On Luther's return from Rome he was made a doctor of the Holy Scriptures, and his career as a reformer may be said to have commenced. The system of indulgences had reached a scandalous height. The idea that it was in the power of the Church to forgive sin had gradually grown into the notion that the Pope could issue pardons of his own free will, which, being dispensed to the faithful, exonerated them from the consequences of their transgressions. The sale of these pardons had become an organized part of the papal system. Money was largely needed at Rome, and its numerous emissaries sought everywhere to raise funds by the sale of "indulgences;" the principal of these was John Tetzel, a Dominican friar, who had established himself at Jueterberg (1517). Luther's indignation at the shameless traffic which this man carried on, finally became irrepressible. "God willing," he exclaimed, "I will beat a hole in his drum." He drew out ninety-five theses on the doctrine of indulgences, which on October 31st he nailed up on the door of the church at Wittenberg, and which he offered to maintain in the university against all impugners. The general purport of these theses was to deny to the Pope all right to forgive sins. This sudden and bold step of Luther was all that was necessary to awaken a wide-spread excitement. Tetzel was forced to retreat from the borders of Saxony to Frankfort-on-the-Oder, where he drew out and published a set of counter-theses and publicly committed those of Luther to the flames. The students at Wittenberg retaliated by burning Tetzel's theses. The elector refused to interfere, and the excitement increased as new combatants--Hochstratten, Prierias, and Eck--entered the field. Eck was an able man, and an old friend of Luther's, and the argument between him and the reformer was especially vehement. In 1518 the latter was joined by Melancthon, who became one of his dearest and most trusted friends.