Saint Cyril of Alexandria (c. 378 – 444) was the Pope of Alexandria when the city was at its height of influence and power within the Roman Empire. Cyril wrote extensively and was a leading protagonist in the Christological controversies of the later 4th, and 5th centuries.
He was a central figure in the First Council of Ephesus in 431, which led to the deposition of Nestorius as Archbishop of Constantinople. Cyril is counted among the Church Fathers and the Doctors of the Church, and his reputation within the Christian world has resulted in his titles Pillar of Faith and Seal of all the Fathers, but Theodosius II, the Roman Emperor, condemned him for behaving like a proud pharaoh, and the Nestorian bishops at the Council of Ephesus declared him a heretic, labelling him as a monster, born and educated for the destruction of the church.
Cyril regarded the embodiment of God in the person of Jesus Christ to be so mystically powerful that it spread out from the body of the God-man into the rest of the race, to reconstitute human nature into a graced and deified condition of the saints, one that promised immortality and transfiguration to believers. Nestorius, on the other hand, saw the incarnation as primarily a moral and ethical example to the faithful, to follow in the footsteps of Jesus. Cyril’s constant stress was on the simple idea that it was God who walked the streets of Nazareth (hence Mary was Theotokos (Mother of God)), and God who had appeared in a transfigured humanity. Nestorius spoke of the distinct ‘Jesus the man’ and ‘the divine Logos’ in ways that Cyril thought were too dichotomous, widening the ontological gap between man and God in a way that would annihilate the person of Christ.
The main issue that prompted this dispute between Cyril and Nestorius was the question which arose at the Council of Constantinople: What exactly was the being to which Mary gave birth? Cyril posited that the composition of the Trinity consisted of one divine essence (ousia) in three distinct realities (hypostases.) These distinct realities were the Father, the Son and the Holy Spirit. Before the Son became flesh in Mary’s womb, Cyril asserted that there existed two natures of the Son—one divine nature and one human nature. Then, when the Son became flesh and entered into the world, these two divine and human natures both remained but became united in the person of Jesus. This resulted in the slogan “One Nature united out of two” being used to encapsulate the theological position of this Alexandrian bishop.
According to Cyril’s theology, there were two states for the Son: the state that existed prior to the Son (or Word/Logos) becoming enfleshed in the pereson of Jesus and the state that actually became enfleshed. Thus, only the Logos incarnate suffered and died on the Cross and therefore the Son was able to suffer without suffering. Cyril’s concern was that there needed to be continuity of the divine subject between the Logos and the incarnate Word—and so in Jesus Christ the divine Logos was really present in the flesh and in the world.