"From the Catholic perspective, one is tempted to say that the only thing lacking for full communion with the Orthodox is full communion. If there are doctrinal differences, they are few, and one can see the way not around them but through them. To be sure, there are understandable anxieties about the relationship between primacy and “jurisdiction.” Vatican II, and the statements of John Paul and Benedict, make clear that the pope governs as a bishop among bishops, not as an emperor or king. In statements on reconciliation with the East, there is no suggestion that papal jurisdiction as it is exercised in the West is a condition for full communion. In these and other matters, it is suggested that such ecclesial reconciliation would in some ways resemble the “undivided Church” of the first millennium rather than the Catholic Church of the second *millennium.
There is, of course, the question of the ecumenical councils that the Orthodox do not recognize as being ecumenical. One remembers, however, that the West did not view Constantinople I (381) or Nicea II (787) as being ecumenical, and for understandable reasons. But they were subsequently approved by Rome and became, so to speak, ecumenical after the fact. Dulles writes: “The dogmatic decrees of the Western ecumenical councils purport to declare truths that should be accepted by all Christians on the basis of divine revelation. But unless or until these councils have been received in the East (as re-read in the light of Oriental tradition), their decrees cannot be binding on Orthodox believers. Full communion, as I understand it, will require the acceptance by both Catholics and Orthodox of all the dogmas that are held by the other community to be matters of faith.”
Here, too, one can agree with Orthodox theologian Fr. John Erickson who has written that, in order to reach unity, we cannot simply return to the “undivided Church of the first millennium.” Neither Catholics nor Orthodox could live with an agreement that simply ignored the developments of the last thousand years. This does not mean that it is necessary to agree on all these developments. The definition of infallibility by Vatican Council I, for instance, is a major obstacle. Clement writes that Orthodox and Catholics must “proceed to a common reflection on decisions made in the centuries of division, and especially on a re-examination of the dogma of 1870, already partially balanced by Vatican II.”
It does seem possible that we could agree on revealed doctrine while, as Cardinal Dulles suggests, “allowing certain secondary questions to stand as matters for theological discussion.” Already, for instance, there would seem to be no essential dogmatic disagreement on the procession of the Holy Spirit as that is presented by the filioque question. And it seems possible that the Orthodox could agree on the Bishop of Rome as the successor of Peter with a primacy of teaching and ruling authority along the lines suggested by Ut Unum Sint. This assumes that there would be accommodations and differences with respect to how that authority is exercised in the East and the West, and, quite *likely, different ecclesiological opinions that would be in the realm of theological discussion and would pose no obstacle to full communion."
firstthings.com/article/2008/11/002-reconciling-east-and-west-14
This article is from the late Catholic Father Richard John Neuhaus, former editor of First Things on Reconciling East and West.
I did not want to be mistaken for a such an honorable man as Michael (Hesychios). 