Analysis suggests Pope Leo XIV's encyclical on AI may contain AI-written passages, with detection tools flagging between 40 and 100 percent of sections

An analysis by Linch Zhang on LessWrong used the AI detector Pangram to examine Pope Leo XIV's encyclical Magnifica Humanitas and found certain paragraphs flagged as between 40 percent and 100 percent AI-written. When The Verge ran roughly 2,000 words through Pangram, it estimated 46 percent was AI-written.

The encyclical, Pope Leo's first and the first to focus on AI, was presented alongside Christopher Olah, a co-founder of Anthropic. Previous encyclicals' opening paragraphs, when run through Pangram, showed 100 percent confidence of being human-written.

AI detection tools like Pangram can produce inconsistent results across different detectors, and accuracy is not guaranteed. Pangram stated in March 2025 that it estimated its false positive rate of reporting human-written work as AI-generated to be approximately 1 in 10,000.