The idea is currently being pushed around that the true meaning of what an earlier pope may have taught or enjoined is to be discerned from what a present pope says.
If you don't accept this, you will be called a Dietrist by PF, and you will be attacked and sneered at. Attacks and sneers are two things he is really good at.
The Catholic Church does not teach thus. She teaches the prescriptivity of Tradition; a prescriptivity enjoined not only upon Clergy and People, but also upon the Roman Pontiff himself.
 "I delivered to you as of first importance what I also received".
I Corinthians 15: the words I have rubricised are respectivly paredoka and parelabon.
 Vatican I: "The Holy Spirit was not promised to the successors of Peter in order that, by his revelation, they might publish a new teaching, but in order that, with his assistance, they might devoutly guard and faithfully expound the revelation or deposit of faith handed down through the apostles".
 When Pope Leo II confirmed the Third Council of Constantinople, he repeated the condemnation of his predecessor Pope Honorius I: "We anathematise ... Honorius, who did not attempt to sanctify this apostolic Church with the teaching of apostolic tradition, but by profane treachery permitted its purity to be polluted."
The condemnation issued by the Council was succinct:
"TO THE HERETIC HONORIUS, ANATHEMA!"
All together now ... ...