D.B. Hart essay: ‘The Myth of Schism’
Under Contents go to page 95

Long story short: Catholicism East and West is the same church except for the scope of the Pope (God-made channel of the church’s infallibility or man-made rank of the divinely instituted episcopate for the good order of the church?), the only insurmountable problem. (One that would remain if Pope Benedict succeeds in purging all the would-be Protestantism and its son, Modernism, from Rome.) For union to happen one side would cease to be. (Its rites would remain but something essential would change.) The ‘tous schismatiques’ view of a very few Greek Catholics is branch-theorism that ultimately says there’s no church.

An outline from Dr Tighe (who explains his position here):

It’s divided into four parts: I., “The Mythology of Division,” II., “Theology,” III., “Doctrine,” and IV., “Ecclesiology.”

In Part I he spends most of the time attacking ideas of “immemorial,” “fundamental” and “ontological” divisions between the Latin West and the Greek East (Romanides, Staniloae, Lossky and Zizioulas for the East and Przywara and von Balthasar for the West) as well as “1204 and All That,” praising JP II’s “Ut Unum Sint” and insisting that before 1729 (for Rome) and 1754 (for the East) few folk in either East or West thought that the Latin and Greek churches were completely separate bodies, one “The True Church” and the other “No Church.”

In Part II he says that there are no real “theological” differences between the East and the West, denying particularly those who assert that there are fundamental differences in Trinitarian Theology (divine simplicity and the filioque) or in regard to the “errors of Augustine” know what they’re talking about, or even that their views should be taken seriously by anybody.

In Part III he says that there are significant “doctrinal differences” while insisting that “doctrinal differences” are much less serious or “deep” than “theological differences.” After specifically denying that there are any such differences as regards the Assumption of the Immaculate Conception (so long as the notions of Original Sin etc. underlying the specific 1854 formulation of the latter are not taken as de fide), he concludes that there are two,” the filioque (not the teaching but the mere fact of its insertion in the Creed) and Purgatory (not as regards post mortem purification and healing, but, rather, the notion of penalties, punishment and “time”). He thinks that the mere presence of the filioque in the Creed, even only in the Latin Church, makes the prospect of reunion impossible, and its removal he sees as an absolute prerequisite for reunion. He thinks, on Purgatory, that “theological reflection” can bring about agreement.

In Part IV he reflects, rather inconclusively, on papal infallibility, thinking it could be formulated in a way that would be acceptable to the Orthodox (although his thoughts on this strike me as quite vague). A bigger problem appears to be “universal jurisdiction” although he doesn’t “name the issue” and his essay sort of segues into that underlying issue and then out of it again without any real concrete suggestions. Then he goes on to assert hat the real problem is “how to justify the continuing division” (ill-founded as he regards it in its origins and justification), when Christian unity is “an imperative” in face of the relentlessly advancing “soothing and saccharine nihilism” that is purveyed by the dominant Western culture and seems likely to triumph everywhere over the next few decades.

The essay is only eleven pages long (pp. 95-106), and it can be read in its entirety at the Google Books link.