I think you may have misunderstood me. I didn't necessarily suggest that the filioque as used by Ambrose of Milan or Cyril of Alexandria was heretical. And while I regard the clause itself as a violation of the Creed, I don't necessarily view it as a violation of the doctrine of the Trinity. I certainly think that the Latins should come up with a better terminology to use in the Creed that better expresses the original Greek meaning such that the clause is naturally ruled out. What I was referring to was the filioque in so far as it concerns modern day Romanists. The phrasing "the Holy Spirit proceeds eternally from the Father and the Son as from one principle" is part of the current dogmatic tradition of Rome. This is where I see the doctrine of the Trinity being clearly violated.
I suggest you read on the subject the many discussions of Pope John Paul II in his dialogue with Orthodoxy, specifically on the Filioque clause. Anyway, in what is eternal (God) it is impossible to have a temporary procession as you suppose. The "one spiration" source is the Father; the Holy Spirit abides in the Son and inherits (this always in eternity) a secondary procession from the Son. Augustine expresses this saying that the Spirit proceeds "from the Father principaliter
" i.e. by principle. And in the Summa, the same Thomas Aquinas defends both definitions in two different chapters of his work:
Therefore, because the Son receives from the Father that the Holy Ghost proceeds from Him, it can be said that the Father spirates the Holy Ghost through the Son, or that the Holy Ghost proceeds from the Father through the Son, which has the same meaning.
and then he adds (and this is the difference you evidence in your post):
As the begetting of the Son is co-eternal with the begetter (and hence the Father does not exist before begetting the Son), so the procession of the Holy Ghost is co-eternal with His principle. Hence, the Son was not begotten before the Holy Ghost proceeded; but each of the operations is eternal.
For the rest, I agree with you that the Catholic Church should find a new way to express this concepts, I hope for a day when all Catholics, both Western and Eastern, should sing together in their languages "who proceedth from the Father through the Son" overcoming all differences, but I don't think the form "from the Father" is complete enough for the Latin understanding of the Creed.
Yet, this is just a secondary part of the topic, so I'll pass to the second point. You wrote:
I've heard numerous Romanist sources claim that the Summa Theologica is the second most authoritative text in your tradition second only to the Bible. Also, I've been told that the Summa has been officially recognized by the Vatican. If this is true, I see some aspects of the Summa as inherently contradictory to Palamism.
First of all, authoritative isn't the same as infallible. Only the Magisterium, in Roman Catholic theology, can express infallible and unchangeable dogmas, and the Magisterium is made of the decisions of the Ecumenical Councils and the "ex cathedra" of the Pope. A proof that the Summa can't be seen as dogmatic or entirely infallible and "official" is the explicit denial of the Immaculate Conception contained in it. Check it yourself if you want. St. Thomas Aquinas denied the Immaculate Conception, or better, he denied that Mary was immaculate since her conception, as he supported the hypothesis that Mary became Immaculate only at birth or after the 2nd month from conception, as many Scholastics held that the rational aspect of the soul developped only at that time, and that sin is a lack of justice (thus, a partially darkened rational soul). Anyway, this reflects the clear fact that the Summa, as good and profitable for Catholics might be, is still a work-in-progress in the theological growth of some doctrines by the Latin Church during the 12th and 13th century, and not a work endowed with infallibility despite its official recognition. If you want, you can compare its contents to the Synod of Jerusalem of 1666-1667 in the Orthodox Church, which is said to contain errors and thus being fallible despite its canons are perceived as useful instruments against Calvinism.
The only documents on the matter of grace being dogmatic are the necessity to preserve Divine Simplicity which is a dogma clearly sanctioned at the Lateran Councils and at Trent (a question which, it seems, can easily be safeguarded by saying that the distinction of Essence and Energies doesn't affect divine simplicity), and that grace - understood in the terms of the Council of Trent, i.e. as the individual "state of grace" of a faithful - is to be identified in LATIN theology with the transformation of the habitus of an individual and can thus be called "created grace". The voice of Pope John Paul II, as I have already said, opened a door to appreciation for Gregory Palamas who was explicitly called "Saint Gregory Palamas" by His Holiness during a conference with a mixed Orthodox-Catholic commission of theologians. You can verify it yourself on the book "How Not To Say Mass" by Father Dennis C. Smolarski. It is said, in the source I read (an official Melkite source) that this recognition came in the few months after Ali Agca's assassination attempt on the Pope's life. The entire matter is briefly mantioned on this webpage (which underlines the controversy on Palamas' figure and the way he was canonized and officially recognized in the Melkite Calendar): http://www.mliles.com/melkite/stgregorypalamas.shtml
On the matter of female priesthood, I must beg pardon. I evidently read too much in your affirmations. On the Chalcedonian/Non-Chalcedonian matter, I didn't mean to move the topic to that subject: I was just parallelling the two situations where different expressions in different languages can convey similar theologies despite all possible misunderstandings.
In Christ, Alex