One Nature Or Two? Explained Simply
The disagreement that split the Church, in ordinary language, including the part where both sides say the same thing.
Start with what nobody disputes
Every Orthodox Christian of either family confesses these four things without hesitation:
- Jesus Christ is fully God. "In the beginning was the Word, and the Word was with God, and the Word was God." John 1:1.
- Jesus Christ is fully man. He was born, hungered, thirsted, wept, slept, bled and died. Luke 2:7; Matthew 4:2; John 4:6; John 11:35; John 19:34.
- He is one: one Christ, one Son, one Person. Not two persons sharing a name.
- The union is real and permanent: never mixed into a third thing, never dissolved, never interrupted. "In Him dwells all the fulness of the Godhead bodily." Colossians 2:9.
Hold those four. Every genuine fifth-century argument was about how to protect all four at once, and every condemned heresy lost one of them.
The two errors both our Churches condemn
Nestorianism: Divided the one Christ until He became two: a divine Son and a human son side by side, with Mary mother only of the man. Condemned at Ephesus, 431. Rejected absolutely by both families.
Eutychianism: The opposite extreme: the humanity swallowed by the divinity like a drop of vinegar in the ocean, so Christ is no longer truly one of us. Rejected absolutely by both families. The Coptic Church anathematised Eutyches. This cannot be repeated too often, because the whole charge of “monophysitism” depends on ignoring it.
The word that broke everything: physis
Physis is usually translated “nature.” In the fifth century it did not carry one agreed meaning across the Christian world.
In Alexandria, following St Cyril, physis was used of a concrete existing individual reality, closer to what others meant by “person” or “acting subject.” To say Christ has one physis was to say: He is one concrete reality, one who acts, one Christ. Not two.
In Antioch, Constantinople and the Latin West, physis was used more abstractly, the set of properties that make something what it is. Divinity as such; humanity as such. To say Christ is in two physeis was to say: He is genuinely God and genuinely man, and neither has been cancelled.
Now read the two confessions again.
The Oriental Orthodox confession
With St Cyril: one incarnate nature of God the Word.
Protecting: The unity of Christ. Everything He does, walking on water and weeping at a tomb, is done by the one same Christ, not by a divine part and a human part taking turns.
Not saying: That His humanity was diminished or absorbed. The word “incarnate” carries the weight: the one nature is the nature of God the Word made flesh, and the properties of divinity and humanity remain fully intact within the union, without mixture, confusion or change.
The Eastern Orthodox confession
Now put them side by side
- The Alexandrian says "one" to mean: not two subjects. The Byzantine agrees, Christ is not two subjects.
- The Byzantine says "two" to mean: divinity and humanity both fully real. The Alexandrian agrees, consubstantial with the Father and consubstantial with us.
- The Alexandrian fears "two" will divide Christ. The Byzantine fears "one" will absorb His humanity. Neither intends what the other fears.
And both use the same safeguards. Chalcedon: without confusion, without change. The Oriental confession: without mixture, without confusion, without alteration. They are guarding the same door with the same locks.
What Christ said about all of this
Nothing. Not a word.
He said “I am the way, the truth, and the life” (John 14:6). He said “Follow Me” (Matthew 4:19). He said “unless you become as little children” (Matthew 18:3). He said the world would know us by our love for one another (John 13:35).
The Fathers who fought over physis were defending Him faithfully and we owe them everything. But the fence is not the field. When two flocks of the same sheep cannot graze together because of the fence, the fence is the problem.
And this is not a modern rationalization
It is the conclusion reached by official theological commissions of both families in the twentieth century, after sustained study, and set out in signed agreed statements.