Council of Florence (1431-1449)

The conciliarist crisis inherited from Constance

The council is born in the shadow of Constance. The decree Frequens had provided for the regular convocation of general councils; Martin V therefore convenes an assembly at Basel, but dies on 20 February 1431 before the organization is stabilized.^[9] His successor, Eugene IV, first confirms his predecessor's acts, then quickly clashes with an assembly dominated by the conciliarist idea: the council claims to act as a permanent power superior to the pope.^[10]

The question is not merely administrative. If a general council can sustain itself, transfer its sessions, judge the pope, and impose an oligarchic constitution on the Church, the Roman primacy received in Catholic tradition is directly undermined. Florence thus becomes the council where two problems intersect: unity with the East and unity of government in the Latin West.

The Byzantine emergency

The other emergency comes from Constantinople. In the 15th century, the Byzantine Empire is no more than a greatly weakened power, encircled by Ottoman expansion. Emperor John VIII Palaiologos knows that Western military aid largely depends on reconciliation with Rome.^[11]

Yet the undertaking is not merely diplomatic. The debates at Ferrara-Florence are long, technical, and theological. The Greeks arrive with their bishops, theologians, monks, and dignitaries; the Latins field cardinals, Dominicans, canonists, and specialists of the Fathers. Union is politically urgent, but it can only be proclaimed by addressing the doctrinal points that have divided the Churches for centuries.^[12]

From Basel to Ferrara

The council opens at Basel in 1431, in a context still marked by the Hussite wars and the reform program of Constance. But the Basel majority progressively enters into conflict with Eugene IV. When the Greek question becomes concrete, Basel wants to impose a venue that suits it; the Byzantines, for their part, ask for an Italian city near the sea, more accessible and safer for an Eastern delegation.^[13]

Eugene IV then approves the minority favorable to the Greeks and transfers the council to Ferrara by decree of late 1437-early 1438. The Ferrara council opens in January 1438; the pope makes his solemn entry at the end of the month. The Greeks, about seven hundred according to the Catholic Encyclopedia, arrive with Emperor John VIII and Patriarch Joseph II of Constantinople.^[14]

From Ferrara to Florence

At Ferrara, the first major discussions concern purgatory, then above all the Filioque. Plague and financial difficulties then push Eugene IV to transfer the assembly to Florence in January 1439. The first Florentine session is held on 26 February 1439.^[15]

Florence is not a mere change of scenery. The city of the Medicis offers the material resources needed to sustain the Greek delegation; it also becomes the symbolic stage of an encounter between the Byzantine East, the Roman papacy, and nascent Italian humanism. The proclamation of Laetentur caeli in Santa Maria del Fiore will give the council its most enduring name.^[16]

Eugene IV

Eugene IV must fight two battles at once. Facing Basel, he defends the pope's capacity to transfer or dissolve a council when the unity of the Church requires it. Facing the Greeks, he seeks a doctrinal union that is not a mere diplomatic truce. His decree Moyses vir Dei of 4 September 1439 condemns the Basel theses that presented as truths of faith the superiority of the council over the pope.^[17]

His position is not that of an isolated administrator. The Basel crisis threatened to produce a new Western schism, culminating in the election of the antipope Felix V by the die-hard Basel faction in 1439. Florence must therefore be read as a council of union with the East, but also as a Roman response to late conciliarism.^[18]

John VIII Palaiologos and Patriarch Joseph II

John VIII Palaiologos arrives with a clear intention: to obtain union and Western aid. But he does not mechanically control the conscience of the Greek bishops. The elderly Patriarch Joseph II accompanies the delegation and signs before his death a declaration admitting the Filioque, purgatory, and Roman primacy. He dies on 10 June 1439, before the official proclamation of the union.^[19]

This death complicates reception. The final text will be signed by most of the Greek representatives, but without a living Patriarch of Constantinople to carry it afterwards. The fracture between diplomatic decision, theological assent, and popular reception becomes one of the keys to the failure.

Bessarion, Isidore of Kiev, and Mark of Ephesus

Three figures dominate the Eastern memory of the council. Bessarion, Metropolitan of Nicaea, ultimately defends the union and will become a cardinal. Isidore of Kiev, Metropolitan of Kiev and all Russia, likewise supports the agreement and will be sent as legate to Russia, where he will be rejected by the Muscovite authorities.^[20]

Mark of Ephesus, on the contrary, refuses to sign. In Orthodox memory, he becomes the witness who prevents Florence from being received as an Eastern ecumenical council. The Orthodox Church in America explicitly presents him as a defender of Orthodoxy at Florence and records his formula of refusal of compromise in matters of faith.^[21]

The Filioque

The first point of Laetentur caeli is Trinitarian. Florence defines that the Holy Spirit is eternally from the Father and the Son, that He has His subsistent being from the Father and the Son together, and that He proceeds eternally from the one and the other as from a single principle and a single spiration.^[22]

"that He proceeds eternally from the one and the other as from a single principle and a single spiration" — Council of Florence, Laetentur caeli, DS 1300^[23]

The precision is crucial: Florence does not posit two competing sources in the Trinity. It intends to confess that the Son receives from the Father all that He is, except being Father, and that the procession of the Holy Spirit "through the Son" in Greek language can be understood as equivalent, in doctrinal substance, to the Latin affirmation "from the Father and the Son".^[24]

The council adds that the insertion of the words "and the Son" into the Creed was made licitly and reasonably, to clarify the truth of faith in a precise historical necessity.^[25]

Unleavened and leavened bread

The second dossier concerns the Eucharist. The Latins use unleavened bread; the Greeks, leavened bread. Florence defines that the Body of Christ is truly consecrated in either wheaten bread, according to the custom of each Church.^[26]

The question of the epiclesis, on the other hand, is not settled by this decree, which concerns only the matter of the bread (DS 1303).^[27]

This point defuses a mutual accusation: Latin usage does not invalidate the Eucharist, and Greek usage is not to be abolished. The Florentine union therefore does not demand ritual uniformity. It asks for a communion of faith allowing the legitimacy of different rites.

Purgatory, heaven, and hell

Florence also formulates a precise doctrine of the fate of souls. Those who die in the love of God, but before having made reparation by worthy fruits of penance, are purified after their death; the suffrages of the living — Masses, prayers, alms, and works of piety — are profitable to them.^[28]

The council affirms at the same time the immediate vision of God for fully purified souls, with degrees according to merits, and the immediate descent into hell of souls that die in a state of mortal sin or with original sin alone, with unequal punishments.^[29]

Roman primacy

The most important passage for Catholic ecclesiology is DS 1307. Florence defines that the Apostolic See and the Roman pontiff hold primacy over the whole world, that the pope is the successor of Peter, true vicar of Christ, head of the whole Church, father and teacher of all Christians.^[30]

"the Roman pontiff is for his part the successor of blessed Peter prince of the apostles and the true vicar of Christ, the head of the whole Church, the father and teacher of all Christians" — Council of Florence, Laetentur caeli, DS 1307^[31]

The text then maintains the order of the patriarchates: Constantinople after Rome, then Alexandria, Antioch, and Jerusalem, with their own privileges and rights. Florence therefore does not abolish the Eastern patriarchal structure; it reinscribes it within a communion in which Rome holds universal primacy.^[32]

Exsultate Deo for the Armenians

On 22 November 1439, the decree Exsultate Deo is addressed to the Armenians. It takes up the decree of union with the Greeks and gives a famous synthesis of the seven sacraments: baptism, confirmation, Eucharist, penance, extreme unction, orders, and matrimony.^[33]

Denzinger notes several formulations that became classic: the sacraments of the New Law contain grace and confer it on those who receive them worthily; each sacrament requires a matter, a form, and a minister with the intention of doing what the Church does.^[34]

Cantate Domino for the Jacobites

On 4 February 1442, the decree Cantate Domino is addressed to the Jacobites — that is, the Copts and Ethiopians in the Latin vocabulary of the time. It contains a very firm doctrinal profession on the Trinity, Christ, the received councils, the sacraments, and belonging to the Church.^[35]

This decree is often quoted for its strict formula on salvation outside the Church. To read it correctly, two things must be held together: the text expresses the classic Catholic conviction on the necessity of ecclesial unity, but it must be interpreted in continuity with the whole magisterium, notably the later distinctions on invincible ignorance and ordered belonging to the Church.^[36][37]

The text says: "The Holy Roman Church firmly believes, professes and preaches that none of those who are outside the Catholic Church, not only pagans but also Jews or heretics and schismatics, can become partakers of eternal life, but will go into the eternal fire which was prepared for the devil and his angels, unless before the end of their life they have been joined to Her."^[38] Father Bernard Sesboüé recalls that this affirmation belongs to the ancient picture of a world then presumed almost entirely Christian, where such a refusal could only come from culpable hardening: this historical presupposition is not part of the dogma, and the decree is to be read within the homogeneous development of the magisterium, with Lumen Gentium 14 and 16.^[39]

A Roman doctrinal success

From the Catholic point of view, Florence provides a major doctrinal dossier. On the Filioque, it takes up and clarifies Lyons II. On purgatory, it fixes a concise formulation that will be taken up in Latin theology. On Roman primacy, it gives an explicit conciliar definition before Vatican I.^[40]

The institutional result should also be noted: the Basel line is marginalized, the antipope Felix V ends up renouncing in 1449, and conciliarism as a permanent-government project emerges weakened from the conflict.^[41]

A failure of reception in the East

The Eastern failure is equally real. The signature of 6 July 1439 does not become the living reception of the Byzantine Church. At Constantinople, the anti-unionists rely on the refusal of Mark of Ephesus; at Moscow, Isidore of Kiev is rejected; after the fall of Constantinople in 1453, the union appears even more as an attempt tied to Byzantine political urgency.^[42][43]

The council thus reveals a fundamental ecclesial law: a union cannot merely be signed by representatives. It must be confessed, taught, celebrated, and received. Florence obtained a very strong doctrinal act; it did not obtain the lasting adherence of the separated Eastern Churches.

A key text for Catholic-Orthodox dialogue

Florence remains unavoidable in dialogue between Catholics and Orthodox because it concentrates the still-sensitive points: primacy, the procession of the Spirit, the reception of councils, liturgical diversity, purgatory, and the role of the people of God in accepting a union. Even when it is rejected by Orthodoxy, it compels a precise formulation of what divides.

A partial model for the Eastern Catholic Churches

The council also left a lasting intuition: Catholic unity does not require complete Latinization. The Greeks may keep their leavened bread; the patriarchates have their rights; Armenians, Syrians, Chaldeans, and Maronites are received in a logic of communion that does not automatically abolish their own traditions.^[44]

This principle would become decisive in the history of the Eastern Catholic Churches: communion with Rome, confession of the Catholic faith, but preservation of an Eastern rite, discipline, and memory.

A lesson on councils themselves

Florence finally teaches that a council must be read according to its acts, its reception, and its real authority. Basel, Ferrara, Florence, and Lateran form a single historical dossier, but not all the claims made in that long process carry the same weight. The Catholic Church receives Florence as an ecumenical council in the line of Eugene IV, not as a validation of the revolutionary claims of the Basel majority.

• Read Constance: the preceding council, indispensable for understanding Frequens and the conciliarist crisis.
• Read Lyons II: the first great medieval attempt at union with the Greeks.
• Read Orthodoxy: the Eastern objections to the Filioque, Roman primacy, and the reception of Florence.
• Read Purgatory: Florence is one of the major magisterial milestones of Catholic doctrine.