Abstract

Introduction: It is likely that Boethius (480-524ce) inaugurates, in Latin Christian theology, the consideration of personhood as such. In the Treatise Against Eutyches and Nestorius Boethius gives a well-known definition of personhood according to genus and difference(s): a person is an individual substance of a rational nature. Personhood is predicated only of individual rational substances. This chapter situates Boethius in relation to significant Christian theologians before and after him, and the way in which his definition of personhood is a particular answer to the question, “Jesus has two natures, a divine nature and a human nature, but is one what?” Among Greek (and Syriac) speaking theologians, the typical answer is that Jesus is one ‘hypostasis’. Among Latin speaking theologians, the typical answer is that Jesus is one ‘persona’. It is Boethius’s definition of ‘persona’ that inaugurates personhood as such in Latin speaking theology. Although the Greek and Syriac theologians that I survey come close to a concept of personhood as a distinct category, they do not have such a concept and did not need it for their theological purposes. I show that Rusticus the Deacon is an early witness to this Latin theological invention, and also show that for later Latin theologians, the rationality condition for personhood does very little metaphysical work for their Trinitarian theology or Christology. Further, this chapter surveys Patristic and Medieval Christian theologians’ answers to the question, “God the Father, God the Son, and God the Holy Spirit are one God, but each is one what?” The same replies as above are typically given by Christian theologians. These two theological questions frame the discussion about personhood (and ‘hypostasis’) and put a boundary around what a satisfying account of personhood (and ‘hypostasis’) would be. In contemporary philosophy, there is a lot of attention paid to the rationality condition for personhood. But if we look at the text in which Boethius defines a person, we do not find any precise criteria for it. In other texts, he says that a rational being is one compatible with (capable of) thought and free choice of the will. What we find is that detailed discussion of personhood shows up in theological questions about the Trinity and Incarnation, but not in e.g., applied ethics. The intrusion of personhood into contemporary applied ethics with a focus on detailed and disputed criteria for rationality as a condition for personhood seems to be a modern development. From a Patristic and Medieval Christian theology point of view, trying to find just the right detailed criteria for rationality in order to define personhood is a wild goose chase. This chapter makes clear another contribution that Christian theology had for personhood. Given the theological issues at play in developing a notion of personhood, Christian theologians came to posit that e.g., an individual human is a person contingently (i.e. not essentially), but God the Father, God the Son, and God the Holy Spirit are each a person essentially. The contingency for created persons is not based on whether e.g., an individual human has conscious acts (as might be the case for John Locke) but on the possibility of a divine person’s assuming e.g., an individual human nature. This sampling of Christian intellectual history spans over one thousand years. I make no claim of being exhaustive. The chapter consists of six sections, where each section covers significant historical conversation partners who together represent the sorts of things that Patristic and Medieval Christian theologians where concerned with in theorizing about ‘persona’ or ‘hypostasis’. 1. Origen of Alexandria and the Cappadocians: Basil of Caesarea and Gregory of Nyssa 2. Miaphysites: Severus of Antioch, John Philoponus, and Peter of Callinicum 3. Boethius and Rusticus the Deacon: Rationality, Subsistence, and the Invention of Personhood 4. Neo-Chalcedonians (II): Leontius of Byzantium 5. Scholastic Neo-Chalcedonians (I): Gilbert of Poitiers, Richard of St. Victor, William of Auxerre, Alexander of Hales, Bonaventure, Thomas Aquinas, and William of Ware 6. Scholastic Neo-Chalcedonians (II): Henry of Ghent, John Duns Scotus, and William of Ockham