ARNOLDI, BARTOLOMEO. - Catholic theologian and philosopher, b. at U-singen (Nassau) in 1405, d. at Würzburg in September 1532. In 1484 he attended the University of Erfurt; in 1491 he obtained his doctorate and, as a master, taught philosophy for several years. Among his students he counted (1501-1505) Martin Luther.
In 1512 he entered the Augustinian Order and in 1514 obtained a degree in theology. During the Lutheran Reformation he remained faithful to the Catholic Church and defended its doctrine with highly regarded polemical writings. From the chair and the pulpit he rose up against the innovators, displaying intense activity, even as an advisor to Conrad of Thüngen, his bishop, with whom he participated in the Diet of Augsburg in 1530.
He wrote various polemical, philosophical, and didactic works. Among the principal ones we recall: *Duo Sermones, primus de Ecclesia Catholica... secundus de matrimonio sacerdotum et monachorum* (Erfurt 1523); *De falsis prophetis... vitandis* (ibid. 1525); *De praedicatione Euangelii recta et mundae* (ibid. 1525); *De merito bonorum operum* (ibid. 1525); *De tribus necessario requisitis... quae sunt gratia, fides et opera* (Würzburg 1527); *De invocatione et veneratione Sanctorum* (ibid. 1528), etc.