Leo XIII, Who Transformed the Church in the 20th Century

Even though he inadvertently destroyed the Catholic party in France, he is one of my favourite Popes because of his great Social Encyclicals, such as Rerum Novarum, and his denunciations of Freemasonry.

From Aleteia

By I. Media

Inheriting a Church grappling with numerous crises, Leo XIII (1878-1903) attempted to respond to them in numerous encyclicals. In Rerum Novarum, in particular, he laid the foundations of Catholic social teaching. His very long pontificate allowed this intellectual to encourage the Catholic Church to face the great challenges of the nascent 20th century.

When Pius IX died in 1878, the Holy See was going through a very grave crisis. Since 1870 and the capture of Rome by Italian forces, the pope had been “imprisoned” in the Vatican and in open conflict with the young Kingdom of Italy. The Church was under pressure in France, with the emergence of a very anti-clerical Third Republic, and in Germany, where Chancellor Otto von Bismarck was waging the “Kulturkampf” to remove the local Church from the Holy See's sphere of influence.

In the United States, a very liberal and individualistic movement was gaining ground, while in Europe the challenge of secularization was becoming increasingly pressing. To address these issues, the conclave chose Cardinal Vincenzo Pecci, a respected figure from the Roman papal nobility, known for his talents as a diplomat and administrator.

Expected to be a short pontificate, but…

The man who took the name Leo XIII had been Archbishop of Perugia for 30 years, but was transferred to Rome a year before the death of Pius IX to become Camerlengo, due to poor health. Everyone expected a short pontificate, even the man himself, who ultimately reigned for a quarter of a century, one of the longest in history.

Although he aligned himself with Pius IX's position on the “Roman question,” continuing to denounce the usurpation by the Italian crown, Leo XIII realistically acknowledged the end of the temporal power of the popes and officially dissolved the Papal States in 1900.

Pragmatic, he made gestures of openness towards the Republicans in France and negotiated with Bismarck to end the Kulturkampf. He also showed interest in the development of the Church in the “New World,” in Latin America and the United States, where he condemned “Americanism.”

Very aware of the developments of his time (he was an avid reader of the press and was the first pope to grant an interview), Leo XIII also devoted his time to intense reflection on the Church and society. He wrote 86 encyclicals, a record number.

A prolific and profound writer

In 1902, a year before his death, Leo XIII, somewhat in the manner of St. Augustine's Retractationes, drew up a list of his nine most important encyclicals, offering a comprehensive overview of his very dense pontificate as an intellectual pope. The philosopher Étienne Gilson even considered him the “greatest philosopher of the 19th century.”

The first is Æterni Patris (1879), on “Christian philosophy,” which proposes as a solution to modernism a renewed study of St. Thomas Aquinas (neo-Thomism), followed by Libertas Praestantissimum (1888), on human freedom, which condemns the excesses of liberalism. 

Then there is Arcanus Divinae Sapientiae (1880), which explains the Church's condemnation of divorce, Humanum Genus (1884), which attacks the “relativism” of the Freemasons, Diuturnum (1881), on political authority, Immortale Dei (1885), on the Christian constitution of states, which criticizes secularism, and Quod Apostolici Muneris (1878), which condemns socialism.

Next came Leo XIII's most famous encyclical, Rerum Novarum (1891), which, in order to face the challenges of modernity, laid the foundations of Catholic social teaching and what would later become known as the “social doctrine of the Church.” Finally, in Sapientiae Christianae (1890), Leo XIII urged Catholics to refuse to obey civil laws when they contradicted religious teachings.

While Leo XIII's thinking had anti-modern overtones, it also pedagogically promoted a “Catholicism of movement” capable of responding to the challenges of the new era. A man of great curiosity, he was the first pope to have his voice recorded and the first to be filmed.

His important spiritual and intellectual legacy has nourished all the pontificates of his successors, right up to Leo XIV today.