FLACIUS (in German Vlacich), Matthias, sumamed Illyricus (1520-1575), a celebrated German theologian of the time of the Reformation, was born at Albona in Illyria in 1520. Having lost his father in early childhood, he owed his education almost wholly to his own unaided perseverance. At the age of seventeen he had resolved to enter a convent in order to devote his life to sacred learning; but on the advice of one of his relations, who had imbibed Reformation principles, he abandoned his intention, and pursued his studies successively at Basel, Tübingen, and Wittenberg. At Wittenberg he fell for a time into religious despondency, and sought the advice of Martin Luther, who was successful not only in removing his doubts, but in inspiring him with much of his own Reformation zeal. In 1544 he became professor of Old Testament literature at Wittenberg, and soon began to take an active and prominent part in the theological discussions of the time. He strenuously opposed the Augsburg Interim and also the compromise of Melanchthon, known as the Leipsic Interim, and was compelled on that account to resign his professorship. From Wittenberg he proceeded to Magdeburg, and in 1557 he was appointed professor of theology at Jena, but soon became involved in a controversy with his colleague Strigel on the power of the human will in conversion. Being a strong upholder of the doctrine of man’s natural inability, be was induced by controversial straits to fall unwittingly into the Manichaean heresy of affirming that original sin was not an accident in human nature, but now belonged to its substance; and as he would not submit to ecclesiastical censure, he was compelled in 1562 to resign his office. After staying for five years in retirement at Ratisbon, he accepted the charge of a ...