The Holy Ghost cannot proceed from the Father in the trinitarian eternal realm any differently than He proceeds from the Father in the temporal realm. The latter procession is from the Father through the Son and, the Catholics teach, the former must be also.
AugustineBoth "through the Son" and "and the son" are equally valid because of the interpenetration of the Father and the Son persons relative to the Holy Ghost, as the above quote explains."If that which is given has for its principle the one by whom it is given, because it did not receive from anywhere else that which proceeds from the giver, then it must be confessed that the Father and the Son are the principle of the Holy Spirit, not two principles, but just as the Father and the Son are one God . . . relative to the Holy Spirit, they are one principle" (The Trinity 5:14:15 [A.D. 408]).
"[The one] from whom principally the Holy Spirit proceeds is called God the Father. I have added the term ‘principally’ because the Holy Spirit is found to proceed also from the Son" (ibid., 15:17:29).
"Why, then, should we not believe that the Holy Spirit proceeds also from the Son, when he is the Spirit also of the Son? For if the Holy Spirit did not proceed from him, when he showed himself to his disciples after his resurrection he would not have breathed upon them, saying, ‘Receive the Holy Spirit’ [John 20:22]. For what else did he signify by that breathing upon them except that the Holy Spirit proceeds also from him" (Homilies on John 99:8 [A.D. 416]).
If the Orthodox understanding is that the Son and the Holy Ghost proceed symmetrically from the Father, and not sequentially, first the Son and then the Holy Ghost, then indeed that is not compatible. But is it truly Orthodox understanding? Why is it that Christ alone claims to be at the beginning of Creation in John? Why is the temporal order in salvation history different than the procession order in the Trinity? Isn't it true that we only perceive Trinity through salvation history?
Know what. I will post that Filoque article tonight along with the relevant cathechism. If you feel like a brief comment here, I'd appreciate it, but I think it is worth a dedicated thread, so hold your horses till then, OK?
Real quick observation on Augustine's pneumatology.... He couldn't read Greek and got confused by the "only begotten" term meaning the same thing as "proceeds". Really, as I look at it now, it may be more a confusion between "proceeds" (not really a good word at all since its root is the Latin procedere and not the Greek word) and "lavete" which the KJV translates as "receive" but which really means take or grasp as in "Take, Eat, This is my Body...." (Lavete, Fagete etc.) His lack of Greek most likely accounts in great measure for his doctrine of Original Sin too.
I don't recall the Fathers using words like symmetrical, but if I am understanding you correctly, then you are on the right track to understanding what Orthodoxy teaches.
One father wrote (can't remember which) that each person has a characteristic unique to Him: The Father is the source, the Son is begotten, and the Spirit proceeds. Orthodox arguments regarding the filioque are ultimately patristic, scriptural, spiritual, and practical, and not based on theoretical or metaphysical arguments of symmetry or asymmetry, but the observation was made by a father, and I thought I'd pass it on.
I am glad that you have come to the realization that there are genuine substantive differences, and not just differences in terminology. Probably the most important thing that can come of these kinds of threads is an understanding of what the other believes.
Orthodox theology has been pretty highly developed by the Eastern Fathers, who were no slouches -- not in a systematic theology kind of way, but in terms of in-depth readings of the Scriptures and the earlier Fathers in order to understand the consensus teaching of the Church. Those of us on this thread who are Orthodox are steeped in that patristic mindset, and we already knew that the differences were substantive, and have tried to point this out.
Which is why these kinds of threads really don't go anywhere, which is OK, as long as we all raise a toast at the end and drink each other's health rather than get upset. If it hasn't been hammered out by now, I very much doubt that a bunch of armchair theologians in pajamas on FR are going to do so...