The word Catholic (katholikos from katholou -- throughout the whole, i.e., universal) occurs in the Greek classics, e.g., in Aristotle and Polybius, and was freely used by the earlier Christian writers in what we may call its primitive and non-ecclesiastical sense. Thus we meet such phrases as the "the catholic resurrection" (Justin Martyr), "the catholic goodness of God" (Tertullian), "the four catholic winds" (Irenaeus), where we should now speak of "the general resurrection", "the absolute or universal goodness of God", "the four principal winds", etc. The word seems in this usage to be opposed to merikos (partial) or idios (particular), and one familiar example of this conception still survives in the ancient phrase "Catholic Epistles" as applied to those of St. Peter, St. Jude, etc., which were so called as being addressed not to particular local communities, but to the Church at large.
The combination "the Catholic Church" (he katholike ekklesia) is found for the first time in the letter of St. Ignatius to the Smyrnaeans, written about the year 110. The words run: "Wheresoever the bishop shall appear, there let the people be, even as where Jesus may be, there is the universal [katholike] Church." However, in view of the context, some difference of opinion prevails as to the precise connotation of the italicized word, and Kattenbusch, the Protestant professor of theology at Giessen, is prepared to interpret this earliest appearance of the phrase in the sense of mia mone, the "one and only" Church [Das apostolische Symbolum (1900), II, 922]. From this time forward the technical signification of the word Catholic meets us with increasing frequency both East and West, until by the beginning of the fourth century it seems to have almost entirely supplanted the primitive and more general meaning. The earlier examples have been collected by Caspari (Quellen zur Geschichte des Taufsymbols, etc., III, 149 sqq.). Many of them still admit the meaning "universal". The reference (c. 155) to "the bishop of the catholic church in Smyrna" (Letter on the Martyrdom of St. Polycarp, xvi), a phrase which necessarily presupposes a more technical use of the word, is due, some critics think, to interpolation. On the other hand this sense undoubtedly occurs more than once in the Muratorian Fragment (c. 180), where, for example, it is said of certain heretical writings that they "cannot be received in the Catholic Church". A little later, Clement of Alexandria speaks very clearly. "We say", he declares, "that both in substance and in seeming, both in origin and in development, the primitive and Catholic Church is the only one, agreeing as it does in the unity of one faith" (Stromata, VII, xvii; P. G., IX, 552). From this and other passages which might be quoted, the technical use seems to have been clearly established by the beginning of the third century. In this sense of the word it implies sound doctrine as opposed to heresy, and unity of organization as opposed to schism (Lightfoot, Apostolic Fathers, Part II, vol. I, 414 sqq. and 621 sqq.; II, 310-312). In fact Catholic soon became in many cases a mere appellative--the proper name, in other words, of the true Church founded by Christ, just as we now frequently speak of the Orthodox Church, when referring to the established religion of the Russian Empire, without adverting to the etymology of the title so used. It was probably in this sense that the Spaniard Pacian (Ep. i ad Sempron.) writes, about 370: "Christianus mihi nonem est, catholicus cognomen", and it is noteworthy that in various early Latin expositions of the Creed, notably that of Nicetas of Remesiana, which dates from about 375 (ed. Burn, 1905, p. lxx), the word Catholic in the Creed, though undoubtedly coupled at that date with the words Holy Church, suggests no special comment. Even in St. Cyprian (c. 252) it is difficult to determine how far he uses the word Catholic significantly, and how far as a mere name. The title, for instance, of his longest work is "On the Unity of the Catholic Church", and we frequently meet in his writings such phrases as catholica fides (Ep. xxv; ed. Hartel, II, 538); catholica unitas (Ep. xxv, p. 600); catholica regula (Ep. lxx, p. 767), etc. The one clear idea underlying all is orthodox as opposed to heretical, and Kattenbusch does not hesitate to admit that in Cyprian we first see how Catholic and Roman came eventually to be regarded as interchangeable terms. (Cf. Harnack, Dogmengeschichte, II, 149-168.) Moreover it should be noted that the word Catholica was sometimes used substantively as the equivalent of ecclesia Catholica. An example is to be found in the Muratorian Fragment, another seemingly in Tertullian (De Praescrip, xxx), and many more appear at a later date, particularly among African Writers.
Among the Greeks it was natural that while Catholic served as the distinctive description of the one Church, the etymological significance of the word was never quite lost sight of. Thus in the "Catechetical Discourses" of St. Cyril of Jerusalem (c. 347) he insists on the one hand (sect. 26): "And if ever thou art sojourning in any city, inquire not simply where the Lord's house is--for the sects of the profane also attempt to call their own dens, houses of the Lord--nor merely where the church is, but where is the Catholic Church. For this is the peculiar name of the holy body the mother of us all." On the other hand when discussing the word Catholic, which already appears in his form of the baptismal creed, St. Cyril remarks: (sect. 23) "Now it [the Church] is called Catholic because it is throughout the world, from one end of the earth to the other." But we shall have occasion to quote this passage more at length later on.
There can be no doubt, however, that it was the struggle with the Donatists which first drew out the full theological significance of the epithet Catholic and passed it on to the schoolmen as an abiding possession. When the Donatists claimed to represent the one true Church of Christ, and formulated certain marks of the Church, which they professed to find in their own body, it could not fail to strike their orthodox opponents that the title Catholic, by which the Church of Christ was universally known, afforded a far surer test, and that this was wholly inapplicable to a sect which was confined to one small corner of the world. The Donatists, unlike all previous heretics, had not gone wrong upon any Christological question. It was their conception of Church discipline and organization which was faulty. Hence, in refuting them, a more or less definite theory of the Church and its marks was gradually evolved by St. Optatus (c. 370) and St. Augustine (c. 400). These doctors particularly insisted upon the note of Catholicity, and they pointed out that both the Old and the New Testament represented the Church as spread over all the earth. (See Turmel, "Histoire de la theologie positive, 1904, I, 162-166, with references there given.) Moreover, St. Augustine insists upon the consensus of Christians in the use of the name Catholic. "Whether they wish or no", he says, "heretics have to call the Catholic Church Catholic" ("De vera religione", xii). "Although all heretics wish to be styled Catholic, yet if any one ask where is the Catholic place of worship none of them would venture to point out his own conventicle" (Contra Epistolam quam vocant Fundamenti, iv). Of later exponents of this same thesis the most famous Vincent of Lerins (c. 434). His canon of Catholicity is "That which has been believed everywhere, always, and by all." "This", he adds, "is what is truly and properly Catholic" (Commonitorium, I, ii).