They made that series partly to provide background for their earliest series on Justinian and Theodora. My own opinion on Justinian isn't nearly so positive as theirs.
They covered this subject from a Secular perspective, not really interested in which position in these disputes The Bible agrees with. And that's fine, an outsider perspective on Christianity can be very useful. So I'm going to take it on myself to provide my Biblically influenced personal perspective. Though the issue central to the last episode, episode IV, is primarily what I'll be talking about.
The first three episodes are all about disputes where who won in the end I feel is pretty strongly agreed to be the Biblically supported position. Most Christians speaking negatively of the Council of Nicea do so from not knowing what that Council actually debated. Last month I did posts on The Council of Nicea and the Homoousion Doctrine partly in preparation for this post.
I feel they should have had another episode between the Council of Nicea episode and the Nestorian controversy episode (Episodes III and IV) on the Pelegian controversy. The chief opponent of Pelagius was Augustine of Hippo, a man I have little fondness for.
Some people think what Pelagius taught has been misrepresented by his opponents.
Recent analysis of his thinking suggests that it was, in fact, highly orthodox, following in the tradition established by the early fathers and in keeping with the teaching of the church in both the East and the West. ... From what we are able to piece together from the few sources available... it seems that the Celtic monk held to an orthodox view of the prevenience of God's grace, and did not assert that individuals could achieve salvation purely by their own efforts...[ Bradley, Ian (1993) The Celtic Way. London: Darton, Longman and Todd; p. 62]Free Will is definitely a Biblically supported Doctrine. Theodore of Mopsuestia wrote "two tomes against him who asserts that sin is inherent in human nature." Which was no doubt an attack on Augustine of Hippo.
The controversy central to the final video of this series was a three way dispute about how Jesus Divine and Human natures relate to each other.
1. The Chalcedonian position, that Jesus had two different but unified or mixed natures, a Divine Nature and a Human Nature.
2. The Nestorian position, that Jesus had two distinct and separate natures, a Divine Nature and a Human Nature.
3. The Monophysite position, that Jesus had one single Nature that was both Divine and Human.
(Monophysite was often used broadly to include other groups that wouldn't have called themselves that. I personally find the best form of Monophysitism to be Miaphysitism.)
All three agree that Jesus was both Divine and Human, and not in a Greek demigod half-god/half-man sense, but fully Divine and Fully Human. I personally find the differences between these three views to be quite semantical and not at a big deal. Especially since I'm not sure what my own view is. But it seems in Christianized Rome is was a pretty big deal.
Last month I expressed support for Traducianism on the issue of who most Human Soul/Spirits are created. Even that doesn't settle the issue. While at fist glance it would seemingly held the Chalcedonian position, a Human Nature inherited from Mary mixed with a Divine Nature provided by the Holy Spirit. But a Monophysite or Miaphysite would retort that we don't refer to most Humans as having two natures, a Paternal and Maternal one, but as having one. Perhaps the Nestorian position would be the hardest to make compatible with Traducianism, but I don't think impossible.
Pretty much all major Christian denomination in the West are considered nominally Chalcedonian (Catholicism, Greek Orthodox, all major Protestants denomination as well as Baptists and Pentecostals). Even though I don't think most average Christians or even Pastors in America have ever actually thoughts about what their position on this debate would be.
One reason why I think Protestants and Evangelicals should tale a second look at this History is because of how much the inciting incident was Nestorius (and it seems even some Monophysites) objected to calling Mary "Theotokos" (God Bearer) a Title that definitely plays into her quasi-Deification. And it seems Nestorius may have inherited this from his mentor Theodore of Mopsuestia.
As someone who likes to draw attention to overlooked Historically important Women, I wish the Extra Credits video on his controversy had talked about some of the Women who were important to these events. Theodosius II's sister Pulcheria worked with Cyril of Alexandria strongly supporting the Chalceodnian position, and was a strong supporter of calling Mary Theotokos. While his wife Aelia Eudocia was a Monophysite who opposed calling Mary Theotokos.
If the Chalcedonian position is correct, it's unfortunate it had such horrible representatives during this time period. Cyril of Alexandria was very Anti-Semtic and generally in support of persecuting non-Believers. However as I expressed before, I blame these negative traits more on his belief in Eternal Damnation.
So again I'm not entirely sure what my position is. I'll stick with being Nominal Chalcedonian for the time being. Nesotrianism can be the most interesting historically to look into, and I may definitely have more to say about that subject on this Blog in the future.