In his first major encyclical, Pope Leo XIV calls for governments to slow and regulate artificial intelligence, warns it fuels misinformation and conflict, and urges limits on lethal AI decisions. The Vatican also documents his personal apology for the Catholi
VATICAN CITY — By the time the text was presented at the Vatican on Monday, the message was already clear: Pope Leo XIV wants the world to ease off the speed of AI—and confront the moral damage, past and present, that technology and institutions can leave behind.
In his first major document as pope. the encyclical titled “Magnifica Humanitas” (Magnificent Humanity). Leo urged governments to slow down and closely regulate the development of AI systems. He warned that AI spreads misinformation, prioritizes conflict, and could push the world toward “unending war.”.
“What is needed is a more active political involvement that is capable of slowing things down when everything is accelerating,” Leo wrote in the encyclical.
The nearly 43. 000-word text. released on Monday. comes about a little more than a year after Leo’s election. and it has been in the works since then. It also reflects a shift in his tone in recent months. including criticism that has drawn the ire of U.S. President Donald Trump after Leo criticized the Iran war.
Leo’s argument for restraint is not only technical; it is also political. He called for “robust legal frameworks. independent oversight. informed users and a political system that does not abdicate its responsibility.” He pressed for the ownership of AI data not to be left solely in private hands. for policy-makers to protect the rights of workers. and for children to be kept safe from the technology. He also urged the cooling of competition between AI companies.
At a Vatican event presenting the encyclical on Monday. Chris Olah. the co-founder of Anthropic—one of the world’s leading AI companies—thanked Leo for addressing concerns raised by disruptive new technology. Olah said companies like his face commercial pressures and need outside scrutiny. He said: “Every frontier AI lab. including Anthropic. operates inside a set of incentives and constraints that can sometimes conflict with doing the right thing.” Anthropic is the company behind the Claude AI tools.
The pope tied AI’s risks to a wider picture of conflict. The document decried the number of wars roiling the world. lamented the weakening of multilateral organisations. and warned that arms industry profits were a driving force behind conflicts. In the English-language text. Leo wrote: “The past 60 years have been marked by conflicts of astonishing brutality. often affecting civilian populations on a massive scale.” He added: “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.”.
In the same encyclical. Leo repudiated the Church’s long-used “just war” theory. a doctrine that has been used since at least the fifth century to evaluate global conflicts. The doctrine generally holds that wars should only be waged to defend against aggression. The encyclical also references how the theory has been invoked by Trump administration officials. including Vice President JD Vance. a Catholic. to defend the Iran war.
“The ‘just war’ theory which has all too often been used to justify any kind of war, is now outdated,” Leo wrote. “The use of force, violence and weapons reflects a relational poverty that always has disastrous consequences for civilian populations.”
Leo also expressed concern that leaders could start wars to divert attention from domestic problems. “We cannot rule out the possibility that some leaders may consider armed conflict as an effective way of diverting attention from domestic problems and a cynical tool for managing difficulties. ” he wrote.
Alongside the warnings about AI and war. Leo delivered a rare and direct acknowledgment of the Catholic Church’s historical handling of slavery. He said any use of AI in warfare “must be subject to the most rigorous ethical constraints” and called it “not permissible” to entrust AI systems with lethal decisions. In the process. he invoked centuries of prior papal teachings on social justice issues. including his predecessor Leo XIII. who published a famed encyclical in 1891 calling for better pay and conditions for laborers during the Industrial Revolution.
Leo then pointed to what he described as “new forms of slavery.” He wrote about people who tend AI systems and factory workers who produce the technological devices used for AI. such as computers and smartphones. He said: “In some regions of the world. children and adolescents work in dangerous conditions. crushing the materials from which rare earth elements are extracted.”.
“The bodies of these people are scarred, injured and worn down so that computational flow may continue uninterruptedly,” Leo wrote. “This reality deeply challenges the moral conscience of our time.”
He also acknowledged that the Catholic Church did not forcefully condemn transatlantic slavery until the 19th century, and he made a personal apology. “This constitutes a wound in Christian memory,” Leo wrote. “For this, in the name of the Church, I sincerely ask for pardon.”
By anchoring the encyclical’s AI warnings in both ethics and history—pushing governments to regulate and companies to face oversight, while also confronting the Church’s own late condemnation of slavery—Leo framed the stakes in terms that go beyond policy.
The letter also urged the world not to give up on addressing the risks of AI systems. Leo invoked the biblical story of the Tower of Babel. where pride drives a human tribe to build a tower tall enough to reach Heaven. angering God. He said the story shows the danger of any enterprise that “aspires to reach heaven without God’s blessing.”.
“With the heart of a shepherd and a father, I ask everyone to abandon the construction of yet another Tower of Babel and to join forces in building up the common good,” Leo wrote.
He acknowledged a psychological trap: the temptation to believe the problems are too large to influence. “A subtle temptation may emerge, namely the thought that the problems are too big and we are too small, and that our choices, therefore, cannot make a difference,” Leo wrote.
“Certainly, not everyone has the same power to make a difference,” he continued. “Yet, no one is without responsibility. We all have our own areas for action.”
For Catholics—Leo said in the opening that he wanted to address both Catholics and all people of good will—the encyclical is one of the highest forms of teaching from a pontiff to the Church’s 1.4 billion members. For policymakers and industry leaders. it reads like a demand for speed limits: regulate AI. restrict its use in lethal decisions. protect workers. and keep children safe. before misinformation and conflict become even more embedded in daily life.
Pope Leo XIV Magnifica Humanitas AI regulation artificial intelligence Anthropic Claude just war theory transatlantic slavery apology Vatican encyclical misinformation arms industry workers rights rare earth elements