Significant fractions of Magnifica Humanitas, the papal encylical on safeguarding the human person in the time of artificial intelligence, is written significantly by AI, most likely Claude. I currently believe Pope Leo himself was not personally responsible (encyclicals tend to be group projects), however the AI usage is likely substantial enough that it’s not the result of minor brushups or AI translation:
Significant fractions of the recent papal encyclical are written with AI-assistance. I provide multiple lines of evidence for this.
We can corroborate the vibes and tonal indications with statistical evidence. Phrases and punctuation much more commonly used by AI are much more present in this papal encyclical than past encyclicals.
The best commercially available AI detector, Pangram, notes that some paragraphs are between 40% and 100% AI, while most paragraphs appear to be 0% AI.
This is unlikely to be a false positive:
0% of paragraphs in past encyclicals I backtested are registered as AI.
Pangram in general has a very low false positive rate
This is overall very unlikely to be a translation artifact (including AI translation). We again have multiple lines of evidence:
All the most prominent signs of AI I observed in English are preserved verbatim in the Italian version, as well as in other translations.
The Italian version of the current encyclical also gets flagged as AI by Pangram (actually more so than the English version), though I’m not aware of academic research or rigorous testing of Pangram’s service when applied to Italian)
Backtesting AI translation of past encyclicals get 0% on Pangram
The specific AI used is most likely Claude, judging by both textual and circumstantial evidence.
Different sections of the encyclical have very different rates of apparent AI usage. This indicates to me that some cardinals used AI assistance for this encyclical and many (probably including Pope Leo himself) didn’t.
Each individual piece of evidence might be explained away, but the consilience of evidence across multiple angles and sources is in my opinion very hard to dismiss collectively.
When you said “however the AI usage is likely substantial enough that it’s not the result of minor brushups or AI translation”, I took that to mean that it’s not the result of humans doing the thinking and AI brushing up the text. In other words, you’re saying that AI has determined some of the actual content/thinking in the encyclical.
Oh sorry! When I wrote that, I wasn’t trying to take a position on whether the actual content/thinking was determined by AI. I just wanted to emphasize that the degree of AI involvement wasn’t minor, like just use AI for grammar and typo checks.
That said, I believe a lot of human effort was also put into the text, and almost certainly the very high-level structure/arguments/ideas came from humans.
I don’t have a strong position on whether the thinking/content was determined by AI. And the evidence doesn’t really let us rule out either hypothesis.
If you’re fine with speculations, my guess is that the answer is “no” for a strong definition of “determined”, but “yes” for a weaker claim like “meaningfully affected.”
In particular I think AI is able to smooth over language far more than they can substitute for actually good thinking, at least as of mid-2026. So (speculating) there are probably subsections where the Vatican wanted to say something in the outline/early drafts but it doesn’t quite look right (because the thinking isn’t quite right), and they were able to smooth it over using AI to seem palatable in “group sycophancy” ways. And the final thinking would’ve been clearer if they forced themselves to rewrite/think over things until it could sound smooth with human levels of clear thinking/polish tradeoffs, rather than AI-assisted levels.
Some other people in our circles have already complained about things that didn’t quite make sense in parts touching on AI ethics and AI consciousness. But ignoring that (obviously the Vatican has various biases, and so does our crowd), I thought the Babel/Nehemiah contrastive pair (Par 7-10) had a sort of artificiality to it. Like it sounded nice (unless you’re allergic to AI public writing, like me), but if you actually drilled down into what the metaphor was doing and then critically contrasted it with either a) a plain-language reading of the Biblical stories themselves or b) how people historically talked about Nehemiah, or c) what goes on in the world of AI right now, it doesn’t quite make sense.
Significant fractions of Magnifica Humanitas, the papal encylical on safeguarding the human person in the time of artificial intelligence, is written significantly by AI, most likely Claude. I currently believe Pope Leo himself was not personally responsible (encyclicals tend to be group projects), however the AI usage is likely substantial enough that it’s not the result of minor brushups or AI translation:
https://linch.substack.com/p/claude-author-of-the-humanitas
Key claims:
Significant fractions of the recent papal encyclical are written with AI-assistance. I provide multiple lines of evidence for this.
We can corroborate the vibes and tonal indications with statistical evidence. Phrases and punctuation much more commonly used by AI are much more present in this papal encyclical than past encyclicals.
The best commercially available AI detector, Pangram, notes that some paragraphs are between 40% and 100% AI, while most paragraphs appear to be 0% AI.
This is unlikely to be a false positive:
0% of paragraphs in past encyclicals I backtested are registered as AI.
Pangram in general has a very low false positive rate
This is overall very unlikely to be a translation artifact (including AI translation). We again have multiple lines of evidence:
All the most prominent signs of AI I observed in English are preserved verbatim in the Italian version, as well as in other translations.
The Italian version of the current encyclical also gets flagged as AI by Pangram (actually more so than the English version), though I’m not aware of academic research or rigorous testing of Pangram’s service when applied to Italian)
Backtesting AI translation of past encyclicals get 0% on Pangram
The specific AI used is most likely Claude, judging by both textual and circumstantial evidence.
Different sections of the encyclical have very different rates of apparent AI usage. This indicates to me that some cardinals used AI assistance for this encyclical and many (probably including Pope Leo himself) didn’t.
Each individual piece of evidence might be explained away, but the consilience of evidence across multiple angles and sources is in my opinion very hard to dismiss collectively.
When you said “however the AI usage is likely substantial enough that it’s not the result of minor brushups or AI translation”, I took that to mean that it’s not the result of humans doing the thinking and AI brushing up the text. In other words, you’re saying that AI has determined some of the actual content/thinking in the encyclical.
Is that what you’re claiming?
Oh sorry! When I wrote that, I wasn’t trying to take a position on whether the actual content/thinking was determined by AI. I just wanted to emphasize that the degree of AI involvement wasn’t minor, like just use AI for grammar and typo checks.
That said, I believe a lot of human effort was also put into the text, and almost certainly the very high-level structure/arguments/ideas came from humans.
I don’t have a strong position on whether the thinking/content was determined by AI. And the evidence doesn’t really let us rule out either hypothesis.
If you’re fine with speculations, my guess is that the answer is “no” for a strong definition of “determined”, but “yes” for a weaker claim like “meaningfully affected.”
In particular I think AI is able to smooth over language far more than they can substitute for actually good thinking, at least as of mid-2026. So (speculating) there are probably subsections where the Vatican wanted to say something in the outline/early drafts but it doesn’t quite look right (because the thinking isn’t quite right), and they were able to smooth it over using AI to seem palatable in “group sycophancy” ways. And the final thinking would’ve been clearer if they forced themselves to rewrite/think over things until it could sound smooth with human levels of clear thinking/polish tradeoffs, rather than AI-assisted levels.
But this is just speculation, of course.
Some other people in our circles have already complained about things that didn’t quite make sense in parts touching on AI ethics and AI consciousness. But ignoring that (obviously the Vatican has various biases, and so does our crowd), I thought the Babel/Nehemiah contrastive pair (Par 7-10) had a sort of artificiality to it. Like it sounded nice (unless you’re allergic to AI public writing, like me), but if you actually drilled down into what the metaphor was doing and then critically contrasted it with either a) a plain-language reading of the Biblical stories themselves or b) how people historically talked about Nehemiah, or c) what goes on in the world of AI right now, it doesn’t quite make sense.