In the third place, the agitation of the Judaizers seems to have died down during the third missionary journey. It appears, indeed, at Corinth, according to the Corinthian Epistles, but seems there to have lacked that insistence upon the keeping of the Law which had made it so dangerous in Galatia. In the epistles of the captivity--Colossians and Philemon, Ephesians, Philippians--it appears, if at all, only in the obscure reference in Phil. iii. 2ff., which may relate to non-Christian Judaism rather than to Jewish Christianity. This subsidence of the Judaizing activity is difficult to understand if the benefits of the Jerusalem conference had been annulled by a serious breach at Antioch. Finally, the whole subsequent history of the Church is explicable only if there was fundamental unity between Peter and Paul. Ever since the formation of the Old Catholic Church at the close of the second century the Church was founded upon the twin pillars of Peter and Paul. How was this unity produced if in the apostolic age there was fundamental disunion? The existence of this problem was fully recognized by F. C. Baur, and the recognition of it constitutes one element of greatness in Baur's work. But the elaborate solution which Baur proposed has had to be abandoned. Baur supposed that the harmony between Pauline and Petrine Christianity was produced by a gradual compromise effected during the second century. Subsequent investigation has pushed the harmony very much further back. The unity between Peter and Paul appears, for example, plainly expressed in the letter of Clement of Rome (about 95 A. D.), who appeals to the two great apostles as though both were of recognized authority; it appears also in the first Epistle of Peter, which even if not genuine is important as attributing to Peter, as though the attribution were a matter of course, a conception of the gospel thoroughly in harmony with that of Paul; it appears in the early traditional account of John Mark, by which Mark is made to be a follower of Peter (compare 1 Peter v. 13) and to have received from Peter the substance of his Gospel, so that when his cordial relations with Paul are remembered (Col. iv. 10; Philem. 24) he constitutes an important link between Peter and Paul. What is more important, however, than all details, is the undoubted fact that before the end of the first century epistles of Paul and genuine tradition about Jesus, which latter must at first have been connected with the Jerusalem Church, appear side by side as possessing high authority in the Church. Finally, the testimony of the Book of Acts is now admitted to be at any rate very much earlier than Baur supposed; and that testimony, so far as the harmony between Paul and Peter is concerned, is unequivocal. Thus the explanation which Baur proposed for the final healing of the supposed breach between Peter and Paul is unsatisfactory. But no other explanation has been discovered to take its place. The very