Here was what may be considered a _dignus vindice nodus_, the Church being divided, and an arbiter wanted. Such a case had also occurred in Africa in the controversy with the Donatists. Four hundred bishops, though but in one region, were a fifth part of the whole Episcopate of Christendom, and might seem too many for a schism, and in themselves too large a body to be cut off from God's inheritance by a mere majority, even had it been overwhelming. St. Augustine, then, who so often appeals to the _orbis terrarum_, sometimes adopts a more prompt criterion. He tells certain Donatists to whom he writes, that the Catholic Bishop of Carthage "was able to make light of the thronging multitude of his enemies, when he found himself by letters of credence joined both to the Roman Church, in which ever had flourished the principality of the Apostolical See, and to the other lands whence the gospel came to Africa itself."[284:1] There are good reasons then for explaining the Gothic and Arian use of the word "Roman," when applied to the Catholic Church and faith, of something beyond its mere connexion with the Empire, which the barbarians were assaulting; nor would "Roman" surely be the most obvious word to denote the orthodox faith, in the mouths of a people who had learned their heresy from a Roman Emperor and Court, and who professed to direct their belief by the great Latin Council of Ariminum. 10. As then the fourth century presented to us in its external aspect the Catholic Church lying in the midst of a multitude of sects, all enemies to it, so in the fifth and sixth we see the same Church lying in the West under the oppression of a huge, farspreading, and schismatical communion. Heresy is no longer a domestic enemy intermingled with the Church, but it occupies its own ground and is extended over against her, even though on the same territory, and is more or less organized, and cannot be so promptly refuted by the simple test of Catholicity. § 2. _The Nestorians._