All right, yes.  But that isn't how anyone has ever interpreted Newcomb's Problem.  AFAIK is literally always used to support some kind of acausal decision theory, which it does /not/ if what is in fact happening is that Omega is cheating.

But if the premise is impossible, then the experiment has no consequences in the real world, and we shouldn't consider its results in our decision theory, which is about consequences in the real world.

That equation you quoted is in branch 2, "2. Omega is a "nearly perfect" predictor.  You assign P(general) a value very, very close to 1."  So it IS correct, by stipulation.

But there is no possible world with a perfect predictor, unless it has a perfect track record by chance.  More obviously, there is no possible world in which we can deduce, from a finite number of observations, that a predictor is perfect.  The Newcomb paradox requires the decider to know, with certainty, that Omega is a perfect predictor.  That hypothesis is impossible, and thus inadmissible; so any argument in which something is deduced from that fact is invalid.

I appreciated this comment a lot.  I didn't reply at the time, because I thought doing so might resurrect our group-selection argument.  But thanks.

What about using them to learn a foreign vocabulary?  E.g., to learn that "dormir" in Spanish means "to sleep" in English.

To reach statistical significance, they must have tested each of the 8 pianists more than once.

I think you need to get some data and factor out population density before you can causally relate environmentalism to politics.  People who live in rural environment don't see as much need to worry about the environment as people who live in cities.  It just so happens that today, rural people vote Republican and city people vote Democrat.  That didn't used to be the case.

Though, sure, if you call the Sierra Club "environmentalist", then environmentalism is politically polarized today.  I don't call them environmentalists anymore; I call them a zombie organization that has been parasitized by an entirely different political organization.  I've been a member for decades, and they completely stopped caring about the environment during the Trump presidency.  As in, I did not get one single letter from them in those years that was aimed at helping the environment.  Lots on global warming, but none of that was backed up by science.  (I'm not saying global warming isn't real; I'm saying the issues the Sierra Club was raising had no science behind them, like "global warming is killing off the redwoods".) 

Isn't LessWrong a disproof of this?  Aren't we thousands of people?  If you picked two active LWers at random, do you think the average overlap in their reading material would be 5 words?  More like 100,000, I'd think.

I think it would be better not to use the word "wholesome".  Using it is cheating, by letting us pretend at the same time that (A) we're explaining a new kind of ethics, which we name "wholesome", and (B) that we already know what "wholesome" means.  This is a common and severe epistemological failure mode which traces back to the writings of Plato.

If you replace every instance of "wholesome" with the word "frobby", does the essay clearly define "frobby"?

It seems to me to be a way to try to smuggle virtue ethics into the consequentialist rationality community by disguising it with a different word.  If you replace every instance of "wholesome" with the word "virtuous", does the essay's meaning change?