We Don't Need No Magisterium: (Jason's Version) (But Actually, We Do)

It seems to me that, respectfully, at the heart of this feel-good ecumenism being advocated in some quarters lurks the re-assertion of the same basic ecclesiology advocated by the Reformers. Just because you're nicer about it doesn't make it any less Reformational than the bitterest of days past. We should all celebrate the fact that we are not taking the Lord's own final judgment into our individual hands, speaking kindly to one another, and hoping and praying for the best. But the Catholic Church speaks clearly on the point of apostolic succession, and combined with Petrine primacy, forms the historically situated basis for levelling the charge of schism against the Reformers. That is, that claim of apostolic visible oneness is not accidental to the claim of authority by the Catholic Church; it is the heart. The reason the Catholic Church doesn't join in the missional-ecumenist party, as it were, is because the Church would have to deny one of her inherent marks, which is tantamount to denying her divine origin. None of us Catholics have the right to do this, whether lay or clerical. Across the divide, we mean different things by the four marks of the Church. The heart of becoming Catholic is acknowledging the authority and origin of that Church which has the audacity to resist the re-definition of the words. Part of my error in being Protestant had been the opinion that I, along with my leaders, had the divine sanction and right to re-define the Church, either in what she believes, or in what she is. John, for all his great work, doesn't get this. This visible unity argument isn't a bludgeon in the hands of a misguided, fanatical minority--even an exceedingly gracious one--it is the Catholic-Protestant divide itself. Always has been. I fear I'm being unclear.
But let me ask a few questions: Let's assume for the sake of argument that the visible unity argument is in error, a polemical false start with no basis in reality. What is the principled means for establishing orthodoxy? Does it exist? Even if we were to agree on the means for establishing it (Scripture), what does Scripture say? Who, or what, settles the disputes that surely inevitably would arise? Are we not in the exact place (just within Protestantism) we are today? How could we speak of "orthodoxy" at all? Will John Armstrong be the arbiter of both the orthodoxy and the shape of such a "Church"? Isn't every dispute between Christians really a dispute about the nature of the Church and the content what she believes? The only way we end it is to agree upon the basis, the origin, of our "core orthodoxy." I absolutely agree there is one. The point from our end is that the physical structures of that orthodoxy are crucial to find and declare it, not accidental or even extraneous. I'm Catholic because I traced the content of that core orthodoxy back to the very means God used to establish it: the visible community headed by Peter, maintained in the Holy Spirit by apostolic succession. I can't see any other option. A visible Church with no principium unitatis isn't (or won't stay) visible, and an invisible Church has no discernable orthodoxy, since its boundaries extend beyond the bounds of its common faith.