+One could argue that this is unfairly interpreting Yudkowsky's Tweets as having a broader scope than was intended—that Yudkowsky _only_ meant to slap down the specific false claim that using 'he' for someone with a Y chromosome is lying, without intending any broader implications about trans issues or the philosophy of language. It wouldn't be realistic or fair to expect every public figure to host a truly exhaustive debate on all related issues every time a fallacy they encounter in the wild annoys them enough for them to Tweet about that specific fallacy.
+
+However, I don't think this "narrow" reading is the most natural one. Yudkowsky had previously written of what he called [the fourth virtue of evenness](http://yudkowsky.net/rational/virtues/): "If you are selective about which arguments you inspect for flaws, or how hard you inspect for flaws, then every flaw you learn how to detect makes you that much stupider." He had likewise written [of reversed stupidity](https://www.lesswrong.com/posts/qNZM3EGoE5ZeMdCRt/reversed-stupidity-is-not-intelligence) (bolding mine):
+
+> **To argue against an idea honestly, you should argue against the best arguments of the strongest advocates**. Arguing against weaker advocates proves _nothing_, because even the strongest idea will attract weak advocates.
+
+Relatedly, Scott Alexander had written about how ["weak men are superweapons"](https://slatestarcodex.com/2014/05/12/weak-men-are-superweapons/): speakers often selectively draw attention to the worst arguments in favor of a position, in an attempt to socially discredit people who have better arguments for the position (which the speaker ignores). In the same way, by _just_ slapping down a weak man from the "anti-trans" political coalition without saying anything else in a similarly prominent location, Yudkowsky was liable to mislead his readers (who trusted him to argue against ideas honestly) into thinking that there were no better arguments from the "anti-trans" side.
+
+To be sure, it imposes a cost on speakers to not be able to Tweet about one specific annoying fallacy and then move on with their lives without the need for [endless disclaimers](http://www.overcomingbias.com/2008/06/against-disclai.html) about related but stronger arguments that they're _not_ addressing. But the fact that [Yudkowsky disclaimed that](https://twitter.com/ESYudkowsky/status/1067185907843756032) he wasn't taking a stand for or against Twitter's anti-misgendering policy demonstrates that he _didn't_ have an aversion to spending a few extra words to prevent the most common misunderstandings.
+
+Given that, it's hard to read the Tweets Yudkowsky published as anything other than an attempt to intimidate and delegitimize people who want to use language to reason about sex rather than gender identity. [For example](https://twitter.com/ESYudkowsky/status/1067490362225156096), deeper in the thread, Yudkowsky wrote:
+
+> The more technology advances, the further we can move people towards where they say they want to be in sexspace. Having said this we've said all the facts. Who competes in sports segregated around an Aristotelian binary is a policy question (that I personally find very humorous).
+
+Sure, _in the limit of arbitrarily advanced technology_, everyone could be exactly where they wanted to be in sexpsace. Having said this, we have _not_ said all the facts relevant to decisionmaking in our world, where _we do not have arbitrarily advanced technology_. As Yudkowsky [acknowledges in the previous Tweet](https://twitter.com/ESYudkowsky/status/1067488844122021888), "Hormone therapy changes some things and leaves others constant." The existence of HRT does not itself take us into the Glorious Transhumanist Future where everyone is the sex they say they are.
+
+The _reason_ for having sex-segregated sports leagues is because the sport-relevant multivariate trait distributions of female bodies and male bodies are quite different: men are taller, and stronger, and faster, and have bigger lungs. If you just had one integrated league, females wouldn't be competitive (in the vast majority of sports, with a few exceptions [like ultra-distance swimming](https://www.swimmingworldmagazine.com/news/why-women-have-beaten-men-in-marathon-swimming/) that happen to sample an unusually female-favorable corner of sportspace).
+
+Given the empirical reality of the different trait distributions, "Who are the best athletes _among females_" is a natural question for people to be interested in, and want separate sports leagues to determine. Including male people in female sports leagues undermines the point of having a separate female league, and [_empirically_, hormone replacement therapy after puberty](https://link.springer.com/article/10.1007/s40279-020-01389-3) [doesn't substantially change the picture here](https://bjsm.bmj.com/content/55/15/865).
+
+(Similarly, when conducting [automobile races](https://en.wikipedia.org/wiki/Auto_racing), you want there to be rules enforcing that all competitors have the same type of car for some common-sense-reasonable operationalization of "the same type", because a race between a sports car and a [moped](https://en.wikipedia.org/wiki/Moped) would be mostly measuring who has the sports car, rather than who's the better racer.)
+
+In light of these empirical observations, Yudkowsky's suggestion that an ignorant comittment to an "Aristotelian binary" is the main reason someone might care about the integrity of women's sports, is revealed as an absurd strawman. This just isn't something any scientifically-literate person would write if they had actually thought about the issue _at all_, as contrasted to having _first_ decided (consciously or not) to bolster one's reputation among progressives by dunking on transphobes on Twitter, and wielding one's philosophy knowledge in the service of that political goal. The relevant empirical facts are _not subtle_, even if most people don't have the fancy vocabulary to talk about them in terms of "multivariate trait distributions".
+
+I spend a few paragraphs picking on the "sports segregated around an Aristotelian binary" remark because sports is a case where the relevant effect sizes are _so_ large as to make the point [hard for all but the most ardent gender-identity partisans to deny](/2017/Jun/questions-such-as-wtf-is-wrong-with-you-people/), but the point is very general: biological sex actually exists and is sometimes decision-relevant.
+
+Yudkowsky's claim to merely have been standing up for the distinction between facts and policy questions doesn't seem credible. It is, of course, true that pronoun and bathroom conventions are policy decisions rather than a matter of fact, but it's _bizarre_ to condescendingly point this out _as if it were the crux of contemporary trans-rights debates_. Conservatives and gender-critical feminists _know_ that trans-rights advocates aren't falsely claiming that trans women have XX chromosomes. If you _just_ wanted to point out that the organization of sports leagues is a policy question rather than a fact (as if anyone had doubted this), why would you throw in the "Aristotelian binary" strawman and belittle the matter as "humorous"? There are a lot of issues that I don't _personally_ care much about, but I don't see anything funny about the fact that other people _do_ care.
+
+If any concrete negative consequence of gender self-identity categories is going to be waved away with, "Oh, but that's a mere _policy_ decision that can be dealt with on some basis other than gender, and therefore doesn't count as an objection to the new definition of gender words", then it's not clear what the new definition is _for_. The policymaking categories we use to make decisions are _closely related_ to the epistemic categories we use to make predictions, and people need to be able to talk about them.
+
+An illustrative example: like many gender-dysphoric males, I [cosplay](/2016/Dec/joined/) [female](/2017/Oct/a-leaf-in-the-crosswind/) [characters](/2019/Aug/a-love-that-is-out-of-anyones-control/) at fandom conventions sometimes. And, unfortunately, like many gender-dysphoric males, I'm _not very good at it_. I think someone looking at some of my cosplay photos and trying to describe their content in clear language—not trying to be nice to anyone or make a point, but just trying to use language as a map that reflects the territory—would say something like, "This is a photo of a man and he's wearing a dress." The word _man_ in that sentence is expressing _cognitive work_: it's a summary of the [lawful cause-and-effect evidential entanglement](https://www.lesswrong.com/posts/6s3xABaXKPdFwA3FS/what-is-evidence) whereby the photons reflecting off the photograph are correlated with photons reflecting off my body at the time the photo was taken, which are correlated with my externally-observable secondary sex characteristics (facial structure, beard shadow, _&c._), from which evidence an agent using an [efficient naïve-Bayes-like model](http://lesswrong.com/lw/o8/conditional_independence_and_naive_bayes/) can assign me to its "man" category and thereby make probabilistic predictions about some of my traits that aren't directly observable from the photo, and achieve a better [score on those predictions](http://yudkowsky.net/rational/technical/) than if the agent had assigned me to its "adult human female" category, where by "traits" I mean not (just) particularly sex chromosomes ([as Yudkowsky suggested on Twitter](https://twitter.com/ESYudkowsky/status/1067291243728650243)), but the _conjunction_ of dozens or hundreds of measurements that are [_causally downstream_ of sex chromosomes](/2021/Sep/link-blood-is-thicker-than-water/): reproductive organs _and_ muscle mass (sex difference effect size of [Cohen's _d_](https://en.wikipedia.org/wiki/Effect_size#Cohen's_d)≈2.6) _and_ Big Five Agreeableness (_d_≈0.5) _and_ Big Five Neuroticism (_d_≈0.4) _and_ short-term memory (_d_≈0.2, favoring women) _and_ white-to-gray-matter ratios in the brain _and_ probable socialization history _and_ [any number of other things](https://en.wikipedia.org/wiki/Sex_differences_in_human_physiology)—including differences we might not necessarily currently know about, but have prior reasons to suspect exist: no one _knew_ about sex chromosomes before 1905, but given all the other systematic differences between women and men, it would have been a reasonable guess (that turned out to be correct!) to suspect the existence of some sort of molecular mechanism of sex determination.
+
+Forcing a speaker to say "trans woman" instead of "man" in that sentence depending on my verbally self-reported self-identity may not be forcing them to _lie_, exactly. (Because it's understood, "openly and explicitly and with public focus on the language and its meaning", what _trans women_ are; no one is making a false-to-fact claim about them having ovaries, for example.) But it _is_ forcing the speaker to obfuscate the probabilistic inference they were trying to communicate with the original sentence (about modeling the person in the photograph as being sampled from the "man" [cluster in configuration space](https://www.lesswrong.com/posts/WBw8dDkAWohFjWQSk/the-cluster-structure-of-thingspace)), and instead use language that suggests a different cluster-structure ("trans women", two words, are presumably a subcluster within the "women" cluster). Crowing in the public square about how people who object to be forced to "lie" must be ontologically confused is _ignoring the interesting part of the problem_. Gender identity's [claim to be non-disprovable](https://www.lesswrong.com/posts/fAuWLS7RKWD2npBFR/religion-s-claim-to-be-non-disprovable) mostly functions as a way to [avoid the belief's real weak points](https://www.lesswrong.com/posts/dHQkDNMhj692ayx78/avoiding-your-belief-s-real-weak-points).
+
+To this one might reply that I'm giving too much credit to the "anti-trans" coalition for how stupid they're not being: that _my_ careful dissection of the hidden probabilistic inferences implied by words (including pronoun choices) is all well and good, but that calling pronouns "lies" is not something you do when you know how to use words.
+
+But I'm _not_ giving them credit for _for understanding the lessons of "A Human's Guide to Words"_; I just think there's a useful sense of "know how to use words" that embodies a lower standard of philosophical rigor. If a person-in-the-street says of my cosplay photos, "That's a man! I _have eyes_ and I can _see_ that that's a man! Men aren't women!"—well, I _probably_ wouldn't want to invite such a person-in-the-street to a _Less Wrong_ meetup. But I do think the person-in-the-street is _performing useful cognitive work_. Because _I_ have the hidden-Bayesian-structure-of-language-and-cognition-sight (thanks to Yudkowsky's writings back in the 'aughts), _I_ know how to sketch out the reduction of "Men aren't women" to something more like "This [cognitive algorithm](https://www.lesswrong.com/posts/HcCpvYLoSFP4iAqSz/rationality-appreciating-cognitive-algorithms) detects secondary sex characteristics and uses it as a classifier for a binary female/male 'sex' category, which it uses to make predictions about not-yet-observed features ..."
+
+But having _done_ the reduction-to-cognitive-algorithms, it still looks like the person-in-the-street _has a point_ that I shouldn't be allowed to ignore just because I have 30 more IQ points and better philosophy-of-language skills? As it is written: "intelligence, to be useful, must be used for something other than defeating itself."