Because the Latin West added a word (filioque) to the Nicene Creed, which was not there when the Creed was formulated and which addition was not approved by an Ecumenical Council (or any of the popes up to and shortly after the Great Schism), the West was guilty of heresy then as it is now
This could only be the case if the word was certainly an "illegitimate addition" in the words of the Council of 879-880. That of course depends on the purpose of the west in adding it, and the meaning attached to it. I would maintain that there is a perfectly Orthodox sense in which the filioque can be understood, as many of yout saintly theologians have said, such as St. Maximus the Confessor, Patriarch Gregory VII, St. Gregory Palamas, Fr. John Meyendorf, Fr. John Romanides, and others, and that it was in this Orthodox sense that the addition was intended.
When the Greek bible was traslated inot the latin Vulgate, the Latin word for proceed is not equivalent in meaning to the one used in the Greek original which actually implies procession from a source and not through a source. The correct theological construct is that the Spirit proceeds (like water from a spring) from the Wisdom and is expressed through the Word although as it is expressed it also proceeds but not in the original sense. By implying that the Widsom of God proceeds (i.e. originates in the Greek meaning of the word) from the Father and the Son, it is also implied that the Son's Divine Economy is the same as that of the Father, which is not what the Church teaches.
It is only implied that when misconstrued back again into Greek. The origin (the derivation or source) of the Holy Spirit we say is from the Father alone by spiration, and not generation, but his cause (the thing that brings about an effect) is from the Father and the Son. I believe this is the same as what you say at Balchernae in that the Spirit "proceeds" from the Father, and is "manifested" by the Son. I think there are a number among the Orthodox who are coming to the same conclusion. I recognize that the way we speak is not the same as the way you speak, but I would hope you recognize that our theological language is just as old as the Cappodocian work. It is certainly used at the same period by Sts. Ambrose and Hilary.
There is no doubt that the Church to this day maintains the "monarchy" of the Father in the Holy Trinity.
No there is not. That is the position of the Catholic Church when it says with St. Augustine that the Holy Spirit proceeds from the Father as principle (fundemental source). "The Holy Spirit proceeds from the Father as Principle (principaliter) and, through the latter's timeless gift to the Son, from the Father and the Son in communion (communiter)." (De Trinitate XV , 25, 47, PL 42, 1095).
The heresy was introduced to combat the Arian heresy among Spanish Visigoths (German tribes) converted to Christianity by "elevating" the Son to a more "godly" status.
Its easy to find it quite a bit earlier than the time of the Visigothic invasion.
As Greek ceased to be used in the West as the Church language by the 4th century
Greek had never been commonly used in the West except among the Greek inhabited coastal colonies and in Rome. The Latin Bible was produced by the second century (St. Jerome revised the existing Latin Bible, he didn't create a new one), and most of the peculiar Latin theological terminology by the middle of the third by Tertullian, St. Cyprian, and Pope St. Cornelius among others.
How fully Catholic is Orthodoxy is best demonstrated by the fact that Byzantine Catholics (Greek-Catholics) do not have to change their Nicene Creed or anything in their worship to be considered fully in communion wiht Rome, so long as they accept the pope as their lord.
That's a rather anachronistic way of phrasing the concept in English. The Eastern Catholics accept that communion with the Pope ensures communion among all Catholics, and that part of this communion is adherence to his teachings to settle disputes, and acceptance of the right of final appeal in canonical and theological questions. The Pope does not "rule" the eastern Churches though, unlike the Latin Rite, which he does rule as Patriarch.
and the issue of the Immaculate Conception is that it was unkown to Christianity until about 200years ago and run completely contrary to the pre-Augustinian Christian understanding of Man's Fall to which Rome subscribed for centuries. In fact, even Thomas Aquinas, could not reconcile the Immaculate Conception which did not become a dogma until the 18th century.
The concept of the Immaculate Conception is clearly present in first millenium eastern thought. Stripped of western theological language anfd baggage to help your understanding, it is the assertion that Blessed Mary was conceived, and her soul infused into her body, filled with the divine grace of the Holy Ghost which united her from her origin to the life of God - the moment of her redemption from the common fate of the children of Adam was at her Conception, instead of her Baptism. It says nothing more and nothing less than this.
St. Thomas actually did hold this doctrine (as did St. Augustine and St. Ambrose before him). The doctrine has nothing to do with the bugabear of "pre- and post-Augustinian doctrines of original sin". "Purity is constituted by a recession from impurity, and therefore it is possible to find some creature purer than all the rest, namely one not contaminated by any taint of sin; such was the purity of the Blessed Virgin, who was immune from original and actual sin, yet under God, inasmuch as there was in her the potentiality of sin." (Commentary on the Book of Sentences, c. 44, q. I ad 3). Where he eventually ran into a difficulty was with his Aristotelean belief that the rational human soul was not infused until some time after conception, when the human body was finally formed (around 40 days). Even so, the famous article in the Summa is concerned with refuting the arguement that Blessed Mary was sanctified prior to animation. Of course, the Catholic Church does not teach that, for the very simple reason he points out - a person without a rational soul cannot be sanctified since they have no soul yet in need of sanctity.
You go ahead in without me. It was too cold in there the last time and I have no reason to believe that anything's improved.
Just for the record. St. Maximums the Confessor went to Latin North Africa, renounced Greek Church, the Patriarch and the Roman Emperor in Constantinople, and called himself Latin who speaks Greek. He approved everything that came from the Old Rome, and followed Western theology. In perspective, it is not surprising that he though the filoque was legitimate.
No one is disputing the elegance and the complexity of Latin. The fact is, however, that Latin became a liturgical lengauge from Greek and that it did not have necessarily the concepts and words equiavlent to those in Greek and that many Latin-speaking clergy didn't speak Greek that well (even St. Augustine is known to have chosen words that do not correspond to the Greek original). And, yes Greek was the language of the Church for quite some time. Latin did not have the necessary complexity of a liturgical language from the start.
Maybe the hints of filioque can be found before the 6th century, but it was specifically introduced into the Creed in Spain in response to the Arian heresy. Even if it was theologically acceptable, the fact is -- and the popes knoew that the additions to the Creed could only be done by Ecumenical Councils. The fact is also that the Greeks were later being accused for "removing" it from the Creed.
The role of the pope as the final arbiter of disputes is something that developed over time and through the efforts of people like Irenaeus and is not something that is found in the early church organization, before the monarchical episcopates emerged in the 2nd century. There is no Bible-based office of the pope, but thanks for clarifying how the Byzantine Catholic churches relate to him.
I am not sure when the east and the west started to differ in their teaching of the Blessed Mother of God, but I believe that the current teaching of the Roman Catholic Church dates to the 13th century at the onset. The orthodox belief was always that she was cleansed of all sin at the moment of conception (and her death) but that she was not conceived free of sin. In other words, the only One conceived free of sin was Jesus. Placing Theotokos on the same plane with Jesus would make her more than human.
However, reading your interesting answers one must wonder why the Churches are still apart. Why is it not possible to go to the status post Seventh Ecumenical Council and throw all these doctrinal issues on the table and explain them in a brotherly manner as two versions of the same orthodox faith expressed in two different manners and let the Synod vote on them? If we are just two faces of the same coin, what is amiss?