One of the doctrinal controversies between the schismatic, so-called Orthodox churches of the East and the Catholic Church is a dogma expressed in one word: Filioque (Fee-lee-OH-kway). But what does this word mean?

Filioque is Latin for “and the Son.” It is found in the Nicene Creed as it is said in the Catholic Church: “I believe in the Holy Ghost… Who proceeds from the Father and the Son .”

When he began his trouble with Rome (c. 870), Photius, the usurping Patriarch of Constantinople, needed an occasion to bring a popular movement against the Latins. He found one in the fact that certain Spanish monks in Constantinople chanted the Filioque in the Creed of their Mass. Photius claimed then, and the schismatic Greeks still claim, that this addition to the Creed was not permissible. Photius’ followers held that the Council of Ephesus, in its seventh canon, forbad additions to the creed. (“It is not permitted to produce or write or compose any other creed except the one which was defined by the holy fathers who were gathered together in the Holy Spirit at Nicea.”) This is a false premise, since the canon was written to forbid the composition of any teaching contrary or contradictory to any truth already expressly defined in the Creed of Nicea-Constantinople. Other creeds had been used before and after Nicea, witness the one attributed to St. Athanasius. And witness also that the Creed of the Council of Nicea was itself reformulated by one Ecumenical Council which took place in-between Nicea and Ephesus: Constantinople I.

As the reader has no doubt garnered by now, the original Creed formed at the Council of Nicea, and later added to at the First Council of Constantinople, did not originally contain the Filioque, which was first added to the Mozarabic Liturgy by the Council of Toledo around the year 600. (The Visigothic Kingdom was a stronghold of Arianism and other Trinitarian heresies, so the Mozarabic bishops, properly exercising their office, inserted the word to defend Trinitarian orthodoxy.) From the Mozarabic Rite it made its way into the Gallican Rite, formally being added to their liturgy at the Council of Aachen around 800. In the 11th century, Pope Benedict VIII formally added it to the Roman Rite, which had, by that time, imported much from the Gallican Liturgy.

Now that we have identified the issue and briefly explained some of the historical controversy surrounding it, it remains for us to defend the truth of the dogma of the Filioque — a dogma one denies at the peril of his soul.

Concerning our dogma, Father Anthony J. Maas, S.J., the great Catholic Scripture scholar says, “As to Sacred Scripture, the inspired writers call the Holy Ghost the Spirit of the Son (Gal 4:6), the Spirit of Christ (Rom. 8:9), the Spirit of Jesus Christ (Phil. 1:19), just as they call Him the Spirit of the Father (Matt. 10:20), and the Spirit of God (1 Cor. 2:11). Hence they attribute to the Holy Ghost the same relation to the Son as to the Father. Again, according to Sacred Scripture, the Son sends the Holy Ghost (Luke 24:49; John 15:26, 16:7, 20:22; Acts 2:33; Tit. 3:6), just as the Father sends the Son (Rom. 8:3, etc.), and as the Father sends the Holy Ghost (John 14:26). Now, the ‘mission’ or ‘sending’ of one Divine Person by another does not mean merely that the Person said to be sent [only apparently] assumes a particular character […], as the Sabellians maintained; nor does it imply any inferiority in the Person sent, as the Arians taught; but it denotes, according to the teaching of the weightier theologians and Fathers, the Procession of the Person sent from the Person Who sends. Sacred Scripture never presents the Father as being sent by the Son, nor the Son as being sent by the Holy Ghost. The very idea of the term ‘mission’ implies the person sent goes forth for a certain purpose by the power of the sender, a power exerted on the person sent by way of a physical impulse, or of a command, or of prayer, or finally of production; now, Procession, the analogy of production, is the only manner admissible in God. It follows that the inspired writers present the Holy Ghost as proceeding from the Son, since they present Him as sent by the Son. Finally, St. John (16:13-15) gives the words of Christ: ‘What things soever He [the Spirit] shall hear, He shall speak;… He shall receive of mine, and shall shew it to you. All things whatsoever the Father hath, are mine.” Here a double consideration is in place. First, the Son has all things that the Father hath, so that He must resemble the Father in being the Principle from Which the Holy Ghost proceeds. Secondly, the Holy Ghost shall receive ‘of mine’ according to the words of the Son; but Procession is the only conceivable way of receiving which does not imply dependence or inferiority. In other words, the Holy Ghost proceeds from the Son.”

Eastern Church Fathers who can be cited in defense of this dogma are Sts. Basil the Great, Gregory Nazianzen, Gregory Thaumaturgus, Gregory of Nyssa, Cyril of Alexandria, and Hippolytus. Here is a passage from the writings of St. Cyril, the hero of the Council of Ephesus:

“Since the Holy Spirit, when He is in us, effects our being conformed to God, and He actually proceeds from Father and Son , it is abundantly clear that He is of the divine essence, in it in essence, and proceeding from it.” Treasury of the Holy Trinity , Thesis 34, quoted in Jurgens, William, A., trans., The Faith of the Early Fathers (Collegeville: Liturgical Press, 1970).