Evidence that the first papal encyclical on AI was substantially written by AI

Linch

May 26, 2026

In the wee hours of Memorial Day, my friends and I stayed up past 4:30 AM California time to listen to the announcement of Pope Leo’s first encyclical, Magnifica Humanitas, on safeguarding the human person in the time of artificial intelligence. We were excited albeit sleepy, eagerly anticipating the event and upcoming essay by the world’s foremost religious authority on a question so central to our world. Still we were an odd audience for this presentation: none of us are practicing Catholics, and most of us didn’t really know what to expect.

I thought Pope Leo’s own speech was good, and addressed the current moment in AI with some of the seriousness it deserves. I thought the other speeches, including by Chris Olah, were less impressive. But that’s okay, I’m not the target audience!

A specific cardinal’s point struck me, however:

Cardinal Parolin made much of a specific prepositional choice in the subtitle: “sulla custodia della persona umana nel tempo dell’intelligenza artificiale,“ which the live translator translated to something like “on the safeguarding of the human person in the time of AI,” and not “sull’intelligenza artificiale“ – “on AI.”

This was supposed to be a big deal. “In the time of AI” supposedly centers the human person in the theological narrative, while a mere first papal encyclical on AI focuses too much on the technology itself and not on human and societal reactions. A fascinating position!

Though as my subsequent analysis will demonstrate, perhaps a more apt preposition here is “by.” As in, the world’s first papal encyclical written in large part by AI.

My article has the following claims, each of which I hope to convince you of:

Significant fractions of the recent papal encyclical are written by AI. 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.

Significant fractions of the recent papal encyclical are written by AI

I was initially very excited to read Pope Leo’s first encyclical, a long treatise on maintaining humanity in the age of AI. The intersection between AI and societal response is one of my greatest intellectual and personal interests, and it’s both exciting and a relief for the world’s foremost religious authority to share a substantial interest in my personal and career obsessions.

Nonetheless – as I kept reading – certain lines jumped out at me as too smooth, too triadic, too… inhuman:

“Technology has the power to heal, connect, educate and protect our common home; but it can also divide, exclude and generate new forms of injustice. In the abstract, technology in and of itself is not a solution to humanity’s problems, just as it is not inherently evil. In practice, however, technology is never neutral, because it takes on the characteristics of those who devise, finance, regulate and use it.”

“We must, then, avoid the “Babel syndrome,” namely the idolatry of profit that sacrifices the weak, a uniformity that neutralizes differences, and the pretense that a single language — even a digital one — can translate everything, including the mystery of the person, into data and performance. The risk of dehumanization — of building a future that excludes God and reduces the other to a means — is an ancient and ever-new temptation that today takes on a technical guise.”

“A dialogue with such kinds of knowledge does not diminish the power of the Gospel. On the contrary, it makes it possible to identify with greater clarity what genuinely fosters the lives of individuals and communities.”

“give stable form to this insight at the ecclesial and international levels, while bearing in mind the growing gap between rich and poor countries and the need for policies that genuinely promote more humane living conditions for all.”

“We cannot be satisfied with merely calling for the moralization of machines — the so-called “alignment” of AI with human values — without also having the courage to insist on a further condition: the possibility of openly discussing the ethical frameworks involved and subjecting them to shared standards of social justice”

I read AI-generated text as part of my job regularly, and believe I have acquired a very good intuition for discerning AI-generated text from those by humans, including in formal writing (both academic and otherwise). Still, any individual phrase that seems AI-generated can be a false positive on my end, the result of an oversensitive nose for AI1. However, the sheer density of these phrases and overall tone in specific paragraphs seem implausibly all a random artifact.

Still, I can definitely be wrong here, and you should not believe my gut intuitions or judgments of vibes on authority (“Trust me bro”).

Intuitions, self-proclaimed expert judgments, and loose verbal reasoning can be a good starting point for an investigation, but if we want any confidence in our conclusions, we need to investigate further and more systematically.

Statistical Evidence and Tells

Three common and well-known tells in AI writing — sometimes genuinely deployed by humans but nowhere their profligate use by AI — are the regularity of em-dashes, the high frequency of specific words like “genuinely”, and the tendency to repeatedly invoke tricolons.

Let’s examine each of them in turn:

Em-dashes

The em-dash (“—”) is punctuation that’s by far most strongly associated with AI. It is also used 127 times in Magnifica Humanitas, much more than previous encyclicals.

Magnifica Humanitas: 127 times em-dash, 6 times en-dash (–), the latter all in citations.2

Dilexit Nos (2024): 0 times em-dash, 26 en-dashes, including 2 in citations. Comparatively long document.3

Laudate Deum (2023): 0 times em-dash, 12 times en-dashes. Much shorter. Also not officially an encyclical.

Fratelli Tutti (2020): 0 times em-dash, 46 en-dashes, of which maybe 5-10 are in quotes or citations. Note that this is 50% longer than Magnifica Humanitas.

Laudato Si’ (2016): 0 times em-dash, 25 times en-dash, of which maybe 10 are in citations or quotes (the piece overall appears to have many quotes). Similar length to Magnifica Humanitas

Lumen Fidei (2013): 26 times em-dash, 0 times en-dash. Some em-dashes in citations.

Note that this comparison actually understates the weirdness of the em-dashes in Magnifica Humanitas. For example, in Lumen Fidei, many of the em-dashes function similarly to speech colons in standard English. A typical use looks like

What was handed down by the apostles — as the Second Vatican Council states — “comprises everything that serves to make the people of God live their lives in holiness and increase their faith. In this way the Church, in her doctrine, life and worship, perpetuates and transmits to every generation all that she herself is, all that she believes.”

Using em-dashes as speech colon replacements is moderately common in formal (human) English writing, but essentially absent in LLM-English. I also did not notice em-dashes used this way in Magnifica Humanitas (though with 127 instances, it was annoying to check all of them!)

“Genuinely”

“Genuinely” is a phrase repeatedly used by Anthropic’s model Claude. It is extremely obvious to anybody who regularly uses it. It’s gotten so bad that in leaked system prompts, Anthropic attempted to explicitly forbid Claude to use that word!

1.4 Tone & Formatting

[...]

Claude avoids saying “genuinely”, “honestly”, or “straightforward”. 4

As far as I could tell, this injunction does not and did not work.

Indeed, Anthropic’s own “Claude Constitution”, which many people believe to be substantially AI-assisted, used the phrase “genuinely” 33 times and genuine overall 50 times (inclusive).

How often is the phrase “genuinely” used in Magnifica Humanitas?

Less so than in Anthropic documents, but substantially more than past papal writings.

Specifically “genuinely” was used 9 times and “genuine” overall (inclusive) 22 times in yesterday’s encyclical, compared to 0 and 5 times, respectively, in Dilexit Nos, which is of similar length. Across a number of other encyclicals I scanned, the highest occurrences were 3 and 10, respectively.

These tells are all statistical. Any individual instance of “genuine(ly)” is plausibly a result of normal human communicative intent that is, well, genuine. But the sheer frequency of these occurrences, vastly out of accord with prior norms and normal human speech, is strongly suggestive of synthetic origin.

Is this due to subject matter?

An obvious rejoinder you might have is that word choices in essays are naturally not independent of subject matter. And it sure seems like an encyclical on AI might meditate more about genuineness more than other encyclicals! For example, an essay on AI deepfakes might be much more concerned about what makes a video “genuinely human” than an essay on climate change.

To investigate this hypothesis, I dived specifically into each use of genuinely in this encyclical:

[Par 23] “A dialogue with such kinds of knowledge does not diminish the power of the Gospel. On the contrary, it makes it possible to identify with greater clarity what genuinely fosters the lives of individuals and communities. Following this perspective, Pope Francis [...] recognizes the importance of listening to scientific research and of encouraging a serious and honest debate among experts while welcoming a diversity of opinions.”

“Genuinely” does not seem critical here, nor specific to questions of AI and authenticity.

[Par 35] The establishment of the Pontifical Commission Iustitia et Pax should also be seen in this light as an attempt to give stable form to this insight at the ecclesial and international levels, while bearing in mind the growing gap between rich and poor countries and the need for policies that genuinely promote more humane living conditions for all.

Also not critical here.

[Par 40] In his social Encyclical Caritas in Veritate, Pope Benedict XVI sought to reassess and expand the concept of development presented in Populorum Progressio, interpreting it in light of globalization. He noted that such development should translate into “real growth, of benefit to everyone and genuinely sustainable.” [42]

Appears to be in a quote, so will give it a pass.5

[Par 57] Along with a greater awareness of the value of every human person and their rights, recognition of minority rights has also grown. Yet, there is st

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