But that's not how they are understood. Rather than a process of integration, dialog, and participation, through which bishops accept these standards, they are considered finished products, reflecting a conclusive end to a certain controversy. Thus, Nicaea ended Arius, Constantinople I ended Apollonaris and the Pneumatomachoi, Ephesus ended Nestorius, etc. etc. But that's hardly the case. To draw out the irony, here's a quote from emperor Justinian in his On the Orthodox Faith about councils:
"Often at councils some things are said by some of those found at them out of partiality or disagreement or ignorance, but no one attends to what is said individually by a few, but only to what is decreed by all by common consent; for if one were to choose to attend to such disagreement in the way they do, each council will be found refuting itself"
The point of this statement is to explain why Constantinople II was being called. It was, in essence, a repudiation of a strict Chalcedonian position, reincorporating a larger Cyrillian corpus. Thus, not only was Cyril's Second Letter to Nestorius considered orthodox, but now his Twelve Anathemas were as well. In addition, Constantinople II decided against Ibas of Edessa and Theodoret of Cyrrhus, whose Chalcedonian theology was sympathetic towards Nestorius (and informed by the "school" of Diodore). However, this decision was itself disputed from those who had formed a new concept of councils in light of Chalcedon. It was what Richard Price dubbed "conciliar fundamentalism": the idea that ecumenical councils were not merely benchmarks, even if highly revered like Nicaea, but pieces of inspired and canonical scripture.
I think there's a real danger in this position. It requires a leap of logic to go from the NT's claim about the Apostolic tradition (or the handing-on of the faith) to particular ecumenical decisions which, in aggregate, become infallible. The process saw pieces of church broken off. The Persian Church of the East was sufficiently detached that it was unaware of the scale of the debate. With fair judgement, they recoiled from the fact that the Roman churches had condemned their teachers Diodore and Theodore (who had become revered as textual analysts), centuries after their death. A system, imposed by a foreign church and reified through a claimed authority, made reconciliation impossible and a kind of join-or-die opposition inevitable.
Councils claimed to be faithful articulations of the faith once received through the Apostles. But by adding to a sacred corpus, beyond the NT scriptures, goal-posts shifted. What was once acceptable became anathema. Whether intended or not, this certainly opens the door to doctrinal development, collapsing conceptual paradigms with the very words of God. For some Orthodox, this is faithful to the idea that the Spirit of God would continue to lead the church. But such is to blur the concept of canon with the idea of inspiration. Early Christians could both claim that the divine scripture was known and closed, while also authoritatively citing works considered to be inspired. But in the turn to councils (which are not as easy to identify as one might think) one reifies their authority and depreciates church councils as on par with irrevocable canon.
"Conciliar fundamentalism" reflected the new norm within Roman Christianity, as councils were given a near scriptural level of authority. Thus, like scripture, the hermeneutic of how to read citations or quotations became important. In the following, from Price's article "The Council of Chalcedon: A Narrative", the conflict over "adding" to Chalcedon involved on how best to read the council. Justinian and deacon Ferrandus both offered approaches that engaged the rules, if not a literal spirit, of conciliar fundamentalism:
This new conciliar fundamentalism, where all the acts and not just the decrees were treated with exaggerated respect, not only developed after Chalcedon, but was closely connected to the dissemination of its acts, since no such acts survived from the ecumenical councils of Nicaea and Constantinople I, and only partial acts from Ephesus I. It found eloquent expression in a letter written by Deacon Ferrandus of Carthage in the mid-540s in protest at Justinian’s First Edict against the Three Chapters (which seemed to reverse some of the decisions of Chalcedon):
If there is disapproval of any part of the Council of Chalcedon, the approval of the whole is in danger of becoming disapproval… But the whole Council of Chalcedon, since the whole of it is the Council of Chalcedon, is true; no part of it is open to criticism. Whatever we know to have been uttered, transacted, decreed and confirmed there was worked by the ineffable and secret power of the Holy Spirit.59Whence came this failure to make appropriate distinction between the decrees of the councils and their debates? The explanation lies, I would suggest, in the likening of conciliar acts to the books of Holy Scripture. As Ferrandus wrote in the same letter, ‘General councils, particularly those that have gained the assent of the Roman church, hold a place of authority second only to the canonical books.’60 Of course not everything in conciliar acts was accorded equal weight, and they manifestly contained utterances by heretics, such as Nestorius and Eutyches;61 but after all not everything in Scripture was of equal weight, and Scripture likewise contained the utterances of the ungodly, such as Jezebel and Caiaphas. Perhaps a still more apt comparison would be with the writings of the Church Fathers: not all of the Fathers were equally venerated, and some of the writings of each one were more central in the tradition than others, but all of them had to be treated with respect and had prima facie authority.The Council of Chalcedon was the first ecumenical council of which complete and full acts were published, and the emperor Marcian in authorizing their publication must have calculated that their honest disclosure of tensions and disagreements would prove the thoroughness and the freedom of the council’s work. For a modern reader they show the human side of what was brought about ‘by the ineffable and secret power of the Holy Spirit’. But by the sixth century the Acts of Chalcedon had come to be read by Chalcedonians as an authoritative text, and the story of the Council of Chalcedon, as revealed in the acts, was viewed as akin to sacred history.
It's possible that Price, in the following, is reading someone like Ferrandus a bit too literally. What if this sanctifying of Chalcedon was not so much a true-belief, or even a conciliar fundamentalism, but a stick to beat Justinian with? Not only did Justinian's policies leave Roman Africa a mess (pulling out to focus on Italian campaign, when Africa's various peoples were not reintegrated into empire), but here was someone who many contemporaries found annoying for playing politics with faith. Theodora, the empress (not consort), was openly miaphysite, and many believed the imperial couple intentionally took up different sides to play them off against each other. This came to an end with the plague, and coming down hard was paramount. Thus Justinian's neo-Chalcedonianism might be a tip of what he truly believed all along, a truly modified Chalcedon, stripped of what he thought seemed like Nestorian baggage. It's hard to say how Justinian's beliefs changed over time, because he died an aphthartodocetae (i.e. someone who believed Jesus' human flesh was heavenly and incorruptible before the resurrection). Anyway, it's quite possible deacon Ferrandus saw through Justinian's nonsense, and would hit him with the now sacrosanct council to push back the emperor's church policies. It didn't work. The result was the reification of conciliar authority as scriptural history.