You’re so out of your flipping league it’s disturbing.
The dogma was *defined* at Vatican I. Meaning, a concrete definition was written for something that had always been believed, assumed, and acted upon.
Who the flip doesn’t know that the Papacy considered itself infallible during the Middle Ages hundreds of years before Vatican I?? Are you telling me that your historical knowledge is THAT impoverished? What do you think got your Protty ancestors all in a tizzy for Pete’s sake?
Bring me up to your "flipping league," I bid you please kind superior person of very elaborately complex yet oddly immoral in practice religion.
The doctrine of papal infallibility was not new and had been used by Pope Pius in defining as dogma, in 1854, the Immaculate Conception of Mary, the mother of Jesus.[5] However, the proposal to define papal infallibility itself as dogma met with resistance, not because of doubts about the substance of the proposed definition, but because some considered it inopportune to take that step at that time.[5] Richard McBrien divides the bishops attending Vatican I into three groups. The first group, which McBrien calls the "active infallibilists", was led by Henry Edward Manning and Ignatius von Senestréy. According to McBrien, the majority of the bishops were not so much interested in a formal definition of papal infallibility as they were in strengthening papal authority and, because of this, were willing to accept the agenda of the infallibilists. A minority, some 10 percent of the bishops, McBrien says, opposed the proposed definition of papal infallibility on both ecclesiastical and pragmatic grounds, because, in their opinion, it departed from the ecclesiastical structure of the early Christian church.[6] From a pragmatic perspective, they feared that defining papal infallibility would alienate some Catholics, create new difficulties for union with non-Catholics, and provoke interference by governments in church affairs.[1] Those who held this view included most of the German and Austro-Hungarian bishops, nearly half of the Americans, one third of the French, most of the Chaldaeans and Melkites, and a few Armenians.[1] Only a few bishops appear to have had doubts about the dogma itself.
https://en.wikipedia.org/wiki/First_Vatican_Council#Papal_infallibility
Regulator: It is important to keep in mind, in case you didn’t know, that whenever the Church “defines” a teaching it doesn’t mean that it wasn’t always held or taught. The “new” definition is to bring about clarity and oftentimes it happens because others have challenged the teaching. It does not mean that it suddenly became teaching. I think this is something that non-Catholics misunderstand.