Contemporary Theologies of Science in the Light of Bonaventure’s De Reductione Artium ad Theologiam

Abstract

For some time now, regardless of the still-common paradigm of Barbour’s practice of science–religion relations, proposals have been emerging to develop a theology of science from a Christian perspective. This article begins by discussing three theologies of science as proposed by Michael (Michał) Heller, Christopher B. Kaiser, and Tom McLeish. It then goes on to present the theological vision of the arts and sciences as contained in the work De reductione artium ad theologiam by Bonaventure of Bagnoregio (c. 1221–1274). The aim of this article is to compare the contemporary variants for a theology of science with each other and then compare them with Bonaventure’s theological project. Thus, we analyze this 13th-century thinker’s concepts and their heuristic relevance to the modern theologies of science.

1. Introduction

In recent decades, analyses of the interaction between science and religion/theology have been dominated by a paradigm based on the work of Ian G. Barbour.1 In the most recent decade, however, a number of studies have emerged that suggest a need to revise this paradigm. A recent exchange between Josh A. Reeves and Peter Harrison focused on the alleged ineffectiveness of this paradigm. The not very revealing term “after science and religion” was even used as a successor to the Barbour project, suggesting a need to initiate a new phase of research on the relationship between science and religion (Reeves 2023; Harrison 2023). In some studies in a similar vein, one can find proposals to develop a new field of research called “theology of science”. The work of Tom C. B. McLeish (2014, 2019) also emphasizes the need to go “beyond Barbour”, and this work exemplifies this approach. A similar suggestion about constructing a “theology of science” was also recently put forward by Mark Harris. In his view, this would be a new “sub-discipline within science and religion” (Harris 2024a, p. 13) while also being an “alternative (or complementary)” approach to the new research project called “science-engaged theology” that has been initiated in recent years (Harris 2024b, p. 7).2

The main objective of this article is to compare some selected contemporary projects for the theology of science with the profoundly theological reflection on human cognition and the various types of knowledge as described by the medieval scholar, mystic, and Christian personality of his time, Bonaventure of Bagnoregio (Giovanni Fidanza, ca. 1221–1274) in his short work De reductione artium ad theologiam. While seemingly far removed from the realities of contemporary theological discussion, the choice of this author and his work was determined firstly by the growing interest in recent years in Bonaventure’s literary legacy, especially from the perspective of the contemporary debate within science and religious studies (cf. Hołda 2023; Boulding 2024; Mantini 2024). Secondly, the aim was to see whether Bonaventure’s views on the relationship between secular knowledge and theological knowledge, the latter being based on Christian revelation, can serve as a useful inspiration for current attempts to develop a theology of science. In other words, we wish to see if classical theological intuitions that were expressed in the Middle Ages can be adapted and used when analyzing contemporary concepts using science as a locus theologicus.

This paper is divided over three parts: The first part comprises a brief discussion of some selected contemporary proposals for constructing a theology of science as a new field of inquiry, one that is more or less related to traditional questions in science and religious studies. These include the projects of Michael Heller (1982, 1996a, 1996b), Christopher B. Kaiser (1996, 2007), and the aforementioned Tom McLeish (2014, 2019). The choice of these projects is not based on any particular criteria, mainly due to a lack of previous work comparing the existing theologies of science. Nevertheless, we are aware that other proposals of this kind exist (cf. Dubarle 1967; Lococo 2002; Tyson 2022). It is worth noting that Kaiser’s and Heller’s proposals arose in the 1990s, before the current “beyond Barbour” revolt.3

The second part of this paper then presents the theological vision of the meaning of human knowledge, especially concerning nature and technology (or in medieval terms, natural philosophy and mechanical arts), from the theological perspective outlined by Bonaventure in De reductione artium ad theologiam. In the third part of this article, the projects for a theology of science presented by Kaiser, Heller, and McLeish are compared with each other and then contrasted with Bonaventure’s theological vision of cognition and knowledge. This article concludes by illustrating the common features of today’s conceptions for a theology of science and pointing out the inspiring aspects of Bonaventure’s approach. Indeed, science as a locus theologicus is an idea that has long been embedded in the tradition of Christian theology, a tradition that for various reasons has been obscured by competing proposals.

2. The Various Contemporary Theologies of Science

Science’s social relevance has increased, and it has been a subject of great interest to theologians of various religions. More often than not, theologians have turned their attention to specific scientific theories and analyzed their implications for certain elements of a religion’s doctrine. These include cosmological theories and theories of evolution in relation to the Christian or Jewish doctrine for the creation of the world and humanity. It is something of a mystery as to why science itself, the conditions of its existence, its knowledge of the world, and the values it actualizes have so far been of relatively little interest to theologians, despite all these aspects being suitable for consideration as part of religious doctrine. Nevertheless, in the last 30 years or so, several projects for a theological reflection on science from a Christian perspective have emerged that address, to some extent, the issues mentioned above. Among these are the proposals of Michael Heller, Christopher B. Kaiser, and Tom McLeish.

2.1. Heller: The Value and Rationality of Science as Theological Topics

The earliest concept considered here originated within Catholic thought in the early 1980s. Polish cosmologist, physicist, philosopher, and theologian Michael Heller (1982), who later won the Templeton Prize, proposed a theology of science in an article. The concept was developed within the context of discussions held at the Second Interdisciplinary Seminar in Castel Gandolfo, which was organized by Polish scholars for pope John Paul II (cf. Życiński 1984). The article, however, did not initially arouse wider interest. Indeed, despite Heller’s subsequent publications (Heller 1996a, 1996b) on the theology of science, it has only been in the last fifteen years that there has been strong interest in this project, and not just among Polish philosophers and theologians concerned with the interaction between the natural sciences and religion (cf. Macek 2010, 2011; Mączka and Urbańczyk 2015; Sierotowicz 2023, 2024; Polak and Rodzeń 2023; Marcacci and Oleksowicz 2023).

Heller built his theology of science not just as a scientist and theologian but also as a philosopher of science. For him, the world is the keystone that connects the mathematical and natural sciences with Christian theology. The world is both the object of scientific investigation and a creation of God, so “the theology of science would explore the consequences of the fact that the empirical sciences investigate the universe created by God” (Heller 1996a, p. 42). In this context, the role of the philosophy of science (i.e., a philosophical reflection on the scientific method) is to analyze the limits of the applicability of the methods of the physical sciences (above all: cosmology, physics, chemistry, and the Earth sciences). It therefore becomes crucial that “[a] theology pushes on beyond those boundaries. The awareness that the world has been created by God permits the theology of science to glimpse aspects and dimensions of the world which cannot be reached by modern empirical investigations” (Heller 1996b, p. 98).

Using the tools of modern philosophy of science, Heller points to certain properties and presuppositions of the mathematical–empirical sciences that are unattainable using their methods. These properties and presuppositions of science can be considered on three levels that are borrowed not from philosophy but rather from the perspective of theological reflection under the new names of theological ontology (of science), theological epistemology, and theological axiology, respectively (Polak and Rodzeń 2023, p. 170). One of the most important issues considered by Heller at the level of theological ontology is the basis of the existence of science4 and by implications the mathematical and empirical methods. The most important of these foundations is the rationality of the world, which means it can be studied within the framework of the sciences: “From a theological perspective, the rationality of the world is the mark of creation. And creation bears the mark of the Creator’s rationality” (Heller 2015, p. 21). Heller here introduces the notion of a rational Creator, which relates to Einstein’s idea of the “mind of God”. This rational Creator is therefore to some extent discernible in the created world through the sciences.5

Concerning the possibility of studying the world through science while simultaneously treating the world as God’s creation, Heller (2015, p. 18) considers the theology of creation to be “the center of interest in the theology of science”. However, the theology of creation must take into account the current image of the world, and this contemporary image is primarily created by science (Heller 2019, pp. 12, 67). A characteristic feature of the modern scientific image of the world is its evolutionary dynamics on a global scale (i.e., the evolution of the cosmos) and on a local scale (e.g., the evolution of biological species). This image has at least three “hot spots” where science meets Christian theological doctrine: the origin of the universe, the origin of life, and the emergence of human consciousness. According to Heller, another useful element for a theology of science (i.e., a theology of creation) is the “reinterpretation of certain religious truths” (Heller 2019, pp. 15, 69–76), such as the creation of the world and of human beings. These issues can be categorized as theological epistemology while also being the theological ontology of science.

Another level of theology of science is theological axiology. According to Heller, embracing the idea of “the mind of God” being reflected in the created world means that scientific discovery is to some extent not limited to a purely ontological or cognitive dimension. God’s purpose in creation also touches on questions of values, and not only “the Universe is impregnated with values” (Heller 1996a, p. 43), because science itself is a value. Cognitive and ethical values are of no interest to the physical sciences. Indeed, such values are invisible to the methods of the sciences. Nevertheless, there are questions about the value of science, as well as values within the methods of science (i.e., so-called epistemic values) and the value of scientific work, and these can be relevant to a theology of science based on revelation (cf. Heller 2019, pp. 94–103).

2.2. Kaiser: From Theological Beliefs in Science to Science as a “Sacred Reminder”

In America, the idea of a “theology of scientific endeavor” has been developed since the 1990s, starting with Christopher B. Kaiser, a physicist, theologian, and member of the American Reformed Church. The concept of a “theology of science” was first proposed and developed in an article by Kaiser (1996), followed by an extensive elaboration in a book (Kaiser 2007). More recently, Kaiser has published an original work that can be viewed either independently of the earlier concept of a theology of science or as a further, highly sophisticated contribution to it. This latter work does not explicitly refer to a “theology of scientific endeavor”, but it seems to present its concrete expression of the treatment of science as a kind of “sacred reminder” (Kaiser 2024).

In the first mentioned work, Kaiser (1996) stated that he is not interested in theories or scientific results in his project but rather in the research practice of scientists. What he wanted to address were certain beliefs upon which scientific practice is based, beliefs through which it operates but does not itself prove. Kaiser therefore considered these beliefs to be of a theological nature “in the work at the frontiers of science” (Kaiser 1996, p. 231). He listed three such beliefs: a belief in the accessibility of the structures of nature, a belief in the existence of the laws of nature, and a belief in the essential unity of the world. In Kaiser’s own words, “these beliefs are inherently theological” and “constitute the theology of science” (Kaiser 1996, p. 233). He also mentioned certain dimensions of the theology of science, namely, the operability of the beliefs in scientific practice and their exemplarity in various religious traditions, not just Christianity. With regard to Judeo–Christian theology and the associated “creationist tradition”, Kaiser lists four themes that link it to the beliefs presented above.6 With comprehensibility (i.e., accessibility), he links the theme of the world, as an expression of God’s wisdom and image, with the autonomy (laws) of natural processes. This in turn links to the theme of God as cosmic Lawgiver, the unity of nature, the non-dualistic character of God’s creation, and finally the possibility of healing or curing human beings through the theme of God the Healer (Kaiser 1996, p. 234).

Although Kaiser (2007) returned to the earlier question of the beliefs on which he claims scientific practice is based, his attention also focused on the new “foundations-preconditions” of the scientific enterprise (Kaiser 2007, pp. 9–13). These are the societal, cultural, anthropological, and cosmic (natural) conditions. Kaiser based his analysis of these conditions on the concept of a “thick description of science”, using the idea of “thick description” borrowed from cultural anthropologist Clifford Geertz. Like in his earlier work, Kaiser sought to link the cosmic condition to the idea of the lawfulness of the universe and the biblical idea of God as a lawgiving Creator, as well as the anthropological condition of God as an “animating governor and governing spirit” (Kaiser 2007, p. 115). The latter two conditions of science, societal and cultural, required him to provide a broader and more complex theological interpretation of various aspects of ancient and modern social life, especially the contemporary society–science–technology triad. Kaiser’s goal was “to explore the theological dimensions embedded in these conditions” (Kaiser 2007, p. 1). The result was the first book-length monograph devoted to a developed variant of the theology of science.

In his latest work, which does not refer to his earlier “theology of scientific endeavor” project, Kaiser provided a theological interpretation of a certain feature of scientific discourse, one that is elusive within science itself, called the “sacred reminder”. Referring to this term, which he borrowed from Donald Walhout, Kaiser posited that “the thoughts of physicists about their own endeavors can serve as a ‘sacred reminder’ for Christians of aspects of biblical theology that are not normally engaged with the empirical world” (Kaiser 2024, p. 367). Kaiser found such a “sacred reminder” in the statements of two prominent scientists, namely, Stephen Hawking and John A. Wheeler. They concerned not only the mystery of the lawfulness of nature that had been expressed by physicists with mathematical equations but also what makes these equations “come alive” (Wheeler) or “experience ignition” (Hawking) in the real world (Kaiser 2024, p. 369).7 According to Kaiser, the mathematical equations describing the world are a “sacred reminder” of the idea of the mind of God—which was used by Hawking, among others—and correspond to the Logos/Word of God. The enlivening actualization of these equations in the real world in turn corresponds to the action of the Holy Spirit. To support these claims, Kaiser developed elements of Trinitarian theology with extensive reference to Christian biblical and patristic traditions.

2.3. McLeish: Science as “An Intensely Theological Activity”

Another recent example is the project of a theology of science proposed by the late physicist and Anglican preacher Tom McLeish (1962–2023). Wanting to go “beyond Barbour”, McLeish emphasized the usually overlooked detail of linking science and religion with the conjunction “and”. In his view, the phrase “religion and science” raises doubts about whether religion and science belong to the same category and the possibility of distinguishing common “‘domains’ of discussion” (McLeish 2019, p. 33). In lieu of these potential complications, McLeish suggested combining “theology” and “science” with the preposition of and exploring a more compelling and practical theology of science.

On the way to developing such a theology of science, McLeish first gives the example of analyzing the debate over a critical assessment of the possible risks of the applications of an exemplary technology, namely, nanotechnology, in terms of the “underlying narrative” in this debate, and especially in terms of our relationship with nature. In his view, “science itself has no such source to draw on—there is a narrative vacuum where the story of science in human relationship with nature needs to be told” (McLeish 2019, p. 35, author’s italics; cf. also McLeish 2014, pp. 249–55). In place of such a narrative, the debate includes references to elements of ancient myths like “Pandora’s box” or the quasi-sacred view of nature. In place of this narrative void, McLeish proposes introducing elements of the biblical wisdom tradition, particularly those drawn from selected chapters of the Book of Job (Job 38:4, 22, 31). The “Hymn to wisdom” found there makes “an extraordinary claim: that wisdom is to be found in participating with a deep understanding of the world, its structure and dynamics”. The message of the Book of Job is a potential source of the “missing narrative” about nature: “It is rooted in creation and covenant rather than pagan or atheistic tradition […]; it points away from stagnation to a future of greater knowledge, understanding, and healing” (McLeish 2019, p. 38).

To strengthen the theological basis of his own conception of the theology of science, McLeish refers to the views of the medieval scholar Robert Grosseteste (1175–1253). Whether one studies Grosseteste’s translations of the works of the Church Fathers or his commentaries on the works of Aristotle, McLeish argues that there are two basic themes running through them regarding nature. The first is the theme of the natural world, which is the creation of God that has been learned by humanity through various sciences. The second theme concerns the sinful fall of humanity and the impossibility of fully knowing or even understanding the world without the assistance of God, especially through the redemptive presence of Jesus: “Furthermore, the reason that this is possible is because this relationship with the created world is also the nexus at which human seeking is met by divine illumination” (McLeish 2019, p. 40; cf. also McLeish 2014, pp. 42–47). Grosseteste’s introduction of metaphysics, or rather a “theology of light”, was in McLeish’s view a means of substantially supplementing the cognitive capacities of the senses as framed by the epistemological perspective of Aristotle, whose natural philosophy gradually came to dominate the medieval worldview.8

With regard to Grosseteste’s theological vision of science, McLeish uses the term “teleology of science” (McLeish 2014, p. 41) rather than “theology of science”. By referring to the Apostle Paul’s phrase “ministry of reconciliation” (2 Cor. 5:17–19), he again wants to emphasize the purposeful nature of man’s intellectual adventure, which is also a journey of reconciliation toward salvation, as well as the practical, ministerial nature of the theology of science. For McLeish, the character of a “ministry of reconciliation” is also possessed by science itself, one of whose functions is to reconcile humanity with the natural world: “Science is the participative, relational and co-creative work within the Kingdom of God of healing the fallen relationship of humans with nature. […] Science turns out to be an intensely theological activity” (McLeish 2019, pp. 42–43).

3. “Theologia Artium” in De Reductione

The work De reductione artium ad theologiam, though small in volume, is not a frequent subject of interest even among scholars of Bonaventure’s life and writings. Nevertheless, especially in recent years, it has provoked considerable debate among a small group of historians, philosophers, and theologians, even on such fundamental issues as the more precise date of its composition or the form and purpose that guided its author (Benson 2011), and even on the question of authorship itself (cf. Hattrup 1997; Benson 2009).9 Nor is the theological interpretation of Bonaventure’s “secular arts” in the perspective of thirteenth-century discussions of the status of knowledge by any means closed (cf. Smith 2021, pp. 251–88). In this section, we will not go into the intricacies of these undoubtedly important questions. Instead, we are primarily interested in the image of the titular arts that Bonaventure presents in his De reductione from the perspective of the theology he preaches.10

3.1. Bonaventure’s Theology of Creation, Knowing, and Reduction

In order to better understand the idea of reductio, which is central to Bonaventure’s work discussed here, we need at least to give a brief introduction to the image he adopted of the creation of the world, its structure, and the possibility of its knowledge by man. The creation of the world was understood by Bonaventure in terms of the so-called metaphysics of light, which has a Neoplatonic origin, having been developed by Augustine of Hippo and renewed in the 13th century by the aforementioned Robert Grosseteste and other Oxford Franciscans. An important theological framework for the image of the Creator God is provided at the beginning of De reductione through a quotation from the Letter of the Apostle James: “Every good gift and every perfect gift is from above, coming down from the God of Lights” (James 1:17; Red. art. 1; cited after Bonaventure 1996, p. 37). God is presented in this passage as the “fontal source of light” from which all creation emanates, and light is the form of God’s creative presence in all kinds of bodies. Light has not only a creational–ontological status but also a cognitive function in relation to rational beings. What is important here is the identification of primordial light with God, who is also truth (Hayes 1996, p. 6). God is not only the creator of the world but also the only guarantor of its full (and certain) knowledge and understanding.11 It is from this perspective that the idea of divine illuminatio emerges.

The question of human knowledge, and more generally the human spiritual journey in search of truth, can be well served by beginning with a synthesizing quote from another of Bonaventure’s works, Collationes in Hexaëmeron: “This is the metaphysical center leading [us] back (reducens), and this is the whole of our metaphysics: emanation, exemplarity, and consummation, that is, to be illumined (illuminari) by spiritual rays of light and to be led back (reduci) to the Most High (summum)” (Hex. 1, 17; cit. after Bonaventure 2018, p. 102). Bonaventure then goes on to say that a person who does not know how things come into being, how they are lead back (reducuntur) to the end, and how God shines in them, will not arrive at true understanding (cf. Hex. 3, 2; Bonaventure 2018, p. 137).

The spiritual (life) journey of man that was outlined by Bonaventure, which leads from the beginning of his/her existence, through a special cognitive effort in her/his life, to the final consummation and return to the Creator, forms a kind of circle (cf. Bowman 1975, p. 181). Between the beginning and the end of this journey, in the light of the Christian faith, which constitutes the final loving union with God, Bonaventure introduces the concept of exemplarism, which together with the concept of the circle is of Neoplatonic–Augustinian origin. From the perspective of revelation, metaphysical exemplarism can be fully understood only in relation to the mystery of the Incarnation of the Word of God. According to metaphysical exemplarism, all entities created by God are but faint reflections of the idea patterns of His mind. In the light of revelation, all creation emanates from the one divine pattern Word (the divine Logos). By virtue of the fact that the Word, eternally born in God, took on the corporeal dimension of the created world in time, human beings are also able to understand more deeply the essence of creation and, to some degree at least, the mystery of the Creator Himself.

A fuller understanding of the meaning of creation and a return to God is not possible, according to Bonaventure, unless man opens himself to “spiritual rays of light”, or in other words, enlightenment (illuminatio). Only in the case of this opening is it possible for the creature to return to a loving union with the Creator through a gradual conformation in some measure to the Incarnate Word. This is the meaning of the term “reduction” (reductio), as introduced by Bonaventure, which literally means “leading back”. Its meaning can be read on an ontological level as the actual return of all creation to its creative source. It can also be explained on a cognitive level as an activity that leads to understanding the world as the work of God and, at the same time, Him alone: “Thus, it becomes clear why Bonaventure can respect the insights of all the human cognitive disciplines on the one hand, and yet see them as limited and in need of the insights of faith and theology on the other hand” (Hayes 1996, p. 8).12

3.2. The Lights of the Arts and Theology

Apart from the introductory (#1) and concluding paragraphs (#26), Bonaventure’s De reductione consists of two thematically distinct but related parts. In the first part (#2–7), the author interprets the fields of arts/cognitions (artes/cognitionēs), which were known in the 13th century as realizations of a particular kind of illumination (illuminatio). Each illumination corresponds to one of the lights touching the human being, ones that ultimately derive from the one light of the divine. In the second part of his work (#8–25), Bonaventure shows “how the other illuminations of knowledge are to be traced back (reduci habent) to the light of Sacred Scripture” (Red. art. 8; Bonaventure 1996, p. 47), as well as to the knowledge and love of God (Smith 2021, p. 278). Bonaventure distinguishes four main lights (plus two others). The main lights include the “exterior light” of the mechanical arts, the “inferior light” of sense knowledge, the “inner light” of philosophical knowledge, and the “superior light” of grace and Scripture. In view of the subject matter of this article, we are interested in the light of the mechanical arts (i.e., the ancient counterparts of today’s technology); the light of philosophical knowledge, especially the light of natural philosophy together with the disciplines based on mathematics (i.e., the ancient counterparts of today’s natural and exact sciences); and the light of Scripture (sacra Scriptura), which is identified with theology (cf. Hayes 1996, p. 2).

Among the “exterior light”, Bonaventure includes seven mechanical arts: “weaving, armor-making, agriculture, hunting, navigation, medicine, and the dramatic arts” (Red. art. 2; Bonaventure 1996, p. 37). The listed skills and crafts led to the production of objects or worked in areas “external” to humans and processed the matter of the “external” world to satisfy basic human needs. Bonaventure borrowed the list of mechanical arts (artes mechanicae) from the Didascalicon of 12th-century theologian Hugh of St. Victor (ca. 1096–1141) (Hugh of the St. Victor 1991, p. 74): “In essence, they [the mechanical arts] offer a description of the basic structures of medieval life, beginning with the peasants working the fields and moving to the major guilds in which the craftsmen of the age were organized” (Hayes 1996, pp. 15–16).13

Associated with philosophical knowledge is the “inner light”, “because it inquires into inner and hidden causes” (Red. art. 4; Bonaventure 1996, p. 41). This light is divided into natural, rational, and moral. Natural light corresponds to the truth of things (veritas rerum), which is the subject of natural philosophy. The knowledge of the truth of things concerns their formal principles (rationes formales) through the human mind (rationes intellectuales), “and in relation to divine wisdom, they are called ideal (rationes ideales)” (Red. art. 4, author’s italics; Bonaventure 1996, p. 43). Moral light, on the other hand, refers to moral principles and human conduct, but will not be discussed in this article.

As principles of creation, divine ideas are called exemplars. In other words, the cognition of the formal causes of things through intellectual forms (concepts) in the human mind, which are reflections of archetypal forms in the mind of God, is made possible by the light that ultimately comes from God. The three “links” of the cognitive chain (i.e., things, the human mind, the Divine Mind) refer to the three sub-disciplines of natural philosophy: “physics in the proper sense, mathematics, and metaphysics”. Physics, according to Bonaventure, studies the coming into being and passing away of things according to natural forces and seminal principles (rationes seminales). Mathematics deals with forms abstracted from the forms of material bodies (formarum abstrahibilium). Metaphysics, on the other hand, involves the knowledge of all entities, reducing them to a single First Principle “from which they proceeded, that is, to God, in as far as God is the Beginning, the End, and the Exemplar” (Red. art. 4, author’s italics; Bonaventure 1996, p. 43).14

Finally, the fourth “superior light” refers to salvific truths, and it has its origins in Sacred Scripture and is related to theology. In Bonaventure’s understanding, this level of truth transcends the cognitive capacity of human reason, which examines the created order of things (Red. art. 5). It is not concerned with the nature or form of thing but rather with their ultimate destiny, which is revealed to man through the historical revelation contained in Sacred Scripture. Indeed, “the whole of Sacred Scripture teaches these three truths: namely, the eternal generation and incarnation of Christ in time, the pattern of human life, and the union of the soul with God” (Red. art. 5; Bonaventure 1996, p. 45). The first truth concerns faith, the second is about morality, and the third relates to the purpose of both. In the second part of Bonaventure’s work, the title reductio (“leading back”) shows how these three truths expressing God’s wisdom are hidden in the corpus of human skill and knowledge, as well as in the world itself (cf. Smith 2021, p. 267).

3.3. The Reduction of the Arts to Theology

The three truths of biblical revelation listed in paragraph #5 of De reductione—namely, the eternal generation and incarnation of Christ, the pattern of human life, and the union of the soul with God—can, according to Bonaventure, be seen in the illumination of the mechanical arts. This becomes possible when we consider “the production, the effect, and the fruit of a work; or if we consider the skill of the artist, the quality of the effect produced, and the usefulness of the product that results” (Red. art. 11, author’s italics; Bonaventure 1996, p. 49).

If we consider “the production” (egressus)15 stage of artisanship, we see the artisan (artifex) making an external object based on the exemplary image of that object held in his mind (in mente). This is not an instantaneous process but rather a temporal one in which the artisan considers how best to render an image of the interior pattern (exemplari interiori). By analogy, Bonaventure says that no creature is brought into existence by the supreme Creator (a summo Opifice) except by the eternal Word in which He planned everything, “and by which Word God Has produced creatures bearing not only the nature of a vestige but also that of an image so that through knowledge and love creatures might become like God” (Red. art. 12, Bonaventure 1996, p. 51).16

In the effect (effectus) of artisanship, in turn, we can see the order of life. Every creator intends to create works that are beautiful, useful, and lasting. With regard to human life, knowledge makes life beautiful, will makes life useful, and perseverance makes life strong. If we consider fruits (fructūs), we will see in an artisan’s creations the union of God and humanity. In the case of an artisan, what he does he does for praise, for his benefit, or for pleasure that he derives from his work. Similarly, God created humanity to glorify Himself, to serve Him, and to find satisfaction and rest in Him. In this way, Bonaventure shows how the enlightenment of the mechanical arts “is path to the illumination of sacred Scripture. […] For this reason sacred Scripture quite rightly makes frequent use of such similitudes” (Red. art. 14, Bonaventure 1996, p. 53).

Like in the mechanical arts, elements of theology should also be seen in natural philosophy. Natural philosophy is concerned with the formal causes of things. According to Bonaventure, these formal causes exist on three closely related levels as formal principles: in matter, in the human soul (mind), and in the divine wisdom (Mind of God). They are considered in three ways, “namely, as regards the relation of proportion (habitudinem proportionis), the effect of causality, and the medium of union”. We are primarily interested in the cognitive–ontological level of the relation of proportion, because “if we consider the formal principles in terms of their relation of proportion, we shall see the Word Eternal and the Word Incarnate” (Red. Art. 19–20; author’s italics; Bonaventure 1996, p. 55).

Intellectual and abstract principles (in the human mind) are, for Bonaventure, something intermediate between seminal principles (rationes seminales)17 in the matter of things and ideal principles (in the Mind of God). Seminal principles are responsible for the birth and formation of the forms of bodies in matter. Similarly, intellectual ideas in the human soul are related to the birth of the word in the mind, and when the ideas are in God, then, according to the corresponding proportion, the God–Father gives birth to the Word (Logos). With similar reasoning, it can also be argued that “the highest and noblest perfection cannot exist in the world” if the world/nature, in which the seminal principles reside, the mind, in which the intellectual principles exist, and the Mind of God, in which the ideal principles exist “are simultaneously brought together in the unity of one person, as occurred in the Incarnation of the Son of God” (Red. art. 20; Bonaventure 1996, p. 57). Therefore, for Bonaventure, all natural philosophy, by virtue of the relationship of proportions, proclaims that the Word of God is thus begotten and incarnate (cf. John 3:16).

As Hayes has pointed out, in paragraph #20 of De reductione, Bonaventure succinctly presents the essence of his cosmic Christology. The incarnate Word–Christ is not only the mediator between the Father and the world, but also the fulfillment of the deepest potential of the created cosmos, and the cosmos without Christ would not have reached fulfillment (consummatio). It would not have returned to its Creator in the sense of reductio (Hayes 1996, p. 30). Therefore, the discovery of the deep theological sense of both the mechanical arts and natural philosophy is an indication of the direction of the cognitive and ontological (and at the same time redemptive) loving union of the whole of creation, especially that of humanity with its Father in the incarnate Word (Logos).

4. What Could “Old” Bonaventure Contribute to New Projects for the Theology of Science?

In order to answer the question of the possible validity of Bonaventure’s concepts for the theology of science, it is first necessary to make some comparisons and systematizations. If we want to compare the variants of Heller’s, Kaiser’s, and McLeish’s theology of science, for the sake of simplicity, we will refer to them by the abbreviations ToS_H, ToS_K, and ToS_M. The first two (ToS_H and ToS_K) are united primarily by the question of scientists’ presuppositions about the science they practice. Heller limits his analysis to biases of an ontological and cognitive nature. Kaiser, in his thick description of science, also considers social and cultural presuppositions. Heller refers primarily to a theology of creation based on the biblical tradition with elements of a Christological perspective (the creator role of the Logos). Kaiser, on the other hand, refers to a deep and comprehensive analysis of the Christian and Jewish biblical tradition as well as the patristic and rabbinic traditions. The guiding idea of his research is to uncover theological aspects “embedded in the foundations of scientific endeavour” (Kaiser 2007, p. 10, footnote #34).

ToS_H and ToS_K share some primarily axiological and teleological dimensions with ToS_M but of the three authors, McLeish elaborates most fully. He states that “science is blind to purpose—it has no ‘teleological’ methodology or goals” (McLeish 2014, p. 214). In place of the axiological void in the narrative of modern sciences and technologies and their relationship to nature, McLeish offers the perspective of an axiology based on the wisdom of the Book of Job, the theology of the Apostle Paul, and the thought of the philosopher–theologian Grosseteste. It is noteworthy that McLeish is aware of the differences between the sciences (knowledge of the world) and technologies (transformation of the world), and the variable purposes attributed to them that are today primarily practical and instrumental.

In a brief comparison of the theologies of science discussed above, one might be tempted to compare them with Bonaventure’s “theologia artium”. But is this even possible, given that seven centuries separate them? It may help to point out that we are comparing only the theology of science rather than the corpus of medieval and modern scientific knowledge. Evidence of the comparability of these theologies can be seen, for example, in the fact that modern theologians quite freely apply ancient terminology and concepts, including Bonaventurian ones, to modern doctrinal issues. As far as the corpus of non-theological knowledge is concerned, it is worth noting, as has also been shown above, that both the theologies of Heller, Kaiser, and McLeish as well as Bonaventure’s vision are not so much concerned with knowledge and concrete theories (although these are also present to some extent) but rather with the conditions and meaning of scientific knowledge of the world (i.e., nature).

Nevertheless, one should always keep in mind the differences between the state of theological and non-theological knowledge in the 13th century and at the 21st century. Bonaventure preached within the context of the gradual transition from a Neoplatonic–Augustinian conception of the world and science to an Aristotelian–Thomistic one. The first site of this breakthrough was the university circles of the 13th century. Bonaventure’s sermon preceded the most famous condemnations of some claims of Aristotelian science by the Parisian bishop Etienne Tempier in 1270 and 1277, after which Aristotelian science made its way into the universities of the time, thanks largely to the creative efforts of Thomas Aquinas. Despite these developments, secular knowledge at the time was much closer to theology than it is today, although this does not mean there was no conflict between the two (cf. Grant 1996). For a long time, theology retained its status as the queen of the sciences. From today’s perspective, the general opinion is that the queen of the sciences is mathematics (increasingly together with computer science), and theology was usually deemed too distant and incomprehensible for scientists. Such are the realities of the rise of the modern theologies of science.

In order to compare the three contemporary concepts of the theology of science with the 13th-century theological vision of the arts, we propose to distinguish four leading themes in Bonaventure’s vision of De reductione, namely: illumination, exemplarism, reduction, and the theology of the mechanical arts. This is of course not an exhaustive list of the extraordinarily rich content of Bonaventure’s work but rather a preliminary outline of a theme that may await future continuation and development. We have chosen these themes because of their relation to the contemporary sciences also understood as locus theologicus.

4.1. Illumination: “A Theological Completion”

By associating various kinds of light with the secular arts and theology in De reductione, Bonaventure introduced the idea of illumination, which is quite mysterious to us. Apart from his reference to the source of light, namely God, we have not said anything more about its nature. In fact, it is not “entirely clear” (Cullen 2006, p. 85) and easy to understand, especially for a modern person who has been formed from the perspective of a different image of the world.

For Bonaventure, following Augustine, illumination is primarily concerned with the question of the certainty of human cognitive activity and knowledge. Man, as a fallen (sinful) being with finite cognitive faculties, cannot have certain knowledge of the world created by God without the help of God Himself. On the other hand, illuminatio cannot be equated with grace or God’s special intervention. Excluded from this sphere of influence is the superior light, which is precisely the light of grace and holy Scripture (Cullen 2006, p. 86).18

As we saw above, of the three contemporary authors discussed here, only Tom McLeish (2019, p. 40) alluded to Robert Grosseteste’s concept of illumination in his ToS_M. However, the thread is not sufficiently developed in his work to be able to say with certainty whether McLeish actually adopts the idea of illuminatio or uses it only in a metaphorical sense. It seems that modern proponents of a theology of science may be moving in the direction of adopting Bonaventure’s idea of illuminatio in a sense that is limited to the superior light (as the light of grace and of Scripture), which is of course nothing new to Christian theology. Reflection on science then becomes a kind of theological completion, especially when it comes to understanding the preconceptions upon which science is based, as is the case with ToS_K and ToS_H. This was especially emphasized by Heller when he wrote about the need to go beyond the limitations of scientific methods in order to understand their meaning (Heller 1996b, p. 98).19 At the same time, it is assumed that cognition within the framework of non-theological sciences does not require any special immanent enlightenment and retains full autonomy within its own methods.20

In another of his works, Quaestio disputata de scientia Christi (Disputed question on the knowledge of Christ), Bonaventure poses a question: whether illumination is “an instance of the general influence (influentia generalis) through which God operates in all creatures, or it is a special influence (influentia specialis) such as that which God exercises by means of grace” (Scien. Chr. q. 4 concl.; Bonaventure 1992, pp. 133–34). He concludes that positive answers to either question are absurd. In the first case, illumination cannot be God’s general interaction with creatures (concursus divinus), since it refers to the preservation of being in existence, while illumination refers to interaction with the cognition of the human mind. Nor can illumination be, as in the second case, a divine influence in the manner of grace, for then it would be knowledge infused and leave no room for experiential or innate cognition. Therefore, Bonaventure gives a third solution (tertius modus), intermediate between the two above. Illuminatio is, according to him, a kind of special influence of the divine eternal reason (ratio aeterna) “as the regulative and motivating principle, but certainly not as the sole principle” (Scien. Chr. q. 4 concl.; Bonaventure 1992, p. 134). Thus, man comes to know the world in a way that is autonomous for him, and from Bonaventure’s theological perspective, he is accompanied in this by the presence of God. Close to this perspective was McLeish when he wrote that “science is the participatory, relational and co-creative work within the Kingdom of God” (McLeish 2019, p. 42).

It is worth mentioning that the limits of scientific and theological knowledge have already been thoroughly analyzed by Tadeusz Sierotowicz (2023) within the framework of Michael Heller’s research program (ToS_H). Sierotowicz used the approach of Hans Urs von Balthasar in his analysis and postulated the adoption of three domains of truth. He wrote: “This third domain of truths is constituted by truths ‘visible’ only under certain conditions, that is only when illuminated by ‘a super-natural ray’” (Sierotowicz 2023, p. 220).

4.2. Exemplarism: “A Christology of Science”

As Cullen states: “Bonaventure’s exemplarism is not an aspect of his thought but rather its heart and center” (Cullen 2006, p. 71). This should not be surprising, since with the metaphysical idea of exemplarism, Augustine of Hippo and later Bonaventure sought to express the deepest and most fundamental truths of the Christian faith about the relationship within the Trinity between the Father and the Son–Word as the first Exemplar (Red. art., 4), as well as Logos’ relationship to the world that was created. Through the Word incarnate in human nature, human beings are not only able to know the Father but also discover the purpose and destiny of all creation. The multiple references to the idea of “God’s self-projection” in the Word and the world in ToS_K and the notion of Word/Logos as the source of the world’s rationality in ToS_H are also not surprising (see Kaiser 2007, pp. 44–45; Heller 2008). Thus, Kaiser’s and Heller’s frequent references to quotes from physicists such as Einstein, Hawking, and Paul Davies, for whom the discovery of the so-called ultimate theory (or the theory of everything) is at the same time a discovery of God’s thought as it is encoded in the natural world. Thus, the ancient idea of exemplarism, despite being unnamed, has become one of the main threads of modern theological reflection on scientific activity.21

With regard to the views of Kaiser and Heller, it should again be made clear that the object of their interest was not the religious beliefs (in the confessional sense) of Einstein or Hawking, but the question whether “the thoughts of [these] physicists about their own endeavors can serve as a ‘sacred reminder’ for Christians” (Kaiser 2024, p. 367). For Kaiser, such a “sacred reminder” is, for example, the realization in the world of certain laws of nature (describable in the language of mathematics) that reflect God’s creative purpose. As is well known, God in this case was conceptualized by Einstein and Hawking not as the Holy Trinity in Christianity or Allah in Islam, but as a more unspecified rational “ultimate instance”. Heller and Kaiser gave this “sacred reminder” interpretation a Christological one, and Kaiser even a pneumatological one. Only such an interpretation can be compared with the concept of Christological exemplarism shown by Bonaventure in De reductione.

Analyses by modern theologians rarely refer to De reductione. This does not mean, however, that there are missing references to the metaphysical idea of exemplarism and the theological idea of the Son–Word as the first Exemplar, based on Bonaventure’s other works such as Itenerarium mentis in Deum, Breviloquium, and the already mentioned Collationes in Hexaëmeron. These works do not address the question of the determinants of the existence of science, which is taken up by ToS_H, ToS_K, and ToS_M. However, they do not lack attempts to reflect, in the light of the Bonaventurian idea of theological exemplarism, on such scientific questions as the evolution of life on Earth or ecology (cf. Edwards 1999, pp. 121–23; 2020, pp. 239–42; Lee 2020). It seems that these works, despite their different perspective, can also provide some inspiration for researchers in the theology of science.22

4.3. Reduction: “A Theological Teleology of Science”

As it turns out, the idea of reduction (reductio) in Bonaventure’s De reductione has nothing to do with the methodological or linguistic reduction of scientific disciplines to theology. Instead, it is rather about something very deeply rooted in Christian thought. Reductio, which means leading back, in relation to the dimensions of the human knowledge selected and discussed in this article, means discovering through philosophia naturalis the formal principles of things that are reflections of divine ideas and through mechanical arts, the hidden intention of the divine craftsman. It is thus a reduction of worldly knowledge to the knowledge of God, which is directly referred to under the light of Scripture. For Bonaventure, reduction also has a soteriological dimension. It is not merely reduced to knowledge, but it is primarily aimed at showing humanity a way back to the Father and to salvific fulfillment (consummatio).

On the cognitive level, the meaning of Bonaventure’s reductio is close to Heller’s reflections on the idea of (non-Kantian) a priori assumptions of scientific research developed by Karl Rahner. According to the German theologian, “God is not the final hypothesis that results from the sketching of a rounded picture of the world; on the contrary, he is the single thesis that is posited with every hypothesis with which we build up our picture of the world” (Rahner 1967, p. 388). Heller, however, is more cautious than Rahner because of his involvement in physics and cosmology and his experience conducting science. Heller believes that the existence of God does not necessarily follow immediately from the a priori assumptions of science, such as the rational investigability of nature or its mathematizability. According to Heller, only “a certain interpretation of the a priori assumptions leads to theism” (Heller 1986, p. 112). It seems that these assumptions can also be regarded as “sacred reminders” in the sense of Kaiser.

From a theological point of view, McLeish has approached the topic of reduction in a more fundamental, soteriological sense. Through an axiological and teleological orientation, he assigned to his ToS_M a primarily servant role in accordance with the Apostle Paul’s message of the “ministry of reconciliation”. Reconciliation is primarily concerned with man’s relationship to nature, but it also applies to science and technology as practiced by man. A sermon echoes from McLeish’s message (physicist Tom McLeish was also an Anglican preacher), just as Bonaventure’s sermon echoed from his De reductione seven centuries earlier. In both cases, the truth about the fallen nature of humanity—who by its own powers, including intellectual ones, will not be able to draw conclusions about its goals from secular knowledge alone—found its place.

4.4. Theology of the Mechanical Arts

One of the most spectacular themes in De reductione, one that is rarely (if ever) discussed by contemporary commentators, is Bonaventure’s quite unique incorporation of the mechanical arts of the 13th century into his theological vision. From antiquity through to the Middle Ages and then the Renaissance, the mechanical arts received little attention from philosophers, let alone theologians (cf. Whitney 1990; Ovitt 1987, pp. 107–36). In Bonaventure’s case, however, they were incorporated into his concept of light and played an important role in deepening his understanding of the ideas of divine exemplarism and reduction.

If it can today be said of the theological vision of the arts that Bonaventure presents in De reductione that it is a kind of theology of science, by analogy with contemporary realities, then nothing should stand in the way of defining his view of the mechanical arts as a kind of theology of technology. Despite the seven centuries that separate us from this view, it seems that theologians and scientists alike can still draw more than a little invigorating inspiration from it, in keeping with Bonaventure’s ever-present message in the concluding paragraph of his De reductione: “it is evident how the manifold wisdom of God, which is clearly revealed in sacred Scripture, lies hidden in all knowledge and in all nature” (Red. art. 26, author’s italics; Bonaventure 1996, p. 61).23

The postulated theological dimension associated with the production and use of technology and technological processes remains the same whether it is 13th-century or 21st-century technologies Both John Scotus (Eriugena) (c. 800–c. 877) and Hugh of St. Victor “linked the mechanical as well as the liberal arts directly to salvation and restoration of fallen man” (Whitney 1990, p. 73). This is also one of the ideas present in Bonaventure’s De reductione. The treatment of modern technology and the human labor it supports as a possible path to liberation and salvation in Jesus Christ the carpenter–artisan (Mark 6:2) is still valid today (cf. Chenu 1960), even if today, the view of the enslavement of human beings by large-scale technologies prevails.

Today’s strong connection, even interpenetration, between science and technology, expressed, for example, in the introduction of concepts such as technoscience, indicates that Bonaventure’s intuition to link the theology of science with the theology of technology seems to be a message that could be worth taking up.

5. Conclusions

In a discussion between Smedes and Barbour in the pages of the Zygon periodical, the former charged Barbour’s paradigm of science–religion relations with a clear shift in emphasis regarding these relations to the side of science, including the charge of treating science as the sole source of rationality, affirming “cultural scientism”, and the implicitly implementing the neo-positivist demand for a unification of science and religion (Smedes 2008a, p. 237). Regardless of the validity of these accusations, a striking feature of the new proposals to develop a theology of science by Heller, Kaiser, and McLeish is the clearly visible shift in emphasis toward theology. This is a natural feature of the variants of theology of science discussed here, regardless of the particular denominational affiliation represented by these authors, although all three were Christian.

When Smedes spoke of “cultural scientism”, he explained that he meant “a cultural mode of thinking” prevalent in modern highly developed societies (Smedes 2008a, p. 242), which expresses a strong faith in science and its associated rationality. The extreme expression of this faith was the neo-positivist program of unifying knowledge, which collapsed in the mid-20th century. Nevertheless, according to Smedes, “cultural scientism” persists, and it has also influenced perceptions of the relationship between science and religion. It seems that Smedes’ expression, “a cultural way of thinking”, can also be applied to the social mentality of medieval people, which at that time was predominantly theocentrism and a particular kind of rationality of the Christian faith. Not surprisingly, theology, as regina scientiarum, had a superior cognitive role to other types of knowledge. In the case of Bonaventure’s concept of reductio, however, this was not a unification in the style of 20th-century neo-positivists with the chauvinistic attitude of theology toward the artes. The goal of Bonaventure’s unification was, first and foremost, to obtain the wisdom to tap into the deepest, salvific purposes of human life. Thus, the guiding idea of De reductione reflected the pursuit of Christian paideia in Augustine’s sense (cf. Cullen 2013, p. 137; Bougerol 1964, p. 163). The theology of science, or, pluralistically conceived, theologies of science, can draw on Bonaventurian inspirations, with theology not being a discipline that subordinates anything, including other sciences, but rather a benevolent complement to them, especially in times of supposedly dominant “cultural scientism”.

In the contemporary proposals presented, science is a source of theological reflection, although, as we have shown, views on how this can be achieved vary. This does not indicate that any of the approaches is wrong. Indeed, they are complementary while sometimes moving in a similar direction, since science as a locus theologicus gives rise to many strands of theological reflection. We therefore see the proposals of Heller, Kaiser, and McLeish as complementary rather than competitive. Against this background, we can better understand Bonaventure’s medieval intuitions. Although the sciences were still in an embryonic stage, the fundamental questions concerning the relationship between faith and knowledge and the relationship of the believer to the natural world created by God were already apparent to the insightful theologian.

Modern conceptions of theology of science turn out to be strongly rooted in the tradition of pre-Thomistic theology. Bonaventure’s work, when one looks at his basic theological concepts and intuitions, turns out to be a surprisingly good guide for developing a contemporary theology of science. Bonaventure’s vision does not juxtapose science and theology but rather inscribes them in an organic whole of human existence, and this is an important reminder for us. Bonaventure points out that dialogue is more important than a relationship of subordination between different spheres of human activity. This vision of dialogue as a new welding together of the various, very different spheres of human activity seems more promising than the vision of feudal subordination and strict dependence.24 Not surprisingly, modern ToS proposals were developed in a climate of dialogue, so they are also critical of the previous institutionalized way of thinking in theology (Heller 1996b, pp. 16–17). Reading the modern proposals in the light of Bonaventure’s work, we see them as an attempt to free theology from the traps it has created for itself in the course of its historical development. This perspective makes us realize that instead of seeking a vague “cultural revolution” in theology, a return to the sources with an open mind can have great liberating power.

Bonaventure’s approach also shows that a theology built on Thomism, despite its great value, fails to capture some important theological intuitions. His work demonstrates the value of pluralism, for it seems that truth is too complex and sophisticated to be fully expressed within a single system. The revealing validity of Bonaventure’s ideas suggests that the pluralism of an approach is an important value that belongs to the heritage of Catholic theology. Reading Bonaventure in the context of today’s consideration of science as a locus theologicus reminds us once again of Hans Urs von Balthasar’s insight that the Truth is symphonic.