It is not my job, or even my desire, to clear up a controversy between these two ancient churches. This is an argument, not so much over the theology of the Holy Spirit as it is an argument over the primacy of the early church councils. The earlier statement, that in the Nicaean Creed, published after the Council of Ephesus, was that the Holy Spirit proceeded from the Father (only implied not stated). It was several centuries later, in Spain, that a Western author added the words “and the Son”, which, in Latin, is filoque. This happened in the year 589 AD at the Council of Toledo, which was not a general council of the churches. He did so, not so much to oppose the authority of the Greek and Roman churches, but in order to oppose the Arianism of the Gothic Christians. This group, following Arius, in the very early fourth century, taught that Jesus was a created person–that he was not God! This is the teaching of the Jehovah Witness group today, and it is considered heretical by virtually all groups, including the Greek Orthodox Church which opposed the change to the Nicaean Creed. The bishop in Spain was trying to establish on credal grounds that the Son is co-equal with the Father–that he is deity. This was a good thing, at least in principle.
The use of the filoque spread gradually across the West, but was not accepted into the official Nicaean Creed in Rome until the year 1014, from which time it was used throughout all of Western Christendom. It was at this time that it became the principal point of contention in the Great Schism of 1054 between the Church in Rome and the Orthodox Church in Constantinople. The argument was not necessarily over whom the Holy Spirit proceeded from, but over the primacy of the earlier Nicaean decision and the fact that it was an upstart Latin bishop who made the unauthorized change. In fact, most Latin fathers had accepted the idea of the Holy Spirit proceeding from the Father and the Son for centuries, including Augustine, Jerome and many more. Even Cyril of Alexandria had accepted the formula. Nevertheless, since the Great Schism the Greek and other Orthodox churches do not acknowledge this decision, as it was not made at a general church council.
But… There is still your question, which is whether the Holy Spirit “proceeded” (ie was sent) from both the Father and the Son, or only from the Father. To most Christians this is a completely unimportant distinction, as it should be, but we ought to at least ask the question, should we not? Sure. Well, Jesus did say this: “That is why I said the Spirit will receive from me what He will make known to you.” (John 16:15) Based on this passage, I would say that it would not be incorrect to say that the Holy Spirit was sent by the Father and the Son as well. The Spanish bishop may not have been authorized by a church council to make the change, but it is not anti-scriptural, and it may have aided in defeating heretical Arianism. But, let me remind you that this, at least in my opinion, is a big argument over a relatively small issue.
I do not want to simply brush off the question, by the way. It does come down to this: Clearly Jesus submitted to the Father, despite his equality with the Father. Is this also true of the Holy Spirit? I think we can make a pretty strong case that both the Son and the Holy Spirit are in some sort of submission to the Father. So, what is the relationship between the Son and the Holy Spirit? That, as Shakespeare said, is the question. Is it Father greater than Son, who is greater than the Holy Spirit, or is it Father greater than the Son who is equal to the Holy Spirit? Is this question contained in the debate over the word filoque in the Nicaean Creed? Let me say maybe so. But the Bible does not make a super clear statement about this, and I am not sure why it matters for everyday Christianity that we figure this one out. However, for the early church, this sort of distinction was very important.
I hope I have added clarity more than confusion to this question.
John Oakes