Pope Leo XIV dropped his first encyclical on Monday, and it's a shot across the bow of the AI industry. Titled Magnifica Humanitas (Magnificent Humanity), the document urged governments worldwide to slow down AI development, warning that current systems prioritize conflict over human flourishing and risk dragging civilization into endless warfare. The Pope specifically called for "robust legal frameworks, independent oversight, informed users and a political system that does not abdicate its responsibility." This marks one of the most direct interventions yet from a global religious leader on AI governance—and it comes at a moment when regulation debates are reaching fever pitch in Washington, Brussels, and Beijing.

The Vatican's AI Intervention

The encyclical didn't pull punches. Leo invoked the biblical Tower of Babel story to illustrate what he sees as humanity's hubristic rush toward godlike technological power without moral grounding. "What is needed is a more active political involvement that is capable of slowing things down when everything is accelerating," he wrote. The document also called for AI data ownership to be removed from private hands alone, demanded worker protections against displacement, and urged safeguards for children from the technology. With 1.4 billion Catholic faithful worldwide, this isn't just theological opinion—it's potential political pressure on legislators from São Paulo to Seoul.

Anthropic's Presence at the Vatican

In a striking development, Anthropic co-founder Christopher Olah was invited to speak at the encyclical presentation in Rome. Olah didn't use the occasion to pump his company's products—he warned that AI "will displace human labour at very large scale" and called supporting those displaced "a moral imperative of historic proportions." The irony is thick: Anthropic has been locked in litigation with Pentagon officials under President Trump's administration over its refusal to let Claude be used for lethal autonomous warfare without human oversight, or for mass surveillance of Americans. The company's safety principles are being tested in court while its co-founder advises the Pope on AI ethics at the Vatican.

Autonomous Weapons and 'Just War' Theory

Leo was unambiguous about weapons: 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. The encyclical also contained one of the clearest papal repudiations ever of the "just war" doctrine that has justified military action since the fifth century. "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." This directly challenges arguments made by members of the Trump administration, including Vice President JD Vance, a Catholic convert who invoked just war theory to defend military operations against Iran.

The Human Cost Nobody Talks About

Beyond headline-grabbing warfare concerns, the encyclical shone light on exploitation hidden throughout AI's supply chain. Leo decried "new forms of slavery" endured by workers who train and maintain AI systems, plus factory laborers producing the devices—computers, smartphones, servers—that power artificial intelligence. "In some regions of the world, children and adolescents work in dangerous conditions, crushing the materials from which rare earth elements are extracted," he wrote. "The bodies of these people are scarred, injured and worn down so that computational flow may continue uninterruptedly." This is a direct challenge to tech executives who prefer to talk about model capabilities while ignoring mining operations in the Congo.

A Historic Apology

In a separate but significant move, Leo apologized for the Vatican's own role in slavery—something no pope has publicly acknowledged before. "This constitutes a wound in Christian memory," he wrote. "For this, in the name of the Church, I sincerely ask for pardon." While past popes have apologized for Christians' involvement in the trans-Atlantic slave trade, none had directly addressed papal authority granting European sovereigns explicit permission to enslave "infidels." The 2023 repudiation of the Doctrine of Discovery—a legal theory based on fifteenth-century papal bulls—never formally rescinded those decrees. Until now.

Key Takeaways

  • Pope Leo's encyclical Magnifica Humanitas calls for slowing AI development and establishing robust regulatory frameworks with independent oversight
  • Anthropic co-founder Christopher Olah joined Vatican officials, warning AI will displace workers at "very large scale"
  • The Pope declared autonomous weapons with lethal decision-making authority "not permissible"—directly contradicting Pentagon policy proposals
  • Leo repudiated centuries-old "just war" doctrine as outdated, challenging justifications used by the Trump administration
  • The encyclical exposed human rights abuses in rare earth element mining and AI labor supply chains

The Bottom Line

Pope Leo just did something Silicon Valley and Washington have failed to accomplish: he connected the dots between AI's technical risks, its human exploitation costs, and the geopolitical dangers of unregulated autonomous weapons. Whether you agree with his religious framing or not, he's right that leaving these decisions to tech companies alone is a recipe for disaster. The Anthropic-Pentagon litigation shows exactly why independent oversight matters—corporate safety principles mean nothing when government contracts are on the line.