Catholic social teaching has deep roots in Scripture and the Church’s Tradition, but it was the previous Pope Leo who defined it as we know it today.
The papal encyclical Rerum Novarum was “groundbreaking” in acknowledging the struggles of workers during the height of the Industrial Revolution, says Centesimus Annus Pro Pontifice (CAPP), a Vatican foundation that promotes Catholic social teaching.
According to a summary of the adocument by CAPP, Rerum Novarum explored the tensions between labor and capital, criticizing both socialism and unregulated capitalism. The document “provided a balanced, moral vision that rejected extreme ideologies and emphasized the protection of human dignity.”
The encyclical was published in May 1891 by Pope Leo XIII. In May 2025, Cardinals elected as pope Robert Cardinal Prevost, who took as his papal name Pope Leo XIV, directly connecting himself to the previous Pope Leo and his social teaching document. The Holy Father said:
“I chose to take the name Leo XIV. There are different reasons for this, but mainly because Pope Leo XIII in his historic encyclical Rerum Novarum addressed the social question in the context of the first great industrial revolution. In our own day, the Church offers to everyone the treasury of her social teaching in response to another industrial revolution and to developments in the field of artificial intelligence that pose new challenges for the defence of human dignity, justice and labour.”