Outwardly, the bond of a common language and common liturgy is often the essential and radical division of a schism.

The Nestorian heresy left a permanent Nestorian Church, the Monophysite and Monothelite quarrels made several more, the reunion with Rome of fractions of every Rite further increased the number, and quite lately the Bulgarian schism has created yet another; indeed it seems as if two more, in Cyprus and Syria, are being formed at the present moment (1908).

We have now a general criterion by which to answer the question: What is an Eastern Church?

What in one case is a schism (as for instance between Orthodox and Jacobites) still remains as a not very friendly feeling between the different Eastern Catholic Churches (in this case Melkites and Catholic Syrians).

Certainly, such feeling is a very different thing from formal schism, and the leaders of the Eastern Catholic Churches, we well as all their more intelligent members and all their well-wishers, earnestly strive to repress it.

To these we must add those formed by missionaries (especially Russians) from one of these Churches.

Later Latin and Protestant missions have further complicated the tangled state of the ecclesiastical East.

Looking at a map, we see that, roughly, the division between the Roman patriarchate and the others forms a line that runs down somewhat to the east of the River Vistula (Poland is Latin), then comes back above the Danube, to continue down the Adriatic Sea, and finally divides Africa west of Egypt.

Illyricum (Macedonia and Greece) once belonged to the Roman patriarchate, and Greater Greece (Southern Italy and Sicily) was intermittently Byzantine.

But both these lands eventually fell back into the branches that surrounded them (except for the thin remnant of the Catholic Italo-Greeks).