In his last comment here on my slavery post, O'Leary proceeds in characteristic fashion by throwing in everything but the kitchen sink. I had claimed, as an aside, that magisterial support in the Middle Ages for the physical punishment of heretics—such as the papal bull Ad Extirpanda—did not meet the Church's own criteria for irreformability. I have made that claim before, and I've made it because AE's subject matter was not any irreformable moral tenet, but rather a prudential judgment on the specific, very time-bound question whether the good of the body politic requires that heretics be physically coerced into confessing their heresies. Those who exercise magisterial authority, including popes, can be wrong about that without logically discrediting their own claims to teach infallibly, and thus irreformably, about "faith and morals" under certain conditions. In this case medieval ecclesiastics, including St. Thomas Aquinas, were wrong about the socio-political importance and necessity of torturing heretics. I've explained why before, but I don't want to distract readers any further by getting into that again. Here, rather, is what O'Leary says in response to my claim that "Ad Extirpanda does not satisfy the Church's own criteria for the infallibility of the ordinary magisterium":
Let's leave aside the rather elementary point that the "ordinary" magisterium of the Church is not to be contrasted with the "papal" magisterium but rather with the "extraordinary" magisterium. Either the pope or the bishops can and do exercise either magisterium (though the bishops can only do so legitimately in communion with the pope). It's bad enough that O'Leary, an ostensibly Catholic theologian, has missed that. But he's actually suggesting that the dogma of papal infallibility is "meaningless" and asserting that the doctrine of the infallibility of bishops, authoritatively taught in Lumen Gentium 25, is "a Bellarminian thesis unwisely embraced, without disucssion [sic], by the bishops at Vatican II." Again, let's leave aside the irony that a theologian who signs himself "Spirit of Vatican II" is rejecting a very important ecclesiological doctrine authoritatively taught by the Fathers of Vatican II. O'Leary is out to end the game before it starts.
If the dogma of papal infallibility is "meaningless" and the infallibility of the bishops, as explained in LG §25, a mere thesis "unwisely embraced," then the question whether the Church's development of doctrine has ever negated an irreformably taught doctrine cannot be usefully debated. Before that question can be usefully debated, there must be some agreement among the participants both that there are infallibly taught doctrines and that there are consistently applicable criteria for identifying doctrines as such. For reasons I've given, the class of "infallible" doctrines is co-extensive with that of "irreformable" ones. Among Catholic theologians who care about teaching with and in the name of the Church, such agreement holds in substance, if not always at the margins. But between me and O'Leary, it does not hold in any sense at all. So, we do not even agree on the premises of the discussion. Perhaps that is why O'Leary consistently misrepresents what I aim to do.
The only useful strategy for the O'Learys of the world—and their name is legion—would be to argue that the historic development of Catholic doctrine precludes any doctrine of magisterial infallibility (ordinary or extraordinary, papal or episcopal) that could be (a) meaningful, (b) useful, and (c) definitively held. If there is no such doctrine of infallibility, then the question which tenets count as irreformable is purely a matter of opinion, and my "development and negation" project is not worth pursuing. That is roughly the tack Hans Küng took in his once-celebrated book Infallible? An Inquiry. A debate about his argumentative strategy is worth having because it can be settled by facts and logic. As I read Küng's book and researched his sources three decades ago, my debate with him was gradually settled. I concluded his case was not compelling on either historical or logical grounds. More important, I soon realized that if he were right, then the claims of the Catholic Magisterium to be preserved from error under certain conditions are so much hot air. In that case, there would be no compelling reason to remain in full communion with Rome, other than to undermine her claims from within.
That, I suspect, is the real point of the O'Learys of the world.