Dissertation Spotlight | Nestorius Latinus: The Latin Reception and Critique of Nestorius of Constantinople

As Christianity spread throughout the ancient world, the communities who worshipped Jesus of Nazareth came up repeatedly against the question of Jesus’ identity. Who was this man? Who did they worship? How did this person fit the narrative of their scriptures? My dissertation addresses a critical point in the development of thought on these questions, what modern scholars refer to as Christology. I focus on the thought of Nestorius (d. 451), the one-time bishop of Constantinople (from 428-431) who was deposed at the Council of Ephesus in 431, exiled to the Egyptian desert in 435, and condemned once more in absentia at the Council of Chalcedon in 451. In particular, my research examines how two Latin-speaking theologians, John Cassian (d. 435) and Alcuin of York (d. 804) conceived of and argued against Nestorius' thought. John, a monk who spoke both Greek and Latin, had been ordained a deacon by John Chrysostom and a priest in the west, possibly in Rome. He was a contemporary of Nestorius and wrote against him while Nestorius was still bishop of Constantinople. Alcuin, who lived centuries later, reprised John's anti-Nestorian treatise in a different theological debate with a bishop named Felix of Urgel (d. 818) who had been (erroneously) charged by Pope Hadrian I with revivifying Nestorianism in eighth century Spain. These two figures provide snapshots of the development of western anti-Nestorian thinking, a topic ripe for discussion and further research.

Interest in the figure of Nestorius was revived in the late nineteenth century when Anglican missionaries working in the patriarchal library of the Church of the East in Qudshanes discovered a manuscript containing Nestorius' final work, translated into Syriac and thought to have been lost since the 14th century: the so-called Bazaar of Heraclides.[1] The treatise was written while Nestorius was in exile in Egypt, between the Councils of Ephesus (431) and Chalcedon (451). It served as a defense of his strict dyophysite Christology over and against the Christology of Cyril of Alexandria and his theological progeny. After this discovery and coupled with Friedrich Loofs' 1905 Nestoriana, scholars had unprecedented access to Nestorius' thought. The majority came to see Nestorius as worthy of exculpation.

Although my research focuses on Latin authors, the first two chapters address Nestorius' theology directly. After my introduction, I first consider Nestorius' theological and philosophical influences, especially the writings of Theodore of Mopsuestia, Nestorius' elder in the Antiochene tradition. In my exposition of Theodore's works, I map what I call a "strict dyophysite" or "thoroughgoing dyophysite" Christology, which is a Christology that not only features two natures in Christ, but two natures that are ultimately separate subjects of predication. The natures are often described as the actors in any story about Christ and the action is parsed according to the appropriateness of that nature acting in that particular way. That is, one may ascribe the effecting of a miracle to divinity proper, while birth and death are ascribed to humanity. The natures have a kind of personal density to the extent that Theodore says in his Sixth Catechetical Homily that if the divine nature were to have left the human nature on the cross, there would remain an independent human subject apart from the divine.

Chapter Three surveys Nestorius' own works. Amongst his extant works we are especially fortunate in that we have his letter to Pope Celestine (Fraternas Nobis Invicem), as well as three homilies (8, 9, and 16 in Loofs) to which John Cassian had access to when he wrote his De Incarnatione Domini Contra Nestorium (On the Incarnation of the Lord Against Nestorius) in 430. While I focus on this small dossier, I draw upon the entire Nestorian homiletical and epistolary corpus to round out my findings. Nestorius was, for better or worse, mostly consistent throughout the entirety of the controversy. I argue that Nestorius was primarily concerned with defending divine impassibility, the idea that God in His divinity is incapable of being acted upon by anything external to Himself.

The principal insight of this chapter has to do with Nestorius' meaning of the word prosōpon (Greek)//parṣupō (Syriac). Nestorius is known to have taught that in Christ there are two prosōpa of the natures, both divine and human, joined in a conjunction (sunapheia) of a single prosōpon of the union. Too often the word is translated by Anglophone scholars as "person", which makes nonsense of the Nestorian position (how are there two X in a single X?). I argue instead that Nestorius has two meanings of prosōpon and he switches between them without signalling that he is doing so. The first meaning I define as "the external manifestation of particular characteristics (= idiomata) appropriate to a given nature." This category is primarily phenomenological, which discloses the ontological. The second meaning is used most commonly in the phrase "prosōpon of the union," though it appears elsewhere, especially in the Bazaar. Whereas this first kind of prosōpon reveals an underlying nature by way of phenomena, the second usage is merely a grammatical concept that, when used to talk about the union of natures, affords one the possibility of talking about the narrative of "Christ" in the divine economy without admitting an actual single subject. The former kind of prosōpon (i.e. of either nature) is always the ultimate subject of attribution and the latter (i.e. the grammatical 'Christ') never is nor reasonably could be as it lacks any genuine ontological existence.

Chapter Four turns to the West's response to Nestorius in form of the De Incarnatione of John Cassian. Cassian's foray into Christology has been regarded as a misstep by most scholars who have written on it, though this is an admittedly small cohort. I show instead Cassian’s profound insight into Nestorius' thought. He marshalled diverse theological resources - Greek and Latin patristic writings, the Creed of Antioch, and Scripture - to argue against it, including the overlooked Libellus of Leporius, which he quotes in the very beginning of his De Incarnatione. Leporius was a monk of southern Gaul, who once believed much like Nestorius that, in order to keep God from "things beneath him" (inferiora se), it was important that Jesus was a "man born with God (hominem cum Deo natum esse) " but not as God. Leporius not only describes his faulty belief, but gives his emended Christology: a single subject (i.e. una persona), dyophysite account, spoken in an Augustinian dialect,[2] which provides Cassian the technical, Christological categories for the rest of his argument against Nestorius throughout the remaining seven books of the De Incarnatione. Cassian's treatise proceeds by taking up Nestorius' exegesis in his homilies and demonstrating, through the una persona paradigm provided by the Libellus, that Nestorius undermines the consensus patrum and Scripture's insistence that Jesus Christ is a single person to whom both the glorious and undistinguished must be predicated.

My next chapter, Chapter Five, addresses Alcuin's use of Cassian's anti-Nestorian arguments in the context of another theological controversy: Spanish adoptionism. Cassian's De Incarnatione unfortunately had few readers in antiquity.[3] While he seems to have intended it for Nestorius and the people of Constantinople more generally (cf. De Inc. 7.31), its immediate circle of readers were Roman clerics (including the future Pope Leo), who held a local synod in Rome in the late summer of 430 and condemned Nestorius, at which point, for the Roman curia, the job of the De Incarnatione was completed. There is no indication Nestorius himself ever read it nor that it was ever translated into Greek. However, centuries later, there is one who read it with more enthusiasm than anyone: Alcuin of York.

Spanish Adoptionism is unfortunately named and should not be understood to be related to earlier forms of 'adoptionism' in the early Church, often associated with Theodotus the Cobbler (fl. ca. late 2nd century) or Paul of Samosata (d. 275). For the sake of brevity, there are two things to know about Spanish adoptionism. First, Pope Hadrian I and others were convinced that the thought of two eighth-century Spanish Bishops, Felix of Urgel and Elipandus of Toledo, was Nestorianism redivivus and second, they were wrong.[4] There is no chance Felix had ever read a word of Nestorius and there is no evidence of any actual Nestorian Christians in eighth-century Spain. Rather, Felix, following a long line of Augustine's interpreters, focused on the genuine humility of the Word in the Incarnation. This led him to call Christ as man nuncupativus Deus (“spoken of as God”), servus conditionalis (“servant by condition”), and filius adoptivus (“an adoptive - though explicitly not adopted – son”), whence comes the name of the controversy. All Felix seems to mean by these titles is that Christ is actually human and does not exempt himself from the conditions of genuine humanity in the Incarnation. With the misdiagnosis in hand, however, Alcuin set out to write his Adversus Felicem in the 790s and naturally turned to the best Latin anti-Nestorian text he knew of, Cassian's De Incarnatione. I show that Alcuin's use of Cassian's arguments in favor of a single persona in Christ, often quoted paragraphs at a time, fall flat against Felix's actual beliefs. Felix was simply not an opponent of the single person Christology Alcuin put forward. Rather, Felix's supposed "Nestorianism" was actually a misunderstanding about what qualities can be ascribed to natures and what may be said of persons.

I argue in this same chapter that Alcuin later realized that Felix was not a Nestorian in the sense that he denied a single ultimate subject of attribution by the time Alcuin wrote his 802 treatise on the Trinity, the De Fide. This text is not typically regarded by scholars as part of Alcuin's anti-adoptionist oeuvre, but I argue that it is. The De Fide is not about Trinitarian theology generally, but is an exposition of Augustine's De Trinitate Books V-VII, wherein Augustine speaks specifically about Trinitarian relations. This chapter argues that Alcuin comes to see that Felix is mistaken about the fact that the quality of 'sonship' is relation- (i.e. person) making and therefore any type of 'sonship' (adoptive or natural) must be predicated of the person, not the nature. Were Felix correct in his assertion that Christ is "adoptive son" as human, but "proper son" as divine, there would necessarily arise two different relations, thus creating two persons, and therefore would fall into the category of "Nestorianism" insofar as there would be two subjects of predication. Felix's error is thus a misapplied Augustinianism with no genealogical relationship to Nestorius' thought, but the concept of "Nestorianism" still operates in Alcuin's thought. The De Fide thus exhibits a theological maturity on Alcuin's part. He moves from shoehorning Cassian's arguments against Nestorius into his debate with Felix to understanding more clearly the logic of Felix's thought itself. One sees here in miniature the trajectory of Western theology's concept of Nestorianism, i.e. the move from a concept based primarily on Nestorius' writings to one in which "Nestorianism" functions as a heuristic category for understanding the distinction between person and nature and the relevant predications allowed to each.

Nestorius Latinus has two principal goals in its argumentation. The first is to offer new insights into Nestorius' Christology based on a careful reading of his extant corpus, including challenging many of the claims made by modern scholarship on the basis of the Bazaar of Heraclides. By situating Nestorius theologically and philosophically, we can finally gain clarity into the central question of his Christology: the meaning (or meanings, in our case) of the word prosōpon. After showing that Nestorius does, in fact, hold to a two subject Christology, Nestorius Latinus turns to two Latin theologians, John Cassian and Alcuin of York, to demonstrate the analytical tools at their disposal in addressing Nestorius' Christology and the later category of "Nestorianism" in Latin theology. These latter two chapters show the way in which "Nestorianism" as a theological category morphed between late antiquity and the early medieval period, having become distanced from the actual writings of Nestorius. Nevertheless, the category proved useful to address the logic of any Christology wherein the persona of Jesus is not the ultimate subject of predication.

I hope, when expanded into a book, to include chapters on Boethius, John Maxentius, and Bede to provide a fuller picture of the occidental response to Nestorianism. In the writings of these theologians we see the variety of ways in which "Nestorianism" becomes a theological category, divorced from Nestorius' actual theological corpus, whereby these authors demonstrate the logic of predication in Latin Christology. The book thus provides a glimpse into Latin Christology generally, so often neglected or relegated to comparison with Greek Christologies, which dominate histories of early Christianity.

[1] The title comes from the Syriac translation, which uses the word 'tegurthō'. It is likely that the original title in Greek included the word 'pragmateia' and the Syriac translator understood this in its economic sense rather than as "treatise."

[2] This is no wonder considering Augustine helped Leporius to write the Libellus at some point between 418-420.

[3] There exist only seven extant manuscripts of the De Incarnatione - considerably fewer than either his Institutes or Conferences. This makes dubious Owen Chadwick's claim that until recently, "Latin Christianity looked upon the Patriarch [i.e. Nestorius] with eyes biased against him through Cassian's misunderstanding," John Cassian: A Study in Primitive Monasticism (Cambridge: Cambridge University Press, 1950): 160.

[4] The standard study on this controversy is John C. Cavadini, The Last Christology of the West: Adoptionism in Spain and Gaul, 785-820 (Philadelphia, PA: University of Pennsylvania Press, 1993).

Joshua R. McManaway is a postdoctoral Fellow in Theology at Holy Cross College (Notre Dame, IN) and a postdoctoral Research Fellow at the McGrath Institute for Church Life at the University of Notre Dame.