John Calvin (1509–1564) was a French theologian and reformer who became the leading figure of Reformed Protestantism from his base in Geneva. Trained as a humanist lawyer, he converted to Reformed Christianity around 1533 and produced the Institutio Christianae Religionis in successive Latin editions from 1536 to 1559, which became the most systematic theological synthesis of the Reformation. As pastor and teacher in Geneva from 1541, he shaped Reformed church polity, doctrines of predestination and the sacraments, and biblical preaching across Europe and the wider Protestant world.
Institutes of the Christian Religion
Institutio Christianae Religionis
That all the ancients communicated under both kinds
Veteres omnes sub utraque specie communicasse
Paragraph 49 of Book IV, Chapter 17 of Calvin's Institutes marshals patristic evidence that both elements of the Eucharist were always administered to all communicants in the ancient church. Calvin cites Gregory I, Gelasius, Cyprian, and others to show that withholding the cup from the laity was considered sacrilege. He argues that the Roman practice of communion under one kind violates both the explicit command of Christ and the universal custom of the church for over a millennium.
That the ancient form of church government was completely subverted by papal tyranny
Antiquam regiminis formam omnino pessum datam fuisse tyrannide Papatus
Book IV, Chapter 5 of Calvin's Institutes demonstrates that the papal system of church governance has nothing in common with the ancient church. Calvin surveys how the early church elected its bishops by clergy and people together, how no bishop claimed primacy over others, how councils were conducted without papal domination, and how clerical offices were held without the pluralism, non-residence, and luxury of the contemporary papacy. He concludes by contrasting the ancient diaconal care for the poor with the current diversion of church revenues to ornamentation and episcopal display.
Prefatory Address to Francis, King of France
Praefatio ad Franciscum Regem Galliarum
Calvin's prefatory letter to Francis I, King of France (originally Basel, 1 August 1536), defending the Reformed faith against charges of sedition and heresy. Written when the persecution of French Protestants was intensifying, Calvin argues that the reformers are falsely accused of promoting disorder and licentiousness, that the true disorder comes from those who suppress the Gospel by fire and sword, and that the king should grant the Reformed cause a fair hearing. He answers the main slanders against evangelical doctrine—on original sin, justification, the sacraments, and Christian liberty—and closes with a prayer for the king and an appeal to divine judgment.