Hm. In Chapter 74, we learn that all ritual magic requires a sacrifice, and Harry muses about all the pulled punches in wizard warfare. Iiinteresting.
Especially since Quirrell/Voldemort specifically mentions that it is possible to sacrifice "a portion" of one's own magical power -- permanently -- to achieve 'great effects'. I imagine a nefarious individual could conceive of a rite whereby the sacrifice of another wizard's life -- and by extension, his magic -- would cause at least some portion of that magic to be transferred to yourself.
Perhaps older wizards were more powerful because... they had more power? One could easily conceive of Godric Griffindor using this method of execution upon potential Dark Lords in order to combat more-powerful ones.
That seems like an effective method of imprisonment. Force the wizard to expend their power permanently in rituals (or just one powerful ritual). Such a prison would be significantly safer than Azkaban, since any wizards which escape would be effectively useless. They would be permanently helpless; some might consider it an even worse fate than dementors.
On further thought, perhaps that is why the public accepts dementors. Imagine what the prison system could have been before dementors were harnessed for prison work. The state would have an incentive ...
Update: Discussion has moved on to a new thread.
The hiatus is over with today's publication of chapter 73, and the previous thread is approaching the 500-comment threshold, so let's start a new Harry Potter and the Methods of Rationality discussion thread. This is the place to discuss Eliezer Yudkowsky's Harry Potter fanfic and anything related to it.
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: one, two, three, four, five, six, seven. The fanfiction.net author page is the central location for information about updates and links to HPMOR-related goodies, and AdeleneDawner has kept an archive of Author's Notes.
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: