This week, we read Cyril of Alexandria's 2nd letter to Nestorius, Nestorius’s Reply, Cyril’s 3rd letter to Nestorius, and The Explanation of the Twelve Chapters (a further elaboration of Cyril's 3rd letter). These documents are part of a debate concerning the relationship between the humanity and divinity of Christ and whether Mary should be called "Mother of God" (theotokos).
In my opinion, this correspondence contains two subjects of interest. The obvious topic is the Christological controversy. But I think the debate itself is interesting, as well. Here we get to see how a major disagreement was handled in the fifth-century church. That's what I want to consider first.
The most noticeable feature of this argument is that Cyril and Nestorius don't mince words. For example, Cyril says things like "certain people have scorned the teachings of the truth and filling their own minds with demonic crookedness they strive to debase the mystery of truth" and "Nestorius introduced a host of strange and profane blasphemies." And Cyril is the nicer of the two! All of this sounds very jarring to us. We more often avoid conflict and try to see how we can get along with those with whom we disagree. Accusing someone of being filled with "demonic crookedness" or of leading others astray would be seen as arrogant in the extreme and not at all "pastoral".
Despite the fact that both Cyril and Nestorius use strong language, there is a world of difference between the two. Cyril is, in fact, pastoral in the true sense of the word: he is concerned above all with building up the church. Nestorius, on the other hand, seems motivated by a personal power struggle. He sarcastically mocks Cyril's style and questions his intelligence. Nestorius also boasts of the success of his own flock and threatens to use his position of power in Constantinople against Cyril. You can practically tell who is on the right side of this debate without even considering the issue.
It's easy for our reaction to be, "what's the big deal?" That was my reaction when I first read these letters in seminary. The differences between Cyril and Nestorius seem subtle and of little consequence. We think, "I'm sure glad we don't fight over that any more" and feel that we are enlightened compared to those ancients. However, over time I have concluded that this is a pretty lame opinion to have. Here is the first reaction I wish I had: "Hey, at least these people cared about the identity of Jesus!" I happen to be part of the PC(USA), a denomination with much more divergent views about Jesus than Cyril and Nestorius, yet we are not even having a debate about Christology. Instead we are fighting about things like ordination standards (which I do think is an important issue) and control of church property (which is disgraceful).
After that artificial first reaction, here is the second reaction that I propose: "Let's try to figure out why this particular point was so important to these people." The only real opinion I had in the past was that I didn't want to call Mary "Mother of God." But I didn't get the Christological distinction. I'll try to do better now. Here are the two positions as I understand them: Nestorius claimed that the human things that Jesus did only happened in his humanity. Only the humanity of Jesus was born. Only the humanity of Jesus suffered and died, etc. Therefore, Mary could be called the Mother of Christ, but not of God. Cyril, on the other hand, said that, because the Word of God and man were united in Christ, all of Christ participated in everything that he did. Even though it makes no sense for God to suffer, somehow through the humanity of Christ, God suffered. And even though it makes no sense for God to be born, somehow through the human birth of Christ, God was born. Therefore Mary can be called the Mother of God.
I think that for Cyril, all of the work of Christ would turn on this point. If the Word of God didn't truly participate in Christ's passion, then salvation was not accomplished. If the divinity of Christ is not communicated to the humanity, then neither is humanity glorified through Christ. This is pretty important, after all.
I do not yet understand the emphasis on Mary, though. I see why Cyril could say that Mary was Mother of God, but why was it important to do so? And what implications does this have for Mary?