"I do not think the dual procession of the Holy Ghost has been defined infallibly."
Sure it was, at Nicea, Alex. But that doesn't end the discussion, AMHN. Where the problem has been for the past 1000 years or so has been with the West's own, often theological and hierarchial if not papal, attempts to justify filioque with novel theology. The understanding of the procession of the Holy Spirit in the East has always been as stated by +Gregory Palamas in the 13th century:
"The Spirit of the supreme Logos is a kind of ineffable yet intense longing or 'eros' experienced by the Begetter for the Logos born ineffably from Him, a longing experienced also by the beloved Logos and Son of the Father for His Begetter; but the Logos possesses this love by virtue of the fact that it comes from the Father in the very act through which He comes from the Father, and it resides co-naturally in Him.
It is from the Logos's discourse with us through His incarnation that we have learned what is the name of the Spirit's distinct mode of coming to be from the Father and that the Spirit belongs not only to the Father but also to the Logos. For He says 'the Spirit of Truth, who proceeds from the Father' (John 15:26), so that we may know that from the Father comes not solely the Logos - who is begotten from the Father - but also the Spirit who proceeds from the Father. Yet the Spirit belongs also to the Son, who receives Him from the Father as the Spirit of Truth, Wisdom and Logos. For Truth and Wisdom constitute a Logos that befits His Begetter, a Logos that rejoices with the Father as the Father rejoices in Him.
This accords with the words that He spoke through Solomon:'I was She who rejoiced together with Him' (Prov. 8:30). Solomon did not say simply 'rejoiced' but 'rejoiced together with'. This pre-eternal rejoicing of the Father and the Son is the Holy Spirit who, as I said, is common to both, which explains why He is sent from both to those who are worthy. Yet the Spirit has His existence from the Father alone, and hence He proceeds as regards His existence only from the Father. Our intellect, because created in God's image, possesses likewise the image of this sublime Eros or intense longing - an image expressed in the love experienced by the intellect for the spiritual knowledge that originates from it and continually abides in it."
So far as I know, and I base this on the comments of the Roman and Orthodox theologians who together came up with an agreed statement on the Creed, this is the precise and correct meaning of the filioque for Roman Catholicism. Thus the Roman Church has apparently agreed that the Creed without the filioque is "normative" and should be what is used for translations and catechesis.
The filioque started out as an attempt to counter Arianism. Its imposition on the Church by Rome was at a minimum misguided and I think, AMHN, you may be right that it at least in part lies at the base of medieval claims of papal supremacy. Remember that in the False Union of Florence, Orthodoxy was not required to accept the filioque. By the time of the Reformation, Rome had reason to harden its positions about papal supremacy, but they weren't cvoming from the East.
Frankly, AMHN, the filioque is only an issue if Rome insists on a dual procession of the HS...and if it really ever did, it doesn't now.
"Remember that in the False Union of Florence, Orthodoxy was not required to accept the filioque."
I'm not sure that the False Union of Florence did not include many false precepts as well, i.e. that of not requiring the Orthodox to accept the filioque. Remember, Constantinople fell to the Muslims within 20 years of this false, and unholy union; and it remains so today. I believe God knows the hearts of men...which are not always revealed in their documents. I fear that the modern form of Florence, i.e. the Ecumenical movement toward pan-Christianity, pan-religion, and ultimately humanism (the true under current of the superficial healing between Rome and Orthodoxy) will have similar, if not even more disastrous, effects
I'm not sure that I agree with you concerning whether or not Rome ever insisted in the issue of the dual procession. But that could be a discussion itself.
I do agree that Nicea and Constantinople defined infallibly the issue of the precession of the Holy Spirit. I would also add that it did so as One Holy Catholic Apostolic Church guided in all Truth by the Holy Spirit.
I would be careful from an ecumenical standpoint to lessen the historical and theological implications of these great heresies (as many of our Saints have categorized Rome’s theology). To do so trivializes the impact this theology has had on the Body of Christ and the complete Protestant fragmentation we’ve seen since the Great Schism.
No, the SINGLE procession was defined at Nicea in terms of the formulation of the creed. I was wondering if the dual procession was defined infallibly. I know the Catechism teaches it, following Aquinas, but this is not necessarily the same as infallible statement from the pope.
Also note that the West does not necessarily view the creed as infallible, but rather as a statement that informs the faithful in the way most consonant with the temporal pastoral needs.