Now this was the point I was trying (badly) to make with Maximillian. I was attempting to point out that the Catechism seems to be at odds with the ancient and extra-biblical dogma of whether or not salvation is limited to those in the Roman Catholic church.
Making a distinction between the small "c" catholic church (the church universal or Body of Christ) and the large "C" Roman Catholic Church is paramount to the discussion.
Exclusivity vs. inclusivity denotes a doctrine that has changed 180 degrees from ancient interepretation to modern, thereby making me question the "ordinary infallibility of the magesterium". If, in fact, I have misunderstood the exclusivity argument, so then, have many, many in the Catholic faith, including those gifted to teach.
That out of the way, many Catholics have misunderstood the exclusivity doctrine. We are a very poorly catechized Church in the US after forty years of gonzo liberal bishops dominating and running AmChurch Catholicism into the earth or deeper still.
We must concede that we no longer reside in Christendom and probably will not again. In Christendom there was a close intertwining of Church and State. Truth does not change but verbal usage does. In the post-"Enlightenment" age we pile layer upon confusing layer of vocabulary and usage. I believe that the ordinary magisterium is indeed infallible. Before the Reformation, the Church, in partnership with most states, prosecuted and destroyed most formal heresies. The State served the Church and the papacy in many ways. In this way, all residents, Catholic or not, were very much subject to the pope. This notion continues to horrify members of reformed churches.
We have, as Catholics, always believed in terms and concepts, not flattering to non-Catholics, such as "invincible ignorance" which actually have a benevolent meaning. If you sincerely believe in non-Catholic beliefs (this is not to be taken lightly for granted) you are not likely to be judged harshly by God for obeying the natural law written in your heart though you lack some aspects of Catholic belief or practice or some graces available through the Mass and those sacraments which you do not have.
It was less likely in the heyday of Christendom (which we mean to necessarily involve Catholicism sharing rule with the state) that Catholic leaders would advertise widely the existence of such concepts as "invincible ignorance." Our leaders sin and we do not deny that.
Misunderstandings arise easily. Luther attacked Rome for the apparent sale of indulgences to fund the building of St. Peter's Basilica in Rome. First, indulgences cannot really be sold. To so deal in sacred goods is to engage in the sin of simony which would have been understood by all concerned. It is claimed (with credibility) that those preaching in Germany claimed that you could buy your dead relatives out of hell by paying for indulgences. Actually, if you are in hell, you are there permanently. Indulgences, in Catholic doctrine apply only to the remission of temporal punishment due to repented and forgiven sins, i.e. to the souls in Purgatory who are on there way to heaven anyhow but more speedily through the indulgences obtained for them by the Church Militant (on earth). If one is in hell, one did not repent and one was not forgiven.
Second, I suspect that a sold indulgence is no indulgence at all, but I am not sure. This sort of question is akin to one as to whether a fornicating Catholic may use condoms. The Church does not advise sinners as to the nuances of how to most efficiently sin so as to minimize sin and punishment.
Third, based partially on grim truth as was the charge, it sure did make effective mincemeat of any Catholic opponent of Luther stupid enough to defend the practice of selling indulgences.
Fourth, the scandal spread by such defenses led to the further consequence of having people of good will ask themselves: If the Catholics are lying about this, what ELSE are they lying about? That is a tempting thought but it does contain multiple logical fallacies.