Christos Anesti!
In recent debates with those of other faiths, I've come across a very interesting question to which I confess I have no distinct and authoritative answer:
By what criteria do we Orthodox
authoritatively,
objectively, and
externally judge whether a given council was ecumenical or not?
If you sit down and think hard about it, it's a much more difficult question than it appears at first blush. We can dismiss standards such as "convocation by the Emperor" or "lots of bishops" as immediately ludicrous on their face. Even the more reasonable alternatives, however, have severe problems:
1. Suppose we say, "ratification by a subsequent council." This raises issues:
-I'm fairly sure there have been heretical councils subsequently ratified by other heretical councils. yet we don't count those as ecumenical.
-Is this a question of "oomph," or can any piddly local council basically create ecumenical councils by fiat? If it's "oomph" that counts, how do we determine whether it's sufficient, without running into the infinite causes dilemma?
2. Suppose we say, "participation by the Pentarchy." This raises issues:
-Does this mean that, since the Great Schism, Orthodoxy has lost its ability to hold new Ecumenical Councils? This would have serious implications as to Orthodoxy's catholicity.
-What of the First Ecumenical Council? Constantinople wasn't even a big-name see at the time.
-What of the Second Ecumenical Council? The Bishop of Rome was not present.
-What of the Ignatian council of 869? What of the Council of Florence? Both had at least ostensible participation by all the Patriarchates.
3. Suppose we say, "ratification by the Pentarchy." This raises issues:
-Again, does this mean Orthodoxy is stripped of the ability to hold new Ecumenical Councils?
-Again, what of the Ignatian council, and Florence, where the Pentarchy apparently ratified 'em, but we Orthodox reject them?
-More importantly, what of Chalcedon and the other councils we
do accept that weren't ratified by the whole Pentarchy?
-Especially, what of Chalceon canon 28, which was rejected by Pope St. Leo the Great, a move apparently accepted as legitimate by St. Anatolius?
4. Suppose we say, "ratification by the laity." This raises issues:
-How many need to ratify a given council? 51%? 66%? 75%? 90%? How can we know what proportion is right? How can we measure whether this consensus exists? Within what length of time should it come to a proper degree of laity acceptance?
-What of all the times when heresy plagued the Church to such extent that probably a majority of the laity were in heresy? (I'm thinking specifically of Maximus the Confessor, and "Athanasius against the world.")
-What makes an ecumenical council necessary at all, under this scheme? If majority rules, and Truth always wins out over the centuries, then why not just leave it to the body of the faithful?
5. Suppose we say, "ratification by the bishop of Rome." This raises issues:
-Why are we still Orthodox, then?

-What of the Photian council of 879, which was apparently ratified by Rome and then deratified? Does this mean the foundations of the Faith are subject to repeal on the whim of one man?
-If true, why was the papacy's vote so frequently ignored (Chalcedon canon 28) or outright opposed (St. Cyprian)?
-Again, it seems this would obviate the need for an ecumenical council except for informational and diplomatic purposes, if the papacy were able to decree authoritatively what was and wasn't true doctrine.
-On the face, it does seem, however, that this rule is the easiest to fit into the majority of historical circumstances.
(My gut inclines me to say that it's a combination of 2, 3, and 4, on something of a sliding scale, but while this answer seems to me the most logically tenable, it is by no means particularly satisfying.)
Finally, I would be extremely interested to see
any authoritative documentation--that is, in the canons or Church Fathers--as to what constitutes a valid ecumenical council. It seems to me that 20/20 hindsight and subjective private judgment is not a wise or solid foundation for something so incredibly vital to Orthodox ecclesiology.
(In particular, Orthodox blogger Perry Robinson
wrote:
With 2nd nicea, the documents in question actually LIST the conditions for a legitimate council and it seems quite strange that they do not list papal ratification and even stranger that NO ONE IS MENTIONING THEM AT ALL, even though it is the one place in an ecumenical council recognised by ALL that discusses and lays down the criteria in question. After a fairly thorough reading of the Seventh Ecumenical Council, I am unable to determine where he gets this. But this'd be just what I'm looking for. Any thoughts?)
Christ is in our midst!
Pax,
--Seraphim