German Lutheran theologian; b. Quedlinburg, Oct. 17, 1582; d. Jena, Aug. 17, 1637. Although strongly influenced by the theologian and mystic Johann Arndt, he became one of the staunchest supporters of Lutheran orthodoxy. After completing his studies (philosophy, medicine, and theology) at Wittenberg, Marburg, and Jena, he was appointed superintendent of the churches of Heldburg in the Duchy of Coburg in 1606. He became professor of theology in 1616 at Jena where he remained, despite many calls from other universities, until his death. He played a prominent role from 1621 to 1630 in directing the unsuccessful work of the movement to develop a supreme tribunal of the Lutheran Church. His theological system, as contained in his Loci theologici (9 v. 1610–22), is the culmination of Lutheran dogma initiated by Melanchthon and, as such, the most authoritative work of the age of orthodoxy following the Formula of Concord (1577). His Confessio catholica (four parts, 1634–37) is an extensive apology and polemic of the Evangelical creed, in which an attempt is made to prove the truth of Lutheran doctrine by citing the testimony of Roman Catholic writers. He is noted also for his exegetical and devotional writings.
Bibliography: j. gerhard and m. chemnitz, The Doctrine of Man in Classical Lutheran Theology, ed. h. a. preus and e. smits, tr. m. colacci et al. (Minneapolis 1962). e. r. fischer, Vita I. Gerhardi (Leipzig 1723). f. lau, Die Religion in Geschichte und Gegenwart 2: 1412–13. y. congar, Catholicisme: Hier, aujord'hui et demain 4:1880. h. rennings, Lexikon für Theologie und Kirche 4:724.
[c. j. berschneider]