AI Slop and Evidence about Evidence: Why Philosophy Journals Should Reject AI-Written Prose

I don't want to read your AI-generated email. Lots of reasons why, but here's the core of it: I want the text to reflect your thoughts. I want to know that you, the human, actually had those ideas and had them authentically enough to express them in exactly the form I see on the page. For personal emails, I want this for personal reasons. For philosophically substantive emails, I want this for evidential reasons. Philosophy journals should also want human-generated rather than AI-generated text for the same evidential reasons.

There Probably Are Good Reasons You Phrased It the Way You Did

The evidential reason: Human experts think differently and better than LLMs. Their word choices, even subtle ones, reflect sensitivities that they might not themselves be aware of. Typically, an expert's prose will be more sensitive to the matters on which they are expert than the output of a language model. When I receive a philosophical email from you -- and more so when I read a journal article -- I want your expert word choices, not blurry LLM approximations.

You might object as follows: Of course I read the LLM outputs before sending, and I wouldn't send the email, much less submit the article, unless I endorsed every word! So, the objection continues, you did think the thoughts expressed. The text reflects your expert best judgment -- maybe even something better than your expert best judgment: your expert best judgment combined with the expertise of an LLM.

I reply: There's a huge cognitive difference between nodding along while reading something and actually productively generating a text. Two reasons: First, once the text is on the page, it's easy to passively let the approximate word suffice, rather than thinking about word choice in the same effortful, active way we do when generating prose de novo. Second, as I suggested above, I doubt that human beings, even experts, have a good sense of all the factors that shape word choice -- everything they're being sensitive to. You would have phrased it slightly differently, and even if you don't know that, or why, a different signal is sent and received.

Evidence about Evidence

I'm talking about evidence about evidence: meta-epistemology. Your email or your article presents evidence for a particular philosophical view (alternatively, evidence that you support a particular philosophical view). In a simple world, I could evaluate this evidence entirely on its face: How good is the proposed view? But in the actual, complex world, it helps to have evidence about the quality of the evidence. The fact that you, an expert human, generated the text is evidence that the view is worth thinking about -- more so than if the text were generated by an LLM. This holds even if the text is exactly the same, which of course it wouldn't be.

An increasingly large part of the function of journals is to provide evidence about evidence -- the value of their imprimatur. The fact that an article appears in Nous or Ethics is evidence that it has been through rigorous review and was judged worthy by several expert humans applying unusually demanding standards of quality and importance. Its appearance in those journals is thus evidence (imperfect of course!) that the reasoning is of high quality and the arguments worth taking seriously.

Similarly, if I know that an email or an article was written by a respected colleague, reflecting their positive creative exertion in trying to choose the right words, guided by their intuitive expertise in how to phrase things, I have better reason to take it seriously than if I know that it was generated by an LLM and reflects only their passive after-the-fact assent.

Philosophers sometimes suggest that we shouldn't care if an argument was human-generated or AI-generated -- that insisting on human-generated prose is fetishizing personal human interaction rather than facts and argument quality. In a way, that's true: A sound argument is a sound argument. Similarly, we shouldn't care if an article was written by David Chalmers and published in Philosophical Review or whether it was written by someone with no institutional affiliation and published on an obscure blog. If the argument is good, it's good -- of course, of course!

But at the same time, we have limited attention, limited time, limited ability to understand the nuances when matters drift even a little from our tightest foci of expertise, and in these cases it's helpful to have meta-evidence. What should I read? How far should I trust the author has the details right, versus how much should I pause critically and chase down independent sources? How much should I let their way of phrasing things, their habitual patterns of thinking, the presuppositions hidden in their word choices and sentence structures, slip gently into my brain, silently strengthening my own associations and predilections?

An Example

To better capture the phenomenon I have in mind, I've selected a random sentence from my most recent outbound email (as of the first draft of this post):

This lack of self-respect is manifested both in her willingness to consider being killed to somewhat improve Josie's life and in her incapacity to develop desires and interests of her own independent of Josie's, as manifested by her being content to rot in a junkyard once her usefulness to Josie has ended.

The topic is Klara from Klara and the Sun, the story of a robot servant who is designed to be utterly dedicated to serving the human girl to whom she has been assigned as an "artificial friend". (I discuss the case in detail here.)

I asked ChatGPT "high" to "write the sentence better", and here is the output:

This lack of self-respect is evident both in her willingness to contemplate her own destruction for the sake of a modest improvement in Josie’s life and in her failure to develop desires or interests independent of Josie’s—as shown by her contentment to decay in a junkyard once she is no longer useful to her.

At first glance, the revised sentence is slightly better -- smoother, more natural. My double use of "manifested" was awkward, and rereading it now I think I should have changed at least that stylistic detail. I could even see approving the LLM output as expressing my own thinking about Klara, if someone asked whether it accurately reflects my view.

However, in several subtle ways the edited version is philosophically worse.

I wrote that Klara's lack of self-respect is "manifested" in her willingness to such-and-such. ChatGPT replaced "manifested" with the slightly more common and natural "evident". Close enough, seemingly? But no. They differ subtly, in an important way. "Manifested" is ontological, "evident" is epistemic. "Manifested" emphasizes the relation between the underlying lack of self-respect and the particular thoughts Klara is having -- that those thoughts arise from a broad insufficiency of self-respect. "Evident" emphasizes that the particular thoughts are evidence of that attitude. Either word might do, but "manifested" is better: I'm not really talking about what evidence we have that Klara lacks self-respect but rather what types of thinking constitute lack of self-respect.

The second change: "consider being killed" is replaced by "contemplate her own destruction". The LLM phrasing is again a bit smoother, more common, more natural. And again, it's not exactly wrong; it's a phrasing I might easily approve. But on careful thought, my original phrasing is again truer to what I really want to say. "Consider" suggests that Klara is seriously weighing the choice. "Contemplate" is vaguer: She might only be thinking idly about it. "Being killed" is vivid and suggests that someone else would be the agent of her death. "Her own destruction" is not as vivid: "Destruction" flattens things a little, morally and emotionally. And it's not quite as clear that someone else, rather than Klara herself, would be the agent of her death.

And so I could continue with the other revisions.

I am focusing on line-by-line prose, not main ideas. Main ideas are a different issue and require a different analysis. One might wrongly think that only the main ideas are important. My point here is that subtle differences in line-by-line prose matter too, and that an LLM's word choices will differ from an expert's, and that there's reason to respect experts' intuitive word choices. If experts yield their writing to a language model, it is probably too easy for them to allow their expert word sensitivities to be blurred away.

Thus, people should prefer human-expert-generated prose in emails and journal articles, for at least this meta-epistemic reason. That a passage was written by an expert human is evidence that the prose accurately tracks important nuances. Being hand-written by a human expert is an (imperfect) high-level indicator of quality.

Those of us who receive emails, or read journal articles, or even who edit and referee journal articles cannot evaluate every sentence with the same close attention to nuance I demonstrated in my example above. We often need to read at two minutes a page, not two minutes a sentence. We all reasonably rely to some extent on the writer's expertise in phrasing.

This is one reason journals should require human-written rather than AI-written prose, even if the latter is endorsed post-hoc by a human expert.

Using LLMs Well

This is not a call for blanket rejection of the use of LLMs in philosophical (or other) writing. They can be useful for generating criticisms and for suggesting topics and readings to explore, as long as one takes the outputs with a cautious grain of salt.

They can also be useful for copyediting after the initial prose is written -- but only either

(a.) for minor grammatical/spelling corrections, or

(b.) in a thoughtful, effortful way, ideally with mechanisms to reduce passivity such as (b.i) having to type in any adjustments by hand rather than simply approving them in a revised document and (b.ii) receiving suggestions from more than one LLM to force you to contemplate several alternatives rather than simply accepting one, and

(c.) in a way that preserves or amplifies, rather than averages away, your distinctive way of expressing yourself.

Such an approach to LLM-aided revision is time-consuming rather than time-saving, a matter of "cognitive onloading" rather than "cognitive offloading" -- an occasion to actively consider your word choice line by line, via input from a few not-very-insightful copyeditors. Had I subjected my email to LLM copyediting, I'd have noticed the awkward double use of "manifested" and consequently considered whether that was the best way to express myself. The result of AI-assisted copyediting following principles (a)-(c) might be prose that even more accurately reflects your best individual thinking than your independently produced drafts.

This argument against using LLMs to generate expert prose is bounded and possibly temporary: If someday LLMs surpass human experts at subtle word choice, this particular argument will no longer apply -- though other excellent reasons might remain not to use LLMs for expert prose writing.

[Mud: image source]