Harry Potter and the Methods of Rationality is a Harry Potter fanfic written by Eliezer Yudkowsky (which you can find here). Yudkowsky is the creator of LessWrong which I often use as a shorthand for the entire Rationality space. I wasn’t around at the time, but I eventually found Scott Alexander’s work at Slate Star Codex, who is linked in the sidebar and is one of the inspirations for this blog. Through SSC, I found writings by Yudkowsky, mostly about artificial intelligence. Last year I tried to read the essays known as “The Sequences” or Rationality: A-Z at LessWrong. I read the first couple of books, but they’re pretty dense and my interest dropped off.
HPMOR, unlike The Sequences, is fiction, and I found it incredibly easy to read. I assume the project began as a way to teach rationality through a common pop culture phenomenon, and it’s pretty solid at doing that. Concepts like Bayesian updating and evolutionary biology are well explained, but are done so partially as a critique of the Harry Potter universe.
The general premise is that Harry Potter’s Aunt Petunia marries an Oxford professor instead of Vernon Dursley. Thus, Harry is raised with extensive training on the scientific method by his adoptive parents, as well as the latest understanding of probability, physics, biology, chemistry, etc. He comes to Hogwarts armed with the scientific method and sets about trying to understand how magic works.
The Harry Potter universe is an excellent substrate in which to do this, because its world is so creative, popular, and complete. But J.K. Rowling’s world also has glaring problems which can be explored in ways that teach social and physical science, and even philosophy. The wizarding government apparently sends people to Azkaban where they are not only kept separate from other people (as we do in our world with regular prisons), but they are also psychologically tortured in the most horrifying way, with their good memories drained by beings of pure evil. They also apparently have no trials, as Hagrid is sent to be tortured in the second book with no oversight. Additionally, wizards have magical healing capabilities and can magically create copies of food, yet muggles in the non-wizarding world die of malaria, tuberculosis, and starvation all the time, and this is never mentioned in the original source material.
A lot of science fiction has similar problems; in The Matrix, the machines get energy from human beings’ thermal energy, but instead of just putting people in comas, they create a massively complex neural interactive computer simulation. This creates both the ranks from which their enemies recruit and uses tons of additional energy. To be sure, science fiction isn’t necessarily made worse because of these internally inconsistencies, but good science fiction should explore these ideas instead of paper over them with hand-waving.
The writing of HPMOR is delightful. A fanfic that explores Bayesian probability in the Harry Potter universe shouldn’t be this well written, but it really is. It’s creative, funny, intense, emotional, and continually pushed me to want more. The actual size of the six books in the series is gargantuan, somewhere over half a million words, or something like the first four actual Harry Potter books combined. If you read just the first “book”, I think you’ll get a general idea and know if you find it interesting yourself. I couldn’t put it down. It makes me wonder in particular about Eliezer Yudkowsky; I had previously thought of him as an AI alignment research person, so it would appear he is somewhat of a polymath who can both write incredibly amazing and addictive fan fiction and be a leading advocate/researcher for AI alignment.
The exploration of magic is the inspiration for the story, but that’s not where it stops. The plot itself is highly compelling and different enough from the actual book(s) that I wasn’t sure exactly where it was going. It also does a nice job of rebuilding the Harry Potter world in a somewhat internally consistent way after all the criticisms. Yudkowsky comes up with a lot of original ideas here that fit into the pre-existing universe really well. There are also a lot of influences from Ender’s Game, which makes a lot of sense given that is also a story of a young child genius using logic and game theory to make it through a school.
This story also makes me think about intellectual property and copyright lengths again. HPMOR is perhaps the best example I’ve ever seen of someone creating an incredible story in a world that they didn’t have IP rights to, and it makes me wonder how many more stories like this could exist if copyright lengths were shorter. Harry Potter was such a huge phenomenon that it really required the modern world to have that huge impact, like Star Wars or Marvel movies. But were copyrights to only last 30 years, we might be able to see amazing works like HPMOR used to build careers on great franchises in the public domain while those cool franchises were still relevant!
In short, I strongly recommend this fan fiction under the condition that you enjoy Harry Potter. Otherwise, a lot of setting and characters may not make sense and I’m sure all of the jokes will fall flat. Other than that, if you’re already reading this blog, you have some vague enjoyment of rationality, empiricism, systematized thinking, etc and this story is educational, creative, and addictive.