CATHOLIC, derived from a Greek word meaning "universal" and used by ecclesiastical writers since the 2nd century to dis tinguish the Church at large from local communities or heretical and schismatic sects. A notable exposition of the meaning of the term, as it had developed during the first three centuries, was given by Cyril of Jerusalem (348) : the Church is called catholic on the f ourf old ground of its world-wide extension, its doctrinal completeness, its adaptation to the needs of men of every kind, and its moral and spiritual perfection (Catech., xviii., 23). The theory that what has been universally taught or practised is true was first fully developed by St. Augustine in his controversy with the Donatists (393-420), but it received classic expression in a paragraph of St. Vincent of Lerin's Commonitorium, ii., 6 (434), from which the well-known formula, quod ubique, quod semper, quod ab omnibus creditum est, is derived. St. Vincent maintained—curiously enough a propos of an extreme Augustin ian theory of grace—that the true faith was that which the Church professed throughout the world in agreement with an tiquity and the consensus of distinguished theological opinion in former generations (cf. op. cit., ii. 3, 6, xx.). Thus the term tended to acquire the sense of orthodox.
Some confusion in the history of the term has been inevitable as various groups, which have been condemned by Rome as heretical or schismatic, have not renounced their claim to the note of catholicity, so that in the modern world not only the Roman Catholic Church but also the Eastern Orthodox Church, the Anglican Church, and a variety of national Churches and minor sects claim to be Catholic, if not the only true Catholic Church. From this point of view the meaning attached to the term "Catholic" and the claim to catholicity will be conditioned by the theory of the nature and constitution of the Church accepted, being rigid and exclusive or tolerant and comprehensive as that is rigid or tolerant. The earlier theologians of the Anglican Church were primarily interested in proving the agreement of the Anglican theology with the teaching of the ante-Nicene Fathers, but with the Oxford Movement a school of theologians arose who interpreted the catholicism of the Church of England in.a much wider sense. A product of this school was the so-called "Branch Theory" of the Church, which maintained that the Anglican, Roman, and Eastern Orthodox Churches were all branches of the one true Catholic Church, and that reunion could be achieved by concessions of these three divisions on contro versial questions which divided them without affecting their catholic character. But this theory has been repeatedly con demned by Roman theologians, who are unable to overlook the Protestant character of historic Anglican theology, and who, since 1896, have, in agreement with the Bull of Pope Leo XIII., Apostolicae Curae, regarded Anglican orders as invalid and the Anglican Church, therefore, as no part of the true Catholic Church (cf. the Encyclical of Pius XI., De very religionis unitate fovenda, Acta Apost. Sedis, Jan. 1928) . It has also failed to recommend itself to the Eastern Orthodox Church.