Harry Potter and the Methods of Rationality

Oh Thoth Trismegistus, oh Ma’at, oh Ganesha, oh sweet lady Eris…I have not laughed so hard in years!

Eliezer Yudkowsky is one of the brightest people I’ve ever met in a lifetime of seeking out gifted- to genius-grade thinkers because people who aren’t usually bore me pretty quickly. Eliezer has spent years studying the deep structure of rationality and probably understands the systematic sources of bias and irrationality in the shared architecture of the human mind as comprehensively as anyone alive. I have previously commented on some of his writings.

Usually Eliezer thinks about questions like how to build human-compatible ethical reasoning into AIs. Serious, deep stuff. When he turns the vast and imponderable force of his intellect to writing, of all things, Harry Potter fanfic, a quite unexpected degree of hilarity ensues.

Read it and laugh. Read it and learn. Eliezer re-invents Harry Potter as a skeptic genius who sets himself the task of figuring out just how all this “magic” stuff works. The science is real – it really would be a lot harder to explain transformation from a human into a cat than mere levitation, for example. When Harry, confronted with a magical time-travel device, is immediately terrified that he might be holding an antimatter bomb, this is actually a more justified fear than many readers may understand.

But the characters are not slighted. Eliezer is very good at giving them responses to the rather altered and powered-up Harry that are consistent with canon. The development of Minerva McGonagall is particularly fine.

Strongly recommended. And if you manage to learn about sources of cognitive bias like the Planning Fallacy and the Bystander Effect (among others) while your sides are hurting with laughter, so much the better.


  1. I have literally never read anything Harry Potter before. Now the first thing I go into in the universe is going to be fanfic written by an uber-nerd?

    …this is going to be awesome.

  2. I completely agree with your recommendation, and in particular, I find the relationship between Harry and Minerva beautifully handled; the story conveys a sense of real, if mostly unvoiced, love between the two of them. But nearly all the focal characters other than Harry have gained surprising depth: Draco, Hermione, and Quirinus are all a pleasure to read about. A lot of the chapters have had me laughing out loud; some of them have had me amazed at the plot twists they hint at.

  3. Followup: Yes, it was awesome. Thanks for the link. (Also, damn you – there were things I was planning on doing tonight…)

  4. It continues to be impressive, but I found that the funniest bits were in the beginning, where Harry is driving the adults up the wall. Later, when he’s dealing with a bunch of challenges that he can’t swamp out as easily, it gets more serious.

  5. I must say that I don’t share Nancy’s reaction, though of course this is a matter of taste. The latest posted episode, with Hermione’s becoming the third general and with negotiations between Hermione, Quirinus, Harry, and Draco, had me laughing out loud repeatedly. For that matter, Severus’s “I have a friend who” conversation with Harry was quite funny on first reading, though the implications are much more serious.

  6. well, it started good and got better and I looked up and it was four hours later; two hours past bedtime. I read fast, but this was a real pleasure to sink into slow.

    Criticism (?)- all the characters are very smart and make rational choices.

  7. I’ve been tracking this now since around when chapter 8 was posted. It is quite well-done, especially in managing to avoid the polemic-tract-trap. It’s still a fun story. I’ve been trying to wait until it’s done to recommend it :)

  8. Ahh. So many times I’ve been in the sorting hat. In fact, I quite often think to myself “It’s a darn good thing I decided not to be evil…”.

    Perhaps next time someone brings up the lack of women in science, engineering, math, etc. I’ll just use the sorting hat metaphor. For I suppose I chose hufflepuff over ravenclaw when I quit grad school. I chose hufflepuff over griffindor several times when I decided the kids needed me more than I needed to have the glory of being a software architect (or whatever). And just about every week you are tempted by Slytherin…

  9. A most excellent story. Thanks for the link.

    Among others I quite like how tales told to Draco by Lucius are often (more or less) hidden references to books, plays, short-stories, light novels, mangas.

    But how did Harry Verres-Evans-Potter, voracious reader of science-fiction, missed reference to “Dune” in the invocation of ‘gom jabbar‘ for a spell?

  10. I only know Harry Potter through the movies, and one thing that’s always confused me is how underpowered and helpless the famous boy magician seems to be. Sure, Harry has lots of impressive trinkets fall into his lap, such as the cloak of invisibility, but except for the mysterious circumstances surrounding the death of his parents and the mark on his forehead, what is so special about Harry compared to the average student at his school?

  11. The movie trailer to the Sorcerer’s Stone, my introduction to Harry Potter, made it look as if Harry was a powerful wizard. Instead he’s rather dull, overall, he’s just good at broom riding. If you read the Author’s Notes for HPatMoR, you’ll see Eliezer outline how protagonists need to be dramatically matched to their antagonists and how many fanfictions power Harry up without powering down Voldemort… I rather feel the true Harry Potter series does the opposite, Harry is such a normal guy against a supervillian that I find it implausible that he wins, even in context.

  12. Wow, thank you Eric for bringing this to our attentions. I just now finished catching up on it, and I am _exceedingly_ impressed. Normally I cannot stomach fanfic, but this is something much more. Entertaining and massively educational at the same time it playfully deconstructs the source. Fantastic! I almost don’t want to call it fanfic.

  13. Great stuff, thanks a lot for the notice. I’ve given Harry Potter a miss, but, I like this. Is the original as good as this? No need for the high rationality & lessons of course. Though I suppose that does ‘adultify’ it. But, the large amount of thought that goes into it – does J. K. Rowling do that, or is that just Eliezer?

  14. techtech said: ” one thing that’s always confused me is how underpowered and helpless the famous boy magician seems to be… what is so special about Harry compared to the average student at his school?”

    In Soviet Russia, point of story misses *you*!

  15. Bill:
    > Great stuff, thanks a lot for the notice. I’ve given Harry Potter a miss, but, I like this. Is the original as good as this? No need
    > for the high rationality & lessons of course. Though I suppose that does ‘adultify’ it. But, the large amount of thought that
    > goes into it – does J. K. Rowling do that, or is that just Eliezer?

    The originals are quite good. They are somewhat soft, not nearly as challenging as the fic, but written well enough. A huge draw of the fic is how much it pulls from the source, and knowing many of the secrets ahead of time gives some of the scenes in Eliezer’s work a shocking depth. Part of the fun of the fic, though, is how characters so often make Better choices, and/or more realistic choices, than happen in the original, and some of the story quietly alludes to that without ever coming too close to stating it outright.

    Careful if you start reading HP; there are lost days down that path…

    1. >Careful if you start reading HP; there are lost days down that path…

      I read “HP” and my brain automatically added “Lovecraft” before I could stop it. There’s lost sanity down that path…Ia! Ia! Cthulhu fthagn! Ph’nglui mglw’nfah Cthulhu R’lyeh wgah’nagl fhtagn!

  16. Thanks for the link, that is sheer genius on the scale of those brilliant Darth Vader diaries. Chapter 5, the first meeting of Harry and Draco, had me crying with laughter.

  17. Awesome. Very funny, thanks for the link. I now have something to do during burnout breaks at work, at least for a few weeks. How do you find this stuff?

  18. It is arguably off-topic for this blog, *even* on this post, but if you like HP, and are tolerant of fanfic, let me commend to you possibly the best fanfic story I have ever read, Don Sample’s Harry Potter and the Key of Dagon.

    It’s a crossover, and I found it at once believable, well written, and quite respectful of both fandoms.

    It is *long*, and I couldn’t put it down, so please don’t start it unless you have time or willpower. :-)


  19. This Harry had precisely the same reaction as I did upon learning about the rules of Quidditch. I can see no value at all in designing a game in which the success or failure of one player on each side, to perform one single act, is scored so highly, rendering all the other effort of the other players largely irrelevant.

    Unless you’re trying to breed narcissistic sociopaths. In that case, get them to play Seeker early and often.

  20. facepalm Says:
    > In Soviet Russia, point of story misses *you*!

    If the point of the Harry Potter movies is that life is boring, you are helpless to change your destiny, and any popularity or success you acquire is mostly dumb luck, then I didn’t miss that point, but I also don’t get why Harry Potter is so popular. The main enjoyment I get out of the movies is seeing the fairly colorful world (during those rare moments where the screen isn’t pitch black).

    For once I’d like to see Harry grab a wand and kick some ass.

    1. >This is a detailed explanation of why HP and MoR fails.

      I think you misspelled “petulant snit”, there. Given a choice between Eliezer Yudkowsky with all his shortcomings and this wanker, I’ll take Eliezer.

  21. Normally, I hate Fanfic. It’s writing for lazy authors, and despite being fans of X, they usually get enough things wrong that it ruins the piece.

    This is good though. I greatly enjoyed this fanfic, I’ll be recommending it to my friends, and I think I’ll even format a copy for my Kindle.

    I think I like it mostly because it’s not just a fanfic, it’s a critical review of Harry Potter, and an introductory text to applied science and logic.

    I’m interested to see if Eliezer has laid out the groundwork and theory of Magic in the HP universe, or if he’s just winging it.

  22. except for the mysterious circumstances surrounding the death of his parents and the mark on his forehead, what is so special about Harry compared to the average student at his school?

    Ah, see, the point of the series is that Harry, in terms of ability, wasn’t special. He’s a basically ordinary boy who was thrust by Voldemort’s actions (and those of others) into a role, and then chooses to try to rise to it.

  23. Monster: Actually, if the fic is right about all the points being thrown into the House competition, then the objection to quiddich’s rules seems a bit less relevant. Sure, the points for the ordinary gameplay don’t matter to the game, but they can quite easily matter to the season. If anything, it seems at least 15% less nonsensical than it did before I read that.

  24. @Alsadius

    But it still doesn’t change the fact that, at least in theory, one of the Seekers might be able to snatch the snitch mere seconds into a match, ending it with a score of 150-0 before all of the spectators have even settled into their seats.

    The only thing remotely like that in any real-world sport is not in team competition, but in individual “battles” like boxing, wrestling, UFC, etc., in which one competitor could theoretically score a knockout/pin scant seconds into the match. And Quidditch is arguably two completely separate games going on at the same time, one between the Seekers and the other involving all the other competitors in solo competition.

  25. The comment about fanfic being the domain of lazy writers touched a nerve. I am a lazy writer – I don’t even write fanfic, but I work for a web host that works with both “real” and “fanfic” authors. I know of a growing number of authors who got their start, “learned the ropes” so to speak, by writing fanfic and going on to become very successful book authors, and in at least two cases Hollywood screenwriters. I also know of three confirmed cases of NYT bestselling writers who started to write fanfic -after- becoming successful.

    MoR is a perfect example of several of the traditional goals of fanfic: using characters and situations that people are familiar with and taking them in new directions, as well as “righting” the perceived wrongs in an existing work. I’m not sure how fanfic is lazy writing. To me, lazy writing is Hollywood’s current infatuation with remaking movies, telling the same story over again with little to no changes at all, just different actors in an attempt to repeat a success, not earn a success.

    Frankly, JKR could have done with fanfic writing experience herself before diving into the HP books because the series is contradictory and weakly plotted, and I say this as a fan.

  26. ErikZ, did you ever create a version of this formatted for Kindle? If so, I would love to get hold of it. The existing PDF requires a magnifying glass.

  27. >I think you misspelled “petulant snit”, there. Given a choice between Eliezer Yudkowsky with all his shortcomings and this wanker, I’ll take Eliezer.

    The fact of the matter is, MoR is not a good /story/. Yudkowsky uses it as a pedestal to shove his opinions on rationality down his readers’ throats, and in the process has written a lot of things that are actually irrational. Even if I give him artistic license, his sanctimonious attitude and unmitigated arrogance are really annoying. Would it kill him to not be an ass?

    Also, it’s been 250k words and he hasn’t progressed beyond Harry’s first year. Yudkowsky should seriously consider plotting things out better and lessening the amount of unnecessary filler content.

  28. This fanfic gives the impression that Rationalism is about being – well more than a petulant snit – also being arrogant, self-serving and wrathful to authority. Not evil, but pretty close neighbors.

    Think about it… what are the buffer zones that keep good folks from evil? Modesty/humbleness, loyalty to friends and community, and willingness to work within a system of law and authority (i.e. change that system properly from within). That DMZ just doesn’t exist for Rationalist Harry Potter.

    I can scarcely distinguish this Potter from the likes of GLaDOS or “Q”.

    I don’t mind Potter being completely out of control. I mind him not misusing rational thought to evade fairly due consequences. I went to a REAL Rationalist prep school with REAL Rationalist teachers, with a headmaster who was in fact quite like Dumbledore, and an assistant headmaster who dealt Rationalist discipline – yes, there definitely is such a thing, and it HURTS and it WORKS.

    Anyway, if this fanfic represents Rationalism (which I assure you it does not), then stupid’s looking pretty good. Or as another great Rationalist said… ‘Years ago my mother used to say to me, she’d say, “In this world, Elwood, you must be,” — she always called me Elwood — “In this world, you must be oh so smart, or oh so pleasant.” Well, for years I was smart. I recommend pleasant.’

  29. @Robert:

    I think you are missing the point of the piece. Rationalist/Scientific Potter also makes a LOT of mistakes. People around him point out the flaws in his behavior and plans; and remind him that being an arrogant git is not a good way to make friends.
    In this particular story, Potter has added his messianic complex to an arrogant perception of everybody else being inferior to him. He’s a much more developed mirror image of Lord Voldemort, wich Rowling herself tried to do but failed miserably throughout all of her novels.
    The original Harry Potter is closer to a mary sue character than a troubled protagonist, because pretty much the only act that has any consequence to him, is the death of Sirius; everything else just slips by and is forgiven just because he is HARRY POTTER, the boy wo lived, savior of makind; not because he learns anything about something.

    Have you ever stopped to think, that maybe, just maybe, the author is presenting Harry’s rationalism wrong, beacuse it is what an eleven year old might interpret rationalism as? There is no doubt MoR Harry is exceptionally inteligent, but there is more ample evidence that he can, has been and will be WRONG about a lot of things, intelligence be damned. In this story, he is seen making choices based on his presumtuos position that he is infalible, wich he is not, and he pays accordingly.

  30. Robert:
    > Think about it… what are the buffer zones that keep good folks from evil? Modesty/humbleness, loyalty to friends and community, and willingness to work within a system of law and authority (i.e. change that system properly from within). That DMZ just doesn’t exist for Rationalist Harry Potter.

    So it’s evil not to be humble? Evil to be proud of what you can do? I’ll grant you loyalty to friends, but to the community? I understand that americans are patriotic to the point of failure, but please… Unless the “community” (which is only a loosely connected gathering of people, in this case people who happen to share the same school) has earned it, it doesn’t deserve any loyalty, at best respectful neutrality.

    And why the hell (pardon my French) would you have to change the system from within to be good? What if the system is so damned corrupt that it’s either impossible or will take so much time that countless innocents are hurt while you play politics? If the system is rotten, it should be cut off. I’m tempted to invoke Godwin’s Law here, but I trust you’re well-versed enough in history for the mere mention of it will let you get my point.

  31. silverlasso: No, the fact of the matter is that hp&mor is the single most popular and respected piece of fanfiction, of any genere, out there. regardless of what the trolls at the dlp like to say.

  32. …so, I’m finally reading this after two years. (Two fucking years for no reason other than I had no round tuitt…) I’m up to the part where Harry’s getting Sorted, and LessWrong said something about divulging the rest of the plot to anyone who can tell what “Oh dear. This has never happened before.” is about.

    Now unfortunately for me, there was a deadline long past for that, but fortunately, I’d prefer to get the plot with the story even if I knew, but meanwhile, I keep looking at that sentence, and feeling the rush of a test, and all I can think of is that it sure sounds like when I played Colossal Cave as a little boy and manage to run it into an error state.

    That is all.

    Well, that and I’m deliberately putting off reading the rest of this thread until I read the remaining 75-ish chapters. I seriously wonder if I’ll ever read another SF story this enriching.

    (Two goddamned years…)

  33. (Of course I’m pretty sure I know what the real answer is (a giveaway at this point), but shutupi’mstillmadabouttwoyears.)

  34. With regards to that “petulant snit” that is complaining about Harry Potter and the Methods of Rationality: the fact that this story is compelling, introduces thought processes and ideas I’ve never thought about consciously before, and is simply just funny in various parts, makes it a worthwhile endeavor to read, even with all its flaws.

    One flaw that bothers me, in particular, was the idea that the universe be completely changed, and not just Harry Potter. It was my initial understanding that the author was trying to see what would happen if Harry was completely different–I only learned later, from second-hand sources (since I never read the comments, or anything else external to the story, while reading it) that the author was changing the story so that everyone would be rational, not just Harry. Even so, I think I would have prefered it if only Harry had changed.

    But overall the story is fantastic, and the jokes are enjoyable.

    And this notion that libraries are only for stories is laughable! For *years* I would only check out non-fiction books from the library; when I checked out my first fiction book (“Encyclopedia Brown”, in the sixth grade) I felt oddly embarrassed, even though I’m sure than no one else was thinking “Oh, how weird, Alpheus is checking out a fiction book!”.

    Libraries are collections of ideas. Most of those ideas take the form of books, which typically contain stories, essays, treatises, pictures, and so forth. Sometimes, those ideas are contained in video and audio tapes, CDs, and DVDs, all of which I have checked out from my public library. And sometimes, ideas are contained in objects–typewriters, letters, etc–and it has only been in the past year or so that I’ve learned that libraries sometimes collect these things, too, usually in connection with an important author; and in this sense, libraries can almost be museums as well–but it’s usually just private libraries that fill this role.

    While some of the complaints that that “petulant snit” has may be legitimate, the ad hominim attacks on the author being a “research assistant”, and the odd claim that libraries only contain stories, are frankly, rather bizzare–and to me, this illustrates that this person is really just bothered that his favorite fictional series is being critiqued.

    I, for one, thought that the Harry Potter series, though enjoyable, was rather shallow in certain ways. At the same time, there’s a certain deepness to it that can be rather surprising, as I discovered, when I read an essay that described the connection Harry Potter had with alchemy. Overall, Harry Potter stories should be accepted for what they are, and to complain when investigated with great scrutiny–especially if those investigations themselves are in certain ways flawed–is rather silly.

  35. The petulant snit is right: the story is clearly flawed. However, many (though certainly not all) of the stated flaws could not be overcome without negating the original purpose of the work, because said flaws are of the sort intrinsic to didactic fiction, mostly the products of a lack of subtlety in its message—something that can’t be eliminated in instructive fiction because subtle allusions to that which the author wishes to impart would require prior knowledge and assuming prior knowledge would negate the instructive value of the story. Heavily didactic fiction will always have such hiccups, lest the allegories become indecipherable and the info dumps mere allusions.
    I think it’s impressive that a piece of fan fiction designed to trick kids into learning about cognitive science is actually quite readable and, at times, very funny. The fact that Eliezer’s prose is a bit basic (the imagery his descriptions conjure is, more often than not, repellently cartoony) doesn’t detract too much from the cleverness of his satire.

    It is not a bad story, a lot of it is very clever, e.g., the existence of the time-tuner as evidence he’s not in a computer simulation, because it’s not Turing computable. Now, it’s quite fun to know that the Harry Potter universe isn’t computable. And I’m certainly glad Eliezer was around to notice this and share it. The book is filled with such clever things; they alone make it worth reading. In a way it’s a sort of like a literary Mystery Science Theater.

    Anyways, it’s certainly far above average. And by the standards of fan fiction, I imagine it’s something of a masterpiece.

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