ADIAPHORISTS (Gr. ἀδιάφορος, indifferent). The Adiaphorist controversy among Lutherans was an issue of the provisional scheme of compromise between religious parties, pending a general council, drawn up by Charles V., sanctioned at the diet of Augsburg, 15th of May 1548, and known as the Augsburg Interim. It satisfied neither Catholics nor Protestants. As head of the Protestant party the young elector Maurice of Saxony negotiated with Melanchthon and others, and at Leipzig, on the 22nd of December 1548, secured their acceptance of the Interim as regards adiaphora (things indifferent), points neither enjoined nor forbidden in Scripture. This sanctioned jurisdiction of Catholic bishops, and observance of certain rites, while all were to accept justification by faith (relegating sola to the adiaphora.) This modification was known as the Leipzig Interim; its advocates were stigmatized as Adiaphorists. Passionate opposition was led by Melanchthon’s colleague, Matth. Flacius, on the grounds that the imperial power was not the judge of adiaphora, and that the measure was a trick to bring back popery. From Wittenberg he fled, April 1549, to Magdeburg, making it the headquarters of rigid Lutheranism. Practically the controversy was concluded by the religious peace ratified at Augsburg (Sept. 25, 1555), which left princes a free choice between the rival confessions, with the right to impose either on their subjects; but much bitter internal strife was kept up by Protestants on the theoretical question of adiaphora; to appease this was one object of the Formula Concordiae, 1577. Another Adiaphorist controversy between Pietists and their opponents, respecting the lawfulness of amusements, arose in 1681, when Anton Reiser (1628–1686) denounced the opera as antichristian.
See arts. by J. Gottschick in A. Hauck’s Realencyklopädie (1896); by Fritz in I. Goschler’s Dict. Encyclop. de la Théol. Cath. (1858); other authorities in J. C. L. Gieseler, Ch. Hist. (N. York ed., 1868, vol. iv.); monograph by Erh. Schmid, Adiaphora, wissenschaftlich und historisch untersucht (1809), from the rigorist point of view.