That influence has been exerted in two ways. It was exerted, in the first place, during the lifetime of Paul; and it has been exerted, in the second place, upon subsequent generations through the medium of the Pauline Epistles. With regard to the second kind of influence, general considerations would make a high estimate natural. The Pauline Epistles form a large proportion of the New Testament, which has been regarded as fundamental and authoritative in all ages of the Church. The use of the Pauline Epistles as normative for Christian thought and practice can be traced back to very early times, and has been continuous ever since. Yet certain considerations have been urged on the other side as indicating that the influence of Paul has not been so great as might have been expected. For example, the Christianity of the Old Catholic Church at the close of the second century displays a strange lack of understanding for the deeper elements in the Pauline doctrine of salvation, and something of the same state of affairs may be detected in the scanty remains of the so-called "Apostolic Fathers" of the beginning of the century. The divergence from Paul was not conscious; the writers of the close of the second century all quote the Pauline Epistles with the utmost reverence. But the fact of the divergence cannot altogether be denied. Various explanations of this divergence have been proposed. Baur explained the un-Pauline character of the Old Catholic Church as due to a compromise with a legalistic Jewish Christianity; Ritschl explained it as due to a natural process of degeneration on purely Gentile Christian ground; Von Harnack explains it as due to the intrusion, after the time of Paul, of Greek habits of thought. The devout believer, on the other hand, might simply say that the Pauline doctrine of grace was too wonderful and too divine to be understood fully by the human mind and heart.[1] [1] Compare "Jesus and Paul," in _Biblical and Theological Studies_ by Members of the Faculty of Princeton Theological Seminary, 1912, pp. 553 f. Whatever the explanation, however, the fact, even after exaggerations have been avoided, remains significant. It remains true that the Church of the second century failed to understand fully the Pauline doctrine of the way of salvation. The same lack of understanding has been observable only too frequently throughout subsequent generations. It was therefore with some plausibility that Von Harnack advanced his dictum to the effect that Paulinism has established itself as a ferment, but never as a foundation, in the history of doctrine.[2] [2] Harnack, _Lehrbuch der Dogmengeschichte_, 4te Aufl., i, 1909, p. 155. (English Translation, _History of Dogma_, i, 1895, p. 136.)