Most of the reactions I've encountered, both in the MSM and in person, have been negative. Some of them evince the sort of outrage reserved for the misconception that, according to the Church, only the formally Catholic can avoid hell—a misconception that many Catholics indeed used to hold, but which the Church never required them to believe and now explicitly rejects. Some of the negative reaction is more level-headed, if more radical, than that: e.g., relativists and universalists merely object to the suggestion that Catholicism has something needful to offer that other religions, including other forms of Christianity, lack. Very unPC of the Church, that. But to me the oddest thing is that, outside the rather narrow circles of Catholic "traditionalism"—at which, I suspect, the document was chiefly aimed, given its timing right after the liturgical motu proprio—hardly anybody has noticed how one of the document's points qualifies the sense in which the Church is said to be catholic.
I say "hardly" anybody because, with his usual eye for the unremarked, Tom Kreitzberg of Disputations has noticed and, rightly, approved. I begin with the point that drew his attention:
...because of the division between Christians, the fullness of universality, which is proper to the Church governed by the Successor of Peter and the Bishops in communion with him, is not fully realised in history.
That was said just after the CDF had indicated that certain other true "churches"—meaning mainly the Orthodox—are deficient insofar as they lack full communion with the See of Peter. So, while said churches lack one of the "internal constitutive principles" of any true, particular church, that Church in which the Church of Christ "subsists" as a unitary whole—i.e., the Catholic Church—also lacks "full realization in history." From that, it can only be concluded that the Catholic Church fails to manifest catholicity fully. I find that rather bracing in a magisterial document. It's not something you would ever have heard Rome say before Vatican II; it certainly bespeaks a development, and a humility, that has been largely ignored amid the cavilling. A few of Tom's commenters seemed to get it; but for the most part the combox focused on a tiresome debate about centuries-old views of sexuality and birth control. Of course the underlying issue there is the usual one, indeed the same one typically raised about the development of official ecclesiological doctrine: the Church's present teaching on certain is said to be discontinuous with that of the past, in such a way as to call into question teachings which have not in fact changed at all. Perhaps it shouldn't surprise me that the examples given have to do with sex—a topic which, after all, is sexier than ecclesiology. But even some of the Orthodox, who could choose to be reassured by the quoted CDF remark, look right past the obvious.
Here's an Orthodox hieromonk in California, reacting to Tom's post:
I wish the document used the opportunity this point presents of really "hosing" the Catholic Church for its responsibility for the divisions. Of course this responsibility is only partial, but there is plenty of precendent for popes and other Catholic leaders professing sorrow in recent times for the role our Church has played in creating these divisions. But the way this paragraph is formulated, the divisions need not have anything to with actions by Catholics. They could just be an accident of history, or the work of aliens from outer space, or even....those dissident easterners themselves!
In other words, what's deficient in the responsum's point at issue is that the CDF didn't take the opportunity to reassure the Orthodox by detailing the Catholic Church's due portion of blame for the schism. Well, of course the CDF didn't do that. Vatican II already had done it in general terms, more than forty years ago, in Unitatis Redintegratio §3; Pope John Paul II expanded on that move in his landmark writings Orientale Lumen and Ut Unum Sint; and such words have been backed with many deeds of fraternity and respect by all the popes since Vatican II, including of course the present pope. Indeed, one of the standard trad complaints against Rome since Vatican II is precisely that her ecumenism is too accommodating toward non-Catholics, including non-Catholic Christians. In any event, I can attest by experience that positively inviting a new round of the old blame game is not going to end up reassuring anybody—which is probably as good a reason as any why owning up to the Catholic Church's due portion of blame for the schism (whatever that was) was not among the responsum's purposes. That document was meant only as a brief clarification of settled Church teaching, and that chiefly for Catholic consumption. But for some Orthodox, apparently, that's not enough. No, the Church must "hose" herself in far lengthier and more concrete terms if she expects to placate other "true, particular churches" with her clarifications. Merely acknowledging that the Catholic Church fails to fully manifest catholicity itself fails to convince the anxious that the bad old days are over.
This is one sort of thing I mean by "accentuating the negative." Whenever the Catholic Church misses a putative opportunity for breast-beating, the specter of her triumphalism is raised anew. I had to deal with that sort of thing a lot as a graduate student in a secular university during the 1980s, when the chief topic of conversation whenever the Catholic Church came up was why Pius XII merited condemnation and further suspicion for not condemning the Nazis publicly while they occupied Rome. My usual response was that, no, he didn't beat his wife. Subsequent work has vindicated my dismissiveness. And I'm inclined to be equally dismissive here.
This default tendency to accentuate the negative, which is to be found as much in intra-Catholic Internet controversy as among Orthodox or anywhere else online, is a way of kicking against the Spirit's goad. God is goading us toward unity. If we stopped kicking against it and each other so much, we might move in that direction. It is, after all, the direction in which most of us admit we are obliged to go.