FLACIUS, MATTHIAS (1520–1575), known as Matthias Flacius Illyricus, was an Italo-Croatian scholar and polemicist; a creative, fiery theological leader of the late Lutheran Reformation. Born in Albona, Istria, Flacius was trained in the humanist schools of Venice under the influence of his uncle, the Franciscan provincial Baldo Luperino, who was sympathetic to Lutheranism. Flacius studied at Tübingen before moving to Wittenberg, where Luther's intervention in a personal religious crisis confirmed Flacius as his passionately committed disciple. The defeat of Lutheran princes in the Smalcald War ended Flacius's career as a Hebrew instructor at Wittenberg and propelled him into the leadership of the Gnesio-Lutheran party, formed by Luther's more radical disciples in opposition to the imposition of the Augsburg Interim (1548) and the compromise settlement worked out by other Lutheran leaders, the Leipzig Interim (1548). Flacius's historical and liturgical research, as well as his biblical, lay-oriented argumentation, led him to criticize both settlements, attacking the Leipzig Interim as a betrayal of Luther's Reformation. As a private scholar at the center of resistance to both interims, Magdeburg (1548–1557); as a professor and counselor at Jena (1557–1561); and later as a consultant and private scholar in Regensburg, Antwerp, and Strassburg, Flacius provided theological leadership and inspired controversy.
Among his major contributions are his pioneering work in Protestant biblical hermeneutics, which climaxed in Clavis scripturae sacrae (1567), and in Protestant historiography, which culminated in his own Catalogus testium veritatis (1556) and in the Magdeburg Centuries, composed by members of a research team that he helped organize and manage.
According to his modern biographer, Oliver K. Olson, Flacius's theology can be described negatively as a program of "de-hellenization," that is, a turning away from Platonism and Aristotle, and positively as an insistent prophetic witness to correct biblical teaching (pura doctrina). That witness led him to fight for the independence of the church from the state and to reject many aspects of medieval ecclesiastical custom and polity. Above all, it led him to defend Luther's doctrine of salvation by God's grace through faith in Christ in controversies with other Protestant theologians, especially his formidable antagonist Philipp Melanchthon. These controversies concerned, most importantly, the role of good works in salvation and the role of the human will in conversion. In the controversy over human will Flacius defined original sin as the formal substance of the fallen sinner, who, he argued, is the image of Satan. This position was misinterpreted even by some fellow Gnesio-Lutherans and contributed to his alienation from most of his contemporaries at the end of his life, when agents of leading Lutheran princes prevented him from finding a permanent home.
Flacius's ardent polemics in defense of Luther's message at a time when it was seriously menaced by political and ideological forces contributed much to its preservation, and his intellectual contributions in liturgics, hermeneutics, church history, and dogmatics greatly enriched Protestant orthodoxy.
Oliver K. Olson provides a superb overview of Flacius's thought and life and a sketch of his two-volume biography, as well as an extensive bibliography, in his essay "Matthias Flacius Illyricus, 1520–1575," in Shapers of Religious Traditions in Germany, Switzerland, and Poland, 1560–1600, edited by Jill Raitt (New Haven, Conn., 1981), pp. 1–17. The classic treatment of the subject to date is Wilhelm Preger's Matthias Flacius Illyricus und seine Zeit, 2 vols. in 1 (Erlangen, 1859–1861). In addition to Olson's articles and dissertation, contemporary studies of Flacius include Günter Moldaenke's Schriftverständnis und Schriftdeutung im Zeitalter der Reformation, vol. 1, Matthias Flacius Illyricus (Stuttgart, 1936), and Lauri Haikola's Gesetz und Evangelium bei Matthias Flacius Illyricus (Lund, 1952).
Robert Kolb (1987)