Since I am Ukrainian Catholic – Byzantine Rite, I will answer from a somewhat different perspective. In discussing this matter with your Orthodox friend, it is important to understand that the argument is not entirely one sided. There is enough blame to go around on both sides.
There were five principal churches: Jerusalem, Antioch, Alexandria, Constantinople, and Rome. Each of these churches, united in a common faith, nevertheless had different liturgies, disciplines, and styles of worship, and were governed more or less independently. While the head of the church of Rome (the Pope) was considered the first among equals, and was generally looked to as source of authority on matters of faith, it was never conceded that he had any right to interfere with matters of liturgy, discipline, or style of worship, not affecting a matter of faith and morals.
In the period from 500 to 1000, the Pope in Rome began to assert that he had supreme power over the entire universal church in all matters. He insisted on what Eastern Christians referred to as “Latinization” of the church. For example, he wished to bar our use of icons. At an ecumenical council held around 843, it was agreed, however, that we could continue to use our icons. That was the last ecumenical council at which East and West were able to reach agreement.
Also during that time period, the Pope took it upon himself to amend the Nicene Creed, by requiring the insertion of the word “filioque,” to indicate his belief that the Holy Spirit proceeded from both the Father and the Son. Now wait a minute, the Nicene Creed’s text was established by the Council of Nicea back in 325, and the word “filioque” was not in there. While the Eastern Church did not necessarily disagree with the concept of double procession, who is the Bishop of Rome, the head of only one of the five co-equal churches of Christendom, to amend their common statement of faith, solely on his own initiative? If there is some reason to amend the Nicene Creed, let’s have another ecumenical council to discuss and pray about it, and have the guidance of the Holy Spirit. Well, the Bishop of Rome disagreed, the parties could not agree, and we had the mutual excommunications and schism in 1054.
Think of it this way: if the Governor of California decided to strike the words “under God” from the Pledge of Allegiance, and insist that the rest of the nation adhere to that, and take steps to enforce his will, what do you think the reaction would be?
In 1596, the Western Ukrainians signed the Union of Brest, which contained the provisions mentioned in my previous post. As for our married priests, in 1054, both East and West allowed married priests. The West adopted the celibacy rule in 1123, but the East never did, so we rejoined, there was no need to require us to adopt a rule that we never had, and had no desire of having. The celibacy of the clergy is not Biblically required, and as the Roman Rite admits today, it is merely a matter of discipline, and not a matter of faith or morals, and therefore is not a requirement for union between us.
This worked fine until about the 1880’s, when Ukrainians began coming to the United States. Once here, our Roman Catholic cousins made fun of our married priests (called us names like “Orthodox” – which we are not), and generally made life miserable. I guess the Roman Catholic priests in the United States were jealous.
To keep peace in the Catholic family, Ukrainian Catholics, despite our traditions, and despite our rights as secured under the Union of Brest, agreed not to have married priests in the United States or Canada,
Many people think of Vatican II as turning the Roman Catholic Church upside down. We Eastern Catholics welcomed it, as it let us resume our traditions. Now, we simply ordain married men to the priesthood in the United States. In 1983, Pope John Paul II (whose mother was Ukrainian!) enacted a separate Code of Canon Law, which applies exclusively to Eastern Catholics.
In many cases, the people who engaged in the Protestant Reformation stole some of our ideas. For example, in traditional Eastern Catholic art, you will not see Mary alone in an icon. Jesus is always in the picture, usually as a babe in arms. That is to emphasize our belief that Mary is not to be worshipped or venerated or honored solely in her own right, but as the agency through whom Christ was brought into the world (theotokos is the Greek word).
As for papal authority, we acknowledge, on paper at least, that the Pope has supreme authority, which he may exercise freely, but there seems to be tacit understanding, at least after Vatican II, that he will not exercise that authority to the detriment of the traditions of the Eastern Catholics.
An earlier example: When Pope Pius XII declared infallibly that Mary was assumed into heaven, it was necessary to resolve a dispute between the Western and Eastern church on whether Mary died first, and then was assumed, or whether she was assumed while still living. Pope Pius XII’s declaration punted on the issue, because it says “at the end of her earthly life” and does not address the matter specifically.
Thus, in discussing this matter with your Orthodox friend, my suggestion is to emphasize the similarities between us, particularly in light of Eastern Catholics, and to narrow the issues for discussion, which relate to the legitimate authority of the Pope of Rome. In the Eastern Catholic view, he has authority in matters of faith and morals, which is a relatively small category, but no authority to interfere in matters of liturgy, worship, or discipline, except in the Roman Rite, of which he is also the head. The confusion stems from the fact that the Pope is head of the Universal Church and head of the Roman Rite, but those are two different roles, and, with all due respect, the Pope needs to concentrate on not getting the two confused!