Interreligious Concordance and Christianity in Nicholas of Cusa’s De Pace Fidei

Abstract

In the months following the Turkish capture of Constantinople in 1453, Nicholas of Cusa composed his De Pace Fidei, a text with which he defended and highlighted the value of interreligious dialogue and peace. Beginning with a textual analysis of its central formula (“una religio in rituum varietate”), I analyze the role that Christianity occupies in the text: I exclude its possible reduction to the una religio or to one of the multiple world religions. I then identify through a literal analysis its role as a mediator between the plurality of historical religions and that religio founded on the fides orthodoxa on which the cardinal rests his argument. In addressing this matter, I also establish how the German cardinal makes the heavenly representatives of Christianity consciously use philosophical and not only theological arguments to avoid the reduction of his position to any kind of historical one. I, hence, argue for the possible transposition of the De Pace Fidei’s method to a contemporary philosophy of interreligious dialogue.

1. The Cultural Context of the De Pace Fidei

In this tragic and violent historical period we are currently living in, the need to revive the discussion on the possibility of interreligious dialogue has become a critical issue. In this, philosophy of religion can, by taking up the task, make use of the rich historical elaboration on the question of the relationship between religions. For this reason, I analyze in this article the interreligious proposal presented by Nicholas Cusanus (1401–1464) in his De Pace Fidei. Through a textual analysis and clarification of the historical and cultural context of its composition, I hope to be able to point not to a solution to contemporary issues but at least to a possible methodological avenue of inquiry worthy of investigation for today’s interreligious philosophical debate. Indeed, I try to show how the special position of Christianity within De Pace Fidei is used by Cusanus to operate a shift of focus of the center of interreligious dialogue from the specific differences of individual positive religions to the possible search for a point of similarity on which it is possible to ground a peaceful dialogue.

This extraordinarily rich text was composed in a few months under the impetus of the Ottoman conquest of Constantinople in September 1453 and represents, if not a unicum in the compositions of the period devoted to the theme of interreligious dialogue, certainly a pearl of rare moderation and speculative depth. The German cardinal’s irenic invitation to a possible concord achievable among peoples and nations who recognize themselves in different traditions and religions is capable of explaining the great fortune the text had both in Cusanus’ immediate contemporaneity, at a moment in history when the entire European intellectual apparatus seemed instead to be only clamoring for new crusader knights ready to set sail for Constantinople, and in the course of the history of European political and religious thought. The uniqueness of this philosophical proposal is made even more evident when compared with the perception of epochal transition that transpires from the documents of the European courts of that period, exacerbated by the internal tensions within Christendom itself. This latter was engaged in those same years with the disputes over primacy between papal and conciliar authority—to which Cusanus himself dedicated his 1437 De Concordantia Catholica and which launched his career as papal legate and diplomatic—with the peasant and Hussite revolts in Bohemia, and with his relationship with the Eastern Church.

Numerous different interpretations of the text have been proposed since its appearance on the European intellectual scene. The dialogue, indeed, has been widely circulating since its publication. As summarized by Monaco (2013b) we are certain that Eimerych de Campo (1395–1460) in Leuven possessed a copy of the text (Imbach 1980), and that, equally, the De Pace Fidei was in Spain, as shown by Juan de Torquemada’s (1388–1468) use of it in his Defensiorum fidei contra Idaeos, Haereticos et Sarracenos, and John of Segovia’s (1395–1458) epistolary exchange with Cusanus. Equally, the text circulated in France and England (Klibansky 1984), in the Roman curial milieu of Pius II, and, most likely, also in the courts frequented by Ficino and Pico, authors who knew the German cardinal and who seem to address similar themes in a related way in some of their texts (Garin 1988; Vasoli 1985). As shown by Celada Ballanti (2021), the irenic dialogue of the German cardinal originates from a tradition that reaches as far as Jean Bodin’s Colloquium Heptaplomeres (1530–1596)—and from there extends to Lessing and Enlightenment thought on tolerance—perhaps even interweaving the utopian genre of the Renaissance in an exchange of cultural influences on which much is yet to be written. The theme of tolerance has been studied in the scholarly literature, which has rightly highlighted its centrality in the cardinal’s text (Watanabe 2001; Monaco 2013a; Matula 2016; Gottlöber 2019). Hence, the importance of the De Pace Fidei both for the history of philosophy of religion (Greisch 2007) and for interreligious dialogue (Hollmann 2014) has rightly been emphasized. It is also interesting to note how, already, from the years following the Protestant Reformation the religious ecumenism of De Pace Fidei was interpreted not only from a Catholic perspective but also through a Protestant religious lens by Johannes Kymeus (1488–1592). The latter initiated an interpretative line that was concerned with understanding the status of fides in the text and showing the absence of ecclesiological reflection, a reading that can also be found in the important biography that Vansteenberghe (1920) dedicates to the cardinal but now opposed by Scotto (2023). In this sense, Biechler and Bond (1990) rightly identify precisely three currents of interpreters: Catholic readers, Protestants, and those who read the De Pace Fidei1 instead as proto-Enlightenment text.

While this polyvocal array of readers belonging to different times and epochs is a symptom of the inexhaustible richness of the text, it is certainly equally true that the arguments with which Cusanus seems to support the central thesis of the text, for which a “concord of religions is achieved in the heaven of reason”, (DPF, XIX) or in other words, for which the realization of a state of peaceful coexistence among peoples professing different religions is possible, present difficulties of interpretation. In particular, the key formula of the text, namely, that there is but “una religio in rituum varietate”, [one religion in a variety of rites] (DPF, I, 6) does not seem to provide clear indications concerning the status of this una religio or the process of its realization. This obscurity and difficulty of interpretation, therefore, makes it difficult to offer an unambiguous reading of the arguments Cusanus proposes and consequently makes his interfaith proposal opaque. In this context, it is particularly the status of Christianity with respect to the una religio that is poorly understood. Following Gaia (1993), it seems to me correct to note that a threefold interpretation of the una religio has been offered in the specialized literature. First, those who think that this una religio should be detected in the empirically given form of the dogmatic faith of Catholic Christianity, a line of interpretation that appears with due differences in authors such as Decker (1959) and Gilson (1952). Second, those who interpret the De Pace Fidei from a pro-Enlightenment perspective, reading in the una religio a form of quasi-natural religion (Von Bertalanffy 1928). Third, those who assign a sui generis status to the una religio, starting from a broader reflection on Cusanian metaphysics (Biechler 1975; Seidlmayer 1954; Stallmach 1984; Gaia 1993).

The purpose of this paper is, therefore, to analyze the relationship between the una religio and Christianity—confronting this third and last group of interpreters in particular—with the hope to bring out the cardinal’s philosophical proposal more clearly. I try to argue for two theses, starting from a textual and literal analysis of the text. First, I try to rule out, following McTighe (1991), the possibility that Christianity can be made to coincide with the una religio of the formula at the center of the text. Therefore, it is necessary to introduce an analysis of the metaphysical categories of the cardinal’s thought that, as we shall see better, are not put into action in the text. Second, I show, through the analysis of the theme of the presuppositio [presupposition], that Cusanus understands Christianity not so much as a set of defined cults and religious practices, nor as a special religio superior to other forms of religion, but rather as a precise and defined point of convergence and mediation between the una religio and the polyphony of cults and rites that different positive and historical religions have generated. To better clarify this last point, we have to distinguish between the historical and theological components of Christianity. This last point enables us to analyze how Cusanus thinks about religious pluralism and clarify his interreligious-dialogue proposal in the De Pace Fidei.

2. The Literary Structure of the De Pace Fidei

For reasons of both expository clarity and argumentative completeness, it is necessary to summarize, albeit briefly, the narrative of the De Pace Fidei since essential elements for its analysis are nested in the literary form of the text. The dialogue opens its narrative by recalling the historical event of the capture of Constantinople by the hands of the Turks, which arouses a feeling of outrage in the main character. This latter, who remains unnamed but appears as an alter ego of the German cardinal, decides to withdraw in prayer to question “the King of the Universe” (DPF, I). However, the narrative does not remain on the level of the contingent and historical event but immediately broadens its perspective of inquiry. A vision is revealed to the rapt and concentrated character in meditation, and the purpose of the text is, thus, shown: how “a certain simple concord can be achieved, and how through it a lasting peace can be established through appropriate and true means” (DPF, I, 1). The De Pace Fidei is proposed as a textual account of this heavenly vision in which peace between religions is discussed in a council or heavenly tribunal. The council, Cusanus tells us, is presided over by the “King of the universe” and envoys and learned men from all the lands and peoples of the earth. In this heavenly tribunal, in which the figure of the “King of the universe” appears more as a defendant than as a judge, an archangel comes forward, who, picking up the wailing cries from the multitudes of voices makes himself their spokesman and questions the Creator about the reasons for such violence. The accusation is motivated by showing how, by the Creator’s own will, “a great multitude cannot exist without great diversity” (DPF, I, 4), since by the same divine will different prophets and teachers spread to different times and places, spreading different forms of cults and rites, and then sedimented throughout history and now perceived as truths and laws for those who received them. It reads in fact:

“Therefore, you placed at the head of your people certain kings and seers, known as prophets, most of whom, delegated by you, using your name established worship and laws and instructed the rude people. (…) You sent to the different nations different teachers and prophets, some at one time, some at another. However, the condition of man on this earth is such that a lengthy custom, adopted by nature, is defended as a truth”.

(DPF, I, 4)

Therefore, it cannot be doubted that it is by divine mandate that different prophets and kings were sent to different times and places, instituting cults and producing laws. These latter, though, as different manifestations or crystallizations of the same message, produced unequal customs and ways of life. Any historically positive religious formation thus appears for Cusanus as a contingently relative translation to a given geographical and historical space and language of an earlier message, that is, as the historical and cultural establishment of an original message that is everywhere presupposed but differently said and understood. The archangel, therefore, after recalling how all kinds of worship presuppose in any case the worship of the same God emphasizes, however, its absolutely unknown character, since the absolute infinity of the latter prevents any determination of it by a finite intellect. Only after this characterization of God’s absconditus [hidden] character does the archangel implore the King of the Universe to come out of the concealment in which he finds himself and show his otherwise invisible face to the people. Cusanus writes that only by showing his uniqueness, “all evil suffering will cease, and all will know that there is but one religion in a multiplicity of rites” (DPF, I, 6). The archangel then pronounces his formula at the center of our analysis—there is but una religio in rituum varietate—as an apodosis of a precise premise concerning the absconditus character of divinity. Pleased with this invocation, the King of the Universe calls forth the “king of kings”, identified in the triune Word-Logos, so that he may discuss and speak to the assembly. The latter, who in a metaphysically interesting manner is defined as “the truth that nourishes the intellect; in whom all things are complicated and through whom all things are explicated”, (DPF, II, 7) takes the floor and states that “since in the sensible world nothing remains stable, and thanks to time opinions and conjectures, and similarly tongues and interpretations, vary as mutable things” (DPF, II, 8), it is necessary to show the uniqueness of truth in order to lead back to the one orthodox faith. Thus, starting with a Greek, easily identifiable in the figure of the philosopher, the Word engages in a discussion with seventeen delegates from different countries and cultures ranging from England to the Far East, being also replaced and helped by Peter and Paul. The succession of discussion topics thus initiates from discussions that have as their object the problem of the uniqueness of truth and then branches off in the direction of the plurality and diversity of rites. Indeed, it is the Word who discusses Wisdom, and the problems related to divine uniqueness and the Trinity; Peter who discusses problems related to the Incarnation and Christology in which a strong scholastic echo resonates both in language and arguments; and finally, it is Paul who discusses the relationship between fides and the plurality of rites such as baptism, communion, and other sacraments.

Literary elements appear as argumentative tools that Cusanus introduces to support his thesis. The stylistic form of the dialogue makes each member of a different cultic and cultural tradition compare and discuss directly with the Word and his intermediaries Peter and Paul, who are concerned with establishing the possibility of peaceful coexistence among religions through the bringing of the various cults back under the banner of the one religio and to the worship of the one God who presupposes them all. The council concludes with the participants’ realization that “all diversity consisted in rites rather than in the worship of the one God” (DPF, XIX, 68) and that, from observing the differences in worship and ritual, it is understood that "all of them have always presupposed from the beginning [ab initio] and worshipped the one God (ibid.). The “King of kings”—representing the divine Word—sends the council members back to earth, away from that intellectual and heavenly space outside of time and space (Aleksander 2014) in which the dialogue took place, so that they may share what they have learned and be able to lead men back to peace. The central claim of the text is, thus, the possibility of establishing lasting peace through the recognition of how, at the origin of the plurality of cults and rituals, the same single religious truth is presupposed. The recognition of a fides [faith] shared by all different historical religions in this one Truth to which the highest worship is due thus becomes the means by which, and not despite which, a lasting peace and concord can be established.

3. Lexical Technicalities and the Place of Christianity in the De Pace Fidei

The main proposal of the De Pace Fidei is, thus, grounded in the formula of una religio in rituum varietate, but, as I mentioned earlier, this statement is not the easiest to interpret. What is particularly opaque is how the relation between religio and the plurality of rites is to be understood, as well as the meaning of the terms involved and their relationship with Christianity. A necessary first step, then, in understanding the irenic formula of the dialogue, in addition to clarifying the role and meaning of the fides orthodoxa sought, is to clarify its key terms, such as religio (and especially its plural religiones) and ritus. The latter term takes on a constant meaning in the text, related to the specific historical and geographical crystallization of each nation and culture and connected to the specific ways in which the ceremony of religious worship is regulated. Indeed, Paul explains to the Tartarus ambassador that rites were instituted as “sensible signs of the truth of the faith” (DPF, XVI). The semantic sphere of “sign” clearly identifies a relation of resemblance between rites and the truth of faith that is not absolute, but always partial insofar as it is historically and geographically connoted. Much more slippery, however, is the semantic sphere of the term religio. As also put on display by Merlo (2013), religio takes on different meanings when used in the plural or singular form. As religiones, especially when linked to the lemma diversitas [diversity], assumes the modern meaning of a set of practices, beliefs, and rituals of a specific group of individuals objectified and represented in a specific conceptual framework where it is then exemplified by the ambassadors present at the council. The plural lemma suggests, in my opinion, a distancing from the medieval meaning of the term religio and refers more to a categorization of religion as an object observable from the perspective of an outside observer who can study its characteristics with an outside eye. This meaning is, hence, distant from how religion was comprehended during the Middle Ages. Religio, on the other hand, refers rather to that unam fidem orthodoxam to which the De Pace Fidei claims to bring back the diversitas religionum [diversity of religions] (DPF, III, 8, 5–6). This latter term almost identifies to fides and suggests in the formula under consideration other than specific historical religious actions or institutionalizations. As it becomes clearer, reading the arguments that the dialogue proposes Cusanus seem to suggest that the precise semantic coordinates of fides can be taken as an awareness of the divine uni-trinitarianism. In this sense, the Fides is meant to be shown to be presupposed by every participant in the dialogue and to be seen as the primal form of religio from which the various historically realized religions can discover themselves to have originated.

That this interpretation of the terms under scrutiny may be acceptable seems to me to be confirmed also by the marginalia affixed by Cusanus to the Codex Cusanus 108, a book now in his personal library in Kues (Biechler 1983, p. 95): at the border of a page of the Lex Sive docctrina Mahometi in which the relationship between law and diversity of rites is discussed, the German cardinal notes “fides una, ritus diversus” [faith is one, the rite is different] a locution that corroborates Valkenberg’s (2014) thesis of an Arabic inspiration of the De Pace Fidei and its central formula, while subtracting preponderance from the Neoplatonic philosophical ascendancy in the explanation of it. The latter sphere of influence, which characterizes Cusan philosophy, would seem to make legitimate an interpretation of the terms related to how unity and multiplicity are thought of and discussed in the context of that same philosophical thought. Hence, it would seem to be a correct interpretation to understand in a Neoplatonic metaphysical context the una religio as the principle of unity manifesting in a plurality of different cults and religions, which would, thus, become historically realized manifestations of the same unity. Yet, as clearly pointed out by McTighe (1991) and Venturelli (2019) who draw on the former, interpreting the formula under scrutiny metaphysically can lead to misinterpretations about the status of Christianity. Although much of the literature on the topic is composed building on this assumption, a timely textual analysis of the De Pace Fidei seems to rule out the use of the metaphysical categories that Cusanus is wont to use to think about the relationship between the One and the many in explaining the formula at the center of the text. Neither the metaphysical pair of Platonic terms of exemplar-imago nor the Cusan technical terms of complicatio [enfolding] and explicatio [unfolding] seem to be employed in the explanation of the relationship between the one religio and the rituum varietate.

Take at such notice the pair of complicatio and explicatio, so much at the heart of the entire Cusanian philosophical and theological proposal that one would only have to casually open any page of one of his texts or sermons to find them. In the De Pace Fidei, the term complicatio appears in only eight occurrences divided into five chapters2 and never refers to religio, but rather is always traced back to the Word or to the treatment of Trinitarian doctrines that are explained and discussed. In the same way, we obtain only six occurrences of explicatio and compounds in five chapters3, and always in the context of the technically philosophical explanations offered by the Word to the participants of the heavenly council, designed to clarify the relationship that exists between God or the first principle and creatures. These categories are, on the contrary, clearly in use in the text’s treatment of Christian theological and doctrinal elements, as in Cusanus’ definition of the Word as “truth that nourishes the intellect; in which all things are complicated and through which all things are explicated” (DPF, II, 7). We are, thus, allowed to rule out the possibility that the relationship between una Religio and rituum varietate can be thought of analogously with the pairs explicatio/complicatio or exemplar/imago. As well noted by McTighe, “pace commentators the formula religio una … remains remarkably free of metaphysical interpretation” (McTighe 1991, p. 168).

Because of what has been said, it remains even more opaque how Cusanus understands his formula and the role that Christianity plays in the De Pace Fidei. This difficulty is made more profound especially if the role of the Christian religion within the dialogue cannot be thought of through the metaphysical categories with which the cardinal usually operates. Kolakowski (2001, p. 104) notes how any formula traceable to the proposition “all religions are in reality one”, under which the Cusanian formula can be inserted with due precision if one interprets rituum varietate as the manifold reality of the different historical institutionalizations of the various religions, may imply two possible interpretations. First, the formula could indicate that all different historically realized religions share a set of statements, dogmatic or otherwise, in which religious people identify. This “belief system” would, thus, be spread across all religious denominations as a central core of shared statement. Translated into the language of the De Pace Fidei, this first interpretation would, thus, suggest that the una religio is identifiable with a well-defined set of propositions, which would in truth represent a shared set of affirmations present in all other positive and historical forms of religion, hidden behind the variety of ritual and worship. Or, secondly, it could be thought that the formula is meant to identify not so much a defined set of religious statements as in the case just mentioned, but rather a fundamentally identical human experience, inexpressible in its pristine quality, which would be disguised in a plurality of different cultural ritual expressions as soon as this is crystallized in a linguistic or cultic—we could say historical—form that is meant to express it. That is, it would be an original and primal experience shared only in its ineffable purity, which would turn into a multiple fixity, and, therefore, equivocal, as soon as one decides to give it a theoretical form. If the first of these two options is almost certainly wrong, since a universal dogma of all religions does not seem to me to exist, it is even more so in reference to the De Pace Fidei. For if the una religio was really as in the first interpretation a not experiential core but a specifically propositional-linguistic one, consisting of a finite and well-defined set of propositions present in the ritual multiplicity of historical religions, this would imply the reduction of every historically realized plurality of worship to the shared singularity of this supposed conditioned core of affirmations, which should be evident and present in every religion of the world. This line of reasoning seems contrary to the importance given in the De Pace Fidei to every singular aspect of every world religion, to be maintained if it does not compromise the worship of the one God. If this interpretation were otherwise true, there would be no need for all that dialogical effort put forth by the Word to show the possibility of establishing a lasting peace through the analysis of each world religion’s specificities, but it would be enough for Him to indicate which religious statements to keep. In doing so, the De Pace Fidei would not propose at all a peaceful coexistence of all religions and concord among peoples as much as a general reductionist equation of them that would be achieved through the elimination of their respective cult singularities in order to bring out the shared central core of religious statement we are posing in this hypothesis. Therefore, the second option seems to me, if not correct beyond doubt, at least more fertile as a hermeneutical rule for approaching the De Pace Fidei. It would indeed indicate the possibility of thinking the una religio, as McTighe (1991) does, as an Ur-Religio, which would be not so much a collection of forms of cults and religious assertions, but rather the realization of the process in which one would proceed by denying every cultural, historical, or linguistic determination by which an originally religious experience would have crystallized. Therefore, following this reasoning, one could almost translate the Cusanian formula into “una ‘Ur-religio’ in rituum varietate” (or una ‘Ur-Fides’, having ascertained the theoretical connection in the dialogue of the terms fides orthodoxa/una religio, where the una religio would represent the worship of what fides orthodoxa knows).

But if it is possible to equate the Cusanian una religio with this concept of Ur-Religion, is it possible, in turn, to equate the notions with Christianity? With the above reasoning in mind, I lead the inquiry in this direction: is Christianity conceivable within the De Pace Fidei as Ur-Religion? And if so, is it so in its historical component or as a theological core epitomized by the positive ritual components? If the una religio is, in truth, an Ur-Religion, which would represent a primal religious experience attainable by denying all forms of worship, how do we relate Christianity to the religio/rituum pair? The question appears more complex given what we have just affirmed, namely, that Cusanus does not address this problem through his most common metaphysical categories, on which we could, therefore, not rely on developing an interpretation. But I try to offer a counterexample of how this makes it less arduous to answer the question posed: I believe that Cusanus purposedly avoids employing metaphysical categories in relation to this formula and that this can lead to a specific interpretation of the role that Christianity occupies in De Pace Fidei.

A treatment that made use of the classical categories of Cusanus’ metaphysics of explicatio/complicatio would indeed force Christianity into a certain position, either Ur-Religion primigenial (complicatio) or a single ritualistic expression of a historical–geographical singularity (explicatio). Now, the second position, for which Christianity would be nothing more than one ritual and celebratory manifestation among many, one of the countless historical crystallizations in the diversitas religionum, and, thus, an explicatio, seems to me to be a position easily eliminated. Those who would support it would have to give reasons for the fact that this would be a devaluation or reduction not only of Christianity itself, as much as and above all its unitarian and Christological theological component, which is, instead, at the center of the text. In the first chapters, the Word guides the discussion to show how the different cults presuppose a Trinitarian monotheistic faith. If Christianity were then, as explicatio, one of the countless historical ritual forms, this would, in turn, undermine the entire literary and argumentative framework of the De Pace Fidei because it would eliminate any claim to legitimacy and authority to the heavenly council and those who preside over it. Finally, it would be necessary to explain why, among the seventeen representatives of the nations and cultures of the world who intervene in the heavenly council space, no one seems to perorate the Christian cause. Let us then carry out the analysis of the first case and ask what would entail if we interpreted Christianity as Ur-Religion as the complicatio of all other positive and historical forms of religion, and then pose the case counterfactual to our thesis—that it is possible to establish an interpretation that makes the one religio, which we have been able to equate with the concept of Ur-Religion, the complicatio of the diverse forms of ritual and worship. The latter view seems to me equally problematic. In this case, the whole project of peaceful coexistence between different religions maintained in their ritualistic and celebratory specificities—the primary intent of the De Pace Fidei—would collapse into a reductionism of the singularities of the different religions to those of Christianity, and, consequentially, this would lead to an exclusivist interpretation of De Pace Fidei. Christianity, according to this interpretation, would represent the original form of religion sought by the cardinal, to which other religious cultures should, therefore, be brought back and reduced. Two arguments prove this thesis erroneous in my opinion: first, it is the same text that in countless passages does not deny totally the cultic specificities of the different religions, but on the contrary, tries instead to maintain them if they recognize the respect for the veneration of the one God. We read, for example, in the Word’s response at the beginning of his dialogue with the Indian concerning statues and images:

“Images that bring to knowledge of things which are allowed in the true worship of the one God are not condemned. But when they distract from the latria worship of the one God, as if something of divinity was enclosed in the stones and statues, then they must rightly be torn to pieces, as they deceive and lead away from the truth”.

(DPF, VII, 19)

It is clearly stated how anything that leads to the veneration of the one God (the unus latriae cultus [the latria cult directed to the only One]) is permitted, as opposed to that which instead leads to distancing oneself from it: therefore, the worship of the one God is the discriminating factor to which attention must be paid (the fides orthodoxa) and that guarantees the possibility of establishing peace, which can then live in the plurality of differences. Secondly, if Christianity were nothing more than the complicatio, or Ur-Religion of the various religions, this would necessarily have to either renounce all its ritualistic components, a position that, if not difficult, is certainly bizarre for a Catholic cardinal to maintain, or either to be an Ur-Religion as historically realized Christianity, which is by definition wrong. We have defined the concept of Ur-Religion not as a set of propositions, dogmatic or otherwise, shared by all the various forms of religion, but precisely as “the negation of all cultic and ritualistic forms” capable of bringing out a primal religious experience not traceable to any positive and historical crystallization or form that would be its manifestation, and, following this definition no historical religion, not even Christianity, can assume the status of Ur-Religion. And thus, if Christianity is identifiable as Ur-Religion, it is solely in its theological aspect related to that uni-trinitarian worship identifiable with the fides orthodoxa. It seems clear, then, that the use of metaphysical categories in relation to the formula of una religio in rituum varietate, or its expansion into Ur-Religio in rituum varietate, prevents giving a precise collocation and explanation of the theoretical position of Christianity, or at least the historically realized form of it. Neither Ur-religion nor one of the historical and positive forms of religio; neither complicatio nor explicatio. How then are we to think of it?

4. Christianity as Mediation

If what I have argued is correct, I believe Christianity is thought by Cusanus to be the way of mediation and connection between the una religio and the rituum varietate. This is precisely because according to the cardinal, in its historically realized component, Christianity has the possibility to find that fides orthodoxa that is fulfilled and obtained in the una religio. If, as the dialogue tries to argue, there is a single faith that supposedly underlies all religions, this means that historically realized Christianity itself also possesses that fides orthodoxa guarantor of peace. If Christianity assumes a privileged role in the De Pace Fidei, it is then because it has been able to recognize within itself, through its revealed theological core grounded on the assumption of a Deus Absconditus [the hidden God], that fides orthodoxa hidden in every world religion. In other words, Christianity would have operated that process of unveiling the fides that it presupposed, opening its reflection to the divine hidden nature. In this recognition of the absconditus character of the divinity, it would have then developed a language, which is necessarily apophatic and negative, to speak about the divine sphere. Cusanus then, consistent with the idea of conjecturality that he believes characterizes all human knowledge and affairs—for which every assertion, even religious ones, partakes of the true in otherness and never in full identity—recognizes that no religious position can aspire to the full and direct possession of truth. In this, historical Christianity, too, will have to recognize in its own position necessarily historical components that do not participate in Truth. This is, in fact, the element that I have shown prevents Christianity from being able to characterize itself as the one religio. But Christianity is, and has been, at the same time capable of operating that meta-reasoning by which it recognizes the character of conjecturality that belongs to all its positive assertions and identifies the character of the historical–geographical contingency of its ritualistic component, precisely because its mysteries are better suited to uncover that character of infinity and ineffability of the first principle. Christianity, thus assumes, for this reason, a closer relative distance from the una religio: it inhabits a median way in the formula under consideration, setting foot both in the una religio through that apophatic and negative metaphysical language that belongs to its speculation, and in the diversitas religionum owing to its historically realized component. Cusanus, as a Christian who speaks and writes to Christians, wants to show how all the religions of the world, including Christianity, are in the situation of being able to be mediated to the peace of the una religio. This can happen if and when all the world religions assume that conjectural metaphysical language already used by Christianity to describe itself and the divine, to perceive and discover the same fides orthodoxa that Christianity has discovered as presupposed in itself.

Indeed, in our brief summary of the literary element of De Pace Fidei, we have shown how the cardinal’s irenic perspective summarized in the formula is realizable through a single condition: the archangel pronounces his formula as an apodosis of the hypothetical premise that the absconditus character of the divinity ceases to be such. Specifically, the archangel’s invocation is prompted by the realization that the infinite character of the first principle determines the impossibility for a finite mind to know it and that, therefore, given the Cusanian principle of the nulla proportion [non-proportionality], divinity must reveal itself. It is the Archangel who prays for God to reveal himself, since should this happen “all sword and hatred would cease” (DPF, I, 6). The unveiling of the infinite principle would, indeed, show its unitary and infinite character, from which Cusanus deduces the condition of the possibility of the una religio. This unitary character, which is then declined in the discussion of the Word in a trinitarian and Christological perspective, is then the root and explanation of the cardinal formula. It is the element that discriminates what can be maintained in the various forms of worship, as we have seen in the case of the discussion with the Indian character. Cusanus, thus, intends to show in the De Pace Fidei to each character representing the various religions, in what Decker refers to as a “dialectic of presupposition” (Decker 1959, p. 119), how his position always presents an unconscious praesuppositio, in which the possibility of recognizing the unity and ineffability of the first principle can be found. And this way of arguing is grounded on the negative language of Christian Neoplatonism, able to speak about an infinite unique God. The polyphony of religions can, thus, be guided to a peaceful coexistence that maintains ritual and cult specificities because (and provided) these do not affect their possession of presuppositional fides.

This dialogical way of arguing can be shown with some examples. The first dialogue the Word holds is with the Greek character, who interestingly does not represent the position of orthodox Christianity at all, but that of the philosophers. The argument put forth against the Greek starts from the assumption that philosophers, by definition, are said to be “lovers of Wisdom”; these would, therefore, seek a single Wisdom, since if there were many different ones, these would refer to the one Wisdom as their common element. We read in the exchange:

“The Word answered: you will see that no other faith is to be presupposed, but everywhere the same. (…) If therefore you all love wisdom, do you not presuppose that it exists?”

(DPF, IV, 10)

The argument holds on the observation that there is something that all philosophical discourse presupposes and that it is, therefore, its hidden foundation or principle. This principium is not evident to the Greek character, but through the discussion with the Word, it is revealed to him as necessarily presupposed and as identifiable in the unitary principle of Wisdom. Similarly, in his dialogue with the Arab about the status of polytheism, the Word notes:

“All polytheists have always presupposed the existence of divinity, and it is it that they worship in all the gods, as partakers of it. For just as there would be no white objects if there were no whiteness, so there would be no gods if there were no divinity. Therefore, the worship of gods testifies to the existence of divinity”.

(DPF, VI, 17)

Therefore, the polytheistic position is also brought back to the monotheistic one, which would, therefore, be its presuppositio. But this is possible because, platonically, a polytheistic cult presupposes that each deity is, precisely, divine and that it is this common property that is the focus of veneration. And as in the case of the Greek, so the Italian or the Arab can find that their worship presupposes the veneration of a single unique infinite God. And again, the text concludes with the theme of praesuppositio, when, at the end of the heavenly council, the guests collect and assemble in texts and books all the different forms of religiosity and worship in history and nations and discover that “from all the texts put together it was found that all, from the beginning, have always presupposed and worshipped the one, God” (DPF, XIX, 68).

Or, again, reference can be made to the dialogue with the Syrian. Here, it is no longer the Word who is the primary interlocutor, but Peter, who is asked to offer concrete examples that can verify the possibility of finding concord in every tradition. The section of the De Pace Fidei that opens with the introduction of the first apostle and is dedicated to the topic of Christology seems to give reason for the interpretation I am proposing of Christianity as the mediating force between diversitas religionum and the una religio. Peter opens his conversation with a question, which concerns the eternal and immortal character of God, and from this, he observes how “almost every religion” thinks that “everyone’s mortal human nature will re-birth to eternal life” (DPF, XIII, 43). Therefore, he states that “human nature must already be previously united with divine nature in some man”, showing how all the various religions presuppose if directed to eternal life a mediating figure between time and eternity, which is obviously identified in the Christological figure. This alone allows for the different religions to give reason for the resurrection sought by all, realizable through a certain participation in an eternal nature that is presupposed to exist and must have been realized historically in the Christ-figure. In this latter, according to the German cardinal’s position, a connection and mediation is found and realized between historical time and eternal time, and between human and divine, such that the two ontological planes are connected. In the same way, within the dialogical proposal of De Pace Fidei, it is Christianity that can connect and mediate between world religions, having recognized in itself and, thus, now knowing, that praesuppositio that all the various historical religious cults presuppose without realizing it.

Therefore, to offer an answer to the question posed in the previous chapter, we need to broaden our gaze and perspective to Cusanus’ entire oeuvre. Following this thesis of a mediating Christianity between the una religio and the rituum varietate, the entire dialogue can be interpreted as the maieutic process in which the various subjects recognize their hidden common presuppositio, which is the impossibility of fully drawing on an abscondita Veritas that is then declined as a unique and triune hidden infinity. And if this happens, it is because, through the awareness possessed by Christianity of the absconditus character of divinity, it can be shown how every positive cult and historical religion—and the realized Christianity itself among the many religions—presupposes those characters that describe the fides orthodoxa, namely, the worship of an absolutely unique God. For this reason and not coincidentally, dialogical is also the literary form of the De Pace Fidei, and out of time and space is that heavenly council in which the protagonist is raptured and conducted, and, not coincidentally, is the fact that the various characters literally speak with the Word and its intermediaries Peter and Paul. The peaceful coexistence among different religions is, thus, sustained by the recognition by each positive and historical cult of common illegitimacy to claim to possess the Truth.

5. The De Pace Fidei and Contemporary Philosophy of Interreligious Dialogue

The De Pace Fidei, thus appears, unlike so much coeval anti-Islamic and apologetic literature, to be a work of deep and thoughtful reflection (as evidenced also by the prolonged time of its writing, which was not rapt and immediately following the receipt of the news of the fall of Constantinople). The cardinal’s irenic proposal passes through an interreligious dialogue that thrives on the recognition, not only of the presence of some kind of truth in all the positions of the members of the council, but also, and above all, of an exclusion of the possibility that there can be full possession of it by anyone. In the conjecturality of all knowledge, the truth is offered for Cusanus always according to gradations that point asymptotically to Truth, and concord is achieved by maintaining one’s religious singularities and specificities in this awareness. As I have tried to show, in this metaphysical horizon, Christianity appears as the mediation between plurality and singularity because it is able to lead the various religious positions back to the discovery of that fides orthodoxa—which is for the cardinal the knowledge of Trinitarian monotheism that substantiates the one religio understandable only through a negative and apophatic approach—that is presupposed in the respective religious positions.

Now, it should be noted, in any case, that the irenic and ecumenical project proposed in De Pace Fidei runs the risk of sounding dated. First, because of Cusanus’ contingent historical knowledge, which, while astounding, greatly reduces the theological and theoretical positions of the world’s various religions. Second, the contemporary sensibility towards religion would require the addition of at least an eighteenth character impersonating the position of the atheist, since, as Vannini notes in his introduction of his translation of the text, “Cusanus does not have the problem of atheism” (Cusano 2023, p. 16) which opens further problems for any contemporary philosophy of interreligious dialogue. Third, in his text, the German cardinal sometimes slips into statements that conceal factual positions of tolerance behind practical and contingent reasons that nevertheless do not guarantee their universality—the obvious example is that of the position of the Jews who, although did not understand the importance of the Incarnation, did not offer problems to concord between religions given their small number of adherents (DPF, XII, 41)—or into exclusivist positions (Aikin and Aleksander 2013). Moreover, the importance attributed to Christianity points toward a relative higher position of it when compared to the other religions. This view clearly runs the risk of being caught up and defeated by the arguments a pluralist can use against an exclusivist. But it must be remembered that it is not the historically realized Christianity that Cusanus has in mind as mediating between the one religio and the rituum varietate, but rather its theological component of an infinite divinity and the consequential apophatic language needed to speak about it. In fact, the most obvious problem with the Cusanian position is that which the fides orthodoxa sought and through which the German cardinal seeks to establish possible peace, which takes the form of a Trinitarian monotheistic theological doctrine. This strains the cardinal’s proposal and seems to make it fall into the exclusivist trap: that is, only by accepting Trinitarian dogmatics would it be possible to follow Cusanus in his arguments.

It would, therefore, be wrong to look to the text of the De Pace Fidei for a solution directly transposable to the contemporary situation; this is trivial. Yet, the dialogue also speaks to our contemporary time: even though it must be admitted that the call for peace and interreligious dialogue unfolds in the conversation of the various religions with Christianity, the latter proposes philosophical arguments in a specific conjectural frame in its tracing of the various faiths back to the fides orthodoxa instantiated in the una religio. Not all the arguments Cusa uses are, as one might have expected, of theological provenance. Particularly, this is evident in the section of the dialogue where the Word is the principal interlocutor, where that “dialectic of presuppositio” unfolds. The discussion is there directed, as we have seen, at demonstrating the presence of faith in a Trinitarian monotheism presupposed in all the various historical and positive forms of religion. But, if we look at the text, what appear are philosophical arguments developed through the philosophical language: thus, the Neo-Platonic argument that “before all plurality there is unity” leads the Greek back to the recognition that there is but one Wisdom sought, by which the Arab is also led back to that fides orthodoxa; polytheism, in the same manner, is led back to a monotheistic cult through the observation that various divinities in order to be such must, platonically, participate in a deity that is presupposed to them. In this the most emblematic example is the explication of the Trinitarian doctrine, which is explained and expounded by resorting to that arithmetical interpretation of the trinity which Cusanus deduces from the school of Chartres, of Unitas [Unity], Aequalitas [Equality], and Connexio [Nexus], and which is originated from a reflection on the nature of the universe, from which it is then traced back to the explication of its principle. The classical trinitarian theological motive is mentioned by Cusanus only later, saying that “some call the Father unity, the Son equality, and the Holy Spirit the nexus; terms these, which though not their own; nevertheless, indicate the trinity satisfactorily” (DPF, VIII, 24). It should be noted though that for Cusanus, the trinitarian theological aspect is always secondary to the apophatic philosophical component that characterizes his philosophy, and any trinitarian explanation is always traceable within the realm of conjecturality that connotes all knowledge. This is why the cardinal uses the adverb “satisfactorily”, because he finds in the cataphatic triad Unitas-Aequalitas-Nexus an assertion that partakes of the truth more than the Father-Son-Spirit triad, but it is not the perfectly exact representation. Secondly, it should be noted how, broadening the survey to the entire Cusanian oeuvre, the arithmetic triad mentioned here is used as an argumentative tool in philosophical matters, and much less so in theological matters, as also highlighted by Trottmann (2017), becoming the metaphysical pivot on which the process of divine explication in the world takes place. Third, and remaining firm in the investigation to the structure of De Pace Fidei, the progression of the arguments examined follows a logic that seems to replicate the formula at the heart of the text (una religio in rituum varietate). In fact, the discussions entertained by the characters in the text deal with topics that, starting from the unitary nature of the divine (una religio), reach questions concerning cultic specificities such as the sacraments (rituum varietate): thus, following the course of the text in reverse, one notices how at its summit is the dialogue that the Word has with the Greek concerning the Oneness of Wisdom, preceded by the prologue and the prayer that the archangel addresses to the hidden deity. The Trinitarian doctrine does not make its appearance until later in the dialogue with the Indian, and Cusanus immediately presses the point that “God, as Creator is triune and one”, but “as infinite, is neither triune, nor one, nor any of those attributes which can be enunciated of Him” (DPF, VII, 20).

In this sense, Christianity plays its role as a mediator in the De Pace Fidei, not by imposing its own categories of revealed theology, as they are also historically connotated, on its interlocutors, but rather by offering the language and the arguments—whose soundness is certainly philosophically debatable—of a conjectural philosophy, which knows that it can never attain totul simul the truth. Put differently, and herein lies, in my view, the possible transportability to contemporary discussion, for Cusanus the cataphatic component of Christian theology is secondary to its apophatic component, which is the real end to which the cardinal’s philosophical arguments aim to lead his interlocutors. In this sense, it is not so much the specific content of De Pace Fidei that may be of interest to a contemporary reader, but also, and above all, its form and method: the conjectural starting point regarding truth or the divine allows for the identification of a point of agreement on which peaceful dialogue can be established. The contemporary philosophy of interreligious dialogue can, thus, fulfill the task that in De Pace Fidei is assumed by that conjectural Christianity that mediates between the una religio and the rituum varietate.

For Cusanus, in conclusion, what Christianity can offer to the dialogue between religions is first a precise philosophical starting standpoint and frame of discussion, and second a specific philosophical language that starts from the assumption of an absconded and unknown truth. This allows for the various positions to talk to each other to discover a shared, presupposed point on which to establish peace. Speaking metaphorically, Christianity seems to operate as a universal translator, as a lingua franca that everyone can speak and adopt, which stays equal in each historical and real situation precisely because it does not say anything of absolute value, hence excluding every theological argument (such as those usually put forth in legitimizing war conflicts) that live by the claim of possessing an absolute truth. And while Cusanus is still far from philosophical discussions about the problems regarding the possibilities of translations of languages as diverse and metaphysically distant as religious ones, this “conjectural Christianity” of his may indicate to the contemporary philosophy of interreligious dialogue a way worth investigating for its form of proceeding and its conjectural starting point. Moreover, even if the methodological aspect of the Cusan proposal were not universally valid for every person of different creeds, it would certainly remain valid for the Christian in his relation to other religions and in his public and political life.