Pope Leo X granted indulgences to people who paid money to help repair St. Peter’s Basilica. However, the Council of Trent shortly afterward abolished indulgences that involved the transaction of money. Isn’t the pope supposed to have access to the treasury of indulgences though and therefore be infallible on these kinds of things?
First, that is an over simplification of the indulgence. Second, the Council of Trent did not abolish indulgences or granting indulgences for the giving of money. Alms giving to the poor or to other worthy causes was always considered what St. Paul calls in Corinthians, “works of gold, silver and precious stones”. What Trent sought to abolish were the abuses that had crept in. The Council called for moderation and abolishment of all evil gains in the granting of indulgences. Such evil gains were akin to “sales commissions” that the likes of John Tetzel obtained.
The complete canon of the Council on indulgences is as follows:
"DECREE CONCERNING INDULGENCES.
Whereas the power of conferring Indulgences was granted by Christ to the Church; and she has, even in the most ancient times, used the said power, delivered unto her of God; the sacred holy Synod teaches, and enjoins, that the use of Indulgences, for the Christian people most salutary, and approved of [Page 278] by the authority of sacred Councils, is to be retained in the Church; and It condemns with anathema those who either assert, that they are useless; or who deny that there is in the Church the power of granting them. In granting them, however, It desires that, in accordance with the ancient and approved custom in the Church, moderation be observed; lest, by excessive facility, ecclesastical discipline be enervated. And being desirous that the abuses which have crept therein, and by occasion of which this honourable name of Indulgences is blasphemed by heretics, be amended and corrected,
It ordains generally by this decree, that all evil gains for the obtaining thereof,–whence a most prolific cause of abuses amongst the Christian people has been derived,–be wholly abolished. But as regards the other abuses which have proceeded from superstition, ignorance, irreverence, or from what soever other source, since, by reason of the manifold corruptions in the places and provinces where the said abuses are committed, they cannot conveniently be specially prohibited; It commands all bishops, diligently to collect, each in his own church, all abuses of this nature, and to report them in the first provincial Synod; that, after having been reviewed by the opinions of the other bishops also, they may forthwith be referred to the Sovereign Roman Pontiff, by whose authority and prudence that which may be expedient for the universal Church will be ordained; that this the gift of holy Indulgences may be dispensed to all the faithful, piously, holily, and incorruptly."