Harry opened his mouth, and then, as realization hit him, rapidly snapped his mouth shut again. Godric hadn't told anyone, nor had Rowena if she'd known; there might have been any number of wizards who'd figured it out and kept their mouths shut. You couldn't forget if you knew that was what you were trying to do; once you realized how it worked, the animal form of the Patronus Charm would never work for you again - and most wizards didn't have the right upbringing to turn on Dementors and destroy them -
I read this as meaning that Harry believes Godric could do it. Maybe I'm assuming too much, though, because I really like that idea.
I think he's just describing what happens when you tell people Dementor's are Death. He considered that a tactic in the WIzengamut to prevent them from being able to cast a patronus, and gives no thought to the possibility that knowing that would enable them to cast the True Patronus.
The next discussion thread is here.
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 84. The previous thread has passed 500 comments. Comment in the 14th thread until you read chapter 84.
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.
As a reminder, it’s often useful to start your comment by indicating which chapter you are commenting on.
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: