Gregory of Nazianzus (ca. 330–390) was one of the famous “Cappadocian Fathers” (along with Basil of Caesarea and Gregory of Nyssa). Gregory was not only an important ecclesiastical leader – indeed, he acted as bishop of several cities and briefly presided over the second Council of Constantinople in 381 – but also an innovative theologian. His understanding of the Trinity helped to articulate and publicize pro-Nicene theology in the 370s and 380s, and his Christological ideas had enduring effects on later Christian thought. Perhaps the most underappreciated aspect of Gregory was his literary genius. Highly trained in classical texts, he was an accomplished epistolographer (more than 240 of his letters survive) and poet (nearly 20,000 of his verses survive). The text presented below – Letter 101 to the presbyter Cledonius – was probably written in the spring of 382 or the spring of 383. Although quite long, it was indeed a genuine letter conforming to a new epistolographical type that developed among Christian leaders in the second, third, and fourth centuries, a type in which an author could explicate exegetical, moral, or doctrinal issues at (sometimes great) length.

The three letters that follow highlight the fact that the Nestorian controversy had as much to do with ecclesiastical politics as it did with theological debate. Indeed, these letters, despite their brevity, illustrate one of the main reasons why Nestorius lost his struggle against the bishop of Alexandria, namely, his failure to draw Bishop Celestine of Rome to his cause. The primary purpose of the first letter, probably written in late 429, was to seek from Celestine information about several clerical exiles who had come to Constantinople from the West. These bishops, including most prominently Julian of Eclanum, had, as a result of the efforts of Augustine of Hippo, been deposed for adhering to the views of Pelagius regarding sin and salvation. Nestorius’s report to Celestine in the first letter hints at his intention to reopen their case, an action that he should have realized the bishop of Rome would not look kindly upon. This intention becomes more explicit in the second letter, written perhaps in early 430, as Nestorius complains of the lack of response from the Roman leader and insists that Celestine send him the dossiers used in the deposition of the Pelagian bishops.

This homily, like most of Jacob’s other homilies, begins with a long introduction. The passionate feeling of sorrow at the discord caused by the council which is expressed in the homily speaks for itself. It is, however, a little hard to discern the force of the biblical testimonia adduced (lines 116–126) in favor of the author’s standpoint, since these are standard testimonia with which any side in the controversy would presumably have been happy. Yet there is also a clear statement of the reasons why the council was unacceptable (lines 143–150): it is the dividing up of the properties, ascribing them either to the human or to the divine nature. It was precisely the emphasis on this aspect in the Tome of Leo and the Letter of Ibas that led to the disapproval of these two particular documents of the council by the opponents of Chalcedon. What Jacob objected to was the suggestion of a schizophrenic Christ; hence the impassioned cry which Jacob puts into the church’s mouth in line 155: “The Son of God is one, he is one!” There is a radical difference of perspective here.

Born to a pagan family in second-century Syria, and well educated in rhetoric and philosophy, Tatian embraced the “barbarian philosophy” of Christianity and wrote numerous works after his conversion. He traveled extensively throughout the Mediterranean, making it as far west as Rome, where, according to his slightly later contemporary Irenaeus of Lyons (Against Heresies 1.28.1), he came into contact with the various teachings of Justin Martyr,1 Marcion of Sinope, Saturninus,2 and Valentinus. He would later return to eastern Syria and set up a school that would influence Christianity in the region for the next several centuries. He initially crafted the Diatessaron (a harmony of the gospels) for students in his school, but it became the standard “version” of the gospels in Syriac liturgy well into the fifth century. He also wrote a series of treatises on the ascetic life, reflecting a regional emphasis on sexual and dietary renunciation that would endure throughout late antiquity.

In the 260s the recently elected Antiochene bishop Paul of Samosata faced an offensive from fellow Syrian church leaders, ostensibly on account of his theological persuasions. In his Ecclesiastical History Eusebius of Caesarea reports that as soon as it became clear that Paul “held low and base views about Christ, contrary to ecclesiastical teaching, that he was in nature an ordinary human being (koinou tēn phusin anthrōpou genomenou),”1 a first synod was summoned (ca. 264), to which clergymen from across the empire hastened. Shortly after this synod, and probably after a few more, Hymenaeus of Jerusalem and five colleagues composed a letter full of ad hominem attacks against Paul and containing a creed that insisted on the eternity of the Son. Finally, at a synod that gathered in 268/269, Paul was cornered by Malchion, an Antiochene priest of great rhetorical skill, and was deposed.

The conversion of Augustine of Hippo (354–430) to catholic Christianity in 386 is a famous story. After he was baptized in Milan, he abandoned his post as professor of rhetoric in that city, and he and his friends formed a small, quasi-monastic circle devoted to the philosophical life of study and asceticism. After the group moved to Augustine’s native North Africa in 388, he composed a series of responses to questions posed by his confrères, writing his answers up in the style of the question-and-answer tradition of Greek and Latin literature.

Simeon of Beth Arsham, who is known as the “Persian Debater,” was a defender of miaphysite Christology during the first half of the sixth century. The miaphysite position insisted on a formulation with one nature in Christ in contrast to the dyophysite (“two natures”) position, whether Chalcedonian or not. Simeon is one of the theologians, who, along with Philoxenos of Mabbug (d. 523), Severus of Antioch (d. 538), John of Tella (d. 538), and Jacob Burdʿoyo (d. 578), played a role in the eventual development of a distinct miaphysite church in the aftermath of the Council of Chalcedon (451).

The First Letter of Clement is an epistle addressed by the church in Rome to its counterpart in Corinth in response to an outbreak of factionalism there. In ancient sources it is ascribed to Clement, a leading figure of the church in Rome toward the end of the first century, but this attribution is now doubted. A late first-century date seems likely nonetheless, with most scholars placing the letter between 80 and 100 CE, and some more precisely in the mid-90s. The First Letter of Clement is thus one of the earliest extant Christian writings, as old as some of the documents that were later incorporated into the New Testament. It was greatly esteemed and extensively read in early Christianity; as late as the fourth century it was even regarded by some as part of the New Testament canon. Since the seventeenth century it has been included in the collection of early Christian writings known as the Apostolic Fathers.

Two works against the Council of Chalcedon are attributed to Timothy Aelurus. The first survives fully in Armenian and as a synopsis in a Syriac epitome; its title in Armenian is very long, so today scholars call it Against the Dyophysites or On the Unity of Christ. Timothy includes over three hundred quotations not only from authors whose views he opposed but also from works cited in support of his understanding of Christology. He also refutes the Definition of Faith promulgated by the Council of Chalcedon and Leo of Rome’s Tome to Flavian of Constantinople in this work, which was endorsed by the Definition. The second work survives in a single Syriac manuscript, which dates to before 562. It consists of four parts: (1) a section-by-section refutation of the Chalcedonian Definition, (2) a section-by-section refutation of the Tome of Leo, (3) a florilegium of quotations from the acts of Ephesus II chosen to demonstrate the bishops’ stunning change of mind at Chalcedon, and (4) a eulogy for Dioscorus of Alexandria along with an exhortation to persevere in the faith.

The Latin title, Epistula Apostolorum, was suggested by Carl Schmidt, the first editor of this previously unknown work. In chapter 2 eleven apostles are indeed named as the collective authors of this work, addressed to the entire worldwide Christian community, but its contents do not correspond to the apostolic or pseudo-apostolic letters of the New Testament. The major part of the Epistula records a dialogue supposed to have taken place on Easter morning in which Jesus answers questions put to him by his disciples in preparation for their future mission. The dialogue occurs within a narrative frame that includes a collection of miracle stories from Jesus’s childhood and ministry (chapters 4–5), a version of the empty tomb story together with an appearance to female and male disciples (chapters 9–12), and a concluding ascension narrative unrelated to the more familiar version in Acts (chapter 51). In many respects this text is more like a gospel than an epistle.

One of the two most important fourth-century Syriac writers,1 Aphrahat is known only through the Demonstrations attributed to him, twenty-two short pieces that address various topics. Nothing about his biography is known.2 The style of the Demonstrations is instructive but often also polemical; Aphrahat poses a problem or describes someone else’s erroneous understanding of a theological point, and then offers a response supported by abundant biblical citation. In many of the Demonstrations, Aphrahat takes issue with positions he attributes to Jews, and this Demonstration is no different. Though it is not explicitly titled Against the Jews, as other pieces attributed to him are, this Demonstration is written as advice to an imagined Christian friend who seeks to answer several objections supposedly raised by Jews about how Christians speak of Jesus. Whether those objections were voiced in reality or were imagined by Aphrahat, the fact that he frames his work as a response to Jewish claims about scripture suggests that he sees as much intellectual and cultural continuity between Christianity and Judaism as he sees difference.

In 610 Sergius became patriarch of Constantinople and later the same year crowned Heraclius as emperor (r. 610–641). Sergius would remain central to imperial religious policy until his death in 638. These were tumultuous years, as the empire faced incursions from Avars to the northwest and, more threateningly, from the Persian shah Khusro II to the east. After Khusro’s initial success, including the capture of Jerusalem and the True Cross, Heraclius and his allies defeated the shah in 627 and restored the True Cross in 630. In the coming twelve years, however, the empire would lose Syria, Palestine, and Egypt to a new invader, the Arab tribes. Internally, Christians of the eastern Mediterranean were divided. In 638 Sergius penned a fateful Ekthesis or “exposition” of faith, in the hopes of ending certain disputes among Chalcedonians. The Ekthesis, issued in the name of Heraclius, repeats the prohibition initially issued in 633 in the Psēphos on teaching either a single or two activities in Christ (the positions known, respectively, as monoenergism and dyoenergism).

Opusculum 7 is another work of Maximus that stems from his involvement in the monoenergist and monothelite controversies discussed in the introduction to Ambiguum 31 to Thomas. Opusculum 7 dates to 641, and so is the latest of the texts included here. Unlike Opusculum 6, this is a lengthy and highly developed “dogmatic book,” which Maximus sent to one Marinus, a deacon. We know little about Marinus’s identity, but Maximus wrote several letters and texts to him. In Opusculum 7 Maximus defends both a fully dyothelite position and a hermeneutic for reading authoritative theological texts. As is clear from his fondness for expositing Gregory of Nazianzus, the latter argument is central. Opusculum 7 responds to the Ekthesis (638), which was the definitive statement of monothelitism, holding that in Christ there are two natures but one activity (energeia) and one will (thelēma). Against this Maximus holds that will is a capacity and process irremovable from activity, and that activity, in turn, is nature (physis) in action. Put differently, human beings share a common human nature, of which things like rational thought, deliberative choice, and self-determination constitute the activity. One of those things is will.

The two rival parties that met in Ephesus in July 431, one led by Cyril and his allies and the other by Nestorius and John of Antioch, failed to reach an accord and instead each condemned the legitimacy of the other. Emperor Theodosius II then intervened by arranging for a smaller group of representatives from each side to have a series of meetings in Chalcedon under his personal supervision. With Cyril under house arrest in Ephesus and Nestorius deposed and sent into exile, it was hoped that the two sides could achieve reconciliation. Some of the Easterners (so called because they came from the Roman diocese of Oriens or “East”), including John of Antioch himself, were willing to agree to Nestorius’s excommunication, but they continued to hold that Cyril’s Twelve Anathemas (also called the Twelve Chapters) appended to his Third Letter to Nestorius were tainted with heresy (especially Apollinarianism) and so insisted that they too had to be condemned. As these negotiations stretched into October, it became evident that a resolution would not be achieved in the short term, so Theodosius finally released all the bishops to disperse to their sees, including Cyril who had already departed for Alexandria.