A word added without a council, and a thousand years of controversy between East and West
Translation update pendingThe French version of this module was thoroughly revised on 17 October 2026: it now comprises three tabs (the history of the addition, the doctrine, the ecumenical dossier up to the 1700th anniversary of Nicaea), footnotes and a full bibliography. This page still reflects the earlier version, with factual corrections; its updated translation is in preparation. Read the revised French module.
A four-syllable Latin word, added to a conciliar creed without a council, which became the most enduring doctrinal grievance between East and West. The dossier is remarkable in that it brings into play two distinct questions that are almost always confused: what the word means, and by what authority it was introduced.
The text and its original state
The so-called Niceno-Constantinopolitan Creed, settled in 381 and received as normative by Chalcedon in 451, states that the Holy Spirit “proceeds from the Father” — τὸ ἐκ τοῦ Πατρὸς ἐκπορευόμενον. The Latin adds Filioque, “and from the Son”.
Two verbs that do not say the same thing The Greek ἐκπορεύεσθαι is a technical term built on Jn 15:26, and it designates origination from the sole ultimate source. The Latin procedere is much broader: it renders ἐκπορεύεσθαι as well as προϊέναι, which does not imply originating. To say in Latin that the Spirit procedit from the Son is therefore not equivalent to saying in Greek that he ἐκπορεύεται from him. Part of the conflict stems from each side hearing its own verb in the other’s language — and this observation is no recent ecumenical invention: it was formulated in the seventh century.
Chronology of the addition
Date
Stage
What was at stake
589
Third Council of Toledo
Reccared abjures Arianism and brings the Visigoths over to the faith of Nicaea. The creed as recorded in the council’s acts contains the Filioque, though a later interpolation has been suggested; the doctrine itself is affirmed in the council’s anathemas. Its function is anti-Arian: to affirm that the Spirit proceeds also from the Son is to affirm that the Son is fully God. The addition is not directed against the East, which lies outside the horizon of this council
8th c.
Carolingian diffusion
The usage passes from Spain to Gaul and then into the Frankish Empire. The Libri Carolini take it for granted
809
Synod of Aachen
Charlemagne has the addition confirmed and asks Rome to adopt it
810
Leo III refuses
The pope approves the doctrine and refuses the addition to the creed. To settle the matter, he has the creed engraved without the Filioque on two silver plaques, in Greek and in Latin, displayed at St Peter’s. The distinction between an acceptable doctrine and an illegitimate addition is thus drawn by Rome itself
1014
Rome gives way
Benedict VIII has the creed sung with the Filioque at the coronation of Henry II. Rome thus held out for two centuries before adopting what the Empire asked of it
1054
Mutual excommunications
The bull of the legate Humbert lines up chiefly disciplinary grievances and charges the Greeks with having “cut” the procession of the Spirit from the Son out of the creed; unleavened bread dominated the polemic of 1053 rather than the bull itself. The rupture is not produced by the word alone
The letter of Maximus the Confessor
Around 645 Maximus the Confessor writes to Marinus of Cyprus a letter that is the most important piece of the early dossier. He reports that the Romans have been accused of teaching that the Son is cause of the Spirit, and he defends them: they do not make the Son a cause; they mean that the Spirit proceeds from the Father through the Son, and they have produced Latin testimonies along with extracts from Cyril of Alexandria. He adds that they are hampered by the impossibility of rendering their thought exactly in another language.
The document establishes three things. The difficulty is identified as linguistic before being doctrinal, seven centuries before Florence. An Eastern Father of the first rank holds the Latin position to be orthodox once explained. And the formula “through the Son” — διὰ τοῦ Υἱοῦ — is presented as the acceptable rendering, which will be exactly the solution adopted by every later attempt at union.
Photius and the formalisation of the grievance
In the ninth century, in his conflict with Rome over jurisdiction in Bulgaria and over his own election, Photius turns a Western liturgical usage into a dogmatic error. His Mystagogy of the Holy Spirit maintains that the Spirit proceeds “from the Father alone” — ἐκ μόνου τοῦ Πατρός —, a formula that is no more in the creed than the Filioque.
His central argument runs as follows: if the Spirit proceeds from two principles, either there are two causes in the Godhead, which ruins the monarchy of the Father, or the Father and the Son merge into a single cause, which ruins the distinction of the persons. The argument is tight. Latin theology answers it by denying that there are two principles — Father and Son are a single principle of the Spirit, as the formula tamquam ex uno principio of Lyons II will state — and grounds that answer in the doctrine of relations of opposition; the Orthodox tradition does not regard the answer as sufficient.
The councils of union
Council
Formula
Outcome
Lyons II, 1274
The Spirit proceeds from the Father and the Son tamquam ex uno principio — as from a single principle
Union signed by an imperial delegation under political pressure, rejected by the clergy and people of Constantinople, repudiated in 1282
Ferrara-Florence, 1439
The decree Laetentur caeli declares that “from the Father through the Son” and “from the Father and the Son” have the same meaning; the Latins hold the Son to be cause together with the Father, but not as a second principle
Signed by the emperor and almost all the Greeks — with the exception of Mark of Ephesus, who refuses. Repudiated in Constantinople in 1484. The city falls in 1453
Florence produced the most elaborate theological formula of the whole dossier, and it failed. The reason is not primarily doctrinal: in Constantinople the union was perceived as the price demanded for military aid that never came in sufficient quantity. The words of Loukas Notaras — “better to see the Turkish turban reigning in the city than the Latin mitre” — are reported by Doukas and their authenticity is disputed; that they circulated says enough about the prevailing mood.
The present state of the dossier
The Roman clarification of 1995. The Pontifical Council for Promoting Christian Unity publishes The Greek and Latin Traditions regarding the Procession of the Holy Spirit. The text states that the Latin Filioque does not mean that the Son is cause of the Spirit’s hypostatic origin, that the Father is the sole source, and — the decisive point — that the Catholic Church recognises the normative, irrevocable and unique value of the Greek creed of 381. It recalls that Catholics of the Byzantine rite recite the creed without the Filioque, and that the pope himself recites it in Greek without the addition.
The Anglican and Old Catholic decisions. The Lambeth Conference asked all member churches in 1978 to consider omitting the Filioque from the creed (resolution 35), and recommended in 1988 that future liturgical revisions print the creed without it (resolution 6). Many provinces have done so in their revised liturgies; others, among them the Church of England, still print it. The Bonn conferences of 1874–1875 concluded that the addition had been made unlawfully, and the Old Catholic churches began in the nineteenth century to recite the creed without it.
What remains. For most interlocutors the doctrine is no longer the sticking point; the question of authority still is. Can a creed settled by an ecumenical council be modified by one part of the Church without another council? That is the question Leo III decided in 810, and that Rome left behind in 1014.
Theological disputations
Six confessional voices, with interjections from Professor Tryphon Goldberg, the site’s Jewish teaching persona.
The Filioque: a question of doctrine or a question of authority?
The two questions are distinct, and confusing them has fed a thousand years of controversy. One can hold the doctrine to be true and the addition illegitimate — which is exactly Leo III’s position in 810.
Orthodox
Both questions arise, and the order matters: the addition is first of all illegitimate, and that is what prevented a calm examination of whether it was true. A creed received by ecumenical councils is the common property of the whole Church; one part cannot alter it. On the substance, Photius’s argument holds: the monarchy of the Father guarantees the unity of the Godhead, and two principles of procession compromise it. The formula “through the Son” is acceptable and patristic; “and from the Son” is not, within the creed.
Catholic
The doctrine is received, and the clarification of 1995 specifies its meaning: the Father is the sole source, and the Son is not cause of the Spirit’s hypostatic origin. On the addition, Rome took a considerable step in recognising the normative and irrevocable value of the Greek creed of 381, and in accepting that the Eastern Catholic Churches and the pope himself recite it without the addition. The history of its introduction is owned: it is Spanish, anti-Arian, then Carolingian, and Leo III opposed it.
Anglican
The Anglican Communion has settled the question of authority without settling that of doctrine, and it is a workable solution. Lambeth recommended in 1978 and in 1988 the omission of the Filioque, on the ground that the creed belongs to the undivided Church and that no part of it should alter it unilaterally. Nothing is taken away from the Trinitarian doctrine of the Thirty-nine Articles; it is the text of the creed that is restored.
Lutheran
The Reformation inherited the Western creed with the Filioque and did not discuss it — the Book of Concord takes over the three creeds without examining this point. It deserves to be said: we kept without discussion an addition whose history ought to have interested us, while we contested everything else that had been added to the primitive deposit. The Lutheran–Orthodox dialogues of the twentieth century reopened the question, and several churches are considering the omission.
Reformed
Calvin treats the procession in the Institutes I.13 without making the Filioque an issue, and the Reformed tradition has kept it by inheritance rather than by decision. Yet the position most consistent with our principles would be omission: we hold that what is not in Scripture cannot bind, and Jn 15:26 says that the Spirit proceeds from the Father. That one can maintain the doctrine without inscribing it in the creed is precisely the distinction we apply everywhere else.
Anabaptist
The radical tradition observes that the controversy concerns a text which neither side disputes was produced by imperial councils, convened by emperors, for reasons that were not only theological. The Filioque enters at Toledo when a king changes religion, spreads when an emperor wants it, is adopted in Rome at an imperial coronation, and is negotiated at Florence in exchange for military aid. The history of this word is a history of power, from the first day to the last.
Synthesis
The two questions must be kept apart, and history keeps them apart of its own accord: Leo III in 810 holds the doctrine to be acceptable and the addition to be illegitimate, a position no one has since held with such clarity. On the doctrine, the letter of Maximus the Confessor shows as early as 645 that the difficulty is partly linguistic, and the Roman clarification of 1995 says in substance what Maximus said. On authority, the disagreement persists and it is ecclesiological in nature: it concerns what one part of the Church may decide on its own. The Anglican voice has settled the second point without touching the first, the Reformed voice observes that by its own principles it ought to have done the same, and the Anabaptist voice recalls that every stage in the history of the word coincides with an operation of power — an objection Tryphon accepts while refusing to draw from it a conclusion about the truth of the statement.
Can the Filioque be withdrawn?
The question is no longer theoretical. Several churches have done it, Rome recites the creed in Greek without the addition, and the bilateral dialogues have raised it explicitly. What is at stake is the cost of withdrawal for each tradition.
Catholic
Withdrawal is possible and already partial: the Eastern Catholic Churches do not say it, the pope does not say it in Greek, and the 1995 clarification recognises a normative and irrevocable value in the creed of 381. A general withdrawal in the Latin rite would pose a considerable pastoral difficulty — changing the text the faithful have recited for a thousand years — without any major doctrinal difficulty, since the doctrine can be set out elsewhere than in the creed.
Orthodox
Withdrawal is the necessary condition, and it would not be a concession: it would be the restitution of a common text. The East does not ask the West to renounce its Trinitarian theology, which has its own legitimate developments; it asks that the creed be recited as it was settled. A theology is set out in treatises, not in the text the whole Church confesses.
Anglican
We recommended it twice and implementation has been uneven, which teaches something: a liturgical decision taken by a consultative body does not implement itself. Some provinces have withdrawn it, others have kept it, and the Church of England allows both usages. This diversity is bearable among us and would not be everywhere — it is a fact of structure as much as of doctrine.
Lutheran
Several Lutheran churches have adopted or considered the omission following the dialogues with Orthodoxy. The obstacle is slight on the confessional level: the Book of Concord receives the creed without commenting on this point, and nothing in Lutheran doctrine depends on the Filioque. The difficulty is that of liturgical books and habits, as for Catholics.
Reformed
The Reformed churches have no binding liturgical text imposing the creed, and withdrawal would meet almost no institutional obstacle among them. Yet it has not been done, which indicates that the question has not been judged important — and that is perhaps the real problem. A tradition that could easily correct an inconsistency and does not shows that the point costs it nothing, and therefore that it does not care about it either.
Anabaptist
Most churches of the radical tradition recite no creed. The question therefore does not arise in the same terms: we confess the faith through life and community rather than through a recited text, and the Schleitheim Confession does not deal with the procession of the Spirit. This absence is not indifference to the Trinity; it is a refusal to make a formula the criterion of belonging.
Synthesis
All the positions agree that withdrawal is doctrinally possible; none holds the Filioque to be necessary to its understanding of the Trinity. The obstacle is liturgical, not theological, as both the Catholic and the Lutheran voices say: what resists is the text the faithful recite by heart. The Orthodox voice states the request in its exact terms — to restore a common text, not to renounce a theology —, which considerably reduces the scope of the dispute. Two methodological observations emerge: the Anglican experience shows that a recommendation without an executive body produces a diversity of usage; and the Reformed voice notes, to its own detriment, that not doing what would be easy is a surer sign of indifference than refusing what would be costly.
Working hypotheses — master’s and doctoral research
Seven lines of inquiry, formulated so as to be falsifiable. The dossier brings together complete conciliar sources, abundant liturgical documentation and a century of fully published bilateral dialogues.
H1. Toledo 589: the anti-Arian function of the addition
Doctorate
History of the councils
4–5 years
Hypothesis. The introduction of the Filioque at the Third Council of Toledo answers an internal polemical need — refuting Visigothic Arianism — and not a position on the East; examination of the acts and of Hispanic anti-Arian texts makes it possible to establish this and to measure whether the addition is already present in earlier sources.
State of research
The anti-Arian function is generally accepted and rarely demonstrated by a systematic study of the Hispanic sources. The possible earlier presence of the addition in local creeds is debated.
Corpus
Acts of the Third Council of Toledo; earlier Hispanic creeds; Reccared’s Libellus fidei; anti-Arian works of Leander and Isidore of Seville; Visigothic liturgical manuscripts.
Method
Record the occurrences of the formula in dated Hispanic sources and code their argumentative context.
What would refute it: An earlier Hispanic occurrence without an anti-Arian context.
H2. Maximus’s letter to Marinus
Master’s
Patristics
12–18 months
Hypothesis. Maximus the Confessor’s letter to Marinus of Cyprus identifies the linguistic nature of the disagreement seven centuries before Florence, and the absence of its use in the medieval controversies — from Photius to Mark of Ephesus — is measurable and significant.
State of research
The letter is known and cited in contemporary dialogues. Its medieval reception, or lack of reception, has not been studied serially.
Corpus
Maximus, Theological and Polemical Opuscule 10, letter to Marinus; Photius, Mystagogy; acts of Lyons II and of Florence; writings of Mark of Ephesus; Nicetas of Nicomedia.
Method
Catalogue the citations of the letter in the Byzantine and Latin polemical corpus, period by period.
What would refute it: Regular use of the letter in the medieval controversies.
H3. Leo III’s silver plaques
Master’s
Liturgical history
12–18 months
Hypothesis. Leo III’s gesture — having the creed engraved without the addition in Greek and Latin — is a deliberate juridical act aimed at fixing a reference text, and its import is comparable to that of a promulgation; the Roman sources make it possible to establish its function and how long the plaques were displayed.
State of research
The episode is reported by the Liber Pontificalis and widely cited. Its juridical characterisation and the question of how long the plaques remained visible have not been addressed.
Corpus
Liber Pontificalis, life of Leo III; acts of the Synod of Aachen (809); letters of Charlemagne; Libri Carolini; inventories of St Peter’s.
Method
Reconstruct the function of the arrangement and search for later mentions of the plaques in the inventories.
What would refute it: A purely symbolic gesture with no attested normative import.
H4. Florence 1439: the conditions of the signature
Doctorate
Byzantine history
4–5 years
Hypothesis. The Greeks’ adherence to the decree Laetentur caeli is better explained by the delegation’s military and financial dependence than by theological persuasion, and the council’s journals make it possible to measure the respective weight of the two factors.
State of research
The political context is recognised. The accounts of Syropoulos and the official acts give divergent versions that have not been systematically compared.
Corpus
Greek and Latin acts of the council; the Memoirs of Sylvester Syropoulos; writings of Mark of Ephesus; imperial correspondence; accounts for the upkeep of the delegation.
Method
Collate the accounts, code the arguments actually exchanged and the documented pressures, and follow individual changes of position.
What would refute it: Substantial theological debates preceding each individual rallying.
H5. The 1995 clarification and its Orthodox reception
Master’s
Ecumenism
12–18 months
Hypothesis. The Roman text of 1995 concedes more than its Orthodox commentators acknowledge, and analysis of the published responses shows that its reception ran up less against its content than against the status of the issuing body.
State of research
The document is cited in the dialogues and its reception is uneven. The Orthodox responses have not been analysed as a corpus.
Corpus
Pontifical Council for Promoting Christian Unity, The Greek and Latin Traditions regarding the Procession of the Holy Spirit (1995); responses published in Greece, Russia and the United States; documents of the Joint International Commission.
Method
Code the objections raised by type — content, authority of the issuing body, absence of liturgical consequence.
What would refute it: Objections bearing mainly on the doctrinal content of the text.
H6. Lambeth 1978–1988: a recommendation without enforcement
Master’s
Practical ecclesiology
12–18 months
Hypothesis. The uneven implementation of the Lambeth recommendations on omitting the Filioque is predicted by each province’s type of governance rather than by its theological position — a hypothesis testable across the whole Communion.
State of research
The diversity of implementation is observed. Its correlation with provincial decision-making structures has not been studied.
Corpus
Lambeth resolutions of 1978 and 1988; successive provincial liturgical books; provincial constitutions; Anglican–Orthodox Dublin Agreed Statement (1984).
Method
Code for each province the state of implementation and the type of liturgical governance, and test the correlation.
What would refute it: A dominant correlation with the declared theological position.
H7. The Filioque in the Reformation confessions
Master’s
Historical theology
12–18 months
Hypothesis. The confessional texts of the sixteenth century receive the Western creed without ever discussing the addition, while they minutely examine other post-apostolic developments; this silence is measurable, and it reveals the actual limits of the scriptural principle.
State of research
The silence has been noted in isolated cases. It has not been set in series with the treatment given to other medieval additions.
Corpus
Book of Concord; Second Helvetic Confession; French Confession; Thirty-nine Articles; Calvin, Institutes I.13; controversies with the anti-Trinitarians.
Method
Record the treatment given to the Filioque and to other medieval developments in the same corpus, and compare.
What would refute it: An explicit examination of the addition in a major confessional text.
Select bibliography
Sources
Maxime le Confesseur. Opuscules théologiques et polémiques. Paris : Cerf, 1998.
Conseil pontifical pour la promotion de l’unité des chrétiens. Les traditions grecque et latine concernant la procession du Saint-Esprit. Rome, 1995.
Studies
Congar, Yves. Je crois en l’Esprit Saint. 3 vol. Paris : Cerf, 1979-1980.
Gemeinhardt, Peter. Die Filioque-Kontroverse zwischen Ost- und Westkirche im Frühmittelalter. Berlin : De Gruyter, 2002.
Halleux, André de. « Pour un accord œcuménique sur la procession de l’Esprit Saint ». Irénikon 51 (1978) : 451-469.
Papadakis, Aristeides, et John Meyendorff. L’Orient chrétien et l’essor de la papauté. Paris : Cerf, 2001.
Siecienski, A. Edward. The Filioque : History of a Doctrinal Controversy. Oxford : Oxford University Press, 2010.
Vischer, Lukas, dir. La théologie du Saint-Esprit dans le dialogue œcuménique. Paris : Centurion, 1981.