What objective, foolproof method do Eastern Orthodox have for working out which side is correct in the case of a Schism?

I'd like to add a little extra to the previous (very good) answers:

The most widespread answer I keep encountering in various Orthodox publications (both online and in books touching such issues) is basically rooted in Matthew 7:15-17 "By their fruit you will recognize them". The flawed teaching shall eventually yield bad fruit and fade away even if takes centuries or even millennia.

For consolidating the argument, the same orthodox scholars use as a precedent example the iconoclast movements of the first millennium BC which were quite tense, with people being persecuted and even martyred for not denouncing icons. And even with it's power and many supporters, after quite a few centuries the iconoclast movement slowly faded away, the truth (or Will of God) came to light and icons were reinstated.

Claims that Orthodoxy is, well, the orthodox path are supported with: following the 7 ecumenical councils (including not altering the Creed with Filioque), having Jesus Christ as Head of the Church (as per scripture) and not the Bishop of Rome etc. The argument I've presented above is not used to claim the righteousness of Orthodoxy, rather it is left as a, quite powerful, open ending, the point being that the will of God - through history and it's convulsions - will eventually tell.

@JohnnySubterfuge - My experience is very similar to yours. After being brought up in Protestant evangelicalism, I asked the same epistemological questions and started thinking about converting to an apostolic tradition while a junior in college. I briefly looked into Eastern Orthodoxy, but the whole thing seemed a bit too foreign for me, and I converted to the RCC when I was 21. In retrospect, I think I did not give Orthodoxy a good enough look. This year, some 30 years later, I have been going to Orthodox catechism classes, and am thinking seriously about making the move.

One thing I have learned this year, is that for Orthodox, less is sometimes more. Yes, on major issues of the faith and practice they are going to be very strict. But on more minor issues, they simply don't take an official position on them. The RCC, on the other hand, feels it necessary to take an authoritative position on even minor issues. For example, the immaculate conception of Mary. The RCC feels it is a necessary position because their doctrine of original sin dictates that a person would be guilty of sin genetically at birth, and since they want to maintain the truth that Christ was fully human, but sinless, they feel this is a necessary doctrine, that was dogmatized at Vatican I even though there was quite of bit of dissension on the issue within the RCC before that. On the other hand, the Orthodox have no such problem to solve. To them original sin is loosely defined so as only include the consequences of it (death) being passed on from generation to generation. We are all guilty because we all choose to sin, and we all choose to sin because that's what we choose to do. They don't try to explain it further, and therefore there is no Christological issue.

So - to answer your question. Major issues within the Orthodox Church would be solved by an Ecumenical Council, and not by any one bishop. But they would believe that all the major issues were already solved long ago by the early Councils. So there is no need for a mechanism to solve a hypothetical 50/50 split between bishops because minor issues are left as mysteries of the Church.

As far as deciding on a question that may be divisive within the Church, the Orthodox Church may not have one "center" such as the Pope, but they do still have Councils of Bishops, much like the Catholic Church, in which such questions can be discussed and decided upon. Even in this manner an agreement may be reached, but unfortunately, there is never any way to totally eradicate division if its proponents are completely unwilling to compromise or let go. So, they may continue on, but by no longer remaining within the community of the Church as it was before the issue.

Another matter you might be interested in, given your conversion from Protestantism, is the nature of the relationship between the Catholic and Orthodox Churches. You are correct that they were One Church until a time, but the "official" separation of the Churches, circa 1055 A.D. and again circa 1438 A.D., was more or less a confirmation of events that had long since past.

One such example is when the Eastern Church (think Orthodox) asked for assistance from the Holy Father in the form of an army to combat the Muslims at their doorstep, the understanding, or "deal", reached was that the Eastern Church would once again come into full communion with the Western Church (think Catholic) in exchange for said army. However, at the end of it all (the totality of all the events) only part of the Eastern Church came back into communion with the Western Church, such as some of the Eastern Rite Catholic Churches, and afterward the two Churches went down their individual paths.

But the true beginnings of this affair had roots in the past. One was the fall of the Western Roman Empire. After some time, those in the still thriving Eastern Roman Empire, including the Emperor, began to question why they should take any direction from the Supreme Pontiff in Rome that was now, to them, nothing more than part of a fallen empire and civilization that had crept into the dark ages. Hence the two Churches developing from that time forward, with the events later being more of a culmination.

There are at least three ways that the Eastern Orthodox use to determine "correctness" on any issue.

First and foremost, they believe they are the earliest church founded by Christ and apostles. "The Orthodox Christian faith is that faith "handed once to the saints" (Jude 3), passed on in Holy Tradition to the apostles by Jesus Christ, and then handed down from one generation to the next, without addition or subtraction." from https://orthodoxwiki.org/Introduction_to_Orthodox_Christianity

Two is they use the earliest occurrence. "The Church keeps the early traditions of Christianity, " from https://orthodoxwiki.org/Orthodox_Church

Three is they use the council approach. For example, Nicea structures the church authority over areas, rather than later idea of a single man over all. See Canon VI of the First Ecumenical Council. This also refers to #2.

So, earliest tradition, council type government, direct unbroken succession with Christ Jesus.

In essence you are asking an epistemological question: How can one side "know" that it is correct in a theological debate? The question could just as well apply to any Christian body, let alone the Eastern Orthodox Church.

Within the eastern Church exists a notion called prelest. It is a Russian word that basically means "deception", but it is a kind of spiritual deception in which the one deceived is absolutely convinced of his (or her) correctness and can sometimes even logically "prove" their position. There are literally volumes written on the subject in the eastern tradition, dating back to the Desert Fathers of Egypt and witnessed in Scriptures such as 2 Corinthians 11:14 (And no marvel; for Satan himself disguises himself as an angel of light.)

One might be tempted to say that such a schism as the one you suggest could be resolved by an 8th Ecumenical Council, or some such thing. Vincent of Lerin prescribes a method for consulting and weighing the writings of the Church Fathers when disputes over Scriptures arise.¹

The Orthodox are sobered, however, by the recollection that on many, many instances those in the past - both pre- and post-schism - who held to what is understood today to be the truth were defeated by just such mechanisms themselves. Perhaps the greatest example of this was the Council of Florence in 1438, wherein all but one eastern hierarch in attendance agreed to reunification with Rome more or less under Rome's terms. A pre-schism example would be that of monothelitism, held for a time during the 7th century by the eastern Patriarchs, but rejected by Rome.

The simple answer to your question is that in the mind of the Eastern Orthodox Church, there is no objective, foolproof method for working out logically who is on the right side of the schism, simply because the Church is not rational in the sense you suggest. Some - perhaps just a few - will remained guided by the Holy Spirit, but others will be deceived or deluded. Those who are deluded will be able to present sound arguments for their position. Protopresbyter Michael Pomazansky writes:

Philosophy [of which logic and epistemology are branches] is rational and abstract. It proceeds not from faith, like theology, but seeks to base itself either on the indisputable fundamental axioms of reason, deducing from them further conclusions, or upon the facts of science or general human knowledge. Therefore one can simply not say that philosophy is able to raise the religion of the Fathers to the degree of knowledge.²

The Church admits the possibility that schisms may arise that are so severe that only a small body of believers may be left. During the schism that resulted during the Council of Florence only a single hierarch - Mark of Ephesus - remained. Although the eastern Patriarchs eventually rejected the council, there is nothing to prevent such a thing from occurring again and remaining in place. "The truth of the One Church," writes Father Michael, "is defined by the Orthodoxy of its members, and not by their quantity at one or another moment."³

<sup>1. Commonitory III.7-8
2. Orthodox Dogmatic Theology (3rd ed.), pp.363-364
3. Ibid., p.222.</sup>