I'm still reading Gravity's Rainbow, which is taking forever. It doesn't help that somewhere in the middle, I decided to take a break, and then the library lost the copy I returned! During my break, I took up a variety of much lighter reading, including Harry Potter and the Methods of Rationality.
This well-known fanfiction takes place in an alternate Potter universe where Harry Potter has been brought up by a scientist. When Harry Potter first discovers the world of magic, he does what any reasonable eleven-year-old would do, and applies the scientific method to it. Harry Potter first tests the existence of magic using pre-agreed protocols. He immediately sees that the wizarding economy is inefficient, and plans to exploit it later. He gets Draco to apply the scientific method to his belief that muggle blood is diluting magic. He tries to use the time-turner to solve NP problems.
Exciting right? I thought it was hilarious. It's also great because it doesn't have as much straw vulcan in it as you might expect. The ideas are mostly taken from the website Less Wrong. Harry Potter isn't right all the time, but that's because he is prey to cognitive bias like anyone else, not because he is "too rational".
But it's not merely about delivering lessons about rationality. Nor is it just about parodying the sillier things the Harry Potter universe. It starts out that way, but soon develops its own story, distinct from the original Harry Potter. It has its share of mysteries, dramas, and dynamic characters. The story discusses many themes that even rational people may disagree on. For example, Professor Quirrell's character has been replaced by a very different character, one who becomes Harry Potter's morally ambiguous mentor.
But since I'm giving this a review, I must also express a few complaints. Though I loved many of the things in the later chapters (eg Hermione calls out Dumbledore for his clear bias towards male heroes), I sort of liked the earlier chapters which were funnier and less serious. I felt the "Humanism" chapters were obnoxious. Harry Potter finds some sappy secular-humanistic way to deal with Dementors. This is pretentious and cliched, and my tastes are too ironic for that sort of thing.
Also, it is much longer than it needs to be. It's not even complete yet, and it's over a thousand pages. I felt way too much time was spent on these wizarding battles that Quirrell uses to teach the kids how to fight. It's a lot like Ender's Game where it goes in great depth about the weightless battles in Ender's military school. I don't particularly care for Ender's Game, or for that part of the book. Quidditch may be an objectively terrible game, but at least it only took up a small part of the books!
But on the whole I enjoyed the work, and I would continue reading it once it gets updated. I highly recommend reading the first few chapters, which are fun even if you don't want to really get into it.