Pope Leo XIV devotes his first encyclical to artificial intelligence

Pope Leo XIV published Magnifica Humanitas (“Magnificent Humanity”), an encyclical letter “on safeguarding the human person in the time of artificial intelligence.” Dated 15 May and presented on 25 May, it was the new pope’s first encyclical — the most authoritative form of papal teaching — and the first ever devoted wholly to AI. That a pontificate only weeks old made the technology the subject of its opening statement was itself the signal: the Catholic Church was placing AI at the centre of its social doctrine, the tradition running back to Leo XIII’s Rerum Novarum (1891) on industrial labour, whose name Leo XIV had taken.

The document frames the choice facing humanity through two biblical images — the Tower of Babel and the rebuilding of Jerusalem under Nehemiah — and rejects the idea that technology is a neutral instrument:

In practice, however, technology is never neutral, because it takes on the characteristics of those who devise, finance, regulate and use it. Therefore, the primary choice is not between a “yes” or “no” to technology, but rather between constructing Babel or rebuilding Jerusalem.

— Pope Leo XIV, Magnifica Humanitas

Across 245 sections the encyclical argued that “ontological dignity” belongs to every person “simply by virtue of existing” and cannot be earned or measured by usefulness, warning against an ideology that reduces people to “a means of achieving results.” It criticised the “technocratic paradigm” and the concentration of power over data, computation and platforms in a few private hands; invoked the principle of subsidiarity to demand transparency and independent oversight of algorithms; and, on the debate most familiar to AI labs, cautioned that “A more moral AI is not enough if that morality is determined by a few” — that “aligning” models with human values could not substitute for public deliberation over whose values. On work it warned that automation can “de-skill workers, subject them to automated surveillance”; on war it held that “it is not permissible to entrust lethal or otherwise irreversible decisions to artificial systems,” concluding that “No algorithm can make war morally acceptable.”

Notably for a magisterial text, the encyclical adopted a description familiar from the labs themselves — that current AI systems are “more ‘cultivated’ than ‘built,’” their inner workings largely unknown even to their developers. Leo presented the letter in person, unusually for a pope, at a Vatican event attended by AI researchers including Anthropic co-founder Chris Olah, whose interpretability research concerns exactly that opacity. Olah told the gathering that AI companies work under commercial and geopolitical pressures that can pull against safety, and that “it is enormously important that there be people outside those incentives — people who care about things going well.” Addressed not only to Catholics but to “all men and women of goodwill,” the text placed the Church, alongside governments and industry, among the institutions seeking to shape how AI is governed.