This week, Pope Francis did something unprecedented. (One could perhaps write that sentence every week). He named, as a Doctor of the Universal Church, a tenth-century Armenian mystic called Gregory of Narek. Now, as the Catholic Church already recognizes 35 other Doctors of the Church, a designation that indicates saints who have made particular contributions to theological learning, you might wonder what’s so unprecedented about it. I’ll tell you.

(Readers who find theology, church history, and canon law boring should stop reading this post right now. You know who you are. We’ll get back to our regularly scheduled posting presently).

Gregory was a priest in the Armenian Apostolic Church. As a formal matter, the Armenian Church and the Roman Catholic Church have been out of communion since the fifth century. By the time Gregory was born, the two churches had already been divided for about 500 years. So Pope Francis has named, as a saint of particular theological distinction, someone from a separated church–someone who was not, in fact, a Catholic at all.

The churches separated over Christology. The Armenian Church declines to accept the Council of Chalcedon (451), which declares that Christ is one person with two separate, but conjoined, natures, human and divine, a position known as diophysitism. Like her sister Oriental Orthodox Churches, including the Coptic and Syriac churches, the Armenian Church holds instead that Christ has one combined human-divine nature, in which the human and divine nonetheless remain distinct, a position known as miaphysitism.

The disagreement does seem a rather technical one. Much turns on the proper fifth-century translation of Greek words like “physis” and “hypostasis.” For centuries, however, the two sides condemned each other as heretical. Chalcedonian Christians, including Catholics, Eastern Orthodox, and Protestants, dismissed Orientals as “monophysites.” That designation has been dropped in our lifetimes, though, both because it is incorrect (unlike miaphysitism, monophysitism is indeed a heresy, but not one Orientals espouse) and because it is rather insulting. Indeed, in 1996, Pope St. John Paul II signed a declaration with Catholicos Karekin I, the patriarch of the Armenian Church, that attributed the centuries of division to semantic and other misunderstandings and explained that, whatever the other differences, Christological controversies should no longer separate the two churches. In fact, current Catholic canon law allows Orientals to receive communion in a Catholic church.

Now, the Armenian Church–my own church, in case you are wondering–has long considered Gregory of Narek, who wrote a beautiful set of reflections called the Lamentations, a saint. Indeed, he’s a very prominent saint, whose prayers are included in our Lenten vigils. But he was not a Catholic. I imagine he himself would have been a bit surprised to find that Rome had declared him a Doctor of the Church, a saint whose theological writings bear special distinction. What’s the explanation?

As far as I can make out, it’s this. When Rome receives part of an Eastern church into full communion, it accepts all of the Eastern church’s saints, as long as they did not explicitly contradict Catholic doctrine. So, when part of the Armenian Church united with Rome in the 18th century to form the Armenian-rite Catholic Church, Rome accepted the Armenian saints, including Gregory of Narek. He was, as it were, grandfathered, and has been a Catholic saint ever since. That’s how, in light of his great contributions, he can be declared a Doctor of the Church today.

Pretty much everyone in the Catholic world seems happy, or at least not unhappy, about this turn of events (though not everybody), including the traditionalists at Rorate Coeli:

It is interesting to note that Gregory lived at a time when the Armenian Church, to which he belonged, was not formally in communion with Rome and Constantinople. However, as those interested in the extremely tangled history of Christianity in the first millennium are well aware, one cannot always speak straightforwardly of “schism” and “heresy” when dealing with the theological and ecclesiastical divisions of Christendom in that era.

Just so. Armenian Apostolic Christians, too, are genuinely pleased. Indeed, Pope Francis’s action is particularly welcome this year, the centennial of the Armenian Genocide of 1915, in which 600,000 to 1.5 million Armenians in Ottoman Turkey, including many Christian martyrs, lost their lives. The monastery of Narek on the shore of Lake Van, where Gregory once lived and taught, was itself a victim of the purge. The monks abandoned it during the genocide, a hundred years ago, never to return. Today, a mosque stands on the site.