I forgot who formulated the idea that difficult-to-understand and difficult-to-believe doctrines tend to have a unifying force for religious communities because they tend to require members of those communities to be more serious about their commitments, or a way for them to show how seriously they take them, by asserting to doctrines that are difficult.

This article says that Nicene Christianity is more difficult to believe and more illogical than some of the heresies. If so, that difficulty may have been a challenge for orthodox Christian believers that allowed them to feel, or demonstrate, more unity with their fellow believers! It may have created a firmer distinction between Christians and non-Christians or near-Christians, for one thing.

Edit: one search found the theory of Laurence R. Iannaccone (which is about different churches within Christianity) who argued that churches that impose more or stronger doctrinal requirements tend to receive more loyalty and commitment from their members. I'm not sure if that was the version that I was originally thinking of, but it seems closely related.

I find the Nicene Creed to be a major stumbling block as a person of Christian faith with a background in formal philosophy. Rather than accepting the inherent paradoxes in Christ's message, it attempts to shoehorn it together using the philosophical swiss army knife of the era, Neoplatonism.

As a result, now Christian orthodoxy is saddled with neoplatonic philosophical vestigial baggage in the term "consubstantial", which means Christians are wedded to and forced to defend a hard metaphysical realism. This comes out hard in Augustine and later medieval Christians. (See Anselm, Aquinas, etc)

They described the faith using the intellectual tools of their era, and now those artifacts are hard-coded into the faith. It would be like if the Nicene fathers were in the early 20th century and described the faith in terms of Theosophy and branded all non Theosophists heretics forever.

As we are in the holiday season it may enlighten readers to know St Nicholas, from whom we derive Santa Claus, was known for two things: secretly giving gifts to the poor and needy, and slapping heretic Arius at this council.

It would be nice to have a new Council, an ecumenical one, coming to agreement to unite Catholic, Orthodox, and as many mainline protestant churches as possible. It may require the Catholic church to make some sort of concession, which is probably the biggest obstacle.

There is no question that not everyone could or would want to unite. But some progress would be nice. To take a historical example the Council of Chalcedon did result in a schism (Oriental Orthodox I think), yet even so, more Christians came out of that Council united than were united prior to it.

The Arian Heresy seems to arise perpetually. Now it is typically of the form, “Christ was a great religious figure, like Buddha, or Mohammed.”; “every religion has X, what makes Christianity different?”; etc.

It directly lead to Magnus to fall and commit heresy

> “rejection of reason,” the same instrumentalized, utilitarian, and reductionist force that has pushed us to the edge of ecological collapse.

This "rejection of reason" is also why we have anti-vaxxers and a host of other problems.

Rejecting reason is insanity.

Maybe a “heresy” is simply that which is valid but not sound.

The ecumenical councils were in some ways the means by which they imprisoned and cut away what is valid (according to some presuppositions) to leave only what is sound (according to the presuppositions of the apostles).

It is the opposite of enlighenment carte-blanche thinking, to take a multivariate attack on delusion through reason anchored in a legacy of wisdom. Too bad the schism broke our understanding of this, but it is still preserved in Eastern Orthodoxy.

Extremely unlikely, as there are a lot of theological dealbreakers: the Catholic veneration of Mary & the saints, Protestant sola scriptura & sola fide, Catholic papal infallibility, among many others.

Why would any of the organizations involved want to do this? Who benefits?

The material conditions are also very different, there's basically no sectarian violence anymore.

But consider how each sect defines unity and the criterion for uniting to others. In my mind, to simplify:

    Evangelicals: we must agree to a common *subset* of beliefs
    Catholics: we must agree to allow contradictory belief systems under the primacy of a single “politically” unifying belief
    Orthodox: we must agree to unite under one belief system

Why?

Every religion in existence has multiple and often contradictory interpretations of doctrine and what is and isn't "canon." Why should Christianity be any different?

At least Catholics recognize Protestants and Orthodox as fellow Christians and aren't burning them at the stake for heresy anymore. That's probably the best we can hope for.

> It would be nice to have a new Council, an ecumenical one, coming to agreement to unite Catholic, Orthodox, and as many mainline protestant churches as possible. It may require the Catholic church to make some sort of concession, which is probably the biggest obstacle.

It was the Protestantism that splintered from the Catholic Church (and then splintered with-in itself), and changed doctrine(s) to what had been accepted for over a thousand years.

For example: the Real Presence. It's been accepted since the earliest times, and both Eastern (Orthodox) and Western (Catholic) Christianity profess it. Are Protestants going to accept it.

Lay members of these various churches certainly seem to believe there are huge theological differences, which they infer from the differences in day-to-day practices. But if you read the views of most of the high-level clergy and theologians in all these churches (and not the fringe, e.g. not the monks on Mt. Athos, or bishops trying to score political points), the differences are incredibly thin and not at all significant when comparing Catholic, Orthodox, Oriental, and Syrian churches to other Christian denominations. The patriarchs of all these churches in particular have been remarkably careful across the centuries, and especially today, to avoid formally committing their churches to views that necessarily prevent union. To be sure there have been many exceptions, but invariably succeeding patriarchs walk them back, it just takes centuries. I get the sense that at any particular time most patriarchs have been amenable to union and willing to make the necessary compromises demanded of the day, but fear conservative factions splitting away, which would be particularly painful for Orthodox and Syrian churches already beset by fragmentation nominally justified by much more minor issues (e.g. Julian calendar).

The biggest sticking points theologically today, from what I gather, arise primarily from 19th century Catholic pronouncements regarding papal infallibility and Mary, specifically the Immaculate Conception and how it relates to Original Sin. Most of the historical disputes (e.g. re miaphysitism, theotokos, unleavened bread, purgatory) have largely fallen away as misunderstandings.

In the case of papal infallibility, all ancient churches admit that the Rome pontiff held supremacy, but there was never agreement on precisely what that meant. The Catholic articulation of papal infallibility offends the synodal view of how doctrine is established, and while many Catholic theologians, including several popes throughout the 20th and 21st century, have publicly explained that popes can only legitimately pronounce what the church, synodally, has already accepted, the precise language used in the formal dogmatic pronouncement is too strictly worded. And it doesn't help that many fringe conservative Catholic theologians are more pro-pope than any pope since the the 19th century and promote this more extreme interpretation.

In the case of the Immaculate Conception, it's not so much that the Catholic view is unacceptable to Orthodox or Orientals, but that the Catholic doctrine is too specific (similar to infallibility) and excludes their alternative framing that beforehand had been understood not to be incompatible with union. Some (all?) the Syrians (Churches of the East), though, seem to accept it, despite not having a tradition rooted in the Augustinian articulation of original sin. And views of the Immaculate Conception among Orthodox and Oriental churches nominally in union with each other differ. (But to be clear, the differences are extremely technical; to most people, including Protestants and especially non-Christians, the varying views of all these churches would be indistinguishable, and theologians themselves often seem to articulate them wrongly, at least compared to how their patriarchs do.)

The Filioque also isn't a theological barrier. The way it's formally understood in Catholicism is not in conflict with accepted Orthodox or Oriental theology, but for various reasons Orthodox see it as an offense to synodality and respect for previous councils' compromises about how far to go in textually articulating the Trinity. I would think most Orthodox theologians see themselves closer theologically to the Oriental churches, but Oriental churches have changed the creed in much more significant ways--IIRC, the Armenian Church added whole new paragraphs. Not that Orthodox theologians are any more willing to overlook these changes, but they certainly don't make much hay about them.

Note that one of the ancient Syrian churches (I always get their names confused) is poised to reunite with the Catholic church. All the doctrinal stuff has long been ironed out, which took about a century, IIRC, from the beginning of earnest dialogue. The sticking point relates to the Catholic church demanding the Syrian church replace their organically evolved clerical disciplines and practices with comprehensive written canonical rules similar to the Catholic church (Latin and Eastern). In truth, the division between the Catholic, Orthodox, Oriental, and Syrian churches have always been primarily cultural (lay) and political (clerical), not theological. The theological differences have tended to be exaggerated on all sides in service of political (clerical, state, and social) machinations. The 19th century Catholic dogmatic pronouncements were largely triggered by political and social revolutions in Europe which caused turmoil among Catholics, with subsequent political and cultural backlashes that resulted in the peculiar theological focus that unfolded and overwhelmed the typical ecumenical circumspection of church leaders.)

Theological differences among churches nominally in union with each other are often arguably no less significant than between churches where union is supposedly not possible. And there has often been de facto union. For example, for several periods throughout the centuries the Orthodox and Oriental churches in Egypt de facto placed their churches under the authority of the rival patriarch while they weathered political winds and suppressions, without the feared theological contamination divisive theologians claimed were inevitable, and despite the claimed differences being deemed much greater and more incompatible than they're believed to be today.