Pope Leo XIV calls for AI slowdown, data ownership limits in landmark encyclical

Pope Leo XIV, the first American pontiff, has issued a sweeping call for the world to pump the brakes on artificial intelligence. In a document released Monday that spans nearly 43,000 words—an encyclical, one of the Church's highest forms of teaching—he warns that AI systems are spreading misinformation, amplifying conflict, and pushing humanity toward perpetual war. The text, titled Magnifica Humanitas, represents the culmination of work begun shortly after his election just over a year ago, and it arrives at a moment when the Pope has grown more vocal in his criticism of global power structures, drawing particular fire from the Trump administration for his opposition to the Iran war.

At the heart of Leo's argument is a simple but radical proposition: the development of artificial intelligence cannot be left to market forces alone. He calls for governments to assert themselves forcefully, to establish robust legal frameworks and independent oversight, to cool the competitive fever among AI companies, and crucially, to ensure that data ownership does not remain concentrated in private hands. "What is needed is a more active political involvement that is capable of slowing things down when everything is accelerating," he writes. The Pope is not asking for a halt to AI development—he is asking for deliberation, for the reassertion of human judgment over technological momentum.

The encyclical also represents one of the clearest papal rejections of just war theory in centuries. The doctrine, which has guided Church teaching since at least the fifth century and which the Trump administration has invoked to defend its military actions, is now, in Leo's view, obsolete. He writes that the theory "has all too often been used to justify any kind of war" and that the use of force and violence reflects a fundamental poverty in human relationships. More pointedly, he raises the specter of leaders deliberately manufacturing conflicts to distract their own populations from domestic failures—a concern that speaks directly to contemporary politics without naming it.

Where the encyclical becomes most visceral is in its treatment of human suffering. Leo draws a direct line from the extraction of rare earth elements—materials essential to the computers and devices that run AI systems—to the children and adolescents working in dangerous conditions in parts of the world, their bodies scarred and worn by labor that most consumers never see. He calls this "new forms of slavery" and invokes his predecessor Leo XIII, who in 1891 called for better wages and conditions during the Industrial Revolution. The parallel is deliberate: just as industrial capitalism created new forms of human exploitation, so too does the AI economy. The Pope also makes a striking personal acknowledgment, apologizing on behalf of the Church for its failure to forcefully condemn transatlantic slavery until the 19th century, calling it "a wound in Christian memory."

On the question of AI in warfare, Leo is unequivocal. He states that entrusting artificial intelligence systems with lethal decisions is "not permissible" and that any military use of AI must be subject to the most rigorous ethical constraints. This is not abstract moralizing—it is a direct challenge to the logic of autonomous weapons systems being developed by major powers.

The encyclical closes with an invocation of the Tower of Babel, the biblical story of human pride leading to divine punishment. Leo uses it to warn against any enterprise that aspires to reach heaven without God's blessing—a metaphor for technological ambition untethered from ethical consideration. The document is addressed not only to the Church's 1.4 billion members but to all people of good will, a signal that the Pope sees this as a matter of universal human concern, not merely religious doctrine.

What Leo has done is give institutional weight to concerns that have circulated among technologists, ethicists, and policymakers for years. By framing AI regulation as a moral imperative rooted in centuries of Catholic social teaching, he has positioned the Church as a voice in a conversation that will shape the next decade of technological development. Whether governments listen, and whether the competitive logic that drives AI development can actually be slowed by political will, remains to be seen.