‘• Pope Boniface VIII, Unam Sanctam:
“We declare, say, define, and pronounce [ex cathedra] that it is absolutely necessary for the salvation of every human creature to be subject to the Roman Pontiff.”’
I am not a Catholic, and have never been a Catholic. So somebody needs to explain this to me. The first quote is ex cathedra. I know what that means. The last three quotes, re: Vatican II, set the top one aside. [I get that they assert we are saved via an imperfect communion, not recognized by us, to the Catholic Church. However, we are not subject to the Roman Pontiff. So whatever this imperfect communion is, it falls short of subjecting us to the Pope.] So how does the Catholic Church justify setting aside an ex cathedra pronunciation?
A very logical question. One with which many Roman Catholics here on FR seem to side step or avoid. Recommend posing the question to an RC poster and wait for the answer.
It is not set aside. Membership in Christ's Church is essential for salvation. By definition the Pope is the head of Christ's Church. Whether someone disagrees on the nature of the Christ's Church (visible vs. invisible) or is in imperfect communion is not relevant. They are still subject to his authority.
But it is also possible to be "associated" with or "partially incorporated" into the Catholic Church without being a fully and formally incorporated into it. Vatican II states: "The Church knows that she is joined in many ways to the baptized who are honored by the name of Christian, but do not profess the Catholic faith in its entirety or have not preserved unity or communion under the successor of Peter" (Lumen Gentium 15). Those "who believe in Christ and have been properly baptized are put in a certain, although imperfect, communion with the Catholic Church" (Unitatis Redintegratio 3; CCC 838)
So just as one is subject to the laws of their state even if they do not agree with them every Christian is subject to the Roman Pontiff.