Pope Leo XIII is primarily known for his intellectualism and his efforts to reconcile the Catholic Church with modern thought and social issues. His most famous contribution is the 1891 encyclical Rerum Novarum , which addressed the rights of workers, advocating for fair wages, safe working conditions, and the right to form trade unions, while balancing these with the rights to private property and free enterprise. This encyclical laid the foundation for modern Catholic social teaching and earned him the titles "Social Pope" and "Pope of the Workers"
. He also sought to revive Thomism—the theological philosophy of St. Thomas Aquinas—as the official intellectual framework of the Church, promoting the study of Aquinas and sponsoring the Editio Leonina of his works
. Leo XIII emphasized the harmony of faith and reason, encouraging scientific inquiry and re-founding the Vatican Observatory to demonstrate the Church's support for science
. Additionally, Leo XIII was a strong promoter of Marian devotion, issuing eleven encyclicals on the rosary and approving new Marian scapulars, which earned him the nickname "Rosary Pope"
. Diplomatically, he improved the Church’s relations with major European powers and sought to restore stability and prestige to the Church after the loss of the Papal States
. In summary, Pope Leo XIII is known for:
- Authoring Rerum Novarum , the foundational social teaching encyclical on workers' rights and social justice.
- Reviving Thomistic philosophy as the Church’s intellectual foundation.
- Promoting Marian devotion and the rosary.
- Bridging the gap between the Church and modern science.
- Enhancing the Church’s diplomatic relations and restoring its influence in the modern world
