Pope Leo urges the “disarming” of AI in a technology-centered encyclical.

On Monday, Pope Leo XIV released a major document centered on the impact of the growing presence of artificial intelligence on humanity, cautioning that the technology could make civilization feel “less human.”

Pope Leo, who has often found himself at odds with the Trump administration over the Iran war and some U.S. officials’ religious reasoning for it, also seemed to brush off the idea that the conflict was a necessary preemptive step for America’s safety.

“Today, more than ever, without prejudice to the right to self-defense in the strictest sense, it is important to reaffirm that the ‘just war’ theory, which has all too often been used to justify any kind of war, is now outdated,” he wrote in his Magnifica Humanitas (Magnificent Humanity), an 82-page teaching known as an encyclical.

Francis also issued a first-ever apology for the Vatican’s role in facilitating and justifying the transatlantic slave trade, calling it “a wound in Christian memory.”

“For this, in the name of the Church, I sincerely ask for pardon,” he wrote. 

But the vast majority of the encyclical was devoted to what Leo clearly sees as humanity’s risk-laden embrace of AI.

Leo called for the “disarming” of AI, warning that the technology could fuel “a race for ever more powerful algorithms and larger datasets, driven by the desire to secure geopolitical or commercial dominance.”

The document marks the first major papal encyclical written in the era of generative artificial intelligence, and it frames the current technological revolution not merely as an economic challenge, but as what the pope calls an “anthropological” one — a crisis touching the meaning and purpose of humanity.

“Please note that the encyclical is not about AI,” Cardinal Michael Czerny, one of the Vatican officials who helped present the document, told Newsmen. “It’s about the human condition during the time of AI.”

In unusually direct language for a Vatican document, Leo — who holds a degree in mathematics — warned of the growing power of IT companies, with influence that can rival that of governments.

At the same time, the pope stressed that technology itself is not inherently evil.

“Artificial intelligence is a great human achievement,” Cardinal Czerny said. “We have a lot to admire and a lot to be thankful for … But we can’t renounce responsibility.”

The Vatican’s concerns extend well beyond Silicon Valley. The encyclical repeatedly echoes broad societal concerns that AI could ⁠hollow out the middle class; ⁠eliminate vast numbers of jobs; ⁠deepen inequality; fuel social fragmentation; and normalize AI-driven warfare.

“There exists no algorithm capable of making war morally acceptable,” the encyclical states.

The warning comes as militaries worldwide are quickly incorporating AI into weapons systems. Newsmen recently watched U.S. forces during exercises in Morocco and saw firsthand the increasing use of AI-assisted targeting and autonomous technologies, including those connected to Maven, the Pentagon’s AI platform.

One of the more striking aspects of the Vatican’s rollout of Leo’s encyclical was the inclusion of Christopher Olah, a co-founder of the AI company Anthropic, who was there in person alongside senior church officials on Monday.