synergism in Christian soteriology, the cooperation within human consciousness of free will and divine grace in the processes of conversion and regeneration. Synergism became an issue in sixteenth-century Lutheranism during a controversy prompted by Philip Melanchthon (1497– 1569). Under the influence of Erasmus, Melanchthon mentioned, in the 1533 edition of his Common Places, three causes of good actions: ‘the Word, the Holy Spirit, and the will.’ Advocated by Pfeffinger, a Philipist, synergism was attacked by the orthodox, predestinarian, and monergist party, Amsdorf and Flacius, who retorted with Gnesio-Lutheranism. The ensuing Formula of Concord (1577) officialized monergism. Synergism occupies a middle position between uncritical trust in human noetic and salvific capacity (Pelagianism and deism) and exclusive trust in divine agency (Calvinist and Lutheran fideism). Catholicism, Arminianism, Anglicanism, Methodism, and nineteenth- and twentieth-century liberal Protestantism have professed versions of synergism. See also ERASMUS, FIDEISM , JUSTIFICATION BY FAIT. J.-L.S.