Here in the United States there seems to be an ongoing, overt (sometimes covert) concern about what is “authentic”, “historical”, orthodox, true orthopraxy, etc. regarding what is correct liturgical practice in the Roman Catholic Church. It is always good to remember that there is no such thing as the Roman Catholic Church. That statement generally gets people’s attention.
Technically I think I stand on pretty solid ground. There are 24 churches in the Catholic Church, all of whom acknowledge the Pope as their temporal and spiritual leader. Each of the churches have their own canon law, their own liturgies, their own organization, their own rules about married priests, and more – they are called eclessia sui juris – self-governing churches. Here’s the list
- Latin Catholic Church (which is popularly called the Roman Catholic Church)
- Coptic Catholic Church
- Eritrean Catholic Church
- Ethiopian Catholic Church
- Maronite Catholic Church
- Syriac Catholic Church
- Syro-Malankara Catholic Church
- Armenian Catholic Church
- Chaldean Catholic Church
- Syro-Malabar Catholic Church
- Albanian Catholic Church
- Belarusian Catholic Church
- Bulgarian Greek Catholic Church
- Križevci Catholic Church (or Byzantine Church of Croatia, Serbia and Montenegro)
- Greek Byzantine Catholic Church
- Hungarian Greek Catholic Church
- Italo-Albanian Catholic Church
- Macedonian Catholic Church
- Melkite Greek Catholic Church
- Romanian Catholic Church
- Russian Catholic Church
- Ruthenian Catholic Church (also known as the Byzantine Catholic Church in America)
- Slovak Catholic Church
- Ukrainian Greek Catholic Church
One of our friars, Fr. Salim, was born into the Syro-Malabar Catholic Church, was ordained in that Church, and only later was granted the privilege to celebrate Mass and sacraments in the Latin Catholic Church. He has bi-ritural faculties – he can celebrate the Rites associated with each Church. But he has always been Catholic, a word derived from the Greek katholika – universal.
Just a little something to keep in mind in the never ending dialogue.
friarmusings 
which ones of these 24 churches are Orthodox? What is the true definition of Orthodox?
In the context of this post, all the above Churches (ecclesia sui juris) are part of the “Catholic” Church, that is, in union with the Pope – and Orthodox refers to the churches, e.g. Greek Orthodox, Russian Orthodox, Romanian Orthodox, that are fully Catholic (re: Sacraments, priesthood, etc.) but are not in formal union with the Pope