Augustin, a German historian, born in Breslau, April 11, 1804, died in Civita Vecchia, Aug. 9, 1874. He studied at Breslau and Halle, and from 1826 to 1828 assisted his brother Johann Anton in his work on the history of celibacy. An essay on the papal decretals procured for him from the university of Halle the degree of doctor of laws, and from the Prussian government a stipend for a literary journey to Vienna, London, and Paris. In 1831 he visited Rome, and became a member of the oratory of St. Philip Neri, professing thenceforward an ultramontanism as extreme as had been his Gallicanism. Ho continued to reside in Rome, and was consultor of the holy office, of the congregation of bishops and regulars, and of the division of the propaganda on oriental rites. In 1848 he published Lettere historico-critiche intomo alle "Cinque piaghe della santa chiesa" del chiarissimo D. Antonio Rosmini Serbati. In this work Theiner denounced the election by laymen of bishops and parish priests, and maintained that the temporal sovereignty of the popes was "indispensable, under the modern formation of society, to the spiritual independence of the supreme pastor of the church." It was translated into Latin (Naples, 1819). Being appointed prefect or keeper of the secret archives of the Vatican in 1851, he issued in succession various compilations therefrom illustrating the ecclesiastical history of nearly all the different Christian nations.
Six folio works were printed in the Vatican. He also began in 1856 a continuation of the Annales Ecclesiastici of Baro-nius, of which 3 vols. fol. have appeared, and an edition of the original work to consist of about 60 vols. 4to, of which 15 had appeared in 1868 (Bar-le-Duc). In 1853, in answer to Cretineau-Joly's history of the suppression of the Jesuits, he published Geschichte des Pontificals Clemens XIV. (2 vols., Leipsic and Paris), which led to a long and bitter pamphlet controversy. In 18G1 he began a documentary history of the pope's temporal dominion, extending from 756 to 1793, entitled Codex Diplomatic us Dominii temporalis Sanctce Sedis (3 vols, fob, Rome, 1861-'3). This was followed by a smaller work in 1864 destined to answer Passaglia's appeal to the Italian bishops, and maintaining the necessity of the temporal power from the declarations, of the councils of Lyons (1245) and Constance. At the approach of the Vatican council in 1869, Theiner entered into a correspondence with Dr. Dollin-ger and Prof. Friedrich, in which he advocated the Old Catholic doctrine and position.
The discovery of this caused him to be debarred all access to the archives, while, in consideration of his age, he was permitted to retain his salary and his apartment in the Vatican. In 1874 Theiner visited Austria to make arrangements for publishing another important literary work, and on his return to Italy died suddenly at the seaside, the pope having sent him his forgiveness and blessing on hearing of his danger. His other works include Geschichte der geistlichen Bildungsanstalten (Mentz, 1835); Versuche des heiligen Stuhls die Volker des Nordens wiede-rum mit der Kirche zu vereinen (Augsburg, 1837); and Die neuesten Zustande der leatlw-lisclien Kirche bcider Ritus in Polen und Bussland seit Katharina II. (Augsburg, 1841).
Johann Anton, a German theologian, elder brother of the preceding, born in Breslau, Dec. 15, 1799, died there, May 15, 1860. He studied Roman Catholic theology at Breslau, and was appointed there in 1824 professor of Scriptural exegesis and canon law. He was from the beginning a zealous advocate of Gallican principles, and eagerly sought to have them introduced and carried out among the clergy of Silesia. Assisted by his brother Augustin, he published in 1826 an extensive work on the history of celibacy (Die Einfuhrung der erz-wungenen Ehelosigkeit, Altenburg, 1828; new ed., 1845). He resigned his chair in 1830, and held a pastoral charge till 1845, when he joined the German Catholics, publishing in vindication of this step Die reformatorischen Bestre-bungen in der Katholischen Kirche (Altenburg, 1845); but soon afterward he joined the Protestant church, and received an appointment in the library of the university of Breslau. He wrote a commentary on the minor prophets, forming part of the Bibelwerk of Dereser, and Das Seligkeitsdogma der romisch-lcatholischcn Kirche (Breslau, 1847).