Again…very clear:
But, if the Western Church agrees with the East that the Spirit proceeds from the Father alone, then what does it mean by “Filioque” – that the Spirit proceeds “from the Father and the Son”? Very simply, and keeping in mind the West’s isolation from the original Greek-language intention of the Constantinopolitan Creed, what the West means to express is a truth that is equally valid, but distinct and parallel to, the original Greek-language intention. For, when the West speaks of the Spirit “proceeding” from the Father and the Son, it is referring to something all-together different than “procession” as from a single source (aitia). It is not advocating two sources or principals for the Spirit, or some kind of “double spiration”, as is all-too-commonly (and wrongly) assumed by many Eastern Orthodox. Rather, it is using the term “proceeds” in an all-together different sense. And the best way to illustrate the two different senses or uses of the term “proceeds” (Greek vs. Latin) is though the following analogy:
If a human father and son go into their back yard to play a game of catch, it is the father who initiates the game of catch by throwing the ball to his son. In this sense, one can say that the game of catch “proceeds” from this human father (an “aition”); and this is the original, Greek sense of the Constantinopolitan Creed’s use of the term “proceeds” (“ekporeusis”). However, taking this very same scenario, one can also justly say that the game of catch “proceeds” from both the father and his son. And this is because the son has to be there for the game of catch to exist. For, unless the son is there, then the father would have no one to throw the ball to; and so there would be no game of catch. And, it is in this sense (one might say a “collective” sense) that the West uses the term “proceeds” (“procedit”) in the Filioque. Just as acknowledging the necessity of the human son’s presence in order for the game of catch to exist does not, in any way, challenge or threaten the human father’s role as the source or initiator (aition) of the game of catch, so the Filioque does not deny the Father’s singular role as the Cause (Aition) of the Spirit; but merely acknowledges the Son’s necessary Presence (i.e., participation) for the Spirit’s eternal procession from the Father to Someone else – namely, to the eternal Son. Father and Son are thus collectively identified as accounting for the Spirit’s procession. This is all that the Filioque was ever intended to address; and it was included in the Creed by the Western fathers at Toledo in order to counter the claims of the 6th Century Spanish (Germanic) Arians. These Arians were of course denying this essential and orthodox truth – that is, the Son’s eternal participation in the Spirit’s procession – an issue which was never challenged or comprehensively addressed in the Byzantine experience, aside from the fact that there does exist throughout the writings of the Eastern fathers the profession that the Spirit proceeds from the Father “through [or ‘by way of’] the Son” – an expression equivalent to the Filioque.