thinkcatholic

What does it mean to be Catholic? The Greek roots of the term "Catholic" mean "according to (kata-) the whole (holos)," or more colloquially, "universal." At the beginning of the second century, we find in the letters of Ignatius the first surviving use of the term "Catholic" in reference to the Church. At that time, or shortly thereafter, it was used to refer to a single, visible communion, separate from others.

Ignatius of Antioch

"Let no one do anything of concern to the Church without the bishop. Let that be considered a valid Eucharist which is celebrated by the bishop or by one whom he ordains [i.e., a presbyter]. Wherever the bishop appears, let the people be there; just as wherever Jesus Christ is, there is the Catholic Church" (Letter to the Smyrneans 8:2 [A.D. 110]).