First Vatican Council (1869-1870)

Nineteenth-century rationalism and naturalism

Vatican I was born in a century when the authority of Christian Revelation was challenged head-on. Rationalist systems reduced faith to a religious opinion, naturalism explained reality without reference to God, and some philosophies presented dogmas as historical formulas revisable according to the progress of human consciousness. The council therefore responded first with a constitution on faith: before treating the visible structure of the Church, it recalled that God exists, that he creates freely, that he can be known by reason, and that he truly revealed himself.^[7][8]

The strength of Dei Filius lies in rejecting two opposite errors. Against fideism — the idea that faith could do without reason and that God would remain unknowable to natural intelligence — the council affirms that God, the principle and end of all things, can be known with certainty by the natural light of human reason from created things. Against rationalism, it affirms that revealed mysteries exceed created intelligence and are known only because God reveals them.^[9][10]

Gallicanism and the Roman question

The other great urgency concerns ecclesiology, that is, the doctrine on the Church: who governs it, and how. For several centuries, French Gallicanism, German Febronianism — an 18th-century current, born around Febronius, which sought to reduce the pope's authority in favour of bishops and princes — and similar currents had tried to limit the pope's authority in the name of national Churches, bishops, or civil powers. In this context, defining the Roman primacy was not only a theoretical question: it was about whether the government of the universal Church depended on Peter's successor or could be conditioned by states and national traditions.^[11][12]

The historical paradox is striking: Vatican I defined the pope's spiritual primacy at the very moment when pontifical temporal power was collapsing. The capture of Rome did not diminish the council's dogmatic content; on the contrary, it forced a sharper distinction between the spiritual government of the Church and political sovereignty over the Papal States.

St Peter's in Rome as the conciliar setting

Pius IX convoked the council with the bull Aeterni Patris of 29 June 1868 — an apostolic letter of Pius IX, not to be confused with the homonymous encyclical of Leo XIII on Christian philosophy (1879). The assembly opened solemnly on 8 December 1869, the feast of the Immaculate Conception, in St Peter's Basilica. The Catholic Encyclopedia stresses the exceptional scale of the preparation: several Roman commissions drafted schemata on faith, the Church, the episcopate, discipline, religious orders, missions, and the Eastern Churches.^[13]

The council held four solemn sessions.^[14] The first two were mostly procedural. The third, on 24 April 1870, promulgated Dei Filius.^[15] The fourth, on 18 July 1870, promulgated Pastor aeternus.^[16] The next day, 19 July 1870, France declared war on Prussia; in September, Italian troops entered Rome; in October, the council was suspended.^[17][18]

A numerous but unfinished assembly

The assembly brought together several hundred bishops from across the world. It represented a Church that had become truly global: Europe, the Americas, the missions of Asia, Africa, and Oceania. This visible catholicity matters, because the definition of Roman primacy was not produced by a small isolated pontifical court; it was voted in an ecumenical council where debates were real and where an organized minority expressed reservations about the opportuneness of defining infallibility.^[19]

The sine die suspension nevertheless left the conciliar work incomplete. Vatican I had begun to treat the Church; it did not yet develop a complete doctrine of the episcopate, of the college of bishops, and of the People of God. That is one reason why Vatican II must not be read as a cancellation of Vatican I, but as an organic complement in a different historical moment.

Pius IX, pope of the Immaculate Conception and the Syllabus

Pius IX governed the Church during one of the longest pontificates in history, from 1846 to 1878. Before Vatican I, he had already marked nineteenth-century Catholicism with the definition of the Immaculate Conception in 1854 and the Syllabus errorum of 1864, which condemned a series of modern errors. Vatican I belongs to the same line: defending the possibility of revealed truth, the doctrinal authority of the Church, and the spiritual freedom of the Apostolic See.^[27]

The figure of Pius IX is often reduced to the loss of the Papal States. To understand the council, both dimensions must be held together: the pope loses an ancient political sovereignty, but obtains a major dogmatic clarification of the Petrine ministry. Outward history seems to weaken him; the conciliar definition specifies what in his office does not depend on temporal power.

The infallibilist majority and the inopportunist minority

Most bishops supported defining papal infallibility. A minority, often called "inopportunist", did not necessarily deny the doctrine itself, but judged its definition dangerous or premature in the political and ecumenical context of 1870. Several bishops of this minority left Rome before the final vote out of respect for the pope, so as not to vote no publicly at the moment of promulgation. On 13 July, the general vote had given, out of 601 Fathers present, 451 placet, 62 placet juxta modum and 88 non placet; on 18 July, after the departure of most of the minority, 533 Fathers voted placet against 2 non placet, out of 535 present, and Pius IX promulgated Pastor aeternus.^[28][29]

This fact matters for avoiding caricature. Vatican I was not a mere unanimous acclamation prepared in advance; there were debates, amendments, and pastoral and political concerns. But the final act does engage conciliar authority: the definition was approved and promulgated as doctrine revealed by God.^[30]

God the Creator, distinct from the world

The constitution Dei Filius begins with a confession of God: one true and living God, Creator and Lord of heaven and earth, spiritual, simple, immutable, distinct from the world in reality and in essence. This insistence directly targets materialism and pantheism: God is neither a part of the world, nor the diffuse soul of the universe, nor an idea produced by human consciousness.^[31][32]

The council also takes up the doctrine of creation ex nihilo. God creates freely, not to increase his own beatitude, but to manifest his perfection through the goods he gives to creatures. Creation is therefore neither an inner necessity for God nor an involuntary emanation, but a free act of goodness.^[33]

Revelation: reason can know God, but does not suffice for supernatural salvation

The most quoted text of Dei Filius affirms that God can be known with certainty by the natural light of human reason from created things. This sentence grounds the possibility of a Catholic natural theology: God's existence is neither purely irrational nor merely received through social tradition.^[34]

But the council immediately adds that God willed to reveal himself through a supernatural way. Revelation is not only useful because man thinks poorly; it is necessary because God destines man to a supernatural end that absolutely exceeds the capacities of human intelligence. In other words, reason can recognize God the Creator; it cannot invent by itself God's intimate mystery, the Trinity, the Incarnation, or man's supernatural vocation.^[35]

Faith: a reasonable, free and supernatural assent

Vatican I rejects a blind vision of faith. The assent of belief is not an irrational leap: God accompanies Revelation with external signs, especially miracles and prophecies, which the council calls most certain signs suited to the intelligence of all.^[36]

At the same time, faith remains a supernatural gift. Man believes because God reveals and because God can neither deceive nor be deceived. Reason can recognize the motives of credibility; it does not replace the interior grace that makes one adhere freely to revealed truth.^[37][38]

Faith and reason: two orders that do not contradict each other

The fourth part of Dei Filius gives one of the most important Catholic formulations on faith and reason. There are two orders of knowledge: one comes from natural reason, the other from divine faith; they differ in their principle and in their object. But since God is the author of rational light and of Revelation, there can be no true disagreement between faith and reason.^[39][40]

The council thus protects science and faith simultaneously. It recognizes the human sciences and the liberal arts as having their own principles and methods; it only refuses that a false opinion, presented as a scientific conclusion, be opposed to revealed doctrine. The formula is balanced: faith does not absorb reason, but reason does not become the sovereign judge of Revelation.^[41]

This architecture explains why Vatican I remains central to Catholic apologetics. It does not merely say "one must believe"; it specifies why believing is not contrary to reason and why human reason does not suffice to exhaust revealed mystery.

Peter's primacy comes from Christ

Pastor aeternus opens with the primacy of St Peter. The council affirms that Christ gave Peter immediately and directly a true primacy of jurisdiction over the whole Church, relying on Matthew 16 and John 21. The corresponding canon condemns the idea that Peter received only a primacy of honour.^[42][43]

This distinction is decisive. A primacy of honour would place Rome first in symbolic rank, without real power of government. Vatican I defines instead a primacy of jurisdiction: Peter's successor has an effective charge over the universal Church, not merely a ceremonial dignity.

The primacy remains in the bishops of Rome

The second chapter affirms that what Christ instituted in Peter must endure in the Church. Whoever succeeds Peter in the Roman see receives, by Christ's institution, Peter's primacy over the universal Church. Vatican I therefore does not present the papacy as a medieval invention or a delegation of the Church to the pope; it roots it in Christ's will and in the Roman succession.^[44][45]

The council does not deny the episcopate for all that. On the contrary, it specifies that the pope's power is no obstacle to the ordinary and immediate power of bishops in their particular Churches; it affirms, strengthens and defends it. This sentence is often forgotten, yet it prevents reading Vatican I as an absorption of the bishops by the pope.^[46]

Supreme, ordinary and immediate jurisdiction

The third chapter defines the nature of the Roman primacy. The Roman Pontiff possesses over the whole Church a primacy of ordinary power, and his power of jurisdiction is truly episcopal and immediate. The faithful and pastors owe true obedience not only in matters of faith and morals, but also in the discipline and government of the Church spread throughout the world.^[47]

Here Vatican I targets the systems that subordinated Roman decisions to civil approval. The council condemns the idea that a political power could prevent the pope's communication with pastors and the faithful or make his ecclesiastical acts dependent on a civil placet.^[48]

Ex cathedra infallibility: a very precise definition

The most famous definition is found in chapter 4. Vatican I does not affirm that the pope is impeccable, permanently inspired, politically infallible, or capable of producing new revelations. It defines a charism limited to the supreme magisterium, exercised under precise conditions, to guard and faithfully expound the deposit of faith.^[49]

"The Holy Spirit was not promised to the successors of Peter so that they might make known, through his revelation, some new doctrine." — Vatican I, Pastor aeternus, DS 3070^[50]

The dogmatic formula can be summed up as follows: when the Roman Pontiff speaks ex cathedra — that is, as pastor and doctor of all Christians, defining by his supreme apostolic authority that a doctrine of faith or morals must be held by the whole Church — he enjoys the infallibility with which Christ willed to endow his Church. These definitions are irreformable of themselves, and not because the Church would subsequently approve them.^[51]

This precision explains why ex cathedra acts are rare. Papal infallibility is not an unlimited extension of the pope's personality; it is a divine assistance given to an office, in a determined act, to preserve the Church in revealed truth.

The Old Catholic opposition

Some opponents of the definition refused to receive Pastor aeternus after the council. The Old Catholic movement was born chiefly in German-speaking countries around this rejection. It presents itself as the defender of the old tradition against the Roman definition; from the Catholic point of view, it separated from communion by refusing a dogma promulgated by an ecumenical council.^[52]

The crisis nevertheless remained limited. Most bishops who had expressed reservations of opportuneness submitted to the definition: Kenrick, Archbishop of St Louis, submitted to it in January 1871, while Bishop Michael Domenec of Pittsburgh had already voted placet on 18 July; outside the council, Newman declared himself satisfied with the moderation of the decree as early as 24 July 1870, and Gratry addressed his public retraction to the Archbishop of Paris after the latter took possession of the see in December 1871 (Montalembert, who died on 13 March 1870, did not live to see the definition).^{[53][54][55][56][57][58]} The conciliar minority did not become, as a whole, a lasting schism. This point confirms that the main disagreement often concerned the pastoral and political opportuneness of defining, not the personal faith of all the bishops involved.

A clarification after the political caricatures

After 1870, the definition was quickly caricatured as if the pope had become an absolute, omnipotent sovereign. The German bishops replied in 1875 that Vatican I had not made the pope an arbitrary monarch: infallibility concerns the quality of the pontifical magisterium in the same domain as the infallibility of the Church, and it is bound to the revealed deposit.^[59]

This clarification is crucial. Vatican I does not authorize the pope to invent new doctrine. The council declares on the contrary that the Holy Spirit was not promised to Peter's successors to reveal something new, but to guard holily and expound faithfully what was handed down by the apostles.^[60]

Vatican II completes without cancelling Vatican I

Vatican II explicitly takes up Vatican I's doctrine in Lumen gentium. It teaches the pope's primacy, but also develops the sacramentality of the episcopate, the collegiality of the bishops in union with the pope, and the role of the People of God. The relationship between the two councils is therefore one of continuity and complement: Vatican I defines primacy and infallibility; Vatican II places these truths within a broader ecclesiology.^[61][62]

It would be wrong to oppose the two mechanically. Vatican II quotes and assumes Vatican I; it does not go back on Pastor aeternus. But it supplies the missing pieces of a work interrupted in 1870, especially on the place of bishops and on the communional structure of the Church.

A Catholic charter of faith and reason

Vatican I remains one of the most useful texts for answering the modern idea that believing means renouncing thought. Dei Filius affirms both the real capacity of reason and its limits. Reason can know God from the created world; it can recognize motives of credibility; it can explore mysteries by analogy. But it does not dominate Revelation as if dogma were a revisable hypothesis.^[63][64]

This doctrine avoids two dead ends: the rationalism that dissolves faith into philosophy, and the irrationalism that would make faith an assent without motive. The Catholicism of Vatican I is more demanding: it asks for a humble intelligence, but not an amputated one.

A sober definition of Peter's ministry

Vatican I also gives the Catholic grammar of the modern papacy. The pope is not a permanent oracle; he is not the owner of Revelation; he is not a rival of the bishops. He is Peter's successor, charged with guarding the visible unity of the Church and confirming his brethren in the faith, with a particular assistance when he solemnly defines a doctrine of faith or morals for the whole Church.^[65][66]

The council thus requires avoiding two symmetrical errors. The first reduces the pope to an honorary president without universal jurisdiction. The second turns infallibility into a permanent doctrinal absolutism. Vatican I allows neither.

An interrupted council calling for a complete reading

The brutal end of Vatican I explains many misunderstandings. Had the council been able to continue its work, it would probably have given a fuller development on the Church and the episcopate. History remembered chiefly papal infallibility because it was the last great text promulgated before the capture of Rome.

Reading Vatican I correctly therefore means reading it with both its constitutions, not only with the sentence on the ex cathedra. Dei Filius shows the Catholic answer to intellectual modernity; Pastor aeternus shows the Catholic answer to crises of ecclesial authority. Together, the two texts seek to protect the same deposit: the revealed truth entrusted to the Church.

• Read papal infallibility: to study the exact conditions of the ex cathedra in greater depth.
• Read the Council of Trent: the great modern doctrinal precedent before Vatican I.
• Read the texts of Vatican II, especially Lumen gentium: the twentieth-century ecclesiological complement.
• Remember the heart of the matter: Vatican I defines the profound compatibility of faith and reason, then the primacy and infallibility of the pope within precise limits, before being interrupted by the capture of Rome.