The pope's Petrine duty is to preserve intact the original revelation by Christ to the Apostles that has been handed down to him and in turn to hand it on to his successor.
The Pope has no right to teach anything contrary to the Catholic Rule of Faith (Scripture and Sacred tradition)... or to change anything revealed to the Apostles by Christ and handed down through the Apostolic succession.
assumed and self-appointed authority IMO
Thank-you and God Bless.