This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 99, 100, and 101. The previous thread is at nearly 500 comments.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system.
Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically:
You do not need to rot13 anything about HP:MoR or the original Harry Potter series unless you are posting insider information from Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).
If there is evidence for X in MOR and/or canon then it’s fine to post about X without rot13, even if you also have heard privately from Eliezer that X is true. But you should not post that “Eliezer said X is true” unless you use rot13.
In the MoR universe, being able to do magic is a sign that the underlying Source of Magic recognizes you in some way. Wizards make ghosts, muggles don't; as Draco puts it, the simplest explanation for that is that wizards have souls and Muggles don't. (Suppose the soul is just some part of the self that persists that taps into the Source of Magic for computation. Then it doesn't require the physical body for computation, and Harry's intuitions about souls from "the brain makes the mind," which is true in our world but possibly not exclusively true in the MoR world, are not necessarily correct.)
In the MLP universe, a cutie mark is the physical manifestation of having found your purpose in life. MLP unicorns can also do magic. If we transport Twilight Sparkle from MLP to MoR with the least number of changes (i.e. the Source of Magic recognizes her and the philosophical interpretation of the cutie mark is the same), we end up with a being who has more directly observable evidence for being morally valuable than wizards... whose only purpose (in the eyes of the story* and protagonist) is to die to extend the life of wizards.
Alternatively, we assume that it's basically a horse with some magical properties, that's just colored that way as a referential joke. Then, yeah, jokes like that do decrease the seriousness of the chapter.
*Originally this was "author," which is not quite fair; the primary purpose of Rita Skeeter in MoR is to be murdered by Quirrel, but as the author's note / other commentary that Eliezer almost put in McGonagall telling Skeeter's children that their mother had gone missing showed that Eliezer was modeling her as an actual person, and the same might be true for the unicorns Quirrel is murdering.