Since Vatican II's encouragement for theological dialogues to take place between the different ecclesial confessions in order to determine the real dogmatic differences which impede the unity of Christians, there is no question that they have done much good in helping re-establish friendly contacts after centuries of polemics and in freeing theologians from mistaken views of the other's doctrinal positions. There was always the hope that further theological study by participants might result in a convergence of views happily overcoming past misconceptions and prejudices.
For example, recent theological dialogues have led to a welcome clarification by prelates of the Non-Chalcedon Oriental-Orthodox communion (not to be confused with the later Byzantine Schism of the Eastern Orthodox Churches), of its Christological doctrine regarding the hypostatic union.
It was the Oriental Orthodox rejection of the Ecumenical Council of Chalcedon's (451) definition that the union of divinity and humanity in Christ terminated in one single Person that led to the Churches of Armenia, Syria, Egypt, and Ethiopia being termed heretical as "Monophysites" ("one nature men"). That is, those who held that Jesus Christ possessed only one (mono) nature (physis), the divine nature.
Thus, the family of Oriental Orthodox Churches has remained separate from both the Catholic Church and the Eastern Orthodox Churches which have adhered strictly to the dogma set forth in the Tome of Pope St. Leo the Great and the Council of Chalcedon. That Fourth Ecumenical Council taught that the Lord Jesus existed in two natures, the divine and the human, which come together "without confusion or change, without division or separation" to form One undivided Person of Jesus Christ, the Son of God incarnate.
Today's Oriental Orthodox seek to avoid the charge of having been "Monophysites", that is, those adhering to the heretical teaching of Eutyches who was condemned at Chalcedon. Rejecting the label of "Monophysites" holding the belief that Christ possessed "one single nature", they prefer to be termed "miaphysites" professing "one nature from two natures after the union in Christ." They resolutely affirm that they have been historically confused with real Monophysites, the followers of Eutyches whom they have always anathematized, and that their "miaphysite Christology" conforms to that of the Council of Chalcedon, though worded differently.
In a recent 2014 Agreed Statement issued by the Anglican-Oriental Orthodox International Commission (AOOIC) (completing previous theological discussions in 1989, 1990, and 1994), we find the Oriental-Orthodox delegates once again happily distancing themselves from Monophysitism and its belief that Christ possessed but "a single nature."
This welcome development signifying basic agreement with Catholic doctrine on the "hypostatic union" (St. Cyril of Alexander's term for the union of humanity and divinity in Christ) is one of the genuine fruits of the ecumenical movement marked by theological Dialogues with the Oriental Orthodox. (See, for example, the Common Declaration of Pope Paul VI and the Coptic Pope of Alexandria Shenouda III, May 10, 1973.)
However, that Anglican Protestants can be found to disagree with their past doctrinal tradition and agree with Oriental Orthodox that the procession of the Holy Spirit is from the Father alone is a disturbing ecumenical setback, for such teaching is at odds with defined Catholic doctrine. As the noted Protestant theologian Karl Barth observed in his Church Dogmatics:
"It is the Unity of the Trinity which must be in danger at every point by the denial of the filioque."
In 2017 the AOOIC published an unfortunate document entitled, "The Procession and Work of the Holy Spirit", which expressed the results of theological work with the Oriental Orthodox in Woking, England, in 2013 and at another meeting in Cairo in 2014. In that document, for the first time, Anglican signers proceeded to profess the same heresy that both the dissident Oriental Orthodox and Eastern Orthodox Churches have used to justify their ancient schisms with Rome, namely, that the Holy Spirit proceeds from the Father alone.
"We agree that while the Holy Fathers speak of a relationship of the Holy Spirit to the Father through the Son, they never hold that the Spirit proceeds [eternally] from or through the Son… We distinguish the eternal procession of the Holy Spirit from the Father alone, and the sending of the Holy Spirit on the day of Pentecost, from the Father, through the Son… When the Holy Fathers proclaim that the Spirit is 'from the Father and the Son,' or that He progresses (proeisi) or flows forth (proheitai) from both, they mean the temporal mission of the Holy Spirit."
Here the Oriental Orthodox maintain their centuries-old denial of an eternal procession of the Holy Spirit from (or through) the Son in the Trinity — the dogma professed by the Catholic Church. It is to be emphasized that none of the fathers of the Church taught that the Holy Spirit proceeded from the Father alone. Moreover, the 2017 document erroneously repeats that:
"When the Holy Fathers proclaim that the Spirit is 'from the Father and the Son', or that 'He progresses (proeisi) or flows forth (proheitai) from both', they mean the temporal mission of the Holy Spirit."
Actually, such language found in St. Cyril of Alexandria's writings (and other Eastern Fathers) properly refers to the Holy Spirit's eternal procession. They clearly taught the Catholic doctrine of the Spirit's procession and distinguished between the Spirit's eternal procession and His temporal mission to the world to sanctify the faithful.
It is certainly true that the Spirit is sent by the Son as well as by the Father to sanctify (the Spirit's temporal mission) but this is only because He ever proceeds from both the Father and the Son. The Son can only send that which is His own, as is confirmed by many texts of Scripture which term the Holy Spirit "the Spirit of Jesus" and "the Spirit of Christ." The Son did not come to possess the Spirit in time but possessed Him from all eternity.
It is not surprising to see the Oriental Orthodox restating their doctrine held for many centuries denying Catholic teaching. It is surprising to see Anglican signatories to the 2017 document blatantly contradicting the explicit belief of the entire Western Church which English Catholics shared for 1,500 years and which the more tradition-minded members of the later Protestant Church of England profess to this day.
It was a pillar of the Church of England, the famous Dr. E.B. Pusey, who wrote a vigorous defense of the doctrine embodied in the filioque in his "On the Clause 'And the Son' in Regard to the Eastern Church and the Bonn Conference: A Letter to the Rev. H.P. Liddon (1876)." As he noted, the eternal Procession of the Holy Spirit from the Father and the Son represented by the filioque has been "the expression of our faith immemorially."
That faith was enshrined, in fact, in Article V of the 39 Articles, the classic Anglican formulary:
". . . the Holy Ghost, proceeding from the Father and the Son."
It is, therefore, stunning to see delegates of the Church of England embracing the grave error of the ninth-century Byzantine Greek patriarch of Constantinople, Photius, which excluded the Son from the Holy Spirit's eternal procession.
It was this Trinitarian error that was resolutely opposed by one of the greatest of English archbishops, St. Anselm of Canterbury (1034-1109), famous for his great tract on the Procession of the Holy Spirit and defense of the filioque.
Interestingly, an earlier Anglican-Oriental Orthodox dialogue (Dublin: 1984) saw the Anglicans regard the filioque as "a valid theological statement, though not as a dogma." The 2017 Agreed Statement obviously went much further with Anglican signatories' absolute rejection of an eternal procession of the Spirit from the Father and the Son.
It will be interesting to see if this 2017 Anglican-Oriental Orthodox document receives the approval of what passes for Anglican authorities. What is also surprising is that more attention has not been paid by both Catholic and Anglican ecumenists to this sorry development.