Possible? Yeah.
Did Pope Leo XIV lean on a large language model to help draft his first encyclical?
Linch Zhang thinks so. An analysis posted on LessWrong suggests chunks of Magnifica Humanitas — a sprawling text about the tech’s impact on us all — are heavily machine-assisted. According to the Pangram detector, anywhere from 40 to 100 percent of the document shows AI fingerprints.
It’s not just a hunch.
The text has that telltale AI scent. Too much “genuinely,” for one. That specific word choice is a known habit of Anthropic’s Claude model. Zhang pointed this out. Another tester ran the first chapter through Pangram section by section. Result: 62 percent flagged as synthetic. The Verge tossed about 2,000 words at the tool and got 46 percent AI-written in return.
The writing feels different. Thinner in some places. Thicker in others.
But it’s not a total bot-job.
Zhang notes Pangram called some parts “essentially 0 percent AI.” Look at the first twenty paragraphs of the previous four encyclicals. Run them through Pangram? One hundred percent human confidence. The Pope’s recent speech transcript? Same thing. Solidly human.
Should you trust AI detectors?
Probably not entirely. They argue. They disagree. Consensus doesn’t equal truth. Yet Pangram commands respect. Back in March 2025 they claimed their false positive rate for flagging human work as AI was roughly one in 10,00 errors.
A tiny margin.
Encyclicals aren’t light reading. Lengthy letters from the pope. They tackle the big moral messes of the day. The New York Times puts it simply: teachings on important social challenges. This is Leo’s first go at it. Francis did the last one in October 2024, but that one wasn’t about the robot apocalypse.
Leo made history differently. First encyclical to center AI. He even presented it alongside Christopher Olah. Co-founder of Anthropic, the company behind the Claude model Zhang thinks might have helped write the Pope.
Ironic, isn’t it?
The Vatican didn’t respond to requests for comment. They never do, really. Silence hangs heavy in these corridors.
