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Rerum Novarum: Catholic social teaching
May 15, 1891 (Leo XIII)· Council, creed or writing· Books & writings
Historical recordConfirmed by archaeology, outside sources or contemporary records.
Pope Leo XIII's 1891 letter on capital and labor, the founding document of modern Catholic social teaching.
See it on the Bible & Christianity map →What it is
Rerum Novarum (Latin 'Of new things') answered the 'worker question' of the Industrial Revolution. Leo XIII defended private property as a natural right and rejected socialism, but he also rejected unregulated capitalism. Employers, he wrote, owe a wage that can support a frugal worker and family; workers may form unions; and the state must protect the poor, limit working hours and shield children. Later popes marked its anniversaries with new encyclicals in 1931, 1961, 1981 and 1991.
Why it matters
It gave the Catholic Church a voice on economics, shaped Catholic labor unions and Christian Democratic parties in Europe and the Americas, and still frames Catholic teaching on work, wages and property.
Think of it like
Like a deed with covenants attached: the owner's title is protected, but it carries duties to the workers and neighbors who depend on the property.
Sources and history
The Latin text, dated May 15, 1891, is published by the Vatican. Its influence shows in later encyclicals that cite it and in Catholic unions, parties and labor reformers of the early 1900s.
Questions and debates
Historians debate whether it was progressive for its day or mainly a defense against socialism, and how far it inspired 1930s 'corporatist' regimes in Austria and Portugal.
Connections (2)
▸Rerum Novarum: Catholic social teaching founded the social teaching expanded by Second Vatican CouncilHistorical record
The connection
Rerum Novarum began a line of papal social teaching, extended in 1931 and by John XXIII in 1961 and 1963. Vatican II's Gaudium et Spes (1965) broadened it from workers' rights to the whole modern world: economic justice, family, culture, war and peace. It opens with 'the joys and the hopes' of people today, 'especially those who are poor.'
When and where
Rome: Leo XIII, May 15, 1891; Pius XI's Quadragesimo Anno, 1931; John XXIII's Mater et Magistra, 1961; Gaudium et Spes, December 7, 1965.
Historical evidence
Gaudium et Spes and John XXIII's encyclicals cite Leo XIII's letter and its successors directly in their notes.
Questions and debates
Scholars debate whether Vatican II continued Leo's natural-law method or shifted to a newer, more dialogue-based 'reading of the signs of the times.'
▸Pope Leo XIV chose his name to echo Rerum Novarum: Catholic social teachingHistorical record
The connection
Two days after his election, Leo XIV told the cardinals he chose his name 'mainly because Pope Leo XIII' had addressed 'the social question' of the first industrial revolution in Rerum Novarum. Today, he said, the church offers its social teaching in response 'to another industrial revolution and to developments in the field of artificial intelligence.'
When and where
Address to the College of Cardinals, Vatican City, May 10, 2025.
Historical evidence
His own words, in the Vatican's official published text of the address.
Questions and debates
It is too early to judge whether his teaching on AI and work will shape this century the way Leo XIII's shaped the last.