Many people think of the Catholic Church as a monolithic structure with a clear leadership and traditions. People also mistakenly refer to the whole as the Roman Catholic Church. But this is not quite accurate.
The Catholic Church actually comprises twenty-two particular Churches in full communion with one another. There are twenty-one Eastern Catholic Churches, and one Latin Catholic Church (i.e., the Church of Rome). Each of these particular Churches is self-governing (the term in Latin is sui iuris, “of their own law”), even while being in communion with the Church of Rome.
Each of these particular Churches is self-governing (sui iuris) because they have their own hierarchy. In other words, what makes a particular Church self-governing (sui iuris) is that each particular Church has its own leaders which govern all the faithful Christians belonging to that particular Church. These hierarchs (whether Patriarchs, Major Archbishops, Metropolitans, Bishops, or otherwise) are in communion with one another, and with the Church of Rome. The correct term is to be in communion with Rome, and not “under the Pope” (as many people will mistakenly say).
Eastern Catholics are the minority in terms of the number of Catholics worldwide. However, they are the vast majority in terms of diversity within the Catholic Church (twenty-one to one!). Eastern Catholics are distinct from the Latin Church in that they have four distinguishing characteristics. They have their own (1) theology, (2) spirituality, (3) canon law, and (4) liturgy. In other words, the Eastern Churches have their own theological way of understand the mysteries of God, their own spirituality and devotional practices, their own laws and customs, and their own styles of liturgy. This is what distinguishes them from the Latin Church.
People mistakenly refer to the Eastern Catholic Churches as ‘Eastern Rite Roman Catholics’, or simply as ‘The Eastern Rite,’ as if there is only one. There are many rites within the Catholic Church, and what makes an Eastern Church is more than simply its liturgical rite. An Eastern Church also has its own theology, spirituality, and canon law. Even the term ‘The Eastern Church’ is wrong, since there are more than one Eastern Churches.
Almost all Eastern Catholic Churches have counterparts in the Eastern and Oriental Orthodox Churches. In fact, those with counterparts all came from their mother Orthodox Churches throughout the past four hundred years or so. Therefore, many Eastern Catholics choose to identify themselves as ‘Orthodox Christians in communion with Rome,’ since Eastern Catholics are meant to be an example of how to be fully Eastern, and yet fully in communion with Rome.
Eastern Catholic Churches are traditionally found in Eastern Europe, the Middle East, North Africa, and India. However, nowadays we can find Eastern Churches throughout the world, speaking a multitude of languages, and serving a vast array of people.
ALL of the particular Catholic Churches share
“equal dignity, so that none of them is superior to the others as regards rite, and they enjoy the same rights and are under the same obligations, also in respect of preaching the Gospel to the whole world (cf. Mark 16:15)…”
(Second Vatican Council, Decree on the Eastern Catholic Churches).