Thomas Cajetan
Luther was summoned by authority of the pope to defend himself against charges of heresy before Thomas Cajetan at Augsburg in October 1518. Cajetan did not allow Luther to argue with him over his alleged heresies, but he did identify two points of controversy. The first was against the 58th thesis, which stated that the pope could not use the treasury of merit to forgive temporal punishment of sin. This contradicted the papal bull "Unigenitus" promulgated by Clement VI in 1343. The second point was whether one could be assured that they had been forgiven when their sin had been absolved by a priest. Luther's "Explanations" on thesis seven asserted that one could based on God's promise, but Cajetan argued that the humble Christian should never presume to be certain of their standing before God. Luther refused to recant and requested that the case be reviewed by university theologians. This request was denied, so Luther appealed to the pope before leaving Augsburg. Luther was finally excommunicated in 1521 after he burned the papal bull threatening him to recant or face excommunication.