“We declare, say, define and pronounce, that it is absolutely necessary for the salvation of every human creature to be subject to the Roman Pontiff.”
The nuancing of this into what the posted article says is complete nonsense. To say that Boniface VIII meant something other than what he said is nothing more than a futile attempt to maintain the fiction of the infallibility doctrine of Vatican I. I am sure the Latin Church wants to believe this. I am sure it wants the Orthodox to believe this. I don’t think we Orthodox should allow the Latin Church that fig leaf.
The way to deal with Unam Santam is to admit that Boniface VIII was simply wrong. The proclamation of dogma by Popes sua sponte has had precisely the sort of unforeseen consequences one would expect to flow from a heresy like the notion of papal infallibility.
P. do you think that Unam Sanctam could have come out of a true Ecumenical Council, even in 1302? You and I both know it wouldn’t have.
I notice it does not say "...absolutely necessary for the salvation of every human creature to declare themselves to be be subject to the Roman Pontiff.”
Oh how true. Either words mean what they mean and are rightly understood by all, or they don't and we are in the world of Alice in Wonderland:
'When I use a word,' Humpty Dumpty said in rather a scornful tone, 'it means just what I choose it to mean -- neither more nor less.'
P. do you think that Unam Sanctam could have come out of a true Ecumenical Council, even in 1302?
How different is it from what came out of the Ecumenical Council of Florence 140 years later?
Really, its the same thing Popes had been and would be writing for centuries. I.e, the Formula of Pope St. Hormisdas, the Questions to the Armenians of Clement VI, Pius XI in Mortalium Animos, or Pope St. Boniface I writing:
"It is clear that this Roman Church is to all churches throughout the world as the head is to the members, and that whoever separates himself from it becomes an exile from the Christian religion, since he ceases to belong to it's fellowship." (Epistle 14.1)
Even the Second Vatican Council in the Decree on Ecumenism paraphrases Unam Sanctum:
It was to the apostolic college alone, of which Peter is the head, that we believe that our Lord entrusted all the blessings of the New Covenant, in order to establish on earth the one body of Christ into which all those must be fully incorporated who belong in any way to the people of God
Either there are many ways to salvation, or there is one way. This is a very simple question of logic which can be approached very simply and understood by all. Those who make a labor of this question as concerns Catholic teaching simply want to avoid the obvious, straightforward, and literal answer given directly in the inital quote.
Its like complicating the statement "Jesus Christ is God and of one substance with the Father" with endless hedging, rephrasing, and redefining, until we eventually come to the faith of Arius.