Thomas Aquinas and Some Neo-Thomists on the Possibility of Miracles and the Laws of Nature

Abstract

This paper discusses how Thomas Aquinas and some Neo-Thomists scholars (Juan José Urráburu, Joseph Hontheim, Édouard Hugon, and Joseph Gredt) analysed the metaphysical possibility of miracles. My main goal is to unpack the metaphysical toolbox that Aquinas uses to solve the basic question about the possibility of miracles and to compare how his late nineteenth- and early twentieth-century followers solved the issue themselves. The key feature to differentiate the two approaches will reside in their use of different notions to account for the possibility of miracles, namely obediential potency for Aquinas and the laws of nature for the Neo-Thomists. To show why neo-Thomist scholars source to this notion, I also briefly discuss how the notion of the laws of nature emerged in the seventeenth century.

1. Introduction

When dealing with the nature and workings of miracles, both Thomas Aquinas as well as his followers discuss a vast number of questions, either from a philosophical or a theological approach. For the former, they would ask whether a miracle is possible at all, what should be the nature of such an event, how this event might come about, how one would be certain that an event is a miracle, and such sort of questions. For the latter, on the contrary, they would inquire into the theological significance of such events and why would they happen at all, that is, what would the ultimate end of a miracle be in relation to the salvation of human beings. This paper will discuss in particular Aquinas’ and some Neo-Thomists’ understandings of the metaphysical possibility. My main goal is to unpack the metaphysical toolbox Aquinas uses to solve the basic question about the possibility of miracles and to compare how his late nineteenth- and early twentieth-century followers solved the issue themselves. The key feature to differentiate the two approaches will reside in their use of different notions to account for the possibility of miracles, namely obediential potency for Aquinas and the laws of nature for the Neo-Thomists.

A plethora of textbooks on Thomist philosophy appeared after Pope Leo XIII’s 1879 encyclical Aeterni Patris, giving a new life to the school of Neo-Thomism. The most important call that Pope Leo uttered in this letter was the renewal of Christian Philosophy by the profound study of the thought of Thomas Aquinas for the profit of the Catholic Church and the whole of society. In particular, the Pontiff encouraged scholars to engage with the natural sciences, which would benefit greatly from their new medieval discussion partner. He wrote: ‘We exhort you… to restore the golden wisdom of St. Thomas, and to spread it far and wide for the defence and beauty of the Catholic faith, for the good of society, and for the advantage of all the sciences’.1 The natural sciences, for the Pope, would profit much from their interaction with the philosophical and theological thought of Thomas Aquinas. A quick survey of the Neo-Thomist works during the final decades of the nineteenth century and early twentieth century present two tightly related traditions, namely a handbook and a research-oriented tradition. The former attempts, mostly, at presenting the whole of Aquinas’ ideas as a system in which different modern science could or not be accommodated, while the latter aims at rethinking Aquinas’ teaching in light of modern scientific teachings. In this paper, I will deal with four authors of the handbook tradition.

If not all, most authors in this philosophical school who wrote Thomist textbooks decidedly engaged with the modern sciences, and the diversity of themes springing from them was copious: from transformism and Darwinism, to the question on the origin of life, scientific atomism and quantum mechanics, the nature of space and time after Einstein’s theory of relativity, the uniqueness of human beings, and, of course, the possibility of miracles and their relation to the philosophical and scientific notion of the laws of nature.

Thomas Aquinas did not have much to say about many of these themes, since they were not present in the philosophical and theological discussions of his time. In particular, as will become apparent below, the notion of the laws of nature, as we understand it today, played a relatively insignificant role in his thought. Early Neo-Thomists, however, writing at the turn of the twentieth century, when modern science enjoyed unprecedented success, assumed the importance of this notion and included it within their Thomistic philosophies of nature, especially in their discussions of the possibility of miracles. This paper will thus explore the ways in which some of these authors incorporated this modern notion into their philosophies and compare this move to Aquinas’ own account.

I will first present my reading on Aquinas’ account of the metaphysical possibility for miracles, giving due attention to his notion of obediential potency, to move into a brief presentation of the historical emergence of the notion of laws of nature, with which we are so used to discuss the possibility of miracles after Hume. I will finally present four key examples of early Neo-Thomists and how they mostly refer to this latter notion in their analysis of the possibility of miracles. I will investigate the works of Juan José Urráburu SJ (1844–1904) and Joseph Hontheim SJ (1858–1929), who influenced much of the works of their later colleagues; I will also present the ideas of Joseph Gredt OSB (1863–1940), who wrote perhaps the most influential handbook on Thomistic philosophy (Vijgen and Elders 2020, p. 14); and Édouard Hugon OP (1867–1929), who is one of the very few who refers to the idea of an obediential potency in creatures when discussing miracles, even if he also discusses the issue under the theme of the laws of nature.

2. Aquinas on Obediential Potency and the Possibility of Miracles

In almost all of his most important works, Thomas Aquinas places his discussion of miracles after his presentation of the doctrine of providence, as a sort of corollary to it, or better, as another way God has at hand to guide creation to the end He intends for it, which is no other than his definition of what providence is. For Aquinas, a miracle is an act of God that goes besides or beyond the natural created causes (praeter causas naturales). This simple and preliminary definition already shows us that Aquinas’ own understanding of miracles is deeply rooted in the intimate and ultimate dependence of creatures upon God.

In his Quaestiones de Potentia Dei,2 Aquinas aims at showing that God can actually do things besides the natural created order, arguing that, if God is the actual creator of all created things, His providence extends to each, and His actions are not ruled by natural necessity but He is free in His actions, then one can hold that God can act independently of the course of nature in producing some new particular effects.

In his Summa Theologiae,3 Aquinas phrases the question in a slightly different manner. Instead of framing the question in terms of God acting beyond the natural causes (praeter causas naturales), he frames it with the notion of order, asking whether God can act beyond the intrinsic natural ‘order’ (praeter ordinem rebus inditum). He answers that as different kinds of orders proceed from different kinds of causes, there are, then, as many orders as kinds of causes. He relates this distinction directly to the one between primary and secondary causes. Given that secondary causes depend upon the primary one, their order depends upon the order that follows from the primary cause. In this sense, the primary cause, God, could not act against the order that follows it, because it would be going against its own nature.4 But, God could act against the order that follows secondary causes, because this order depends upon God as a cause. Therefore, God could establish a new order if He wanted.5 In fact, Aquinas adds in his the de Potentia Dei, that God has not created everything He could, allowing for God to do new things not yet done.6

In addition, Aquinas posits the existence of a created passive potency to be actualised only by the divine active power. This is what he had previously called obediential potency, by which every creature would obey the direct commands of its creator.7 This potency is rooted in the primordial order through which creatures depend upon their creator. Ultimately, given that God has the power to do everything that does not imply a contradiction, and that nothing prevents there being an obediential potency in creatures, God can command this potency to be actualised by His active power without any natural created means.

This obediential potency appears all throughout Aquinas’ works, mostly when discussing miracles or other graces that God imparts on human beings or spiritual substances (like the grace of prophecy, for instance).8 For example, when discussing whether faith can make a man to work miracles in the de Potentia Dei, Aquinas states that “holy men are said to work miracles, not as though they were the chief authors of miracles, but because as divine instruments they announce, as it were, to natural things the divine command which nature obeys when miracles are wrought”.9

So, what is this potency to obey God that is in natural things? In a nutshell, it is nothing more than a metaphysical inclination to receive from, and respond to, God whatever God wants to offer, or to request from, the creature. Ultimately, by being the creator, God owns creation, and so He can give more to creation than what He had given so far. This metaphysical inclination is called ‘obediential potency’. Miracles, then, are rooted in the very metaphysical constitution of creatures, and, as such, are deemed possible both from the perspective of the creator (given God’s infinite power) and from the perspective of the creature (given this inclination inherent to their being a creature). Obediential potency, thus, by opening the possibility for creatures to be transformed by the power of God, accounts for God working beyond (besides, above, or contrary to) the course of the natural causal order.

To elucidate further this metaphysical notion, Aquinas explains that there are two kinds of passive potency in creatures. There is, first, a natural passive potency that corresponds to the natures of created things, which is proportionate to natural agents. This natural passive potency is limited by the nature of finite creatures. The second passive potency is only proportionate to the first cause, namely God, who is the only one that can actualise this potency making a creature to be higher than its own nature. In Aquinas’ own words: “in every creature, there is a double passive potency: one in comparison with a natural agent; the other in comparison with the first agent, which can reduce any creature to a higher act than a natural agent can reduce it, and this is usually called the obediential potency of a creature”.10

Passive potency, for Aquinas, is the potency by which natural things can be acted upon by other things. This two-fold distinction that Aquinas brings to the metaphysical discussion table refers to the two different kinds of causes, namely created causes and the uncreated cause. Obediential potency refers only to the latter and cannot be actualised by the former. In this sense, obediential potency is not a passive potency in reference to the nature or the essence of a creature by being this or that creature, and in this sense is not a natural passive potency (and hence natural causes cannot act upon it). It is a passive potency that exists only in relation to God as the only agent who can reduce it to act: “As there is a natural [passive] potency for natural changes, so there is an obediential potency for miraculous conversions”.11 Now, Aquinas explains in the disputed questions de Veritate that this obediential potency cannot be reduced in its totality, since God’s power is infinite, while natural passive potencies can be fulfilled.12 In a way, thus, this obediential potency is an unlimited passive potency in comparison to God’s unlimited power. So, given that the only agent that can reduce the creature’s obediential potency to act is God, this passive potency is in creatures so that God can perform miracles. Thus, this obediential potency allows God to actualise creatures into any effect capable of being produced by the divine power. In this sense, obediential potency finds its limits only in the power of God and in what God can bring about without inherent contradiction.

Now, this is a passive potency found in every creature, as I said, not due to its own essence of being this or that creature, but by being a creature. That is, by the very fact of being created, every being includes in its own essence this passive obediential potency. This argument helps to see where this potency resides in the metaphysical constitution of beings: clearly it cannot reside in the creature’s esse, for it is a passive potency and esse is the first principle of actuality of things. So, it must reside in the creature’s essence, but, again, not due to being this or that particular kind of creature, but by being a creature simpliciter. Now, since obediential potency is in every creature for the very fact of being a creature, it is the whole creature that is lifted by God’s power when God performs a miracle by receiving in its totality what God wishes: “in the whole creature [in tota creatura] there is a certain obediential potency, by which the whole creature [tota creatura] obeys God in order to receive in itself whatever God wills”.13 Again, this means that the essence or nature of the thing does not limit God’s action in it, but rather, that the creature is always open to God’s bestowing of His infinite power over it, obediently receiving what God wants to share.

3. The Historical Birth of the Laws of Nature

It is a common place in the historiography of the notion of ‘laws of nature’ to affirm that before Descartes, even if its use was widespread across Europe, the phrase vaguely expressed regularities in nature. In this regard, Milton claims: “The evidence available from the sixteenth-century writers shows that the word lex and its cognates were widely (though not particularly frequently) used in connexion with the natural world. It is one thing to recognise this, but quite another to suppose that a well-defined notion of a scientific law was already in existence. Most of the remarks made about laws were extremely vague, and there was not even an approximate consensus as to what kinds of laws there were. Moreover, the laws that were mentioned were given no clearly defined explanatory role” (Milton 2008, p. 683; my emphasis). John Henry agrees with this idea, affirming that early references to the laws of nature “are merely references to the regularity of nature. According to this usage it is one law of nature that the sun rises in the morning, and another that bees make honey. This is not what modern scientists mean by laws of nature… the concept of a law of nature as a specific and precise statement which codifies observed regularities in nature, but which is also assumed to denote an underlying causal connection, and therefore can be said to carry explanatory force” (Henry 2004, p. 79; my emphasis).

For early modern authors, thus, the laws of nature were explanatory, there needed be some consensus as to the kinds of laws there were, and these laws codified the observed regularities in nature expressing causal connections. For instance, Descartes had his three laws of motion, as did Newton a few decades after him. With these features in mind, when confronted to the question about the origin of the modern notion of the laws of nature, Henry has no hesitation in affirming that “the concept of laws of nature played at best a very minor role in natural philosophy before the seventeenth century, and it was a far cry from the kind of concept we see in Descartes, Newton, and subsequent science” (Henry 2004, p. 76), and that “Descartes was effectively responsible for single-handedly introducing the notion of laws of nature into natural philosophy” (Henry 2004, p. 114).

The key to this lack of usage relies in the fact that the medieval philosophy of nature had no need for such a notion, because it relied on the explanatory concept of formal cause. Formal causes explained the ways in which natural things behaved, and so, a notion such as the laws of nature, was unnecessary to explain this behaviour. In a world filled with formal causes, the affirmation that some ‘laws of nature’ ruled the behaviour of things was simply meaningless, and, hence, this notion was not part of the mostly Aristotelian philosophical system.

Consider how Aquinas uses the phrase ‘laws of nature’ when discussing the Eucharist in one of the last things he wrote in his Summa Theologiae (which is, as it happens, one of the very few instances he used the term applied to the behaviour of nature and not of human beings): “every change made according to the laws of nature is a formal change”.14 This statement identifies the ‘laws of nature’ with formal causation. For Aquinas, thus, the notion of the laws of nature, if at all useful, was nothing but a metaphor to refer to formal causality; a metaphor brought from the realm of human behaviour, which is ruled by the natural law, which is the participation of the divine law in the hearts of human beings. In fact, when discussing that it was necessary for human beings to receive a law from God to guide their actions in the Summa Contra Gentiles, Aquinas opposes the behaviour of irrational creatures to that of human beings, explaining that the former are guided through a natural inclination that follows their species, that is, their final cause that follows their formal cause.15 Even when Aquinas brings this notion into the discussion of miracles in the de Potentia Dei, he is quick to make a similar suggestion stating that the law of nature (note the singular in the original) refers to the internal order of creation: “the supreme law of nature which is God’s ordinance with regard to all creatures”,16 a notion far from that of Descartes and the one used by modern scientists.

Now, after the Renaissance and early modern dismissal of the medieval Aristotelian worldview, a new corpuscular conception of nature replaced it, an image that required mechanistic explanations of natural phenomena. This new image implied that there were insensibly small and indivisible portions of matter, with nothing but shape, size, and a changeable degree of motion. The material world was, thus, reducible to and arose because of the arrangements and motions of the underlying atoms. Now, atoms had no powers of their own, since they lacked internal formal causes. These atoms, however, had a regular behaviour, which could be described with precise mathematical formulations. These formulae were, for Descartes, the very laws of nature, laws that were imposed on nature by the most perfect of lawgivers: God. If there were laws of nature, then there was a divine lawgiver in charge of the created order.17

If one considers this historical birth of the notion of laws of nature, one sees that this notion is alien to the thought of medieval thinkers such as Aquinas, and thus, it might seem odd that Thomist thinkers felt compelled to bring it into their own treatises and handbooks. Still, by the early twentieth century, this notion was so engraved in the view of nature, and, not least importantly, had been used to deny the very possibility of miracles by Hume, that Thomist scholars faced the challenge of addressing this issue. After presenting Aquinas’ own metaphysical analysis of the possibility of miracles through the notion of obediential potency in the previous section and the rise of the modern notion of the laws of nature, the rest of the paper will present how some Neo-Thomist scholars from the late nineteenth and early twentieth century incorporated the notion of the laws of nature into their Thomistic systems.

4. Juan José Urráburu

Juan José Urráburu was a Spanish Jesuit priest who wrote mostly during the final decades of the nineteenth century and who was profoundly influential in the works of many twentieth-century Neo-Thomists. Figures like Joseph Gredt and Édouard Hugon, both of whom will be discussed below, reference Urráburu’s ideas throughout their works. In fact, Joseph Louis Perrier, who wrote what would be one of the first histories of neo-Scholasticism in the nineteenth century, defines Urráburu’s work as “one of the greatest treasures neo-Scholastic literature possesses” (Perrier 1909, p. 181). Urráburu wrote a massive eight-volume magnum opus titled Institutiones philosophicae, published in the final decade of the nineteenth century (given the length of this work, he decided to publish a somewhat shorter version titled the Compendium Philosophiae Scholasticae in five volumes (Urráburu 1902–1904)). I will briefly present his ideas on the laws of nature and miracles in the Institutiones.

Urráburu places the discussion about miracles right after his analysis of the laws of nature, in the volume dedicated to the philosophy of nature or cosmology.18 It is rather telling that, even if he acknowledges that this is a theological topic, he does not treat it in the volume devoted to natural theology or theodicy, preferring this location instead (Urráburu 1892, p. 381). The volume is divided into two books and each book into disputations. Urráburu devotes the fourth disputation of the first book to the laws of nature and to miracles together, showing how essentially linked these two themes are in his work.

Urráburu explains that as the rational creature participates in the eternal law of God, which is called natural law, the irrational creatures participate in the eternal law, and that participation is called the law of nature or the physical law (Urráburu 1892, p. 356). Urráburu is quick to emphasise that this law of nature is called ‘law’ by similitude and analogy, since only rational creatures can follow a law properly speaking (Urráburu 1892, p. 358). Therefore, “law of nature is not the constant and uniform operation itself, nor properly the constant and uniform mode of operation, but the sufficient reason of the same, or the internal principle, whence the uniform and constant operation flows” (Urráburu 1892, p. 359), for they are not strictly laws, but only by means of a metaphor. In fact, the law of nature is the internal principle whence the uniform and constant operation flows. The laws of nature, then, are nothing more than some tendency or inclination or necessity impressed by God by which things are determined towards some operation (Urráburu 1892, p. 359). These inclinations, or laws, rule the operations of all material things.

In a move that not many scholars followed in later works, Urráburu asks about the nature of these laws of nature, wondering whether they are to be identified with the forces and properties of natural things or whether they are something distinct from them (Urráburu 1892, p. 362). Given that both the notions of ‘force’ and ‘property’ do not imply the tendency or inclination towards some operation that the notion of ‘law’ implies, they cannot be identified with it. Rather, the laws of nature are like the norms and rules to which forces must be subjected in their operations (Urráburu 1892, p. 363). Instead, the laws of nature are to be identified with those divinely impressed natural inclinations to attain their ends. And these natural inclinations are nothing but the very nature of natural things.

Given that the nature of each natural thing is constant and universal, then the physical laws are constant and universal (Urráburu 1892, p. 365). If the laws of nature were not constant and universal, there would be serious (philosophical and theological) difficulties: (1) it would be impossible to know the nature of things; (2) the condition of human beings on Earth would be miserable; and (3) it would be impossible to experience God’s providence and wisdom (Urráburu 1892, p. 368). As constant and universal, the laws of nature are also said to be necessary, but conditionally necessary (Urráburu 1892, p. 370). There are two kinds of conditions that are required for the laws of nature to rule the operations of natural things with necessity: (1) that condition regarding the primary cause, that is, the divine concurrence in the action of secondary causes; and (2) those conditions regarding the order of other secondary causes (Urráburu 1892, p. 371). Thus, if all the conditions on the part of secondary causes are present as well as the divine concurrence, the natures of things, as far as they are concerned, cannot but act; therefore, the laws of nature will be commanded to be executed, because they are necessary, albeit conditionally necessary.

Urráburu explains that, in this sense, the laws of nature are not absolutely necessary. God could deny his concourse to secondary causes, or even not contribute as much as the secondary causes themselves naturally require. Ultimately, the fact that God denies his concurrence to secondary causes, through which the physical laws rule the constant operations of creatures, involves no contradiction (Urráburu 1892, p. 372). Or God could overwhelm secondary causes with more or a different power in its concurrence, bringing forth a different or more robust operation: “if God, going beyond the secondary causes, should impress another and different power, or should bring forth a concurrence for a different or more robust operation, for example, of a man’s hand to support the enormous weight of a thousand kilograms; what, if anything, would make it inconsistent or contradictory to the essences of things?” (Urráburu 1892, p. 373). Therefore, Urráburu concludes that it is not absolutely impossible for something to happen outside the order of nature, or for the course of nature to suffer some exceptions from time to time (Urráburu 1892, p. 374).

This is, ultimately, the basis for speaking about miracles happening in the created natural order. As with many other Neo-Thomist scholars, Urráburu defines miracles to be sensible events that happen beyond the order of created nature, and which can only be performed by God (Urráburu 1892, p. 382). After a long discourse on whether angels could perform miracles (following Aquinas, Urráburu holds that they could, as could human beings, as long as they participate in God’ power as an instrument in the principal agent’s power) and what are the ends of miracles (Urráburu 1892, pp. 395–413), Urráburu asks whether these events are possible at all. The first reason he acknowledges is an a posteriori reason, namely, the testimony of countless witnesses throughout history. He recognises, however, that he cannot demonstrate these statements, except by a long discussion concerning the sincerity and truth of the Holy Scripture, and the nature of the wonderful deeds which are narrated in them, which theologians are wont to discuss in depth (Urráburu 1892, p. 416). So, he suggests offering some philosophical arguments. Among these, he mentions the fact that, since God is the cause of all being in all things, then God could certainly perform miracles (Urráburu 1892, p. 382). Second, he states that God did not create everything he could have created, so he could bring about things that surpass the nature of created things (Urráburu 1892, p. 418). Finally, God could bring about (1) that an effect expected due to some physical law does not follow; (2) that an effect is produced when it should not have been produced, or that it is produced far longer than natural causes would require; and (3) that the opposite effect than that expected occurs. That is, God could deny or reinforce his concurrence with natural causes, as stated above (Urráburu 1892, pp. 419–22).

5. Joseph Hontheim

Joseph Hontheim was a German Jesuit theologian, who contributed to the volumes of the Philosophiae Lacensis, an eleven-volume work devoted to the whole of philosophy inspired by Thomas Aquinas’ thought, directly inspired by Pope Leo XIII’s Aeterni Patris, and referred to as the “most important contribution of Germany to Scholastic philosophy” in the nineteenth century (Perrier 1909, p. 197). Hontheim wrote the volume on natural theology, while, for instance, Tilman Pesch SJ (1836–1899), wrote the one on natural philosophy. Both Hontheim and Pesch discuss the matter of the possibility of miracles in their respective volumes, and both make explicit reference to the laws of nature in their discussions. I have decided to include Hontheim in my presentation and leave Pesch’s views for another occasion, for, contrary to what many others did, Hontheim did make this move in a volume dedicated to natural theology (as I have stated above, Urráburu, for instance, does not, Hontheim 1893; Pesch 1897).

Hontheim places his treatment of miracles near the end of his volume within the treatise of divine providence, as Aquinas would usually do, after the treatises of creation, conservation, and divine concurrence. He straightforwardly accepts that it is usually the case that when miracles are considered, the discussion surrounds the notion of physical laws, by which he means the laws of nature, and hence he would do so (Hontheim 1893, p. 814). These laws are defined as the constant modes according to which natural things under certain conditions produce certain effects in a certain way (Hontheim 1893, p. 814). He also calls them directive principles, which are impressed upon natural things, by which their operations, whenever the same conditions recur, are produced in constant and uniform ways. As with Urráburu, Hontheim also states that the name ‘law’ is an analogy taken from human natural law, which is imprinted by God in human nature (Hontheim 1893, p. 814). As such, physical laws are also the principles of operations imprinted in natural things by God.

After this brief analysis of what physical laws are, Hontheim quickly moves into the discussion of miracles, which he defines as a sensible work done by God apart from the natural activity of natural things (Hontheim 1893, p. 814). Given this definition, Hontheim excludes a few instances of God’s activity from miracles: the initial creation of the world, eucharistic transubstantiation, the general creation of human souls, and the like, all of which are either not works done apart or besides the usual works of nature or are not sensible divine works (Hontheim 1893, p. 815).

When discussing the possibility of miracles, Hontheim sees only two ways to show that they are not possible: either because of some feature of physical laws or because of something in God, and he will argue that nothing in either case makes miracles impossible. With regards to God’s nature, neither the immutability of his will, nor his wisdom, nor providence prohibit him performing miracles. First, even if God wills the laws of nature to be obeyed, he does not want so always, for he has reserved that he would at some point act otherwise. That is, together with the constancy of the general physical laws, God has predetermined some exceptions from eternity and wills them immutably (Hontheim 1893, p. 817). As for God’s wisdom, Hontheim argues that performing miracles is the most fitting and wisest way to manifest to men the divine perfections and that nature is wholly subject to God (Hontheim 1893, p. 817). Finally, in terms of God’s providence, to the challenge that miracles would challenge the certainty in the natural course of affairs, Hontheim states that this certainty and human providence are not destroyed by the free actions of men, much less by God’s miracles, which, he claims, happen very rarely. That is, as long as miracles happen rarely, then the laws of nature would hold and certainty about them as well (Hontheim 1893, p. 818).

In reference to physical laws, Hontheim also argues that there is nothing to prohibit God performing miracles, and he offers three reasons. First, God could deny his preserving influence on things, create new things, or withdraw his divine concourse with secondary causes. Second, God could transform locations, local movements according to direction and speed, energy, qualities, structure, forms of bodies throughout or through each of their parts in an instant, or through a continuous influx without the cooperation of the created power. Finally, God could introduce certain forms into natural things, which no created power introduces, as in bilocation (Hontheim 1893, p. 816). Ultimately, the root of Hontheim’s argument rests in a comparison between human and divine action in relation to the laws of nature: “if man, by his free intervention, can modify the events of things in various ways, so that they turn out differently than they would otherwise, how much less does the necessity of physical laws hinder God’s intervention” (Hontheim 1893, p. 816).

6. Édouard Hugon

Hugon’s placement of his discussion on miracles is intrinsically linked to that of the laws of nature, and as such, is placed right after it, in the second volume of his Cursus Philosophiae Thomisticae (Hugon 1905), devoted to philosophy of nature (and as with Urráburu, Hugon does not discuss miracles in depth elsewhere either in this work or in his volumes on dogmatic theology, in which one would expect to have a treatment of miracles within the doctrine of providence) (see Hugon 1935, 1927). This volume is divided into treatises according to the four Aristotelian causes, and Hugon places this discussion in the treatise on the final cause of the universe, which has three questions: the first one on nature, the second on how nature is ruled, and the third on the proper final cause of nature (in which Hugon includes his views on evolutionism). The second question is devoted first to the laws of nature and second to miracles.

Hugon explains that the laws of nature, or laws of physics as he calls them, are the principles by which natural causes are directed to act consistently and uniformly (Hugon 1935, p. 279). The laws of physics express the order of nature, which is defined as the suitable arrangement of natural things for the attainment of an end, whether particular to each, or common to all (Hugon 1935, p. 278). Thus, both the laws and the order, can be universal, if they refer to the whole of material creation, or particular, if they refer to parts of it (Hugon 1935, pp. 278–79). Additionally, there is a most universal order which is the order of divine providence (Hugon 1935, p. 280). In terms of the kinds of laws, Hugon mentions cosmic, astronomical, physiological, and chemical laws as some examples of them (Hugon 1935, p. 281). These laws imply a kind of hypothetical necessity, but are formally contingent, because they exist in contingent created things (Hugon 1935, pp. 279–281).

Since physical laws are contingent, they do not exclude exceptions to them. Hugon offers three arguments for holding this position. He explains that these laws concern either the natural operations of things, or their properties, or their very essences. In each of these cases, exceptions might occur. The natural operations of things depend on the operation of the primary cause, God, who could withdraw his concurrence, and so the operation of the created cause could cease and not follow the laws of physics. Additionally, God, the creator, could produce the effects of nature without the operation of nature. In the case of the properties of things, as effects of their essences, and thus could be separated from them. In this case, the essence would remain the same. So, it is possible that there are exceptions to the laws of nature also in this case. Finally, essences, when considered physically and concretely (in contrast to metaphysically), could be changed, as in when something is changed into another thing by substantial change. It could be possible for God, then, to change one thing into another, sourcing the obediential potency in things (Hugon 1935, p. 280).

These exceptions to the laws of nature are what Hugon understands miracles to be: “the derogation introduced in the physical laws, that is, miracles…” (Hugon 1935, p. 282). In particular, Hugon explains that a miracle is an unusual event that is apart from the universal order of nature (though not the most universal), thus apart from the laws of physics, and the cause of which is hidden in principle to any created understanding. That is, the cause of miracles is no other than God (Hugon 1935, p. 283). To prove this statement, Hugon explains that since no creature can cause events outside the universal order of nature, which is the definition of a miracles, then only the Creator can be truly called the cause of miracles (Hugon 1935, p. 287).

When discussing the actual metaphysical possibility of miracles, Hugon considers three different reasons for it: first, the obediential power of the creature, or the capacity which the creature has so that it can be raised to all the effects which the Agent first wishes to induce in it; second, the laws of nature, which are derogated by a miracle; and third, the author of miracles, namely God. As for the first one, following Aquinas, Hugon explains that miracles are not inconsistent with the obediential potency: given that creatures are totally subject to God, their obediential potency extends to those things that God absolutely can produce, that is, to things that involve no contradiction (Hugon 1935, p. 292). As for the second, following those ideas explained above, Hugon holds that given that the laws of nature are contingent, then, absolutely speaking, they can be suspended and changed. In fact, miracles do not properly eliminate or change the laws of physics, but only suspend the particular effect of a certain law in a particular place and time. Hence a miracle is only the suspension of a particular effect or a particular exception to the laws of nature (Hugon 1935, p. 292).

In terms of the author of miracles, Hugon explains that there are four reasons according to which miracles are possible: God’s power, goodness, immutability, and wisdom. With regards to power, Hugon reminds the reader that, since God is the most universal cause, exceeding every power in nature, the divine power alone can bring about whatever nature can produce. Moreover, the divine power can cause things that nature is totally incapable of causing. In terms of God’s goodness, Hugon claims that even if the created order represents God’s goodness, it does not do so to the extent of God’s infinite goodness, meaning that God’s infinite goodness can be represented in other ways, one of which is miracles, through which God’s goodness shines. As per immutability, Hugon explains that by performing a miracle, God does not change his decrees, but fulfils in time what he had decided from eternity. Finally, regarding divine wisdom, Hugon states that in performing miracles, God does not act like an imperfect artisan who needs to correct the deficiency of his work; but that, since the order given to things does not correspond to the divine wisdom completely, the divine wisdom is not limited to this order, and therefore can operate apart from it (Hugon 1935, pp. 292–93).

7. Joseph Gredt

The case of Joseph Gredt is interesting in that he changed his text rather vigorously from the first edition into the subsequent editions of his classic Elementa Philosophiae Aristotelico-Thomisticae. In every edition, however, the discussion about the possibility of miracles is always linked to the notion of the laws of nature. In fact, it is always because of the discussion about the laws of nature that Gredt analyses miracles. There is, however, an important change of placement of this discussion. In the first edition (Gredt 1899), Gredt places the analysis of the laws of nature and of miracles within the philosophy of nature, right after his discussions on more traditionally Aristotelian notions such as motion and time, and just before his discussion of the problems of the origin of the world (through Laplace’s nebular hypothesis) and the origin of different living species (through Darwin’s theory of evolution and other transformist proposals). Within that context, by the end of the nineteenth century, Gredt introduces his discussion of the laws of nature and links it directly to that of miracles (I will discuss the details below, as these do not change drastically throughout editions). Now, at least from the seventh edition from 1937 (the last one published while Gredt was alive), Gredt places this discussion within the metaphysics, in the section of the operative divine attributes, within the discussion on providence (in fact, it identifies with it), right after creation and conservation, and before the problem of evil (Gredt 1937, pp. 275–81). This movement might be evidence of the difficulty that neo-Thomist scholars found in discussing such an alien notion to the thought of Thomas Aquinas.

For Gredt, law and providence are the ordering of things to an end, the law being the order according to which the creature must act, of necessity if it is not a creature endowed with free will (which is my focus in this paper, Gredt 1937, p. 275). Providence is, for Gredt, the guiding of things according to that law (Gredt 1937, p. 275). Following Aquinas on natural law (i.e., on the law guiding creatures endowed with free will), Gredt defines a law as a certain rule and measure of action and distinguishes this natural (moral) law and the law of nature, which he calls ‘physical law’. As such, Gredt defines the law of nature as a natural inclination, imprinted on the creature by God to act in a determined way according to the eternal law. This law of nature enables the creature itself to act according to the eternal law (Gredt 1937, p. 275). Gredt divides physical laws into two types: (1) the laws that emanate from the very essences of things (in which he includes gravity and chemical affinity); and (2) laws that result from a determined but contingent arrangement of bodies, to which belong the laws that govern the motions of the heavenly bodies. This second group assumes the existence of the first (Gredt 1937, p. 275).

After a rather short presentation of the notion of providence, Gredt moves to the consideration of miracles, which, strictly speaking, are events that surpass the order of all created nature, i.e., the physical laws, and which are effectuated by God (Gredt 1937, p. 276). Thus, Gredt mentions “the resurrection of the dead and the interpenetration of bodies” as examples (Gredt 1937, p. 276). In addition, less strictly, an event that does not surpass the order of the whole of created nature can also be considered a miracle. In this sense, Gredt mentions the parting of the Red Sea: “the stagnation of the waters could have happened by the efficient causality of God…, without anything being done against the laws of nature“ (Gredt 1937, p. 277). In both senses, miracles are the extraordinary means of divine providence (Gredt 1937, p. 277).

The very possibility of a miracle depends, in Gredt’s account, solely on the absolute dominion of God over all created things (Gredt 1937, p. 277). Since God is extraordinarily capable of doing something above and beyond nature, God could do something above and beyond nature, and thus proceed miraculously. This account means that the very laws of nature depend for their working on divine concurrence to hold them. A miracle happens when divine concurrence is absent and the action that is required given the physical law does not follow (Gredt 1937, p. 277).

8. An Internal Development within Thomism

Pope Leo XIII’s impulse to Thomistic philosophy and theology around the world in the final decades of the nineteenth century favoured the springing of a vast number of textbooks offering different systematisations of Thomas Aquinas’ thought. This paper presented a quick survey of but a few Neo-Thomist scholars writing at the turn of the twentieth century on the metaphysical possibility of miracles. Probably following Pope Leo XIII’s advice, they attempted to engage with the modern world and in particular with the natural sciences of the turn of the century.

My main contention in this paper is that there is a clear trend among neo-Thomist scholars to move away from Thomas Aquinas’ own terminology and conceptual metaphysical analysis of the possibility of miracles. As I have shown above, Thomas Aquinas made little to no use of the notion of the laws of nature when discussing the metaphysical possibility of miracles. This notion, after all, played an insignificant role in his Aristotelian philosophical framework, only gaining prominence, momentum, and philosophical importance after the seventeenth century, as I have also shown above. On the contrary, Thomas Aquinas devoted his arguments throughout his main works to showing how the notion of obediential potency was a key metaphysical tool to unwrapping the problems of explaining the possibility of miracles at all. The terminology of the laws of nature served him as a simple metaphor to refer to internal formal causality when discussing the natural world, while the notion of obediential potency referred to the ultimate relation of utmost dependence that creation has to God, for the very fact of being created. What is more, the very placement of Aquinas’ discussion of the metaphysical possibility of miracles expresses this dependence. He always examines this possibility after his presentations of the doctrines of creation and providence, showing the metaphysical connection between these doctrines, again, for the fact that creation intrinsically depends upon God in all its being and actions.

The authors I presented in this paper can be compared to Aquinas’ own strategy in various ways, the first being the place in which they discuss miracles. Both Juan José Urráburu and Édouard Hugon prefer to locate this discussion within their treatises on natural philosophy, disregarding the topic completely in their volumes on natural theology or theodicy (with Urráburu being explicit about it!). In contrast, Joseph Hontheim and Joseph Gredt place the consideration of the metaphysical possibility of miracles within their discussions of providence, in the treatises of natural theology or theodicy. In a way, these latter authors are closer to Aquinas in spirit, in the sense that they understood that the very possibility of miracles depends upon the understanding one has of the doctrines of creation and providence. In the case of Hontheim, one may present some qualifications to this statement: he was asked to write a volume on natural theology for the series Philosophiae Lacensis, and even if he was aware of the other volumes, such as Tilmann Pesch’s on natural philosophy, he still decided to include this discussion here. Pesch, writing in the same series, decidedly included the discussion on miracles in his volume and, as I mentioned above, also referred to the notion of the laws of nature as the key to solving the conundrum.

Still, even if placing their discussion on miracles in different sections of their works—either in the treatises on philosophy of nature or in the ones devoted to natural theology—all of them frame the question of the possibility of miracles around the modern notion of the laws of nature. Urráburu and Hontheim are more explicit in reinterpreting this notion as an analogy or metaphor following Aquinas, although this idea is also present in the writings of Gredt and Hugon, who might be said to follow Aquinas more closely in the fact that he includes a short reference to the obediential potency of creatures in relation to God’s power and will.

Perhaps the most striking similarity of all of these presentations is that they all consider the laws of nature to have a conditional or hypothetical necessity. This conditional necessity, which is seen as the central notion to solve the issue of miracles, is explained in terms of the natural conditions surrounding an event, but also in terms of the divine concurrence to every action in nature as primary cause. They all agree in affirming that a miracle occurs when God withdraws (or reinforces) this divine concurrence in the action of secondary causes. This is the ultimate mechanism for God to perform a miracle. The argument, put in simple terms, affirms that since the laws of nature work under the condition of God’s concurrent causation with secondary causes, were God to change this causation, the laws of nature would be momentarily suspended.

It might be argued that I handpicked some individual authors that fit my hypothesis, namely, that neo-Thomist authors tend to discuss the possibility of miracles within the framework of the modern notion of the laws of nature. However, if one were to look at the work of the great neo-Thomist Réginald Garrigou-Lagrange OP (1877–1964), or even the later lesser-known scholars like Karl Frank SJ or J.M. Aubert, one would find similar strategies. Garrigou-Lagrange structures his analysis of the possibility of miracles referring to the hypothetical (i.e., conditional) necessity that the laws of nature have and only refers to the obediential potency of creatures when discussing the supernatural end of human beings and the possibility of a divine revelation.19 German Jesuit Karl Frank, in a more extensive study, places the discussion of the possibility of miracles right after the analysis of the laws of nature within his treatise of natural philosophy, concluding that given the contingent necessity of the laws of nature, God could perform miracles by withdrawing his concurrence (Frank 1926). Finally, French philosopher J.M. Aubert, in a similar though shorter discussion, treats the theme of the possibility of miracles in his volume on natural philosophy right after discussing the notion of the laws of nature (Aubert 1965, pp. 291–96). Neither Frank nor Aubert refer to the obediential potency of creatures to explain this possibility. In fact, many other neo-Thomists engage similarly in this discussion, referring the problem of the possibility of miracles to the notion of the laws of nature, including Michaele di Maria SJ (Di Maria 1913), Albert Farges (1921), Stanislas-Alfred Lortie (1917), and R.P. Phillips (1964), among many others.

9. Conclusions

This paper presented an exploration of Thomas Aquinas’ reliance on obediential potency to discuss the metaphysical possibility of miracles and the subsequent incorporation of the notion of the laws of nature by late nineteenth- and early twentieth-century Neo-Thomists to this discussion. In doing so, it provides some valuable insights into the evolving philosophical and theological discussions surrounding miracles understood within the Thomist school. Aquinas’ metaphysical approach was rooted in the creature’s inherent inclination to obey God. The historical emergence of the laws of nature, predominantly introduced during early modernity and adopted by later thinkers, brought forth new opportunities for engagement with the modern world for Neo-Thomists.

The scholars presented in this paper attempted at reconciling the modern discourse on creation being ruled by certain laws of nature with the idea of God intervening in that creation through miraculous actions. These perspectives showcase an intellectual journey marked by the assimilation of new concepts into a rich philosophical tradition, all in pursuit of comprehending the metaphysical underpinnings of miracles. In this sense, I do not want to claim that these authors denied their Thomistic heritage. In fact, they very well follow Aquinas in much of their work and only move from his teachings in order to engage with their contemporary philosophical issues and jargon. Thus, even if in their attempts at creating a conversation with the modern world much of the Neo-Thomist school neglected some valuable metaphysical tools at work in the thought of Aquinas, one can argue that they were still following Aquinas’ example in adopting the philosophical problems of their own time. Just like Aquinas embraced the Aristotelian tradition and attempted a fruitful dialogue with Christian theology, neo-Thomist scholars engage with the natural sciences and their problems for philosophy and theology.