Pope Leo XIV on Monday called for robust regulation of artificial intelligence and urged developers and governments to slow the pace of AI deployment, releasing his first encyclical, "Magnifica Humanitas," at a Vatican presentation that also featured Anthropic co-founder Christopher Olah.

The document, one of the most authoritative forms of papal teaching, frames AI as the defining question of the era and sets the first American pope on a direct course with the Trump administration, which has worked to deregulate the industry and has ordered federal agencies to stop using Anthropic's technology. Leo declared that it was "not permissible" to entrust irreversible, lethal decisions to AI systems, and warned that the concentration of AI capability among a handful of private firms threatens children, workers and the most vulnerable.

What the text says

Leo wrote that "merely regulating it is insufficient" and that AI "must be disarmed, welcoming and accessible." He called for "robust legal frameworks, independent oversight, informed users and a political system that does not abdicate its responsibility," arguing that "a more moral AI is not enough if that morality is determined by a few."

On warfare, the pope said autonomous weapons systems make conflict "more 'feasible' and less subject to human control," and demanded transparency over the chain of command for AI-directed strikes. He declared the Catholic Church's centuries-old "just war" theory "outdated" given the technological advances of warfare, and said humanity is "slipping into a violent culture of power, where peace no longer appears as a responsibility to be taken on, but as a fragile interval between conflicts."

The pope, a former math major, signed the encyclical May 15, the 135th anniversary of Leo XIII's 1891 "Rerum Novarum," the founding document of modern Catholic social teaching on workers' rights during the Industrial Revolution.

Anthropic at the Vatican

The decision to release the encyclical alongside Olah drew criticism from observers who saw it as a papal stamp of approval for a firm valued at hundreds of billions of dollars and currently suing the Trump administration over access to its models. Anthropic is the third-most valuable U.S. private company, behind OpenAI.

Olah told the Vatican audience that AI labs operate "inside a set of incentives and constraints that can sometimes conflict with doing the right thing," and called for outside critics willing "to say hard things." He added: "We need more of the world — religious communities, civil society, scholars, governments — to do what His Holiness has done here: to take this seriously, to look closely, and to push events in a better direction."

Brian Boyd, U.S. faith liaison for the Future of Life Institute, compared Olah's inclusion to a papal audience with a head of state, calling it "a recognition of (how) this is an extremely powerful company that's currently winning this race to replace human workers" rather than an endorsement.

On labor and slavery

Leo extended the encyclical's labor argument with the first papal apology for the Holy See's historical role in legitimizing slavery, citing earlier decrees that granted European sovereigns authority to subjugate "infidels." He wrote that "the pursuit of greater profits cannot justify choices that systematically sacrifice jobs, because the human person is an end, not a means."

Paolo Carozza, a Notre Dame law professor and chair of the Meta oversight board, called the document "a defining document for our era, a profound and prophetic document."

The counterpoint

Today's dossier draws from PBS NewsHour, carrying Associated Press wire copy, and from NBC News, both center to lean-left in posture. The Trump administration, which the encyclical implicitly rebukes on both deregulation and the Anthropic dispute, had not publicly responded by press time. Industry voices warning that slowing U.S. development would cede ground to Chinese labs, a frequent argument from administration officials and from firms lobbying against new federal AI rules, were not represented in Monday's reporting on the document itself.

The encyclical's call for "a slower pace in adopting AI" lands as Anthropic's court fight with the Trump administration over military access to its models continues and as OpenAI presses toward public markets, setting the commercial timetable against which the pope's appeal will be measured.