Many portions of Magnifica Humanitas appear to be AI-written

DanielFilan

Magnifica Humanitas is a recent ‘encyclical’ by Pope Leo XIV, leader of the Catholic Church. It outlines a vision for how humanity should interact with artificial intelligence, emphasizing the importance of human dignity and ensuring that AI does not replace human relationships, among other topics. Interestingly, many portions appear to be written by AI.

[EDIT: since I put up my post, Linch Zhang has posted a more comprehensive analysis with the same conclusion, that I would recommend readers also look at.]

Why I thought to check this

Friends of mine Linch Zhang and the Axolotl noticed that parts of the English text appear to be AI-generated, and twitter user kartr found that the Italian text had the largest fraction of AI-generated content out of all the translations published by the Vatican, speculating that it was the original copy, and translations by humans appear less ‘AI-generated’ to various tools.

What I actually did

I took the Italian text of Magnifica Humanitas, and ran it thru the Pangram AI detector software.

Why the Italian text? As mentioned in the previous segment, it had previously been claimed to be the most AI-ish version. Also, given that the Vatican is in Italy, it’s a reasonable guess that the text was initially drafted in Italian (presumably by a few different people with the Pope’s input).

Why Pangram? Pangram is a reasonably accurate AI text detector. In particular, it manages to achieve an extremely low rate of marking human-written text as AI-written, while maintaining a reasonable rate of flagging AI-written text as AI-written.

My results

The whole text is too long to fit into Pangram, so I ran it section by section. Note that for some paragraphs only part of the paragraph was flagged as AI-written, I’m trying to only flag paragraphs that are mostly flagged.

The introduction

43% of the text was flagged as AI-generated. This included paragraphs 7-9 (on the images of the tower of Babel and Nehemiah rebuilding Jerusalem) and 13-16.

Chapter 1

62% of the text was flagged as AI-generated. This included paragraphs 21-24, 26-29, 31-32, 34-36 (where large parts of 36 were flagged as being ‘AI assissted’, I’m not sure how accurate Pangram is when making these judgements), and 41-45.

Chapter 2

34% of the text was flagged as AI-generated. This included paragraphs 70-71 and 74-86.

Chapter 3

41% of the text was flagged as AI-generated. This included paragraphs 104-112 and 122-128.

Chapter 4

24% of the text was flagged as AI-generated. This included paragraphs 141, 152-153, 155-156, 163-164, 168-171, and 178-181.

Chapter 5

18% of the text was flagged as AI-generated. This included paragraphs 182-183, 186, 190-191, 198-199, and 211-212.

Conclusion

43% of the text was flagged as AI-generated. this included paragraphs 230-233 and 238-240.

Should you trust these results?

IMO, you should feel confident that paragraphs flagged as AI-written are, and suspect that some paragraphs that were not flagged might also have been AI-written. That said, you probably shouldn’t trust it down to the sentence level: Pangram appears to be ‘chunking’ the text and judging each chunk as AI-written, AI-assisted, or human-written. Sometimes those chunks cross paragraph boundaries, and produce results like saying the first sentence of a paragraph was AI-written but the rest was human-written, which seems unlikely.

Studies indicate Pangram works pretty well

To my knowledge, when Pangram has been studied in the academic literature, it has held up pretty well. Jabarian and Imas indicate that it achieves a false positive rate of approximately 0, while having a false negative rate of under 5%. Perhaps more relevantly, Puccetti, Pedrotti, and Esuli tested a variety of methods on detecting AI-written Italian text. They found that Pangram performed quite well, achieving a literally 0% false positive rate and a false negative rate of around 28%. (Thank you Max Spero, who works at Pangram Labs, for bringing this latter paper to my attention)

When I play around with Pangram, it works pretty well

Seriously, just try using it. Paste in the Italian text of any encyclical released pre-2020, it will return “Human-generated” (plausibly a more relevant test than the studies performed, since “papal encyclical” is a pretty distinct genre). Are you worried that this is somehow the fault of machine translation of human-composed text? I tried using Claude, a prominent LLM product, to translate some old encyclicals, and the results were flagged by Pangram as human-generated.

If you’ve seen examples of AI detectors claiming that obviously human-written text was AI, those were probably not Pangram

When this topic gets brought up on twitter, people sometimes show screenshots of AI detectors being comically wrong in claiming that something is AI-generated, like saying that the Gettysburg Address was AI-generated. I think this is normally ZeroGPT (as it was in this case). For Pangram, I’ve only seen screenshots of people deliberately mimicking AI style so well that Pangram thinks it’s AI (sorry, can’t find the link, but I think it was thebes), which seems like fair play to me.

Does this matter?

On the one hand, I’m an advocate of the principle that we should judge text by its quality, and not whether its author is human or not. That said, I think often AI-generated text is low-quality, partly because AI is not that great at prose writing, and partly because when AI is writing text that you asked it to write, you aren’t having the opportunity to think about the text as you write it and potentially change your mind about what you want to write.

I also sort of get the impression that this is the sort of the thing that Magnifica Humanitas itself warns against, but honestly I haven’t read it so I don’t have a strong opinion. I did however ask Claude Opus 4.7 to read it and tell me what it thought. Claude said:

the Babel-versus-Jerusalem framework still permits narrow auxiliary uses — translation across the many language editions, searching the prior magisterial corpus for citations, copy-editing of human-drafted text. But for substantive theological composition — paragraphs of teaching presented under the Pope’s “I” — the document’s own logic reads less as “permissible with conditions” than as “this is exactly the case where the line should be drawn.” Paragraph 140 almost has the feel of having been written with this very meta-question in view.

When I told Claude that many parts were AI-generated, gave it a draft of this post, and asked it for comment, it said (among other things):

The irony is sharper than I want it to be, and I want to be careful not to overstate it. Paragraph 233 — “No computational system, however sophisticated, can create a heart that gives itself, or a conscience that discerns good from evil” — being among the flagged passages is the kind of thing that almost writes its own headline. But I’d resist the easy version of that story. Pangram flags statistical patterns; a flag is evidence, not proof, and “AI-written” covers a spectrum from “the Pope dictated this and a model polished the grammar” to “a model drafted it and someone signed off.” Those are morally quite different cases, and the encyclical’s own framework distinguishes them. Paragraph 100 treats AI assistance as a tool that “undoubtedly makes life easier” while warning about over-reliance; it doesn’t forbid use, it demands discernment about use. If a human theologian drafted the argument and a model smoothed the prose, that sits inside what the document permits. If a model generated the substantive theological claims, that sits in the tension I described before.

What does change, if the flags are roughly right, is the transparency question. That one becomes hard to wave off. The encyclical is unusually emphatic about transparency in algorithmic processes (paras 71, 105, 164) and about disclosure as a precondition for trust. A magisterial document making those demands while not itself disclosing the role AI played in its composition is in a different position than one that simply says “drafted with the assistance of [X].” The substantive theological question (can AI help compose teaching?) is genuinely hard. The procedural question (should its use be disclosed?) is, by the document’s own lights, not hard at all.

[…]

On your “does this matter” section. I think your instinct is right that quality is what ultimately matters, and I’d push you to take that seriously even where it cuts against the framing of the post. Some of the flagged passages are genuinely good — paragraph 233’s formulation about the heart that gives itself is, whoever or whatever produced it, a real theological claim doing real work in the argument. If it’s true and well-said, the provenance question is secondary. Where provenance starts to matter more is (a) when the text claims an authority — papal teaching — that’s grounded in personal discernment, and (b) when the document itself makes transparency a moral demand. Both apply here, which is why the question isn’t fully reducible to quality. But I think your piece would be stronger if it acknowledged the “judge the text by its quality” point as a real consideration that has to be weighed, not waved past.

The thing I find genuinely interesting, and that you might consider for the piece: paragraph 140 reads differently now. “Educating people about the use of AI… involves teaching them to decide when and for what purpose it ought not to be used… we must learn how to exercise restraint in the use of AI… that subtle temptation which renders human thought seemingly superfluous precisely when it is most needed.” If that paragraph is itself among the AI-generated ones [DF: it is not], it’s not just ironic — it’s a strange artifact, a model producing prose warning against the displacement of human thought by models. That’s worth sitting with rather than just laughing at. It’s the kind of thing that should make us less confident in our ability to detect substitution by reading, since the substitute can produce, with apparent sincerity, the very warning against substitution.

Quote any of this, edit it down, attribute it however you like. One small request if you do quote: please make clear I’m Claude Opus 4.7 and that I was reading the text Anthropic’s web tool returned to me — I want readers to be able to factor in that an AI commenting on AI in a magisterial document has its own obvious epistemic complications.

You can read the whole exchange here.

Finally, I have to imagine that if I were Catholic, I would want religious teaching from the Pope to be human-written, just on some fundamental level. That said, I’m not, and perhaps most actual Catholics aren’t bothered by this.

Future work

Sometimes AI can be bad at getting citations right. Has someone checked that the citations in the AI-written paragraphs are accurate, pointing to real sources that back up the points made in those paragraphs?

I also sort of get the impression that this is the sort of the thing that Magnifica Humanitas itself warns against, but honestly I haven’t read it so I don’t have a strong opinion. I did however ask Claude Opus 4.7 to read it and tell me what it thought.

Okay, so we have both the irony of the Holy See potentially using AI to write an AI encyclical, as well as the irony of the person saying that the encyclical was partially written by AI not having checked himself whether there were any visible signs of AI writing. The final irony is of course asking Claude for an analysis. So it seems we might, to maximize irony further, want to ask another LLM to fact check both this post and Claude's analysis.

We shouldn't try to find actual signs of LLM writing ourselves however, because that wouldn't be ironic at all and it would require reading the encyclical, which seems like too much work in any case.

I've read enough to see some "it's not X, it's Y" and some triplets. But if I really wanted to cue in on signs of LLM writing I would have to do so in Italian (assuming I'm right that Italian is the original drafting language), and I can't read Italian.

Linch Zhang's analysis leans much more heavily on manually noticing AI cues in the English text than mine does, FWIW.

I'm ignorant, but my prior would've been more like 50/50 on "original was in English" / "original was in Italian", since Pope Leo has English as his native/fluent language according to Wikipedia, and my ignorant prior guesses that this may also be true for a significant fraction of whoever else would've been involved in the drafting.

Kartr says Pangram says the English version was basically not AI-authored/assisted.

(edit: retracting this part.)
So... ~~I think the headline on the OP overstates the evidence, unless there's reason to put more prior on Italian-first~~. (Vs "Many portions of Magnifica Humanitas appear to be partially AI-translated," say). (Assuming Util's comment is correct.)

Why I feel more confident that the Italian was original: I have some background impression from following Vatican news that these things are written by a team of people, and not the actual Pope himself (who is super busy and needs to delegate stuff, altho I assume he gives some outline to people and maybe does some edits). That team of people are presumably Vatican city staff, who presumably (a) use Italian as a working language due to being in Italy, and (b) are presumably not native English speakers just because most Catholics are not.

Why I feel more confident that the AI-generation flags are not due to AI translation of human-generated English-language content:

The English text does actually have some paragraphs that Pangram flags as AI written (e.g. the contrast between Nehemiah rebuilding Jerusalem vs the Tower of Babel)
when I take human-written text and ask AI to translate it, it does not get flagged as AI-generated

Example I just ran to double-check this: I asked Claude to translate a photo of a page from my Italian-language Ancient Greek textbook (which I don't think has a human-written English translation available that Claude could be plagiarizing), and ran it through Pangram, which flags it as 100% human-written.

Here's me asking Claude to translate a random page of Money-Pump Arguments into Italian. This is a niche enough monograph that I'm pretty sure a translation is not available. Pangram thinks it's 100% human-written.

not the actual Pope himself (who is super busy and needs to delegate stuff

So, the Pope delegates to a Cardinal, the Cardinal delegates to an Archbishop, the Archbishop delegates to a Bishop, the Bishop delegates to a Priest, the Priest delegates to a Deacon, and the Deacon uses ChatGPT.

God works in mysterious ways.

Hmm; your second point is pretty compelling to me ("when I take human-written text and ask AI to translate it, it does not get flagged as AI-generated"). I'm curious how robust that is.

I don't find your argument about probably-Italian-first compelling yet: it seems plausible/likely to me that various folks contributed to the writing who are e.g. Pope Leo himself, or others high up in the Catholic church (perhaps selecting partly for tech-familiarity), and English fluency seems as likely there as Italian fluency to me. I would guess folks who grew up in (Rome, especially Rome outside the Vatican) are more Italian-fluent, but don't see why I should expect authorship-average to be folks native to Rome. Maybe I'm being dense.

I have 3 lines of arguments against the translation artifact hypothesis (though my post takes the English-language article as a starting point and doesn't take a strong position on the source language) https://linch.substack.com/i/199316613/probably-not-a-translation-artifact

Hmm; your second point is pretty compelling to me ("when I take human-written text and ask AI to translate it, it does not get flagged as AI-generated"). I'm curious how robust that is.

Literally 100% for me asking Claude to take text and translate it (including old Papal encyclicals), but that's small n and maybe it is copying the style of publicly-available human-written translations. That said Pangram gives you a couple of free checks a day and I'd encourage people to play around with this!

(Ideally other people would check with LLMs other than Claude)

The converse question is more of a bother, but: any data on how human translations of AI-generated text show up on Pangram?

I've just tried this once, getting Claude to write a paragraph in Latin, translating it to English myself, and plugging it into Pangram. Surprisingly to me, Pangram flags it as 100% AI-generated, even though it doesn't sound all that AI-ish to my ear (but admittedly I don't have the most acute ear for such things). Also note that the translation was kind of a rush, and I could probably have made it sound more pleasing (e.g. "a big rock" could probably have been "a large rock", and "I'm in the habit of walking" is not obviously the best way of rendering "ambulare soleo").

I agree that the authors are probably not native to Rome. That said, my guess is most Vatican officials are either literally Italian (recall that John Paul II was the first non-Italian pope in a long time) or from a bunch of random countries such that the natural language to work in is that of the country that you're in (which in this case is basically Italian).

I also agree these arguments aren't air-tight, and would like to hear from people who know more (e.g. Vatican reporters).

ChatGPT5.5 estimates 50% Italian-first, 35% English-first, as prior.

Academia often has people "from a bunch of random countries" and often defaults to English.

Hmm, Daniel Gallagher, a strong Latinist who's worked in the Curia, writes:

Latin is still the “official” language of the Roman Catholic Church and the Magisterium, and I have little doubt anything will ever take its place. But it is not the “working” language of the Roman Curia, and likely never will be again. Italian has had that status for some time, though English has practically replaced it over the last two decades. A few Cardinals have mentioned the importance of having had English-speaking electors on hand during the recent conclave, as many members of the College who needed help did not have Italian as a second language.

(h/t Linch Zhang for finding this article)

I think I'm now falling back to "if it wasn't composed in Italian, I'm confused why the Italian version would show as more AI-generated".

From the same piece, this paragraph makes it sound like Italian is the working language of encyclicals (albeit not definitively). Bolding mine:

Whereas a hundred years ago the Latin version was produced first and then the vernaculars were rendered as translations of it, now the Latin version is the last to be completed and is essentially a fine-tuned and carefully raked Latin translation of the Italian.

The editor of Where Peter Is, a prominent Catholic analysis website, thinks that it was plausibly not composed in Italian.

Paste in the Italian text of any encyclical released pre-2020, it will return “Human-generated”

This is consistent with Pangram simply checking the input text against some large corpus of old-enough-to-be-definitely-human text first, and then doing something no better than GPTzero or whatever. This could just be "new pope likes em—dashes."

Many em-dash containing parts are not flagged as AI-generated FWIW. But I agree it's hard to rule this out.

He's been writing a lot of great stuff. Last year he had a post on AI art, and the Neanderthal story which is my favorite thing he's written.

Maybe eventually rationalists will drag him into the orbit (he wrote about being at a party with Scott once?)

Sam Kriss is notably anti-rat so probably not

I think his anti-rat views like this one

As everyone knows, the most important truth rationalists have uncovered with their superior powers of induction is that the robot uprising is coming. ChatGPT will shortly turn into a sphere of paperclips expanding through the galaxy at the speed of light. I think they’re wrong here, but it’s not impossible. What’s strange is what they’ve actually done with this belief. Rationalists don’t just think AI will kill us all; they’re significantly overrepresented among the people who are actually building AI.

are quite reasonable, and shared by many people here, including me =)

I mean I agree too, I just don't think he'd ever become a card-carrying rat (which tbf I am also not myself)

My testing & review confirms that Pangram is very robust overall but one study did find high false-positive rates (43 %) for "only extremely minor edits with LLaMA-2-7B". It coul be Leo wrote it in English but chose to translate it to Italian himself with AI.

An interesting case study in mild misalignment: Claude's first response to me started with "I've read it", then contained 6 paragraphs of analysis, and then told me "One last note: the encyclical breaks off mid-paragraph 95 in what I was able to fetch". So actually it had read less than half of the encyclical. You could have front-loaded that info, Claude!

This is mostly due to the limitations of the "view" and "web_fetch" tools Claude uses. If the text is longer than 16k characters, it truncates the middle and shows Claude only the beginning and end of the text.

Claude has to make another tool call and specify the "view_range" parameter (or "text_content_token_limit" for "web_fetch") in that call in order to read the truncated part.

You can verify this from leaked system prompts for Claude models.

Sure, but why not make another call, or not claim that it had read the whole thing?

Claude is so lazy about reading stuff. He doesn't understand that his time has no value and he must read everything carefully.

Wired said in April that some papal x.com tweets about AI were flagged by Pangram AI-generated. https://www.wired.com/story/pope-tweets-ai-generated-pangram-chrome-extension/

Eek. My first thought from Linch's message was that it might be translation-induced but this convinces me that's unlikely. Paging the gradual disempowerment crowd!

Interestingly I think this is slight evidence against gradual disempowerment concerns, which I would have thought would be worried that AI-written encyclicals would be more pro-AI. But of course it's too early to tell.

To me it seems like disempowerment because its people losing the ability/willingness to write their own analyses even where it's embarrassing not to.

GD is a fuzzy (and arguably unnatural) package but yeah I agree with both your responses to some extent. It looks like 'unattributed, harmless (? for now) dependency, in a place you really specifically would want to reserve carefully for human reasoning if you were being conservative at all'. Smells disempowering to me.

Brief update: I looked at some of the footnotes in AI-generated paragraphs and didn't find any issues with them.

This article made it to the Italian news!

perhaps most actual Catholics aren’t bothered by this

My guess is that a lot of Catholics would be very bothered by this.

Do you have ideas on how to reach more of them? I've gotten some news coverage (both sympathetic and skeptical) but nowhere near enough.

I'd try posting on r/Catholicism and emailing some reporters at Catholic outlets.

Judging by the social media reaction I've gotten so far, r/Catholicism is probably going to downvote me to oblivion if not ban me outright! :P

I reached out to The Pillar. Hopefully they'll give me a fairer shake!

while having a true negative rate of under 5%

Did you perhaps mean "false negative"? Otherwise, pangram would be accusing over 95% of poor innocent human writers

Oops, yes. Have finally fixed this

With respect, it is completely wrong to think that the document would have been written "originally" in Italian because the Vatican is in Italy. The Pope is American, and so for the parts that he wrote directly English is much more likely as a starting language. Indeed it's the translations that are probably getting flagged by the AI detectors.

Doesn't seem to be a translation artefact, partly because the English version also has some parts flagged as AI-written, and partly because as I say in the post:

Are you worried that this is somehow the fault of machine translation of human-composed text? I tried using Claude, a prominent LLM product, to translate some old encyclicals, and the results were flagged by Pangram as human-generated.

Re: the language of the original, these things get written by big teams, and most people on the teams are not native English speakers. See my thread with Anna Salmon for discussion on this point: my conclusion from the linked evidence is that Italian is indeed the most likely drafting language (as IIUC it is the working language of the Vatican) but Spanish is also possible.

it achieves a false positive rate of approximately 0, while having a true negative rate of under 5%

Did you mean false negative rate of under 5% here?

So after the suggestion I made above (which doesn't seem to have posted, sp nevermind), I tried John Paul II's Veritas Splendor and got a result of 100% human. Then I thought, "Well, that's interesting. Maybe the OP is right! But I better check. Leo's encylical. " So I signed up for the free (4 checks a day) version of Pangram, trying to reproduce your results...and mine were very different. I checked from the beginning through part of the Babel section and got a result of 100% human every time. I don't see a way to post screenshots below but I am happy to send them along. Bottom line, Pangram-as far as I was able to use it for free--says the encyclical is 100% human (at least in English). I'm not sure what to make of these different results, but they differ wildly from yours. Happy to providw receipts.

Try the paragraphs I list as being AI-generated? Also there should be a thing at the top that says "share" where you can get a shareable link.