Johannes Oecolampadius occupied an important place in the Reformation at the intersection of northern humanism, Protestant theology, and the Reformed tradition. As a young humanist, he was an expert in the biblical languages and a colleague with the most prominent German humanists of his day, including Erasmus, Johannes Reuchlin, Jakob Wimpfeling, and Philipp Melanchthon. Yet where many German humanists embraced Luther’s theology, Oecolampadius charted a different course, specifically on the questions of the Lord’s Supper and church discipline. His thought would form the foundation upon which subsequent reformed thinkers would build, including that of Martin Bucer and John Calvin.

Born Johannes Hausschein in 1482, he came from a wealthy family at Weinsberg in the Palatinate. From 1499 to 1503, he studied arts at Heidelberg, then after earning his master of arts proceeded to the famous law school at Bologna. In 1506, he began work as a tutor to the sons of the Elector Palatine, Philip the Upright. Like many humanists, he soon traded out his German last name for its Greek equivalent, Oecolampadius (“house light”). The newly dubbed Oecolampadius would receive a prebend as preacher back home in Weinsberg in 1510, a position that his parents endowed for him. He would serve there until 1512, even writing a first theological treatise on the Seven Last Words of Jesus in a way that evoked both humanism and more recent mysticism.

Oecolampadius soon took up studies in the higher faculty of theology, beginning at Heidelberg in 1512. During one year there, he studied Greek and came under the influence of the noted humanist Wimpfeling. From 1513 to 1515, Oecolampadius studied theology at Tübingen, which culminated in his licentiate. He also became acquainted with Reuchlin and Melanchthon, who urged him to pick up Greek and Hebrew as part of his studies. In 1515, he moved on to Basel as pastor, where he also worked on Erasmus’s critical edition of the New Testament. Oecolampadius then returned to Weinsberg to serve as pastor. His assistant during this stay was Johannes Brenz, the future Lutheran reformer. In 1518, Oecolampadius received his doctorate in theology from Basel, and shortly thereafter he became preacher and confessor at the Augsburg cathedral through the influence of another notable humanist, Willibald Pirckheimer.

It was during his time at Augsburg that Oecolampadius began to grapple with the burgeoning Protestant Reformation. Like many other humanists, he supported Luther’s early reforms, but was undecided on the extent to which those reforms should go. Yet as a pastor charged with the cura animarum, he had grown discontent with the penitential system and wrote briefly about its reform, as well as a tract in defense of Luther (the 1520 Iudicium de Lutherano). With the controversy reaching a peak and direct calls for reform being lodged regularly, however, Oecolampadius chose to take a respite from his parish work in order to immerse himself in the writings of both the church fathers and Luther. Ironically, he chose for his sabbatical the Birgittine monastery at Altomünster near Augsburg, but when his tracts on reform and Luther were discovered, he was forced to leave the monastery. After departing Altomünster in 1522, he spent time as chaplain to the humanist knight Franz von Sickingen at Ebernburg castle before heading for Basel in late 1522.

Oecolampadius would establish himself as a chief progenitor of the Reformed tradition in his nine years at Basel. By 1523, he was named lecturer in Bible at the university, where he first devoted time to Isaiah, then Romans, which he published that year. Through these and subsequent lectures, Oecolampadius soon began to establish his own unique theology rooted in a humanist approach to the biblical languages. This emerged most clearly in his position on the Eucharist. He soon departed from Luther’s affirmation of the Real Presence and began teaching that a humanist reading of the Greek New Testament could only yield a symbolic presence of Christ in the sacrament. He articulated this position in his 1525 treatise on the topic, Genuina expositio verborum Domini interpretatione: Hoc est corpus Meum. This touched off a controversy that would splinter the Protestant movement, with Oecolampadius and Ulrich Zwingli representing ideas that would eventually hold sway amongst the South German and Swiss reformers, and Luther those of the northern German reformers. The debate reached a head in 1529 at the Marburg Colloquy, where the two sides agreed to terms on fourteen doctrinal articles, but could not reach a compromise on the Eucharist. The fallout resulted in three separate confessions being submitted to Holy Roman Emperor Charles V at the 1530 Diet of Augsburg.

In addition to his duties as lecturer, Oecolampadius also assumed the pastorate at St. Martin’s in Basel in 1525. This proved a highly auspicious time for the sake of reform in the city. The council issued a mandate in 1525 requiring toleration of both Catholic and Protestant religious practice, but taking no official stand on either. Later that year, Oecolampadius was able to celebrate the first Reformed Lord’s Supper under the cover of religious toleration. He would serve as a representative for Protestant reform in the region, first at the unsuccessful 1526 Baden Disputation, then at its victorious successor in Bern in 1528 (along with Zwingli, Bucer, and Wolfgang Capito). But tensions remained between the two sides in Basel until 1529, when riots erupted and necessitated a definitive political resolution to the religious question. That year Basel went Protestant, in part adopting a reform treatise of Oecolompadius’s entitled “Reformation Act.”

Despite support for his reforms, Oecolampadius was displeased with certain aspects of the resolution, particularly the approach to church discipline. Basel authorities opted to leave regulation of religious matters in the hands of the city council, not the church. Oecolampadius wrote a treatise on excommunication, entitled Oratio de reducenda excommunicatione, that proposed ecclesiastical governance of religious affairs in the city as an exercise of church discipline (as opposed to governance by the council). His proposal was ultimately rejected, however, much to his chagrin. Despite this failure in Basel, he provided a template for the use of church discipline in Bucer’s Strasbourg and Calvin’s Geneva, and indeed for much of later continental Reformed practice. Influential, if not wholeheartedly accepted, Oecolampadius died on November 24, 1531. He left behind a widow, Wibrandis Rosenblatt, whom he had married in 1528; she would later wed Capito, and then after his death Bucer.