AI may have been used to write part of Pope Leo XIV’s latest encyclical on the impact of AI on humanity. An analysis by Linch Zhang posted on the LessWrong forum found the following specific paragraph: Magnifica Humanitas According to popular AI detector Pangram, between 40 percent and 100 percent are written by AI.
This document includes known characteristics that appear in AI-generated documents, such as the greater use of the word “authentic” (which appears in Claude’s text in Anthropic) than in previous encyclicals, Zhang said. Another ran Pangram through a document’s text section by section and found that 62 percent of its first chapter was flagged as AI-generated. when The Verge We ran a document of approximately 2,000 words through Pangram and estimated that 46 percent was written by an AI.
AI detection is not foolproof
Still, other parts are recorded as being written by humans. Zhang notes that Pangram flagged some sections as “0% AI in nature.” The first 20 paragraphs of the last four encyclicals, when run in pangrams, were 100 percent sure that they were written by humans. The transcript of Pope Leo’s speech, broadcast via Pangram, was also rated as 100 percent human.
AI detection is not foolproof. Different AI detectors may display different results, and even if there is a consensus, there is no guarantee that it is correct. However, pangrams are generally respected among AI researchers. In March 2025, Pangram announced that it estimated that the false positive rate for reporting human-written work as AI-generated was “approximately 1 in 10,000.”
An encyclical is a long letter issued by a pope intended to convey teachings that address important moral and social issues of the time. new york times. This encyclical is the first by a pope, the most recent being written by Pope Francis in October 2024. The encyclical is also the first to focus on AI and its far-reaching implications, with Pope Leo presenting the encyclical alongside Anthropic co-founder Christopher Oler.
The Vatican did not immediately respond to a request for comment.
