Here, again, Baur displayed his true intellectual greatness by detecting and facing the problem. He saw clearly what has seldom been seen with equal clearness since his day, that the historian must explain the transition not only from the historical Jesus to apostolic Christianity, but from apostolic Christianity to the Old Catholic Church. And for this latter problem he proposed a solution which was not wanting in grandeur. But his solution, despite its grandeur, has succumbed. Baur's reconstruction of the second century, with the supposed gradual compromise between Pauline and Petrine Christianity, resulting finally in the Christianity of the Old Catholic Church, was one of the first elements in his system which had to be abandoned; it was destroyed, in the first place, by the criticism of A. Ritschl, and, in the second place, by the painstaking labors of Lightfoot, Zahn, Von Harnack and others, by which, through a study of second-century documents and their literary relationships, it was shown that the New Testament books cannot be scattered at will anywhere throughout the second century in the interests of a theory of development. Ritschl showed that the importance of specifically Jewish Christianity had been enormously exaggerated by Baur; and the study of patristics tended to place the New Testament books much earlier than the late dating which the theory of Baur required. Thus Baur did not succeed in overcoming the fundamental objection raised against him by the very existence of a Church that appealed both to Peter and to Paul. If Peter and Paul were really in fundamental disharmony, how did the Church come to bring them together so confidently and at such an early time? This question has never been answered. The very existence of the Church is a refutation of Baur; the Church never could have existed unless the apostles had been in fundamental agreement. But Baur may also be refuted directly, in a purely exegetical way, by an examination of the sources to which he himself appealed. Baur established his hypothesis of a conflict between Paul and Peter on the basis of the Pauline Epistles. Subsidiary evidence, thought to be found in other books of the New Testament, was soon shown to be illusory. Thus Baur and the early Tübingen scholars detected an anti-Pauline polemic in the Book of Revelation, which they attributed to John the son of Zebedee. This use of the Apocalypse was soon abandoned even by Baur's own disciples. The theory of Baur, therefore, stands or falls with his interpretation of the Pauline Epistles, especially 1 and 2 Corinthians and Galatians.