This is going to sound like it is only really for real theology nerds – a set of technical terms that sounds so darn similar that you can never remember which is which. If they’d used two completely different words, such as ‘Bob’ and ‘Steve’, you’d feel differently. The words sound the same, almost, but they say two very important things about an exciting subject. 

Take yourself back to the fifth century, and you’ll find excitement and hubbub all around you about this. How are we to understand the Son of God come in the flesh? How can it be that God became a man? What, in Christian faith, are we actually saying when we declare that ‘he was born of the virgin Mary’? 

The Greek word ‘hypostasis’ was the word that was used in the same way that ‘person’ was used in Latin. In a sense, it is a better word to use because we get confused by ‘person’ because we have a specific modern meaning for that. It had a wide range of meanings, but in philosophy it meant something like ‘being’ or ‘substantial reality’.

But when theologians wanted to say ‘the Son of God shares something with the Father, but is also distinct from him’ they choose specific words to do the job. They said: ‘Christ has the some substance, or stuff, as God, but he has a different hypostasis’. He is of one being with the Father. But he isn’t identical to him. That was the debate at Nicea in 325, and you can thank Basil and the guys from Cappodocia for that. 

Chalcedon: Two Natures, One Person

However, there was more to be said. In Chalcedon in 451, the issue was: how were Jesus’ humanity and his divinity actually related? How did these two things exist in the same man, such that we can say ‘fully God, fully man’? And yet – we also want to say he’s only one person, or hypostasis? 


Here’s the solution. Christ is one hypostasis, or person, but he has two natures – divine and human. The divine and human natures of Christ are joined together in a “hypostatic union”. That was Chalcedon in 451.

Leontius: Humanity Personalised in The Word

But still: what was this union like? How were the two natures joined? Clearly, in Jesus of Nazareth we do not have two persons, a human and a divine one, competing to run him. That much had been decided. But… where did this one person come from? Heaven, or earth? 

Some claimed that Christ’s human nature was ‘anhypostatic’, which means roughly ‘non-personal’, as if the centre of his personhood was really his divinity, his godness, rather than his humanity. Surely, it had to be said that in Christ the ‘deeper’ reality was his divinity? He was the divine logos before he took on flesh, yes? 

But some others were uncomfortable with this. Surely if Jesus wasn’t a human person, then he was a kind of a shell, and inert human body or nature just possessed by divinity. 

Step forward your hero and mine, Leontius of Byzantium (d. 543). He said: look – the union of the divine and the human natures in Christ is ‘anhypostatic’ in that Christ’s human nature is not personal in itself, but also ‘enhypostatic’ in that in is personalised by being united to the eternal person who is the second person of the Trinity. This makes his hypostasis or personhood fully human and fully divine.

Why it Matters

Is this the kind of debate which is really about as much use as deciding how many angels can dance on the head of a pin? Why should you know this?

You should know it because getting this wrong has devastating consequences. These precise terms are used not because they explain everything, but because they prevent misunderstanding.

If Jesus is not fully God and fully human, then the cross – which is our only hope – is either pointless or unjust. If he’s not fully God, then it is the punishing of an innocent third party for our crimes, which is perverse. If he’s not fully human, then the whole thing is irrelevant to us, since he is not like us in any way. When we are sloppy about our language – and I am looking at you, preachers – then we lead people to accept not the true God, and his true work, but some warped substitute. 

Photo: Amish Patel, flickr