Mäuslein) (1497-1563. Reformer. Born in Dieuze, Lothringen, he studied among other places in the humanists' school in Schlettstadt, where he met M. Bucer.* In 1512 his family urged him to enter the Benedictine monastery near Lixheim. In 1518, while still there, he was sent a packet of Luther's books, perhaps by Bucer, that made him “the Lutheran preacher.” He left the monastery in 1527 and came to Strasbourg, where he became Bucer's secretary, and deacon in the cathedral church under Matthew Zell. In 1531, through Bucer's recommendation, he went as preacher to Augsburg.
Here Musculus was part of the struggle between the Roman Catholics, the Lutherans, the Anabaptists, and the Bucerian version of the Reformed faith. Two of the major issues were the interpretation of the Lord's Supper and the question of the relationship of the magistrates to the church. Musculus stood with Bucer, and since he could not be reconciled to the Interim of Charles V (1547), he left Augsburg in 1548. Through H. Bullinger's* influence he was appointed professor of theology at the old Franciscan college in Bern in 1549 after preparing an acceptable doctrinal statement on the Supper question. He began his theology lectures where he had left off preaching in Augsburg-on Psalm 104. His extensive commentary on the Psalms was published in 1550.
Bern was in continual conflict with Geneva over the relationship of the church to the magistrates: who was to control church appointments, who was to exercise church discipline, and who had control of church goods. Musculus supported the magistrates' right to control the churches and to order discipline. Of the major Reformation centers in Switzerland, Bern was the only one that did not sign the* of 1551. On many issues, however, Musculus insisted upon the principle of adiaphora: “let us be tolerant where nothing is unsuitable to the glory of God, the purity of our faith or the salvation of souls.” During the Bern years Musculus published a number of commentaries, translations of various patristic sources, and his important Common Places of 1560 (ET 1562). The influence of these works were felt in the , Hungary, and England, as well as in Germany and Switzerland.