On the Feast of the Solemnity of the Most Holy Trinity, which is celebrated on the first Sunday after Pentecost, the preface in the Roman liturgy includes the following words:
Who, with Your Only-begotten Son and the Holy Spirit Are one God, one Lord; not in the unity of a single person, but in the trinity of a single nature. For that which we believe on Your revelation concerning Your glory, that same we believe of Your Son, that same of the Holy Spirit, without difference or discrimination. So that in confessing the true and everlasting Godhead, we shall adore distinction in persons, oneness in being, and equality in Majesty.
These three sentences are perhaps the most concise summary of several centuries’ theological discussions on the Holy Trinity. Earlier, this prayer was used much more frequently, i.e. on all the Sundays that did not have their own preface. It was, indeed, a presumed preface of the Roman Catholic Church. Its remarkably dogmatic nature is surprising. Obviously, there are a lot of fragments in the liturgy that express the teaching on the Holy Trinity, but liturgical texts are hardly ever so speculative. Here, in a distinguished place, at the very beginning of the Canon, we are provided with dogmatic formulas that include the concepts of person, essence, unity, equality, and distinction.
For many generations of the faithful, the preface on the Trinity was probably the most philosophical text they encountered on a regular basis. The proper understanding of the preface must have required a certain knowledge of the concepts it involved. In this sense, we can say that philosophy precedes theology. However, it seems that the liturgical use of these formulas may also lead to another conclusion. It is because liturgy is not just a subject of explanation, but also a source of understanding. Holy celebrations are a context that shapes the understanding of texts that appear in those contexts. Thus, for the faithful, not the lay applications of the philosophical concepts that occur in the preface but their liturgical use, might have become the most important context that shaped their understanding, not only in theology but also in philosophy itself. In this sense, we can also say that theology becomes the source of philosophy.
Metaphysics of the Trinity and Trintarian Ontology
Therefore, the relationship between dogmatics and metaphysics comprises two fundamental, though not always clearly distinguished aspects. In the encyclical Fides et ratio, John Paul II wrote that “speculative dogmatic theology presupposes (praesumit) and implies (complectitur) a philosophy of the human being, the world, and, more radically, of being”. These two expressions are perfect to describe both aspects of the relationship between dogmatics and metaphysics, although I am not sure whether the pope was actually thinking about them in this fragment. On the one hand, dogmatics always presupposes a certain metaphysics, because, to formulate its statements, it uses concepts that are derived from philosophy. On the other hand, dogmatics also implies a certain metaphysics, because, modifying the existing philosophical concepts, it indicates and inspires some philosophical solutions. The teaching on the Holy Trinity illustrates this very well. On the one hand, Trinitarian dogma uses the concepts of hypostasis, essence, or relation, which were taken directly from Greek metaphysics. In this perspective, metaphysics seems to be a preliminary condition for practicing dogmatics.
On the other hand, Trinitarian dogma, which comes from revelation and is expressed in philosophical terms, becomes the source of philosophy. New meanings that were ascribed to philosophical concepts in the dogmatic context, became the inspiration for the development of a new Christian philosophy. For example, the concept of a person, spectacularly developed in the context of Trinitarian disputes, entered into broad philosophical circulation and, in time, it even lost its theological connotations.
This two-fold relationship between dogmatics and metaphysics is clearly seen in the contemporary philosophical discussions on the Holy Trinity. On the one hand, analytic metaphysics help theology explain the nature of the Holy Trinity, and, on the other hand, theological teaching on the Holy Trinity can inspire the development of a new Trinitarian ontology. Metaphysics of the Trinity, i.e. metaphysical interpretations of the assumptions of Trinitarian theology are mainly developed in the Anglo-Saxon analytic philosophy of religion. Such interpretations have flourished within the last several decades. Trinitarian ontology is mainly carried out by theologians within the context of the Continental tradition of philosophy.
It is surprising that the metaphysics of the Trinity and Trinitarian ontology are developed almost totally independently of each other. I do not know any analytic philosopher who deals with the problem of the Trinity and refers to the works of Trinitarian ontologists. Nor do I know any theologian who takes the results of the work on the analytic metaphysics of the Trinity into account in developing a program of Trinitarian ontology. I do not even recall any work in which both of those approaches would be discussed at the same time.
To a certain degree, this is understandable. Both programs are developed within different disciplines (philosophy or theology), they are based on different philosophical traditions (Anglo-Saxon or Continental), they are often developed by the members of different denominations (Protestants or Catholics), and they are described in different languages (English or German and Italian). Furthermore, the way the thinking developed in both approaches is different. I suppose that theologians may be embarrassed with both the dispassionate distinctions of Richard Swinburne and the frivolous thought experiments of Brian Leftow. Analytic philosophers, in turn, may be confused by the all-embracing visions of Piero Coda or the eclectic thought of John Milbank. Taking all of this into account, I find it even more necessary to attempt to bring these approaches closer to each other. In the conclusion to my reflections here I will suggest that bringing them together could be based on the analytic ontology of relations. It is so, because the category of relation turns out to be crucial both for the metaphysics of the Trinity, which analyses the assumptions of the dogma, and for the Trinitarian ontology, which analyses its implications.
Adoring the Relational Proprietates
The Trinitarian dogma was formulated and explained with the use of metaphysical concepts that acquired new meanings in the theological context and could, in turn, influence ontology. In this way, the metaphysics of the Trinity changed into Trinitarian ontology. In the Preface on the Holy Trinity, we read that “in confessing the true and everlasting Godhead, we shall adore distinction in persons, oneness in being, and equality in Majesty.” Unfortunately, the English translation is not precise in this case. In the original Latin text, the technical term proprietas is used, which denotes the properties that make the persons of the Trinity distinct from one another. What we shall adore is not the very “distinction in persons,” but their personis proprietates, i.e. particular personal properties.
According to the traditional doctrine, what makes the persons of the Trinity distinct from one another are only their mutual relations, and proprietates are precisely relational properties. It was said that the Father’s properties are paternity and active spiration (shared with the Son, provided that we accept filioque); the Son’s properties are filiation and again active spiration (shared with the Father); and the only property of the Spirit is passive spiration (to the Father and the Son). Since all these differences have a relational nature, they do not violate the full identity of nature. This means, however, that the concept of relation is in the very heart of the teaching on the Holy Trinity.
For classical metaphysics, the fact that Christian theology used the concept of relation to describe God was thoroughly confusing. Though the Greeks had the category of relation, they usually treated it as the weakest kind of being. For example, Aristotle used to say that “what is relative (to pros ti) is, to the lowest degree among all things, a kind of a nature or substance, and it is subsequent to quality and quantity.” The reason why relations were disregarded was the conviction that they were ontologically dependent beings, not only as compared to the substance but also other kinds of accidents. Trinitarian theology used the available concept of relation, but gave it a totally different status. The stone rejected by philosophers has become the cornerstone of the building of the theologians. In the Holy Trinity, relations were understood not as accidental, but as essential for their terms. The persons of the Trinity do not merely stand in relations, but are rather constituted by relations or are even identified with the relations. This approach resulted in a revolutionary change in the image of the world. As Joseph Ratzinger wrote in his Introduction to Christianity,
The sole dominion of thinking in terms of substance is ended; relation is discovered as an equally valid primordial mode of reality. It becomes possible to surmount what we call today “objectifying thought”; a new plane of being comes into view.
Unfortunately, as he further indicated, the task of developing a new philosophy resulting from this discovery “is far from being completed,” although “modern thought depends on the possibilities thus disclosed, without which it would be inconceivable”. It is the very concept of a relation, formulated for Trinitarian theology, that has become the foundation for the new Trinitarian ontology.
In 1976, Klaus Hemmerle, the Bishop of Aachen and one of the founders of the Focolare movement, published a short text called Theses Towards a Trinitarian Ontology, which has become the program of the whole approach to developing the idea of a new ontology inspired by the doctrine of the Holy Trinity. The context in which Hemmerle carried out his considerations included the great tradition of medieval theology—especially that of Aquinas and Bonaventure—German idealism, the philosophy of dialogue, the thought of Martin Heidegger, and the structuralism of Heinrich Rombach.
Hemmerle’s objective was to create an ontology that would start from what is the most distinctive for Christian experience. The proprium of Christian life is love expressed in the Trinitarian dogma. Therefore, Trinitarian ontology must break with the traditional primacy of a substance and recognize the primacy of a relation. This is because love is an act of going beyond oneself. In the Trinitarian ontology, “What becomes central is . . . movement (no longer understood in Aristotelian terms) and relation (likewise no longer understood as a category or even as the accident weakest in Being).”
In other words, Christian ontology, i.e. the ontology of love—that is Trinitarian ontology—must be a dynamic and relational ontology. However, the primacy of relations should not lead to the elimination of substance. We should rather treat this primacy as the essentiality of some relations for their terms. In this way, we are truly able to show that standing in relations is necessary for the realization of the very nature of the substance. “Everything fulfills itself and brings that which is its own most to perfection by entering into its relatedness, into its being-beyond itself, into its self-having as self-giving, into its character as to and for each other.”
Piero Coda and Giulio Maspero
The idea of Trinitarian ontology became very popular in Italy, in particular among the members of the Focolare movement. In her teachings, Chiara Lubich often pointed to the practical conclusions resulting from the doctrine of the Holy Trinity. One of the places in which Hemmerle’s program was developed was the University Institute Sophia in Loppiano, established by Lubich. Piero Coda was a rector of the institute for a long time. As far I know, Coda is the only official professor of Trinitarian ontology in the world. He is also the author of numerous theological works concerning the Trinity, as well as of many important texts dedicated to Trinitarian ontology. In his works, the context of Trinitarian ontology has been significantly enriched, especially by the thought of Antonio Rosmini, Sergei Bulgakov, and Pavel Florensky.
Coda defines Trinitarian ontology simply as a view of the world from the point of view of the Holy Trinity. He explains that the word “ontology” means “giving a word to being, i.e. to the reality in which we are, to live and meet,” and the word “Trinitarian” is related to the “light from which and in which we can see, interpret and live with that reality”. This light is the reality of the Holy Trinity revealed in the Incarnation and available in the community of the Church. Coda distinguishes the broad and narrow sense of Trinitarian ontology. In the broad sense, it is “each interpretation of the reality which explicite or implicite starts from the place into which Christ led us”; and in the narrow sense it is an interpretation which “takes into account a strictly ontological meaning.” In both senses, the starting point of Trinitarian ontology includes the concepts that ancient theologians worked out to describe the Holy Trinity, such as “subsistence, knowledge, love, relation, person, freedom, creation, unity, perichoresis, and communication”.
Another important Italian center for investigating Trinitarian ontology is the group Relational Ontology Research working at the Pontifical University of the Holy Cross. In his works the leader of this group, Professor Giulio Maspero, undertakes an impressive project in the reconstruction of patristic Trinitarian ontology, in particular the thought of Gregory of Nyssa. Maspero defines Trinitarian ontology “not only as an ontology of the Trinity, but also as an ontology from the Trinity, that is, consideration of the being of the created world in the light which flows from the Trinitarian revelation.” Thus, the basis for Trinitarian ontology is the theological teaching on the Holy Trinity.
That is why, it does not so much justify its concepts, such as a person or relation, but it rather assumes them and uses in explanation of the created reality. The Church Fathers, especially Gregory of Nyssa, proposed a significant revision of classical metaphysics. The difference between the persons of the Holy Trinity was to be relational only. “The Father, the Son, and the Spirit are, therefore, the same thing, God, but the one is not the other because they are distinguished by the relations inherent in their own names.” The category of relation, understood in this way, gains an entirely new status. According to Maspero, “it is not just an accident, but subsists in a unique, non-created, and absolutely divine substance”. Such a change of the status of relation was an “authentic ontological innovation, which, by virtue of the analogy between God and the world, had to significantly influence the way of understanding the entirety of reality. The result of this new interpretation of the world was the revision of classical Greek metaphysics based on the “inclusion of relation as a co-principle of being, along with substance and inseparable from it to the point of identifying its immanence.”
The last attempt to develop a Trinitarian ontology was made recently by John Milbank. In his lecture given at the New Trinitarian Ontologies conference at Cambridge in 2019, he referred directly to Hemmerle’s program continued by Coda and Maspero. However, Milbank placed Trinitarian ontology in the new context of such thinkers as Henri Bergson, Alfred North Whitehead, or, notably, Francis Herbert Bradley. Milbank first distinguishes three senses of Trinitarian ontology. First, it can be understood as metaphysics of the Holy Trinity itself; second, as the theory of the relation between the Trinity and the world; third, as a study of the creation in the perspective of the Holy Trinity In the third, the most proper sense, Trinitarian ontology is, according to Milbank, who clearly refers to Hemmerle, “re-thinking Being as such, or ontology, in sufficiently Christian, which is to say, Trinitarian terms.”
At first, Milbank develops the idea of Trinitarian ontology in a direction similar to that of Coda and Maspero. Milbank says that the “Trinitarian revision of ontological categories” consists in “a heightened place for event, motion, relation, and personhood with respect to an inherited priority of substance.” Then, Milbank introduces a relatively new issue into Trinitarian ontology, showing its radically apophatic or even irrational consequences. Although apophatic motives appear in almost all authors, never have they played such a fundamental role, leading to such extremes, as in this case. Milbank notes that the main categories of Trinitarian theology are basically contradictory, conflicting, or (in his words) “aporetic”:
We have [in Trinitarian theology] the positive aporias of one as three, of substantive relation, of person as jumping like a physical quantum between person and essence according to perspective, of motions that are motions but have always already been made, and of fulfilled act that does not cancel an absolute potency.
Milbank takes all those refined concepts, created throughout the centuries by Christian thinkers, and now are carefully analyzed by contemporary philosophers of religion, as merely expressions of the helplessness of human thought which faces the Mystery. However, if the Holy Trinity is contradictory, the world must be contradictory, too—at least as long as it is analogical to the Trinity. “Creation is the image of the Trinity,” says Milbank, “because both go beyond the borders of formal logic.”
Milbank’s two fundamental ideas of Trinitarian ontology, i.e. relationality and aporeticism, meet in his thesis on the inconsistency of the very concept of relation. “If the substantial relation in God is paradoxical, the same refers to relations as such,” he says. In this aspect, Trinitarian ontology receives unexpected support from British Neo-Hegelian Bradley, the author of the famous arguments for the contradiction of the concept of relation. While Bradley concluded that relations are just appearances, while in reality there is only an indivisible Absolute, Milbank, in turn, enthusiastically approves the contradictions, treating them as vestigia trinitatis.
Work in Progress
It seems that although several decades have passed since the publication of Hemmerle’s manifesto, Trinitarian ontology is still a work in progress. Coda is clearly much more interested in Trinitarian ontology in a broad sense. He does not attempt to develop ontology in the proper sense. Coda emphasizes, for example, that “in Trinitarian ontology, the subject is to be viewed and considered in the Trinitarian grammar, which connotes and gives it a dynamics of relation”, but he does not provide any deeper analysis on how the key categories of substance and relation refer to each other. Maspero is clearly closer to Trinitarian ontology in a narrower sense, trying to analyze the basic categories of being. Maspero’s views, however, are formulated in essentially historical and not systematic mode. For instance, he does not pose the fundamental ontological problem of the relationship between the categories of substance and relation.
Milbank, in turn, goes further in systematic analysis of the strictly ontological meaning of relation. In the way which is typical of him, Milbank is not satisfied with historical exegesis, but he develops the idea of relational ontology in a dialogue with various thinkers. Nevertheless, I think that his criticism of rationality goes too far. Trinitarian ontology was to be a view of the world in light of the Holy Trinity. However, it turns out that the light is, paradoxically, apophatic darkness. What is more, we can doubt whether this is really apophatic, because negative theology questions merely the law of the excluded middle (and double negation), while Milbank calls for the rejection of the very law of contradiction. The acceptance of real logical contradictions in dogmatics does not only go against centuries-long tradition, but also leads to destructive consequences, both in philosophy and in theology. If it were the case, how could we maintain the fundamental thesis of Balthasar that “formal creaturely logic is grounded in the Trinity and molded by it”?
EDITORIAL NOTE: This is an excerpt from Pawel Rojek’s essay „Dogmatics and Metaphysics: Methodological Aspects of the Metaphysics of the Trinity and Trinitarian Ontology” to appear in the forthcoming Dogma and Method: Introduction to Interdisciplinary Researches in Dogmatic Theology, edited by Robert J. Woźniak, ROR Studies Series, Roma: Edizioni Università della Santa Croce, 2021.
 Saint Joseph Daily Missal (New York: Catholic Book Publishing, 1957), 669.
 John Paul II, Encyclical Fides et Ratio, §66.
 In another text, I suggested a similar distinction between philosophical theology and theological philosophy, see P. Rojek, "Post-Secular Metaphysics: Georges Florovsky’s Project of Theological Philosophy,” in: Beyond Modernity: Russian Religious Philosophy and Post-Secularism (Eugene, OR: Pickwick 2016), 97-135, see: the discussion in D. Demjaha, "Christianity or Barbarism,” in: The Routledge Handbook of Postsecularity, ed. by J. Beaumont, London: Routledge, 160.
 Aristotle, Metaphysics, XIV, 1 1088a24-29 (Indianapolis: Hackett Publishing Company, 2016), 241.
 J. Ratzinger, Introduction to Christianity (San Francisco: Ignatius, 2004), 184; see also: J. Ratzinger, "Concerning the Notion of Person in Theology,” Communio 1990, vol. 17, 439-454.
 Ibid., 184.
 K. Hemmerle, Theses Towards a Trinitarian Ontology (New York: Angelico, 2020).
 Ibid., 35.
 Ibid., 38-41.
 Ibid., 51.
 See: Th. J. Norris, The Trinity. Life of God, Hope for Humanity. Towards a Theology of Communion (Hyde Park, NY: New City, 2009); Th. Norris, “A Spirituality that Inspires Ontology: The Discovery of God-Love and the Renewal of Ontology,” in Claritas: Journal of Dialogue and Culture 2012, vol. 1, no. 2, 31–37.
 P. Coda, From the Trinity: The Coming of God in Revelation and Theology (Washington, DC: CUA, 2020).
 P. Coda, "L’ontologia Trinitaria: Che Cos’è?,” Sophia 2012, no. 4, 160.
 Ibid., 165.
 P. Coda, „La Trinità Come Pensero. Un Manifesto,” Sophia 2017, no. 9, 12.
 G. Maspero, A Trinitarian Ontology: The Relational Approach, New Trinitarian Ontology, University of Cambridge, 13 September 2019. See also: G. Maspero, "Life as Relation: Classical Metaphysics and Trinitarian Ontology,” Theological Research 2014, vol. 2, p. 31-52.
 G. Maspero, A Trinitarian Ontology, p. 5.
 Ibid., 7.
 Ibid., 6.
 Ibid., 15.
 J. Milbank, "Most Entanglings: Time. Relation and Aporia in Trinitarian Ontology,” New Trinitarian Ontology, University of Cambridge, 13 September 2019.
 See, e.g. G. Maspero, A Trinitarian Ontology,.
 J. Milbank, "Most Entanglings”; see also K. Kilby, „Aquinas, the Trinity and the Limits of Understanding, International Journal of Systematic Theology 2005, vol. 7, no. 4, 414-427.
 J. Milbank, ibid.
 Ibid.; see also: F. H. Bradley, Appearance and Reality (Oxford: Clarendon 1897).
 P. Coda, La Trinità Come Pensero, 15.
 See P. Rojek, "Towards a Logic of Negative Theology,” in: Logic in Religious Discourse (Ontos Verlag, 2010), 192-215; see also my criticism of the concept of antinomy in theology: "Orthodoxy and Logic: The Case of Pavel Florensky’s Theory of Antinomy,” in: Theology and Philosophy in Eastern Orthodoxy: Essays on Orthodox Christianity and Contemporary Thought (Eugene, OR: Pickwick 2019), 120-144.