the eve of All-saints, therefore, in 1517, he
publicly fixed up, at the church next to the castle of that town, a
thesis upon indulgences; in the beginning of which, he challenged any
one to oppose it either by writing or disputation. Luther's propositions
about indulgences, were no sooner published, than Tetzel, the Dominican
friar, and commissioner for selling them, maintained and published at
Francfort, a thesis, containing a set of propositions directly contrary
to them. He did more; he stirred up the clergy of his order against
Luther; anathematized him from the pulpit, as a most damnable heretic;
and burnt his thesis publicly at Francfort. Tetzel's thesis was also
burnt, in return, by the Lutherans at Wittemburg; but Luther himself
disowned having had any hand in that procedure. In 1518, Luther, though
dissuaded from it by his friends, yet, to show obedience to authority,
went to the monastery of St. Augustine, at Heidelberg, while the chapter
was held; and here maintained, April 26, a dispute concerning
"justification by faith," which Bucer, who was present at, took down in
writing, and afterward communicated to Beatus Rhenanus, not without the
highest commendations. In the meantime, the zeal of his adversaries grew
every day more and more active against him; and he was at length accused
to Leo X. as a heretic. As soon as he returned therefore from
Heidelberg, he wrote a letter to that pope, in the most submissive
terms; and sent him, at the same time, an explication of his
propositions about indulgences. This letter is dated on Trinity-Sunday,
1518, and was accompanied with a protestation, wherein he declared, that
"he did not pretend to advance or defend any thing contrary to the holy
scriptures, or to the doctrine of the fathers, received and observed by
the church of Rome, or to the canons and decretals of the popes:
nevertheless, he thought he had the liberty either to approve or
disapprove the opinions of St. Thomas, Bonaventure, and other school-men
and canonists, which are not grounded upon any text."

The emperor Maximilian was equally solicitous with the pope about
putting a stop to the propagation of Luther's opinions in Saxony;
troublesome both to the church and empire. Maximilian, therefore,
applied to Leo, in a letter dated August 5, 1518, and begged him to
forbid, by his authority, these useless, rash, and dangerous disputes;
assuring him also, that he would strictly execute in the empire whatever