"On other threads this week, there was some, for lack of a better term, exasperation with the idea of ecumenism between the Orthodox churches and the Catholic churches because of theological differences. I think that focusing the discussion strictly on theological issues (and more likely, theological differences)somewhat misses the point."
Well, sometimes beating the same old dead horse can get exasperating! :) The outlining of theological differences however, and defining them as clearly as possible, allow us to come to a better understanding of where Latins, Eastern Rite Catholics and the Orthodox are coming from. In other words, understanding where and what the differences are can lead us to better understand the respective phronemas which determine the way we as Latins, Eastern Rite Catholics and Orthodox Christians respond to the world around us. We do respond differently.
"In my view, greater cooperation between the Orthodox and Catholic churches will happen because the practical advantages are so compelling."
In a societal/civilizational context that may well be true.
"And perhaps that's a better tack to take than to debate the theological differences and to quote from ancient documents ad infinitum."
Its clear that on a number of issues which divide us, the papacy springs to mind, the quoting of ancient declarations won't change any minds, so your point is well taken. But as I said there has been value to those "quote wars" because they do in fact demonstrate very different approaches to and understandings of the ultimate reality of our Faith.
"I think we also need to define what is meant by "communion." Do we mean more cooperation on issues of mutual concern?"
I don't think that's the way the Orthodox have been using the term.
" Do we mean shared Eucharistic celebration? Do we mean unification as one church on an institutional level?
Short of institutional unity, with the bishops of the particular Churches in communion with each other (and per force a shared Eucharistic celebration)all that would be left would be inter communion and that would have to be a matter of economia for the bishops of the Churches. For the Orthodox, economia is almost always a matter of personal, individual situations. Churchwide inter communion with non Orthodox would require at a minimum a consensus among the Orthodox Churches to do so and then Synodal approval in the Churches. We looked at this in the 1990s and found that we could not come to consensus so for now that's out. It seems to me that communion should mean full unity, with the bishops of the particular Churches "in communion" in a formal sense, with each other.
Cooperation on other issues is quite another matter. What issues do you see as areas of cooperation?
"For the Orthodox, economia is almost always a matter of personal, individual situations. Churchwide inter communion with non Orthodox would require at a minimum a consensus among the Orthodox Churches to do so and then Synodal approval in the Churches. We looked at this in the 1990s and found that we could not come to consensus so for now that's out. It seems to me that communion should mean full unity, with the bishops of the particular Churches "in communion" in a formal sense, with each other."
It seems to me, then, that an approach that might bear some fruit is individual Othodox churches coming into communion with individual Orthodox churches in situations where it makes sense. Sort of a variation on what the Melkites and the Orthodox churches (Antioch?) are doing in Lebanon. I see some potential between individual eastern Catholic churches and Orthodox churches. It's like the old saw about how you eat an elephant; one bite at a time.
Of course you'll run into the the same old arguments about uniatism, but for some of the churches it wouldn't really matter. How would unity between say the Ruthenians and the Coptic Orthodox present much of a threat to anyone? Both churches traditionally operate in different regions and using different languages.
"Cooperation on other issues is quite another matter. What issues do you see as areas of cooperation?"
This is the part where I'd challenge the Orthodox to start looking at the upside risk of cooperation as opposed to the downside. One significant potential benefit I see accruing to the Orthodox is access to greater numbers of Christians; an issue that will increase in importance in my view given the abysmal birthrates in certain predominantly Orthodox countries.
Given the hour, I can't wax poetic right now but I can and will list the opportunities I see in future threads/conversations.