that which has already actualized all its potentialities, by definition, cannot evolve.” (509) The agency of such intraspecific changes Carreño subsumes generally under the secondary causes that are part of divine governance.

When addressing the case of macroevolution or transspecific diversification in Chapter 7, Carreño first addresses the notion of species. Following many Thomists before him—although not to the extreme of some who postulate in reality only three species of living things (n.b., De Koninck was not among them)—Carreño proposes a similar dualism (he calls it an “asymmetry”) between the philosophical and biological notions of species that must make use of a certain concordism between disciplinary approaches. Philosophically, we can argue that species must be diverse based upon various accidents, but in practice it is hard to determine whether closely related animals are diverse in species.

The account of evolutionary transitions that Carreño defends is what was defined above as transgenerational substantial transformation. He argues that the other two proposals are philosophically and empirically underdeveloped. By contrast, in transgenerational substantial transformation, “substantial change involves—and to some extent elevates—the generative act, so its terminus a quo is, from the very moment it begins to exist, a new living being of a new species.” (532) Having proposed the material cause (breeding population), final cause (perfection of the universe), and the formal cause (a new kind), Carreño adds to this a clarification about the agency, namely that the progenitors of an individual of a new kind are properly speaking instrumental causes of the new species and concurrent secondary causes with God’s ultimate, primary causality (535). Carreño is indeed keen to emphasize the roles of the perfection of the universe and the appetite of matter as principles in this cosmological picture, as well as the cosmos itself as a network of causality (542–550), principles made use of by Maritain and (I might add) De Koninck. Indeed, despite the fact that neither Carreño nor Tabaczek cite De Koninck Cosmos, it was a happy result that so many of De Koninck’s theses in that short, unfinished work are developed in more detail by the two authors.

Chapter 8 (“The Resulting Cosmological Picture”) applies the causal model of the prior chapter to the cosmos and its biological history on Earth in a grand sweeping account. Carreño sketches out four modalities of evolution based upon whether the evolutionary change is intra- or transspecific and whether or not the change is accompanied by an increase in perfection either accidentally or essentially. The route through biogenesis and the emergence of the vegetative and sensate souls to anthropogenesis is a clear, direct application of the resources Carreño develops previously in the entire book. The key to the cosmological picture is also clear: “The appetite for forms leads matter . . . to aspire to the perfection and actuality embodied in mankind, and most especially, in the human soul, which thus constitutes the culmination of the corporeal universe.” (582) Again we meet De Koninck’s arguments in Cosmos. What De Koninck did not discuss was the paleontological hypothesis read in a philosophical light. Carreño proposes three: (1) that all species and individuals of the taxonomic genus Homo are rational animals; (2) that all individuals in the species Homo sapiens, and only they, are rational animals; (3) that only some individuals belonging to the species Homo sapiens are rational animals. Carreño, in a dialectical fashion, argues against all three to manifest the underdetermination of the issue. However, in his opinion, the first hypothesis “is the most plausible because of its philosophical coherence and consistency with the data and facts of biology and paleoanthropology.” (611) Thus, “the origin of our species in an initial couple, perhaps about four mya [million years ago], cannot be ruled out.” (613) Nonetheless, in his brief conclusion, Carreño admits (618) that “Natural-historical knowledge has not said its last word.”

FURTHER REFLECTIONS

What is most rewarding about the study of these two treatments of a vast and complex issue is the compatibility not just in broad strokes but in many details proposed by the authors. Their methods are also exemplary: sustained and serious engagement with the relevant sciences and a thoroughgoing development of Thomistic philosophical principles. In what remains, I wish to highlight two themes: a point of disagreement about the nature of the vegetative soul and a point of agreement about the role of cosmic-scaled instrumental causality.

The Intrinsic, but not Immanent, Nature of Vegetative Life‍

At this point, we must take some notice of a debate which has arisen amongst Thomists about the relationship between life defined by autonomous self-motion and interior, immanent activity. On the one hand, Feser contends that “The mark of a living or organic substance is that in addition to transeunt causation it exhibits immanent causation, in which the effect remains within the agent and perfects it.” (Feser, Aristotle’s Revenge, 39. See also Oderberg, Real Essentialism, 180) In this sense of “immanent,” even vegetative activities are included (e.g., nutrition is an interior perfection of the nourished thing). Carreño offers a similar view, contending that “autonomy and immanence express different aspects of the operation carried out by the living being, whether corporeal or spiritual.” (57; cf. 58n133) On the other hand, Marie George maintains that

‍plants and animals, unlike non-living things, take in materials from the outside and through their own activity transform some of these materials into their own substance. The activity of nutrition, however, is not of itself perfective of the agent, but rather of the ‘new flesh’ it produces. This product, the ‘new flesh,’ perfects the organism as a whole. Immanent activities have no product but of themselves perfect the agent. (George, “An Aristotelian-Thomistic Discussion of the Definition of Life,” 5)

‍It is therefore a mistake, at least an equivocation, George argues, to call the vital activities of plants immanent actions. In this, she agrees with Yves Simon, who also distinguishes the vital activities of plant life both from the motions of non-living things and from immanent activity or operation properly speaking. Simon contends: “To call [the vital activity of plants] for that reason also an immanent action betrays a totally materialistic outlook.” (An Introduction to Metaphysics of Knowledge, 83n46; see also 82: “Every immanent activity, since it remains as well as originates in the agent himself, deserves the name of vital activity. But the converse is not necessarily true, and we should be aware of the harmful equivocations to which such a view may lead.”) In turn, Simon follows John of St. Thomas:

While an organism with a vegetative life does not operate by way of an immanent action, but a transeunt one, nonetheless, because it operates by moving itself this suffices for the notion of life, just as is clear in the action of generation itself (which is a vital one and nevertheless is a transient action, both making use of and requiring alteration). (Cursus Phil., IV, q. 1, a. 4, Reiser p. 40; and see also q. 3, a. 2, p. 88.)

‍I disagree with Carreño that there is a development of the Thomistic meaning of “immanent operation” (70n167, and 55–57, 215–16), and find George’s reading of key Thomistic texts clearer. The distinctions offered below indicate that one is really equivocating on the term, as Simon warned. A sign of this is that Carreño has to extend “immanent action” to living locomotion (see 89). I agree with him (57n132), however, that immanent action cannot be extended to the inanimate, as Tabaczek maintains (see his “Aristotelian-Thomistic Contribution to the Contemporary Studies on Biological Life and Its Origin,” 17).

The point of John of St. Thomas’s reference to generation is that all of the vegetative operations are on a par as physical changes; furthermore, nutrition, respiration, growth, healing, and the like are teleologically ordered to generation as to their end. Even though such activities complete and perfect an organism in various ways, these perfections of the agent are by way of products (nutriment, free energy, mature tissue, repaired tissue, etc.). Furthermore, these activities are physical motions (chemical changes, biological growth), since nutrition or respiration are realized as potentialities of a motion, not conserved and maintained like an act of seeing, while growth and healing involve changes that terminate in a substantial change (matured or restored living parts). The continuous nature of such activities is not to the point; continued acts of digestion, breathing, growth, or healing are initiations of new acts, not the maintenance of the same act, as is the case with the same act of seeing or thinking. That such metabolic-level activities arise in living things as operationally closed systems should not be conflated with immanent action any more than that living things are continuously, thermodynamically open systems should be conflated with the numerical sameness of any such acts. Finally, the interiority of immanent action and vital operations must be distinguished. A vital operation such as nutrition perfects the agent’s substance (not mere spatial interiority) as a terminus. An immanent action such as sight or thought is itself the interior terminus of the action and thereby perfects the agent’s operation.

I therefore propose to clarify the debate by distinguishing between immanent versus transeunt action and intrinsic versus extrinsic agency. On the one hand, only living things from animals and above possess immanent action (sensation, appetite, thought, volition). On the other hand, plants, animals, and human beings are self-movers, sharing in vegetative, metabolic agency. They are also able to act as agents extrinsically (even plant roots push things around), sharing this in common with non-living agents. A strength of this set of distinctions is that is shows the uniqueness of the most fundamental mode of life, the vegetal (see George, “The Definition of Life,” 6). While in other cases the activity of the transitive agent’s action is in the patient and perfects the patient, only in vegetal vital activities are transeunt action and intrinsic agency united. (Hence Aquinas, in Q. Disp. de Anima, a. 13, c., says that animate agency exceeds inanimate agency as to its mode of doing—intrinsic versus extrinsic—but not as to what is done, since “not every action of the soul transcends inanimate nature,” giving the effects of the vegetative power as examples; see also George, “On the Meaning of ‘Immanent Activity’ According to Aquinas,” 549–50.) In all other cases, intrinsic agency is joined to immanent activity, and extrinsic agency is joined to transeunt activity. This set of distinctions also begins to clarify the hierarchical distinctiveness of living kinds. We look to the presence of nested organization of various capacities which belong by nature to certain substances yet not to others: some things are non-living (e.g., they do not metabolize), others are living but non-sentient, some sentient but non-intelligent, and some are intelligent. (David S. Oderberg, “Restoring the Hierarchy of Being,” in Neo-Aristotelian Metaphysics and the Theology of Nature, 94–124, uses the idea of proper subsets of powers; see also defenses of natural kinds in Austin, “A Biologically Informed Hylomorphism,” and in Essence in the Age of Evolution; and Travis Dumsday, “Is There Still Hope for a Scholastic Ontology of Biological Species?”)

The Importance of Instrumental Causality

The second theme is instrumental causality. Both authors emphasize its importance. However, since these books were published at the same time, Carreño relies upon work of Tabaczek’s prior to Theistic Evolution. Tabaczek makes no mention of Carreño’s first, Spanish edition. The following section, then, puts them into dialogue to show their mutual compatibility.

Tabaczek emphasizes the cosmological context of the set of total causes needed for the eduction of substantial forms from the potency of prime matter, whether in the case of the generation of offspring of the same species or in speciation events (41). One must not focus on the proximate causes of generation or speciation alone, but must recognize “an evolutionary causal matrix,” a multifariously-sourced causal network (“causal polygeny”) up to and including the cosmos itself as the backdrop (48; and see 219–20). Indeed, “the proportionate cause of the emergence of a new species is not a single law or force but a concurrence of many causal influences constitutive for a speciation event or rather a history of an evolutionary transition.” (49) This matrix for the generation of offspring (or speciation events) layers together primary and secondary as well as principal and instrumental causes. God is the primary cause of the essence, coming into being, and existence of the new organism (or a new species). As primary cause of the essence of the new substance, God concurrently causes the progenitor(s) as secondary causes of educing the substantial form of the offspring from the potentiality of primary matter; as principal cause, He also actuates them as instrumental causes of that essence (whether of the same or of a new species). This is a crucial point. He is the primary cause of the progenitor(s) insofar as they are secondary causes of the coming into being of the offspring; He is principal cause of their instrumentality in bringing about the very existence (actus essendi) of the new substance.

Carreño, following Jacques Maritain, agrees with Tabaczek that “the whole cosmos must be activated . . . by a universal divine motion, which makes possible the causal effectiveness of creatures.” (316) Likewise, Carreño agrees that a matrix of secondary causes within the cosmos must be invoked to explain the eduction of substantial forms, whether in the generation of the living or in speciation events (344–45). However, he finds Tabaczek’s “evolutionary causal matrix” insufficiently articulated.

For something to act as a second[ary] cause, it must be capable of generating (under the action of the first cause, of course) an effect proportional to its virtuality; and even when it acts as an instrumental cause, the main cause assumes and elevates the type of efficiency that corresponds to the instrument. (345)

In other words, the appeal to a cosmic-scaled causal matrix is not enough: “The problem here is not one of mere mechanical sufficiency but perfective proportionality.” (345) Thus, a team of men are mechanically sufficient to pull ashore a sailboat when any one of them individually is not; however, a similar strategy of “summation” across a matrix of secondary causes in the cosmos is not available when the question regards the sufficiency needed for the eduction of a form with a higher perfection (e.g., biogenesis or the eduction of the first animal species). One must indicate the point at which instrumentality enters. This need for perfective proportionality, Carreño concludes, “is what led Maritain to conjecture the existence of a superelevating motion that elevates and perfects the generative operation of the living being, and it is also what makes this aspect of Tabaczek’s theory somewhat opaque, not only with respect to evolution but also the origin of organic life.” (346) Carreño disagrees with Tabaczek on where exactly the instrumentality lies, especially in cases of speciation events of more perfect species. In view of Tabaczek’s evolutionary causal matrix, Carreño notes:

If this complex can cause the mentioned effects [transspecific evolutionary change], it is only as an instrumental cause. The main cause has to be perfect enough to account for the effect produced, and, at least of the ones known about, Maritain’s hypothesis still seems the best candidate. Against those who fear a “divine interventionism,” we must insist that the causality proposed by Maritain is inscribed and operating in the very nature of matter, and therefore does not require “special” actions on the part of the Creator. As previously said, God acts in the world, but as God, not as creature. (347)

‍Carreño’s position is that the sufficiently proportionate, total cause of the eduction of a superior form requires an ultimate, eminent agent along with a proximate, virtual one:

The superelevating divine motion acts as a main cause, communicating to the generative act of the corporeal living being a virtuality that allows it to educe—in conjunction with other secondary causes—from matter a substantial form specifically different from that of the progenitor (or progenitors, as the case may be). (553)

This focus upon satisfying the conditions of the principle of proportionate causality can be traced to not only the greater perfection of the educed form but also to the evolution of species as a universal effect. A universal effect requires a universal cause, and one cannot appeal to the cosmos as the ultimate matrix of secondary causes both because they cannot be “summed” to produce something ontologically superior and because at the point of generation the essence as such is only instrumentally caused by the progenitor(s). Nonetheless, this cosmic matrix of causes is a necessary set of secondary agents. As Carreño emphasizes, the total cause must “be perfect enough to account for the effect produced” and this sufficiency is found by including the action of God as the primary and principal agent “operating in the very nature of matter” and thus not in a special or miraculous mode but according to the natures of the secondary and instrumental causes involved.

However, despite Carreño’s criticisms, Tabaczek would agree. In response to an objection that his schema introduces a form of occasionalism by its reliance upon instrumental causality, Tabaczek answers that

the instrumental causation in question—which we can verify both within the methodology of science and the philosophical inquiry concerning causal dependencies in nature—is real and irreducible solely to the sort of divine action that a merely empirical inquiry might mistake for actions of creatures. This type of divine agency seems closest to a direct divine intervention in the natural order of the created world. Yet, it is neither miraculous nor occasionalist, since it is exercised in and through creatures, “giving” something they, in fact, do not themselves have to offer. This shows the depth of the involvement and the nature of the causal activity of God as the primary and principal cause of all things, and it effectively protects my analysis and explanation from falling into the pitfall of deism. (218; see also 52)

Thus, contrary to Carreño’s reading, Tabaczek’s causal matrix is not merely a set of secondary causes to the exclusion of instrumentality. Tabaczek clearly emphasizes that the progenitors are both secondary and instrumental causes (as detailed above). The two causal schemas are in accord on this crucial point.

CONCLUSION

Having reviewed the contributions of both Carreño and Tabaczek at length and noted where they disagree or fail to fully come to terms with their agreement, I would like to conclude by applying to their efforts a moniker of Ed Feser’s in a recent article: their projects are part of the new neo-scholasticism. Or, in other words, their efforts continue the tradition of perennial philosophy within the school of Thomism. The convergence in essentials and disagreement in harder points is an illustration of this. Indeed, it is a welcome development that one can now say that, given the work of Tabaczek and Carreño, there is a substantive Thomistic position on biological evolution.