Even while Luther was meeting with Miltitz circumstances were shaping up
which drove him to break silence. He had stated his willingness to
recant if someone proved his error. An ambitious professor at the
University of Ingolstadt, John Eck, with an enviable reputation as a
disputant, saw in this his opportunity to win renown and also favor with
Rome.
Andrew Carlstadt of the Wittenberg faculty had espoused the cause of
Luther publicly and had been engaged in an extended debate with Eck
through the medium of pamphlets. Now a public debate between the two was
arranged for Leipzig. In preparation Eck drew up a series of twelve
theses, directed not so much at his differences with Carlstadt as with
the theology of Luther. The champion of Roman orthodoxy clearly was
baiting Luther into the arena.
After months of wrangling about procedures and proper invitations, and
with much pomp and pageantry, the debate got under way on June 27, 1519.
Several hundred Wittenberg students were there—a sixteenth-century sort
of college cheering section. During the ensuing eighteen days of debate
they frequently became embroiled with the Leipzig University students
who sided with Eck. Carlstadt and Eck matched wits for four days over
the relation between grace and free will. The erudition and cleverness
of Eck gave him a decided advantage over the Wittenberg scholar, but
spectator interest was being reserved for July 4 when Luther would take
the field.
For another four days Eck and Luther discussed the divine right of the
pope with the Ingolstadter insisting that the divine plan of government
was a monarchy with the pope at its head. Luther agreed that the church
was a monarchy but that Christ was its head. The passage in St. Matthew
concerning the rock upon which Christ would build his church was quoted
by Eck with the interpretation that Peter was the “rock” and since he
also was the first pope it was clear that papal supremacy had been
established by Christ.
Luther declared the passage should be considered along with Peter’s
previous statement, “Thou art the Christ....” This confession, he said,
is the “rock” on which Christ built his church.