What does filioque mean?

Filioque is a Latin phrase meaning 'and the Son.' It was added to the Nicene Creed by the Western church to say that the Holy Spirit proceeds from the Father and the Son — rather than from the Father alone, as the original creed stated.

Why did the filioque controversy cause a church split?

Two reasons: procedurally, the East argued that no one had the authority to alter an ecumenical creed unilaterally. Theologically, the East believed that having the Spirit proceed from both Father and Son introduced two sources within the Trinity, threatening divine unity and the Father's unique role as the single source of the other persons.

Does the filioque appear in the original Nicene Creed?

No. The original Nicene-Constantinopolitan Creed (381 AD) says the Spirit 'proceeds from the Father.' The filioque was added in the Western church, beginning in Spain in the late sixth century, and gradually spread to Rome over the following centuries.

Has the filioque controversy ever been resolved?

Not officially. It remains one of the formal theological divides between Eastern Orthodoxy and Roman Catholicism. Various ecumenical dialogues have explored possible paths forward, but no formal agreement has been reached that would reunite the Eastern and Western traditions.

The Filioque Controversy: One Word That Split the Church

In 1054 AD, Cardinal Humbert walked into the Hagia Sophia in Constantinople and placed a bull of excommunication on the altar. The Patriarch of Constantinople responded by excommunicating the Cardinal. With that, the Christian church formally split into East and West — a division that persists to this day. Many issues fed into that rupture, but at the heart of the theological disagreement was a single Latin word added to the Nicene Creed: filioque.

What Is the Filioque?

The original Nicene Creed (as finalized at Constantinople in 381) states that the Holy Spirit "proceeds from the Father." The Western church, beginning in Spain in the late sixth century, added the phrase "and the Son" — which in Latin is filioque. The Western version now read: the Holy Spirit proceeds from the Father and the Son.

This addition spread gradually through the Frankish church and eventually to Rome. The Eastern church — centered in Constantinople — rejected it, both on procedural and theological grounds.

The Procedural Objection

The Eastern church's most immediate complaint was straightforward: no one had the authority to add to the Nicene Creed. The Council of Ephesus (431) had explicitly forbidden any additions or alterations. The Creed was an ecumenical document — ratified by the whole church. For the Western church to unilaterally modify it was, in Eastern eyes, an act of ecclesiastical arrogance.

The East argued: even if the theological content of the addition were acceptable, the process was not. You cannot change what the whole church agreed upon without calling the whole church to deliberate.

The Theological Objection

The deeper disagreement was about the inner life of the Trinity. The Eastern tradition, drawing on the Cappadocian Fathers (Basil of Caesarea, Gregory of Nazianzus, Gregory of Nyssa), insisted that the Father alone is the single source and principle within the Trinity. The Son is eternally begotten of the Father; the Spirit eternally proceeds from the Father. The Father is the monarchy — the one source.

If the Spirit proceeds from both Father and Son, the East argued, this introduces two principles or sources in the Trinity — which threatens the unity of God. It also, they claimed, diminishes the Spirit by making him dependent on both the Father and the Son rather than proceeding directly from the Father alone.

The Western Response

Western theologians, drawing on Augustine of Hippo, defended the addition. Augustine emphasized the unity of the divine essence more than the distinct personal originations. In his view, the Father and Son together form a single principle from which the Spirit proceeds — an expression of the love between Father and Son that spirates the Spirit. The filioque protected the full equality of the Son by affirming his role in the procession of the Spirit.

Where Things Stand Today

The filioque remains one of the formal theological differences between Roman Catholic and Eastern Orthodox Christianity. Most Western Protestant churches inherited the filioque version without much reflection on its history.

In 2003, the North American Orthodox-Catholic Theological Consultation issued an agreed statement suggesting that the original Greek text — without the filioque — should be the common basis for future dialogue. Some Anglican communities have moved toward using the original text. But no formal reunion has followed. The single word that split Christendom has not yet been resolved.