The Cappadocian Fathers: Basil, Gregory of Nyssa, and Gregory of Nazianzus

The three Cappadocian Fathers — Basil of Caesarea (c. 330–379), his younger brother Gregory of Nyssa (c. 335–c. 395), and their close friend Gregory of Nazianzus (329–390) — did more than any other 4th-century thinkers to give the Nicene doctrine of the Trinity, affirmed at the Council of Nicaea in 325, a philosophically defensible technical vocabulary. Basil, educated in rhetoric and philosophy at Athens alongside Gregory of Nazianzus (where, according to Gregory's own funeral oration for Basil, Oration 43, the future emperor Julian was a fellow student), became bishop of Caesarea in Cappadocia in 370 and used his authority to organize monastic life through his Asketikon, while also composing the Hexaemeron, nine homilies on the six days of creation that engage directly with Greek natural philosophy, including Aristotelian and Stoic cosmology, to defend a created, temporally originated cosmos against pagan eternalism. His treatise On the Holy Spirit (375) argues, largely through liturgical usage and scriptural exegesis rather than syllogistic proof, for the full divinity of the Holy Spirit alongside the Father and the Son.