The book is devoted to the relationships between Nicene and Homoian Christianities in the context of broader religious and social changes in post-Roman societies from the end of the fourth to the seventh century. The main analytical and interpretative tools used in this study are religious conversion and ecclesiastical competition. It examines sources discussing Nicene–Homoian encounters in Vandal Africa, Gothic and Lombard Italy, Gaul, and Hispania – regions where the polities of the Goths, Suevi, Burgundians, and Franks emerged. It explores the extent to which these encounters were shaped by various religious policies and political decisions rooted in narratives of conversion and confessional rivalry. Through this analysis, the aim is to offer a nuanced interpretation of how Christians in the successor kingdoms handled religious dissent and how these actions manifested in social practices.

This chapter explores the reception of classical ethical philosophy in the fourth-century Cappadocian Father, Gregory of Nazianzus, by focusing on the first of his five Theological Orations (Or. 27). An Athenian-trained rhetorician who became the most widely studied and imitated author in Byzantium, Gregory weaves together various strands from ancient ethical discourse in order to set out the moral and cultural prerequisites for performing theology. Gregory’s construction of the ideal theologian reflects late-antique discussions about the proper exegesis of texts, the moral character expected of teachers and students, and the policing of discourse. Finally, Gregory distinguishes the appropriate performance of theology from theology performed simpliciter through a set of qualifications that reflect a recognisably Aristotelian framework, one that can be traced back to the Nicomachean Ethics.

The bitter division in Alexandria that led to the Council of Nicaea began as a theological dispute between Alexander, the bishop of Alexandria, and a significant number of his clergy, including a presbyter Arius, and quickly overflowed into a feud among eastern bishops. “Arianism” was assumed by scholars and theologians to be a coherent set of heretical teachings embraced by a succession of followers. Historians have now identified sets of alliances rather than genealogies as well as the polemical construction of “Arianism” by Athanasius and Marcellus. This separation of Arius from later “Arianism,” together with the continuing lack of consensus with regard to theological or philosophical genealogies as the source of his thought, encourages another look at the particular social and religious context of the initial local controversy. The central issues of monotheism, apophatic theology, incarnation, and changeability in fact map over traditional Christian apologetic theology and the literary and ecclesiastical legacies of the Great Persecution. Arius’s insistence on divine monotheism and transcendence together with his defense of a “living image” may echo the contemporary arguments with Celsus and Porphyry in Eusebius and Athanasius as well as a refutation of polytheism.

Locke omitted the Trinitarian dogma from his elucidation of the Christian religion in "The Reasonableness of Christianity." This omission implicitly made belief in the Trinity unnecessary to salvation and attracted much criticism, leading John Edwards and others to accuse Locke of Socinianism. Locke refused to clarify his position on the Trinity even when Edwards and Stillingfleet pressured him to do so. His public silence on the Trinity was surprising to many, because the "Reasonableness" appeared in the middle of the heated Trinitarian controversy of the late seventeenth century. Locke actually expressed, unsystematically and at times ambiguously, his views on Christ’s nature and mission in his public writings on religion and in various manuscript notes, and he focused on Trinitarian issues in "Adversaria Theologica" and other manuscripts. His Christological reflections and his consideration of Trinitarian issues denote a heterodox, non-Trinitarian conception of the Godhead, which presents both Socinian and Arian elements, although he never expressly denied the Trinity. Irenic and prudential reasons contributed to his choice to avoid public discussion of the Trinitarian dogma.