[Footnote 13: "Virtus omnis ex his causam accipit, a quibus provocatur" (Tertull., de bapt. 2.)] [Footnote 14: The plan of placing the apologetic theology before everything else would have much to recommend it, but I adhere to the arrangement here chosen, because the advantage of being able to represent and survey the outer ecclesiastical development and the inner theological one, each being viewed as a unity, seems to me to be very great. We must then of course understand the two developments as proceeding on parallel lines. But the placing of the former parallel before the latter in my presentation is justified by the fact that what was gained in the former passed over much more directly and swiftly into the general life of the Church, than what was reached in the latter. Decades elapsed, for instance, before the apologetic theology came to be generally known and accepted in the Church, as is shown by the long continued conflict against Monarchianism.] [Footnote 15: The origin of Catholicism can only be very imperfectly described within the framework of the history of dogma, for the political situation of the Christian communities in the Roman Empire had quite as important an influence on the development of the Catholic Church as its internal conflicts. But inasmuch as that situation and these struggles are ultimately connected in the closest way, the history of dogma cannot even furnish a complete picture of this development within definite limits.] [Footnote 16: See Tertullian, de pudic. 10: "Sed cederem tibi, si scriptura Pastoris, quae sola moechos amat, divino instrumento meruisset incidi, si non ab omni concilio ecclesiarum etiam vestrarum inter aprocrypha et falsa iudicaretur;" de ieiun. 13: "Aguntur praesterea per Graecias illa certis in locis concilia ex universis ecclesiis, per quae et altiora quaeque in commune tractantur, et ipsa repraesentatio totius nominis Christiani magna veneratione celebratur." We must also take into account here the intercourse by letter, in which connection I may specially remind the reader of the correspondence between Dionysius, Bishop of Corinth, Euseb., H. E. IV. 23, and journeys such as those of Polycarp and Abercius to Rome. Cf. generally Zahn, Weltverkehr und Kirche waehreud der drei ersten Jahrhunderte, 1877.] [Footnote 17: See my studies respecting the tradition of the Greek Apologists of the second century in the early Church in the Texte und Unters. z. Gesch. der alt christl. Litteratur, Vol. I. Part I. 2.] [Footnote 18: See Euseb., H. E. II. 2; VI. 43.]