More on the 1672 Synod of Jerusalem

I'm writing these more or less of the top of my head, with an occasional wikipedia glance to make sure that I have at least my dates right. Maybe I'll edit for grammar/coherency later, but I wanted to at least throw some rough topics out there.

While pointing out the convergence of Catholic and Orthodox doctrine on a wide range of issues, and thus demonstrating the closeness of Catholicism and Orthodoxy compared to the gulf that separates both from Calvinism, the Synod of Jerusalem also reaffirmed the Orthodox rejection of the "filioque clause." The Catholic reading of the Nicene Creed states the Holy Spirit proceeds from both the Father and the Son ("and the Son" = "filioque" in latina lingua), a clause rejected by the Orthodox, who proclaim that the Holy Spirit proceeds from the Father alone. I've always found it a little strange that this was such a huge point of controversy. Many of the differences between Orthodoxy and Catholicism seem to be differences of semantics and cases of looking at the same phenomenon from two different vantagepoints. For example, at risk of oversimplifiying a complex topic into one sentence, Catholicism views original sin as the presence of a stain, whereas Orthodoxy views it as an absence of holiness. Presence of the negative or absence of the positive? Seems like it could be two different ways of looking at the same phenomenon.

But in the filioque clause, we find an actual theological difference between the two traditions that can't be reconciled as "looking at the same thing from two different angles." The Holy Spirit either proceeds from just the Father, or from both the Father and the Son. Both can't be right. But isn't it a pretty minor topic to base the theological roots of a schism on? The filioque clause has come up over and over for 1,000 years as a major point of theological contention and reason, on both sides, for not reconciling. My rough conclusion on why a topic seemingly so tangental to the basic premises of Christianity has historically become such a huge point of contention is simply that the two sides needed something theological to justify what has always been fundamentally a political split.

Thoughts?