Thanks. That fits the timeline, but I don't think that it fits the students' reaction:
"Merlin preserve us," said Penelope Clearwater in a strangled voice. "You mean that's how men would treat us if we didn't have wands to defend ourselves?"
Of course, slavery ties in to rape (my reading of their reactions), but it doesn't make sense for Penelope to say "us" here. (Penelope has white skin.)
There's also the sense of slavery in which men were (or are) owners of their wives and unmarried daughters, but that doesn't seem to be what you mean.
If I see George being treated badly by Bill, I might conclude that Bill would treat me badly in the same circumstance, even if I know that George has green eyes and I have hazel eyes and Bill has some weird prejudice I don't entirely understand having to do with eye color.
Someone raised in a culture that considers skin color of no more significance than eye color would presumably react similarly even if they know that George has brown skin and they have pink skin and Bill has a prejudice having to do with skin color.
Update: Discussion has moved on to a new thread.
The load more comments links are getting annoying (at least if you're not logged in), so it's time for a new Harry Potter and the Methods of Rationality discussion thread. We're also approaching the traditional 500-comment mark, but I think that hidden comments provide more appropriate joints to carve these threads at. So as of chapter 67, this is the place to share your thoughts about Eliezer Yudkowsky's Harry Potter fanfic.
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. The fanfiction.net author page is the central author-controlled HPMOR clearinghouse with links to the RSS feed, pdf version, TV Tropes pages, fan art, and more, 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: