When Pope Pius IX declared he was the tradition, he redefined the Catholic Church.

Ideas & Philosophy · Published 3 October 2026 Swipe more like this →

In short: In 1869, the First Vatican Council gathered to confront modern secularism. It ended with a controversial dogma: papal infallibility. While the majority sought to solidify the Pope's supreme authority, the decision triggered international political backlash, a schism that birthed the Old Catholic Church, and an abrupt, war-driven adjournment.

Convoked by Pope Pius IX in 1868, the First Vatican Council was the 20th ecumenical council of the Catholic Church. Its primary mission was to address the perceived threats of 19th-century philosophical trends, including rationalism, liberalism, and secularism. The council sought to clarify doctrine through the Dogmatic Constitution on the Catholic Faith, adopted unanimously in April 1870, which defined the Church's stance on revelation and faith.

The council's most enduring legacy, however, was the definition of papal infallibility. This doctrine asserts that the Pope, when speaking ex cathedra on faith or morals, possesses the infallibility promised to the Church. The proposal faced significant resistance, not necessarily from theological doubt, but from pragmatic concerns. A minority of bishops—roughly 10%—feared the dogma would alienate non-Catholics and invite state interference. When Cardinal Filippo Maria Guidi suggested the Pope be guided by the counsel of bishops, Pius IX famously countered: "I am the tradition."

The final vote on 18 July 1870 saw 533 bishops in favor and only two against. The aftermath was immediate and turbulent. The dogma prompted the formation of the Old Catholic Church, led by figures like Ignaz von Döllinger, who was excommunicated in 1871. Meanwhile, secular states reacted with hostility; Prussia initiated the anti-Catholic Kulturkampf, and the Austrian Empire annulled its 1855 Concordat. The council itself was cut short when Italian forces captured Rome on 20 September 1870, forcing an indefinite adjournment in October.

The council's abrupt end left several documents, such as the schemata Supremi pastoris and Tametsi Deus, unfinished. Though some proposed reconvening in Mechlin, the council never met again. The event remains a pivotal moment in ecclesiastical history, marking a shift toward ultramontanism that fundamentally altered the relationship between the papacy, the global episcopacy, and the secular powers of the modern era.

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