Pope Leo XIV used his first major teaching document in Rome on Monday to call for a halt to what he described as the blind deregulation of artificial intelligence, directly challenging the Trump administration's drive to loosen AI rules and setting up a sharp clash over the future of the technology.
The Vatican has been moving deeper into the AI debate for almost a decade, engaging with Silicon Valley leaders while warning that powerful systems must be held in check by ethics and law.
Leo, the first US-born Pope and a former maths student, had already signalled shortly after his election that artificial intelligence was one of the biggest challenges facing humanity. His first encyclical, Magnifica Humanitas (Magnificent Humanity), was therefore closely watched by theologians and tech executives before its publication on 25 May.
Leo's Case Against Unchecked AI
In Magnifica Humanitas, Pope Leo XIV takes a direct approach. He criticises what he calls a 'culture of power' driving the AI race, particularly the development of increasingly sophisticated systems for remote warfare. It is, he writes, 'not permissible' to entrust irreversible, lethal decisions to AI systems.
That warning runs squarely counter to the direction of travel in Washington, where the Trump administration has sought to scale back oversight and encourage rapid AI deployment in defence and other sectors. Read that way, the encyclical also serves as a message to Catholic lawmakers and voters to resist the push for deregulation.
Experts quoted by the Associated Press said the document is likely to become a reference point well beyond church circles. Scholars of technology and Catholic social teaching argue that it sets out a framework that regulators, corporate boards, and ordinary users will increasingly have to confront as AI reshapes work, education and warfare.
In his first #encyclical "#Magnificahumanitas", on the Church's social doctrine in the era of #ArtificialIntelligence, Pope Leo XIV appeals for the safeguarding of humanity, promotion of truth, dignity of work, social justice, and peace.https://t.co/4Mev5jVPxD pic.twitter.com/EtoMGByPFe
— Vatican News (@VaticanNews) May 25, 2026
Taylor Black, a Microsoft AI executive who also directs the AI institute at the Catholic University of America, said the tools now being rolled out raise questions that go far beyond efficiency. They force people, he argued, to ask: 'What does it mean to be human?'.
Leo grounds his argument in long-standing Catholic teaching. He traces the Church's social doctrine and applies its core principles, justice, solidarity, the dignity of work and the universal destination of resources, to the digital age. The encyclical insists that economic gain cannot override those values.
'It is not enough to invoke ethics in the abstract; robust legal frameworks, independent oversight, informed users, and a political system that does not abdicate its responsibility are required,' he writes. 'A more moral AI is not enough if that morality is determined by a few'.
Vatican And Big Tech
The setting for the launch was striking. The Vatican unveiled the encyclical at an event featuring Anthropic, the US AI company that is currently suing the Trump administration after the company refused to grant the US military unrestricted access to its systems. The administration ordered agencies to stop using Anthropic's technology in February.
Vatican officials said Anthropic had been invited as part of a broader effort to keep Silicon Valley engaged in discussion about the human cost of AI, not as an endorsement of any one company. Even so, critics argued that the presence of co-founder Christopher Olah risked looking like a papal seal of approval.
THIS IS HUGE MORAL MOMENT…
— Christopher Webb (@cwebbonline) May 25, 2026
Pope Leo XIV’s first encyclical, Magnifica Humanitas, is focused on AI ethics, human dignity, labor displacement, and regulating artificial intelligence.
And the Vatican chose to partner with Anthropic, currently in a major legal fight with the Trump… pic.twitter.com/7tdTk6Bdhi
Leo's own text is far less accommodating. He repeatedly warns that the concentration of data and decision-making in a handful of private companies poses a danger to children and other vulnerable groups, and he calls for firm external regulation of the sector.
Olah welcomed the pressure, saying it is exactly what the field needs. He warned of a 'real possibility that AI will displace human labour at a very large scale' and said researchers need 'informed critics who will tell the labs when we are failing' and 'moral voices that the incentives cannot bend'.
Brian Boyd, US faith liaison for the non-profit Future of Life Institute, compared the encounter to a papal audience with a head of state. In his view, Anthropic is 'an extremely powerful company that's currently winning this race to replace human workers', and bringing its leaders into the room reflects that reality rather than rubber-stamping their choices.
War, Jobs And Power
One of the most striking parts of the encyclical is Leo's willingness to question his own Church's teaching. He argues that rapid advances in AI-driven weapons have helped normalise war, dulling public awareness of its human cost, and says the Catholic doctrine of 'just war' no longer fits a world of opaque, autonomous systems.
He does not name specific conflicts, instead speaking of 'opposing imperialisms' and rival powers competing to preserve or seize supremacy. He calls for full transparency from developers so that, even when AI is used in combat, the human chain of command behind any strike can still be traced.
The text returns repeatedly to labour and inequality, drawing a direct line to the Industrial Revolution. Leo signed Magnifica Humanitas on 15 May, the 135th anniversary of Rerum Novarum (Of New Things), the 1891 encyclical by Pope Leo XIII that helped shape modern Catholic social teaching on workers' rights and the limits of capitalism.
'The pursuit of greater profits cannot justify choices that systematically sacrifice jobs, because the human person is an end, not a means, and the economic order must remain subordinate to human dignity and the common good,' Pope Leo XIV writes.
He also extends the argument into history, issuing what is described as the first papal apology for the Holy See's role in legitimising slavery by authorising European rulers to subjugate and enslave so-called 'infidels'. By pairing that apology with his warning on AI, Leo presents moral abdication in the face of economic or technological power as a recurring failure, not a new one.
Paolo Carozza, a Notre Dame law professor and chair of Meta's oversight board, called the encyclical 'a defining document for our era', praising it as a 'clear, comprehensive, and coherent voice', insisting that technology serve humanity rather than diminish it.
None of Leo's comments changes the legal picture overnight, and the Trump White House has given no sign that it plans to reverse course. But with this encyclical, the world's most prominent religious leader has placed the Vatican firmly on the side of tougher AI rules, at odds with Washington's push for faster growth and fewer constraints.
