The phrase “Filioque” literally means “and the Son“. It occurs in the Western version of the Nicene Creed, which we say in every Sunday Mass. Eastern Christians say that the Holy Spirit descends from the Father through the Son. We say that the Holy Spirit proceeds from the Father and the Son. This issue more than any other divided the Eastern and Western Churches.
Filioque is a theological formula of great dogmatic and historical importance. On the one hand, it expresses the Procession of the Holy Spirit from both Father and Son as one Principle; on the other, it was the occasion of the Greek schism.
The dogma of the double Procession of the Holy Spirit from Father and Son as one Principle is directly opposed to the error that the Holy Spirit proceeds from the Father, not from the Son. Neither dogma nor error created much difficulty during the course of the first four centuries. The local Council of Alexandria (362) and by Pope St. Damasus (378) condemned the teaching that the Holy Spirit derives His origin from the Son alone, by creation. The first undoubted denial of the double Procession of the Holy Spirit we find in the seventh century among the heretics of Constantinople when St. Martin I (649-655), in his synodal writing against the Monothelites, employed the expression “Filioque”.
In the Western church the first controversy concerning the double Procession of the Holy Spirit was conducted with the envoys of the Emperor Constantine Copronymus, in the Synod of Gentilly near Paris, held in the time of Pepin (767). The synodal Acts and other information do not seem to exist. At the beginning of ninth century, John, a Greek monk of the monastery of St. Sabas, charged the monks of Mt. Olivet with heresy, they had inserted the Filioque into the Creed. In the second half the same century, Photius the successor of the unjustly deposed Ignatius, Patriarch of Constatinople (858), denied the Procession of Holy Spirit from the Son, and opposed the insertion of the Filioque into the Constantinopolitan creed. The same position was maintained towards the end of the tenth century by the Patriarchs Sisinnius and Sergius, and about the middle of the eleventh century by the Patriarch Michael Caerularius, who renewed and completed the Greek schism. The rejection of the Filioque, or the double Procession of the Holy Spirit from the Father and Son, and the denial of the primacy of the Roman Pontiff constitute even to-day the principal errors of the Greek church. The doctrine of the Filioque was declared to be a dogma of faith in the Fourth Lateran Council (1215), the Second Council of Lyons (1274), and the Council of Florence (1438-1445). Thus the Church proposed in a clear and authoritative form the teaching of Sacred Scripture and tradition on the Procession of the Third Person of the Holy Trinity.
As to the Sacred scripture, the inspired writers call the Holy Spirit 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 (Mat. 10:20) and the Spirit of god (I Cor. 2:ll). Hence they attribute to the Holy Spirit the same relation to the Son as to the Father. Again, according to Sacred Scripture, the Son sends the Holy Spirit (Lk. 24:49; Jn. 15:26; 16:7; 20:22; Acts 2:33; Tit. 3:6), just as the Father sends the Son (Rom. 3:3; etc.), and as the Father sends the Holy Spirit (Jn. 14:26). It follows that the inspired writers present the Holy Spirit as proceeding from the Son, since they present Him as sent by the Son.
The teaching of Sacred Scripture on the double Procession of the Holy Spirit was faithfully preserved in Christian tradition. Even the Greek Orthodox grant that the Latin Fathers maintain the Procession of the Holy Spirit from the son.
Following are only some of the later documents in which the patristic doctrine has been clearly expresssed: the dogmatic letter of St. Leo I to Turribius, Bishop of Astorga, Ep. XV, c. i (447); the so-called Athanasian Creed; several councils held at Toledo in the years 447, 589 (III), 675 (XI), 693 (XVI); the letter of Pope Hormisdas to the Emperor Justius, Ep. lxxix (521); St. Martin I’s synodal utterance against the Monothelites, 649-655; Pope Adrian I’s answer to the Caroline Books, 772-795; The Synods of Merida (666), Braga (675), and Hatfield (680); the writing of Pope Leo III (d. 816) to the monks of Jerusalem; the letter of Pope Stephen V (d. 891) to the Moravian King Suentopolcus (Suatopluk), Ep. xiii; the symbol of Pope Leo IX (d. 1054); the Fourth Lateran Council, 1215; the Second Council of Lyons, 1274; and the council of Florence, 1439.
Moreover, there are certain considerations which form a direct proof for the belief of the Greek Fathers in the double Procession of the Holy Spirit.
First, the Greek Fathers enumerate the Divine Persons in the same order as the Latin Fathers; they admit that the Son and the Holy Spirit are logically and ontologically connected in the same way as the son and Father [St. Basil, Ep. cxxv; Ep. xxxviii (alias xliii) ad Gregor. fratrem; “Adv.Eunom.”, I, xx, III, sub init.]
Second, the Greek Fathers establish the same relation between the Son and the Holy Spirit as between the Father and the Son; as the Father is the fountain of the Son, so is the Son the fountain of the Holy Spirit (Athan., Ep. ad Serap. I, xix, sqq.; “De Incarn”., ix; Orat. iii, adv. Arian., 24; Basil, “Adv. Eunom”., v, in P.G.., XXIX, 731; cf. Greg. Naz., Orat. xliii, 9).
Third, passages are not wanting in the writings of the Greek Fathers in which the Procession of the Holy Spirit from the Son is clearly maintained: Greg. Thaumat., “Expos. fidei sec”., vers. saec. IV, in Rufius, Hist. Eccl., VII, xxv; Epiphan., Haer., c. lxii, 4; Greg. Nyss. Hom. iii in orat. domin.); Cyril of Alexandria, “Thes”., ass. xxxiv; the second canon of synod of forty bishops held in 410 at Seleucia in Mesopotamia; the Arabic versions of the Canons of St. Hippolytus; the Nestorian explanation of the Symbol.
The only Scriptural difficulty deserving our attention is based on the words of Christ as recorded in John 15:26, that the Spirit proceeds from the Father, without mention being made of the Son. But in the first place, it can not be shown that this omission amounts to a denial; in the second place, the omission is only apparent, as in the earlier part of the verse the Son promises to “send” the Spirit. The Procession of the Holy Spirit from the Son is not mentioned in the Creed of Constantinople, because this Creed was directed against the Macedonian error against which it sufficed to declare the Procession of the Holy Spirit from the Father. The ambiguous expressions found in some of the early writers of authority are explained by the principles which apply to the language of the early Fathers generally.
Adapted from the Catholic Encyclopedia, copyright © 1913 by the Encyclopedia Press, Inc.