I'm highly sympathetic to the intuition that the liar sentence is devoid of meaning in some important respect, but I don't think we can just declare the liar sentence meaningless and then call it a day. Because in another respect, it definitely seems meaningful. I understand what a sentence is, and I feel like I understand what it is for a sentence to be true or false. If someone wrote on a blackboard "The thing written on the blackboard of room 428 is false," I feel like I would understand what this is saying before I went to check out room 428....
It would be helpful to know more about the sorts of things they typically post about, but I understand you probably don't want to inadvertently reveal the smart-wrong individuals you have in mind.
The reason I say this is because there are probably a lot of people out there like me - people who, while liking the LessWrong community and its stewards overall, have some serious bones to pick with some of the "core" "rationalist" beliefs and approaches to various questions. These two things in combination beget an urge to respectfully but pe...
Harry has decided, I'm sure correctly, that Quirrell's ability to flawlessly adopt any persona and simulate any intention for long stretches of time while simultaneously furthering his own (true) goals makes him impossible to trust. But if Harry buys into Quirrell's claims, Harry is equally capable of perpetual, undetectable duplicity and therefore equally unworthy of trust. And if he believes that's the case, it's just going to isolate him further, since he'll conclude that anyone who wants to be his friend is either irrational or overlooking the factors ...
I feel almost certain that Harry is living in a computer simulation. I know he ruled it out because he decided the existence of the Time Turner renders the universe non-computable, but how can he be sure that he's actually going backwards in time instead of the universe "simulating going back to the past and computing a different future?"
Ah, thanks.