One of the most intriguing of the new directions in Neoplatonic scholarship, and one that still needs a huge deal of research, concerns Christian Neoplatonism, and in particular Patristic Neoplatonism. I will investigate how, through which channels, and with what adaptations the trans-school philosophical doctrine of oikeiōsis was received and transformed by the two main Patristic Neoplatonists: Origen of Alexandria (end second - first half of the third century CE) and Gregory of Nyssa (second half of the fourth century). I will also endeavor to assess how much Gregory’s oikeiōsis theory owes to Origen – a great deal, I suspect.
The doctrine of oikeiōsis, or "appropriation, familiarization," is generally associated with Stoicism, but it is actually found also in Peripatetic philosophy and in Platonism. The Stoics seem to have made the most of the so-called "social oikeiōsis" (a notion that has been called into question in recent scholarship), which is closely related to the theory of kathēkonta or "appropriate acts" toward other people. As I will argue, Christian Neoplatonism elaborated both on the notion of oikeiōsis toward other people and on that of oikeiōsis toward the divinity, but they also introduced the remarkable innovation of an oikeiōsis of the divinity itself toward itself (thanks to the relational element introduced by the triad of divine hypostases) and of the divinity toward its own creatures. The latter kind of oikeiōsis in Origen, Didymus, and especially Gregory of Nyssa culminates in the eventual apokatastasis. This is the eschatological universal restoration in which all rational creatures, after purification and illumination, will voluntarily return to God, the supreme Good (a view later rejected by mainstream Christianity especially under the influence of Augustine and Justinian, who advocated the eternity of hell).
I will begin with preliminarily examining how the doctrine of oikeiōsis was received by two Platonists who can be regarded as close to the so-called Middle Platonism, but at the same time took the Bible as their authoritative text and also absorbed many Stoic elements: Philo of Alexandria (first half of the first century CE) and Clement of Alexandria (end second - beginning of third century CE). My research will then focus on the two Christian Neoplatonists who made the most of the philosophical doctrine of oikeiōsis and will argue that they brought it to bear on pivotal issues of ethics, theology, and eschatology. In sum, what emerges from my exploration is that it is Origen who thoroughly Christianized the oikeiōsis doctrine, but especially Gregory identified apokatastasis as the Godhead’s oikeiōsis or eventual re-appropriation of all beings, which belong to it. This is clearly most relevant to the eschatological theory.
Both Origen and Gregory especially invested the oikeiōsis doctrine with a strong ethical thrust, integrating it completely with their Christian Neoplatonic ethical framework, which is profoundly informed by the paradigmatic and normative nature of the telos, the ultimate end. I will finally contend that these Christian Neoplatonists, as well as other early Christian and Jewish Platonizing sources, can help clarify the philosophical doctrine of oikeiōsis itself, which poses substantial problems and which these Platonists received. They even present the technical vocabulary of oikeiōsis, which for instance in Hierocles’ famous, non-technical passage on the "contraction of circles" is absent (and this has raised concerns in recent scholarship). Therefore, it is useful to consider these Christian Platonists' texts when assessing the philosophical doctrine of oikeiōsis altogether.
What is Neoplatonism? Purpose and Structure of a Philosophical Movement to New Directions in Neoplatonism