Joliann Adam Mohler, a German theologian, born at Igersheim, Wurtemberg, May 6, 1796, died in Munich, April 12, 1838. He studied at Mergentheini, Ellwnngen, and Tubingen, was ordained priest of the Roman Catholic church in 1819, and in 1820 became tutor in the seminary of theology at Tubingen, and in 1822 private lecturer on theology. Before entering on his new office he visited the principal Catholic and Protestant universities of Germany. On his return he began in 1823 a course of lectures on church history, patrology, and canon law, which at once established his reputation. He strongly sympathized with the reformatory movement then agitating the Catholic church of S. W. Germany; he advocated the restoration of communion in both kinds, the abrogation of the use of Latin in the divine service, etc.; but in later years he abandoned these views, and the articles expressing them are not included in the collection of his minor works published by Dr. Dol-linger (Gemmmelte Schriften und Avfsdtze, 2 vols., Ratisbon, 1839). In 1825 he published Die Finheit in der Firche, and in 1826 he was appointed extraordinary professor in Tubingen. In 1827 he published Athanasim der Grosse (2 vols.. Mentz), and an essay on sacerdotal celibacy, directed against the liberal Catholic theologians of Baden and Wurtem-berg, followed in 1829 by Fragmente am und uber Pseudo-Isidor. In 1828-'30 he gave a course of lectures on the comparative theology of the Christian churches, a summary of which was published under the title Syinbolik, oder Darstellung der dogmatischen Gegensdtze der Katholilen und Protestanten nach ihren offent-Uchen Bekenntnisssehriften (2 vols., Mentz, 1832; 7th ed.. Ratisbon, 1871; English translation by Robertson, 2 vols., London, 184-3). This is regarded as his greatest work.

The Protestant theologians maintained that he had represented ideal Catholicism, and misrepre-sented, at least partly, the doctrinal systems of the reformers. Some of the most distinguished Protestant divines wrote against him; specially Baur (Der Gegensatz des Katholi-cismus und Protestantismus, Tubingen, 1833; 2d ed.. 1836), Marheineke, and Nitzsch. Mohler answered them in his Neue Untersuclmngen der Lehr gegensdtze zwischcn Katholiken iind Protestanten (Mentz, 1834). Baur replied again in the new edition of his work, but the continuation of the controversy was forbidden by the government, and Mohler was censured for reviving an obsolete contest. He consequently resigned his professorship at Tubingen, and when the Prussian government offered him one either at Bonn, Breslau, or Munster, he chose Bonn, but subsequently declined when the archbishop of Cologne demanded that he should expressly retract his work on "Unity in the Church.'" In the spring of 1835 he began in the university of Munich a course of lectures on the Epistle to the Romans, followed by others on church history and patrology; but his lectures were interrupted by sickness in 1836, and he never fully recovered.

In 1838 the king of Bavaria appointed him dean of Wurzburg. At the time of his death he was collecting materials for a history of mo-nachism. A large posthumous work on the Christian literature of the first three centuries was edited by Prof. Reithmayr of Munich (Patrologie, vol. i., Ratisbon, 1839). A Catholic biography of Mohler, by Peithmavr, is added to the fifth edition of his "Symbolism." The best Protestant biography is that of Prof. Kling of Marburg.