Thanks, guys, this is actually a good, respectful and interesting discussion.
I think we are focusing on the issue of doctrine. That is, to what extent can you say that independent opinions in a church negate its doctrine? And what is the solution to this problem?
We all know the rather gross saying about “opinions,” which is unfortunately quite accurate.
The problem in Protestantism is that somebody who asserts his “opinion” and has the personal force of character to convince others - but within a religion that has no authority strong enough to assert the essential doctrine, regardless of this person and his opinions - is going to end up by creating something entirely different.
It may be different with a relatively limited focus, such as the difference between Lutheranism and Calvinism, or it may be different in the way that Islam, a product of the Arian Christianity and latent Judaism and paganism circulating in that environment, is different from orthodox catholic Christianity. Which is to say, an entirely different understanding of God, creation, life, law, and humanity.
By way of accelerating the forum that seems to have gotten a flu, I’d like to anticipate a Protestant point which I think is quite valid, even though it is not dispositive of the question.
The valid point is that similarly how the Catholic flakes are excommunicated by their stated beliefs and actions, the Protestant flakes render themselves outside of the Protestant pale by their de-facto rejection of the Bible.
I think there is a true analogy here. We ask for certain beliefs and actions (or refrain from actions) in order to be Catholic, and we wait for no formal excommunication (always slow in coming) before we say that the flake is excommunicated by her very actions. The Protestants ask for certain concepts that they firmly hold as biblical, and once those are breached, the flake is Protestant In Name Only.
So we both believe in the idea that the flakes excommunicate themselves rather than the given community of faith excommunicates them administratively; the latter, if it happens at all, merely confirms the loss.
Having acknowledged this, I think we still have a crisis of authority in the Protestant Ecumen, in a way in which we don’t have it in the Catholic Church. That is because the criteria of what is and what is not permissible can be drawn in the Catholic Church with infinite precision, if that’s the mind of the Church; or they can be left vague, again if that is the mind of the Church. For example, permissible family planning is defined in the Catholic Church with great precision (certain methods are OK in some circumstances and certain methods are never OK). Abortion, euthanasia, human cloning, gay “marriage”, destructive embryonic research are clearly defined (never OK). Just war is deliberately left on a case-by-case basis. Liturgical innovation is not fully excluded but a firm boundary exists. Etc.
This is where the crisis of authority really is: the Protestant flake can plausibly insist on her scriptural interpretation. No magisterium exists to arbitrate that — it cannot exist in Protestantism in principle because the scripture is supposed to self-interpret. So, while in principle both the Catholics and the Protestants have the mechanism of self-inflicted excommunication, the Catholic boundary can be drawn with infinite precision when needed; a Protestant is left to wonder for herself and usually ends up in a likeminded community that confirms and reinforces the heresy.