John Calvin and other Reformed Protestants placed a great deal of emphasis on discipline, and one noted historian has even argued that Calvinist discipline contributed to “the making of the modern mind.”1 Some Reformed leaders, such as Martin Bucer, claimed that discipline was the third mark of the true church, the other two being the pure preaching of the Gospels and the proper administration of the sacraments. There were differences of opinion among Reformed thinkers, however, about how discipline was to be carried out. In Zurich, Ulrich Zwingli asserted that the Christian magistrates had the exclusive authority to discipline the faithful, including the right to excommunicate. By contrast, Bucer maintained that discipline should be under the purview of the pastors who were to be assisted by elders.2 John Calvin, who had gotten to know Bucer during his stay in Strasbourg (1538–1541), reflected the older reformer’s ideas on discipline. Although he never specifically recognized it as the third mark of the church, he placed enormous emphasis on discipline, describing it as the “sinews” of the church, and made the establishment of a new disciplinary institution, the consistory, a condition for his return to Geneva in 1541. Calvin composed the Geneva’s ecclesiastical ordinances that prescribed that the consistory be comprised of the city’s pastors and elders. Consistories became the prime instrument of discipline among the Reformed in sixteenth-century Europe.