ADIAPHORA. — Under this name is indicated a famous controversy in the Protestant field. Adiaphora (from ἀδιάφορα, "indifferent things and acts") are defined by Protestants themselves, in the title of article IX of the "Formula of Concord," as the middle or indifferent things.
This polemic had two aspects: the first, in the 16th century, proposed by Melanchthon (v.), concerned only ecclesiastical usages and ceremonies; the second, in the 17th and 18th centuries, presented by Spener, touched upon the question of all indifferent acts.
1) In 1548, Emperor Charles V, without consulting the Holy See, had promulgated the famous "Augsburg Interim," by which he sought, in his own way, to address the religious questions tearing apart Germany. The Interim was quite favorable to Protestants but contained several provisions disagreeable to Catholics; hence it was opposed by the former and provoked violent opposition especially in northern Germany. Elector Maurice of Saxony, wishing to assist the emperor and calm tempers, commissioned Melanchthon to explain the clauses of the Interim; and Melanchthon published the conclusions in the so-called Leipzig Interim (1548).
This considered as adiaphora or indifferent things, and therefore such that they could be practiced without violating Sacred Scripture, dignities, feast days, Latin hymns, the use of the surplice, candles, and even the Mass (without transubstantiation) and the cult of the saints. The intransigent Lutherans, led by Flacius Illyricus (v.), one of the Magdeburg Centuriators, a fanatical Lutheran, violently opposed such interpretations. Thus arose the schism between the Adiaphorists or Melanchthonians and the Anti-Adiaphorists or Flacians. The controversy lasted until 1580, when the "Formula of Concord" was drawn up, in which, at article IX, the question is decided in the sense that the Church of God can change certain ceremonies and rites that are neither commanded nor prohibited by Sacred Scripture.
2) The question revived in Germany a century later with the Pietist movement, whose promoter was Philipp Jakob Spener (1635–1705). This time, however, it extended to human acts.
Spener maintained that worldly amusements, such as dancing, the theater, etc., ought to be forbidden. Since a Christian must do nothing that is not for the glory of God and the good of the neighbor, there could be no indifferent or adiaphorous actions. His opponents, and he had many, insisted that the aforementioned actions were simply indifferent or adiaphorous and in no way sinful. The controversy gradually shifted from a practical to a speculative one, that is, while admitting that in the abstract indifferent acts might exist, it was debated whether this was possible in concreto. In this way, the struggle lost its original virulence.