"Hard cases make for bad law."

I'm not /sure/ that there is such an effect, but I would be willing to bet in favor of it. Not standing next to someone who obsesses over the Trolley Problem when I'm waiting for a train, that sort of thing.

"This is an example of what I call "lifeboat questions"--ethical formulations such as"What should a man do if he and another man are in a lifeboat that can hold only one?" First, every code of ethics must be based on a metaphysics--on a view of the world in which man lives. But man does not live in a lifeboat--in a world in which he must kill innocent men to survive."

-Ayn Rand

This is my impression of UDT.

[another stray thought] ...so then CEV would be like trying to extract a fully formal grammar for a given language, only harder.

Not really, CEV doesn't depend on everyone's extrapolated volitions converging to total moral agreement.

(I tried to come up with a better CEV analogy, but I'm not sure if that's doable without stretching the metaphor far beyond any real explanatory usefulness; the ideas of volition and extrapolation don't actually have any obvious linguistic analogues, as far as I can tell. The platonic computation of morality could be compared to universal grammar or something, but it's not a strong analogy (for the purposes we're interested in) because universal grammar doesn't have the recursive/reflective property that morality does (we can ask ourselves "Should I make this change to the algorithm I use to answer 'should' questions?", and although I suppose we could also ask ourselves if we should change our linguistic algorithms, that wouldn't loop back on itself like morality does, so the problem of "extrapolating" it wouldn't be as difficult or as interesting).)

My impression is that people tend to be exposed to grammar early on in school, in the form of a lot of arbitrary-seeming rules, which do not necessarily correspond with the colloquial spoken language

And indeed, they're not supposed to. "Grammar" in the sense of school consists of rules for signaling high status via speaking and writing. (The level of "arbitrariness" is what you'd expect given this.) Nothing to do with "grammar" in the sense of theoretical linguistics.

In that sense, language is value-neutral.

Linguists, however, are too hasty to jump to this conclusion in their attempt to explain that "evaluating" different language varieties is not their subject as linguists. There may be legitimate arguments (aesthetic, utilitarian, etc.) for why some forms of language are "better" than others; it's just that such arguments are strictly irrelevant from the point of view of theoretical linguistics (though not sociolingustics, etc).

Valley-girl English and Ebonics and West Virginia dialect are all equally valid and internally consistent, according to this approach.

There is also value in maintaining a common standard. Try speaking Ebonics outside black ghettos and besides the status hit, people will have a hard time understanding you.

Can this same analysis be applied to moral codes? If it can, even in principle, then we have some problems. As I understand it, "morality" is all about values. I think EY has considered this issue seriously, and has alluded to it in Three Worlds Collide.

You should look at the metaethics sequence.

Agreed, what we learn as "grammar" in school doesn't correspond to the real rules of the language we use - either because the "rules" taught are "wrong" (like "not splitting infinitives"), or they're teaching a different language from the one you learned at home - in fact, I suspect this last one is the main reason schools feature prominently teaching something that people learn naturally : it's part of an effort from central governments to impose a common language to the whole nation, instead of the local dialects that existed before widespread schooling. Teaching grammar rules explicitly makes sense if you're teaching a second language (which was the case for Welsh kids learning English, or Basque kids learning French).

here's a linguist writing about something similar:

The fact is that almost everything most educated Americans believe about English grammar is wrong. In part this is because of misconceptions concerning the facts. In part it is because hopeless descriptive classifications and antiquated theoretical assumptions doom all discussion to failure. Amazingly, almost nothing has changed in over a hundred years.

... though his conclusion seems to be "teach the correct rules of grammar at school", whereas mine is more "what's the point? People figure out the rules independently of what factoids they're forced to memorize in school".

Note also that although the distinction between count-nouns and mass-nouns is a real one, a) it does not always match up with some physical difference between a countable and uncountable quantity, and b) the people who insist that "less" should only ever be used with mass-nouns are talking nonsense. "Less" with count-nouns is found all over the place in the speech and writing of competent language users.

More likely, a typo.