The sweeping encyclical, titled “Magnifica Humanitas” (“Magnificent Humanity”), was released on Monday and spans nearly 43,000 words. It marks the Pope’s first major doctrinal intervention on AI and global security since his election just over a year ago.
“What is needed is a more active political involvement that is capable of slowing things down when everything is accelerating,” the Pope wrote, calling for “robust legal frameworks, independent oversight, informed users and a political system that does not abdicate its responsibility.”
Warning Over Autonomous Weapons and AI-Driven Warfare
A central concern in the document is the rapid evolution of autonomous weapons systems, which Pope Leo said may have advanced “practically beyond any human reach to govern them.”
Speaking at a Vatican event where the encyclical was launched, he warned that entrusting machines with lethal decision-making would be “not permissible,” urging world leaders to ensure that any military use of AI remains under strict ethical control.
The Pope also cautioned that modern conflicts risk being shaped not just by politics but by technology and profit motives, pointing to what he described as a global “violent culture of power.”
“The past 60 years have been marked by conflicts of astonishing brutality, often affecting civilian populations on a massive scale,” he wrote.
“Just War” Doctrine Declared Outdated
In one of the most striking theological shifts in the document, Pope Leo appeared to repudiate the Church’s long-standing “just war” theory, which has guided Catholic moral thinking on armed conflict for centuries.
“The ‘just war’ theory which has all too often been used to justify any kind of war, is now outdated,” he stated.
He added that “the use of force, violence and weapons reflects a relational poverty that always has disastrous consequences for civilian populations,” signalling a stronger anti-war stance than many of his predecessors.
The Pope also warned that political leaders may be tempted to use war as a distraction from domestic problems, cautioning against what he described as the “cynical” manipulation of armed conflict for political gain.
Tech Industry Under Ethical Scrutiny
The encyclical directly addresses the fast-growing artificial intelligence industry, including concerns about corporate control over data and the pressures shaping AI development.
At the Vatican launch, Anthropic co-founder Chris Olah, whose company develops the Claude AI system, acknowledged those pressures.
“Every frontier AI lab, including Anthropic, operates inside a set of incentives and constraints that can sometimes conflict with doing the right thing,” he said, adding that external oversight is necessary as companies face intense commercial competition.
Pope Leo echoed those concerns, warning against allowing AI data and infrastructure to remain solely in private hands, and urging policymakers to “cool” the race between competing AI firms.
Call for Global Regulation and Political Responsibility
The Pope’s message repeatedly stressed that governments must take a more active role in shaping AI’s trajectory rather than leaving it entirely to market forces.
He called for “independent oversight” and warned that societies risk drifting into dangerous technological dependence without clear ethical boundaries.
“A subtle temptation may emerge, namely the thought that the problems are too big and we are too small,” he wrote. “Yet, no one is without responsibility.”
The encyclical also referenced the biblical Tower of Babel as a metaphor for unchecked technological ambition, warning against efforts that “aspire to reach heaven without God’s blessing.”
Human Cost of the Digital Economy
Beyond AI governance and warfare, Pope Leo drew attention to the labour conditions underpinning the global technology supply chain, including mining and manufacturing work tied to electronics and rare earth materials.
He described what he called “new forms of slavery” affecting workers in parts of the global supply chain, including children exposed to hazardous conditions.
“The bodies of these people are scarred, injured and worn down so that computational flow may continue uninterruptedly,” he wrote, urging renewed moral responsibility across industries.
In a rare personal admission, he also acknowledged the Church’s historical failure to strongly oppose transatlantic slavery earlier, calling it “a wound in Christian memory” and asking for forgiveness “in the name of the Church.”
Outlook: A Moral Framework for the AI Era
Pope Leo’s encyclical positions AI not just as a technological challenge, but as a defining moral and political issue of the century.
By linking artificial intelligence, global conflict, labour exploitation, and historical injustice in a single framework, the document calls for a rethinking of how power, technology, and ethics intersect.
While its recommendations carry no legal force, encyclicals represent one of the highest forms of teaching in the Catholic Church, meaning the message is expected to influence global debates on AI governance, warfare ethics, and corporate responsibility in the years ahead.