To which I replied: we only know the Trinity from its manifestation in the economy of salvation. That which is true in the temporal sense must be true in the eternal sense.
To that I got no answer.
That's what Aquinas understood, at least from my reading of him in the Summa. The generation of the Son and the procession of the Spirit are necessarily immanent in God.
To which I replied: we only know the Trinity from its manifestation in the economy of salvation. That which is true in the temporal sense must be true in the eternal sense.
My understanding is that all Three Persons are present and cooperate in every act of God attributed to a single Person in Scripture, since they all possess the same nature. According to Aquinas, the Persons differ in origin (in a similitude to natural generation, as like being generated from like) and relation.
We only know the Trinity based on what is revealed to us about the Trinity, and many things have been revealed. By this same argument, since the Holy Spirit was involved in the economy of our salvation -- i.e. Christ was sent to us by means of the Holy Spirit -- then this must be true in the eternal sense, and the Son must be begotten of the Father and the Spirit both.
The phrase "proceeds from the Father" as Kolokotronis points out, is a direct quotation from Scripture. As bobjam pointed out on this thread and as I pointed out on the other thread, when Orthodox simply use the word "God," we are generally talking about the Father, who is the personal point of unity of the Trinity. There is also unity of essence, nature, and energies. But for the Orthodox, these impersonal things are not what we talk about when we speak of "God." The chief prayer that Christ taught us to pray to God begins "Our Father."
I would also mention that a post on the earlier thread stated that the Spirit must proceed from the Father and the Son because the Spirit was not present at the beginning. This seems to me to be applying concepts such as time to the Trinity, and this is highly problematic. Time itself is a created thing. Even what we will experience in the next life (commonly described as eternity) is taught by the Fathers to be a created thing, and God is still outside and beyond even this.
Anyway, I pretty much exhausted myself yesterday, and like the others, don't have a whole lot more in me on this subject. I think that your posting has shown what Catholics believe, and I hope we have done an adequate job of sharing what the Orthodox believe, teach, and live.
Great Lent is indeed a rough time to get into these things. Most of us are very aware of the fact that the temptations to say things we would regret are higher now than at any other time of the year. We are also in church a lot. I will be standing through, making prostrations, and chanting in about 9 hours worth of services yet this week. Most of us have added things to our prayer rule. We're on our 5th week without meat and our 4th without any egg or dairy products, and have several weeks to go on both. I'm not by any means complaining -- it is a joyous time for us, affectionately known by some as the "Lenten Spring."
The only reason that I'm spelling this out is to make sure that you understand that for me anyway, my FR activity (as you can see by examining my track record over the past 5 weeks) comes in spurts as energy and time allow, and only for as long as I'm able to maintain a good attitude. When I can't, then it's back to prayer. Lack of engagement should not be taken either as an indication that we have nothing to say in response to a given argument, nor as an indication that we are upset or uninterested.