Cappadocian Fathers

The Cappadocian Fathers, also traditionally known as the Three Cappadocians, were a trio of Byzantine Christian prelates, theologians and monks who helped shape both early Christianity and the monastic tradition. Basil the Great (330–379) was Bishop of Caesarea; Basil's younger brother Gregory of Nyssa (c. 335 – c. 395) was Bishop of Nyssa; and a close friend, Gregory of Nazianzus (329–390), became Patriarch of Constantinople. The Cappadocia region, in modern-day Turkey, was an early site of Christian activity. While these three men are typically discussed as the Cappadocians, Macrina, Basil and Gregory's sister, was significant in forming them theologically and in terms of their interpretation of how to live out Christian religious practice.

The Cappadocians advanced the development of early Christian theology, for example the doctrine of the Trinity, and are highly respected as saints in both Western and Eastern churches.

An older sister of Basil and Gregory of Nyssa, Macrina, converted the family's estate into a monastic community. Basil the Great was the oldest of Macrina's brothers, the second eldest being the famous Christian jurist Naucratius. Another brother, Peter of Sebaste, also became a bishop. Their maternal grandfather had been a martyr, and their parents, Basil the Elder and Emmelia of Caesarea are also recognized as saints.

The fathers set out to demonstrate that Christians could hold their own in conversations with learned Greek-speaking intellectuals and that Christian faith, while it was against many of the ideas of Plato and Aristotle (and other Greek philosophers), was an almost scientific and distinctive movement with the healing of the soul of man and his union with God at its center—one best represented by monasticism. They made major contributions to the definition of the Trinity finalized at the First Council of Constantinople in 381 and the final version of the Nicene Creed, finalised there.

They made key contributions to the doctrine of the Trinity and to the responses to Arianism and Apollinarianism.

Subsequent to the First Council of Nicea, Arianism did not simply disappear. The Council of Nicea had asserted that the Son was of the same substance (homoousios) as the Father. The semi-Arians taught that the Son is of like substance with the Father (homoiousios) as against the outright Arians who taught that the Son was not like the Father, but had been created, and was therefore not God. So the Son was held to be like the Father but not of the same essence as the Father.

The Cappadocians worked to bring these semi-Arians back to the orthodox cause. In their writings they made extensive use of the (now orthodox) formula "one substance (ousia) in three persons (hypostaseis)". The relationship is understandable, argued Basil of Caesarea, in a parallel drawn from Platonism:

any three human beings are each individual persons and all share a common universal, their humanity.