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Harry Potter and the Methods of Rationality

(Harry Potter and the Methods of Rationality)

4.40  ·  Rating details ·  15,496 ratings  ·  1,551 reviews
Harry Potter and the Methods of Rationality is a work of alternate-universe Harry Potter fan-fiction wherein Petunia Evans has married an Oxford biochemistry professor and young genius Harry grows up fascinated by science and science fiction. When he finds out that he is a wizard, he tries to apply scientific principles to his study of magic, with sometimes surprising resu ...more
ebook, 2184 pages
Published March 14th 2015 by hpmor.com & fanfiction.net
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Chelsea Warren The series has concluded. It ended yesterday on March 14th with 122 chapters in all! :)
Eva If you plan to read the Harry Potter series eventually anyway, you should read all of it before reading HPMoR, because HPMoR contains multiple spoiler…moreIf you plan to read the Harry Potter series eventually anyway, you should read all of it before reading HPMoR, because HPMoR contains multiple spoilers for the original series (even though things happen differently, most story and world conditions remain in place, and many surprises are revealed much earlier in HPMoR than in the original). I had read books 1-4 years ago, started reading HPMoR, realized I was getting some content ahead of where I'd reached in the original, went back and reread the first five and then picked up HPMoR again, reading them in parallel for a while, which was fun, but then I realized I was getting spoilers again, so I finished books 5-7 before continuing and finishing HPMoR. So. Since things are out of order and it's not really possible to stay completely ahead of spoilers otherwise, I'd recommend reading the whole series first.

If you don't plan to read the original, you can understand most of HPMoR having only read part of the series, but why put yourself at that disadvantage? HPMoR can often be a challenging read, leaving the reader to exercise their own rationality to figure out why something would or wouldn't work, what options are available that Harry or another character should use, or what's really going on. Or--to recognize a joke.

Besides, the books are enjoyable and highly influential. They've shaped the thinking of a generation. So it's good to know what it's all about.(less)

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Hussain Elius
This review has been hidden because it contains spoilers. To view it, click here.
Feb 18, 2012 rated it it was amazing
AI researcher and decision theorist Eliezer Yudkowsky probably woke up one day and asked himself a single question: what would have happened in Harry Potter’s first year in Hogwarts, had he not been such an insufferable idiot?

You might not have considered him to be an idiot in the first place, but as the book progresses and the new Harry makes his way around Hogwarts, facing the same problems and situations, it becomes impossible to ignore the oh so logical and natural way he handles them this
Jul 10, 2012 rated it it was ok
I wanted to like this, honestly. When I stumbled upon it and read that description, I figured it was going to be brilliant. So naturally it wasn't. The author leaves a note saying if you don't like it by chapter five, wait until chapter ten, and if you still don't like it by then, get out. That's exactly what I'm doing.

This isn't the first book (so to speak) where the idea is wonderful but it's executed horribly. For starters, the writing is a bit sloppy at times, and when I say at times, I mean
Toby Toldya
Mar 21, 2013 rated it did not like it
Great idea; terrible execution. In fact, I think the summary is completely misleading. While some scenes had me laughing out loud, I spent most of my time cringing or raising one eyebrow or the other; HPMOR is saturated with Yudkowsky's blatant disdain and a condescending tone.

Characters are, for the most part, wildly out of character. Harry completely fails to act like an 11 year old boy, and reads like a thinly-veiled, sociopathic self-insert. Draco is also worrying sociopathic, even beyond t
Xi Xinghe
Sep 10, 2012 rated it it was amazing
Recently I've been wondering just what exactly I wanted from literary fiction. Surely I did not expect life-changing epiphanies, at least not from every single book. But neither did I want my books be merely means to cheap escapism, which I had, perhaps mistakenly, long associated with genre fiction. Somehow I seem to be asking both too much and not enough, and therein lies the reason for my inability to rekindle the kind of pure unadulterated love I used to have for reading. No longer can I sim ...more
Mar 26, 2014 rated it did not like it
Shelves: ebook
I wanted to love this book, I really did. I mean, the premise itself was what got me hooked. I'm sure we've all thought that there was something to be desired in the Plausibility and Possibilities department of the original Harry Potter series, so I jumped at the idea of a realistic story inspired by the methods of rationality! Turns out it wasn't inspired by it so much as it was drowned by it. Spoiler Alert: I didn't finish the book. Yudkowsky left a note about how the series hits its stride at ...more
Jan 12, 2011 rated it it was amazing
Shelves: top
This is the funniest thing I have ever read. I have never read something this funny before. It was extremely difficult to do anything except read it until I had "finished" it, and now it's hard to do anything but think about it and wish there was a lot more of it for me to read.

I guess I'll just read some of his rationalist essay series instead!
Mar 22, 2012 rated it liked it
I can't decide if this was really good or really bad. As a novel (or the majority of a novel) it was pretty terrible. As fanfic it seemed pretty good (to me, which doesn't mean anything, because I am not the kind of guy that reads fanfic at all). I guess I'll go with three stars which seems to say both of those things at once.

Concept that I like: take 11-year-old Harry Potter, about to enter Hogwarts. Make him an incredibly astute and science-minded young boy, and then see just how he'd react to
Jan 02, 2012 rated it it was amazing
Update: 15 March, 2015

OMG! It's over. It has been a wild ride, one of the best I've ever been on. The ending was satisfying in ways I cannot express. Yudkowsky has wowed, amazed, and blown minds through this epic, and I can't wait to read more of his work in the future!


I have never felt the need to take fan fiction seriously. They are, at best, exercises of creativity in a predetermined world, and the best of them usually do not stray too far from the established lore. As it stands, “Harry Pot
Thomas Frank
May 02, 2013 rated it it was amazing
Shelves: favorites
If you are a geek, you will most likely enjoy this book far more than the actual Harry Potter series. This is especially true if you're a fan of smart characters who don't make stupid decisions that leave you screaming at the author (I always get this unbelieving look in my eyes when, in the first movie, Harry keeps leaving his invisibility cloak on the ground in random places.)

Also, this is the book that sparked my interest in science and rationality. So there's that, too.

I've always considered
Nov 12, 2012 rated it did not like it
I wanted to like this fanfic. As a mathematician and an atheist I should have liked this fanfic.

I didn't. The writing is poor (even for fanfic) and the characterisation worse. The author has turned Harry Potter into the most unsympathetic and unlikeable child I can possibly imagine - which I would guess from his bio is also a blatant Mary-Sue.

Should have been called Harry Potter, the Snotty Little Git.
Douglas Summers-Stay
Mar 02, 2011 rated it it was amazing
Imagine if Ender Wiggen were put in Harry Potter's place, and the cunning of other characters upgraded in a similar way. Yudkowsky is a gifted writer, and he plays off the tropes of fanfiction and the idiosyncrasies of the world of Hogwarts in a way that transcends the genre. The books is at times laugh out loud funny, touching, inspiring, and always very smart. Writing fanfiction in order to get more people to read your blog about obscure logical fallacies!? You'd have to be a genius to actuall ...more
Aug 02, 2018 rated it it was ok
When I read a novel and I loved it, I always want the story to never end. The longer the better. Oh how I wished "Harry Potter" series never ended. But while reading a story, the thought that it's a long one becomes an issue, then I believe the story is not fulfilling it's purpose.
The idea behind this book is pretty great, I concur. But as I continue reading I fill like I'm reading a science book or a paper about a theory instead of a novel. It's not that the science part isn't interesting, it's
Feb 26, 2014 rated it did not like it
Update 2: I must seem to be fixated on Yudkowsky, but the fact is several of my good friends are quite his champions and won't let me forget how much I disliked his writings... The other day I took the time to read the previously skipped "omake" sections and want to comment on that, especially on the Council of Elrond one. It makes some points of my dislike blindingly clear.

Briefly, Yudkowsky obviously conflates conventional morality/"goodness" with weakness - both of character and of reason - w
Jan 31, 2014 rated it it was amazing
Recommended to Richard by: Elliot Reed
This is an enormous fan fic version of the first book in the Harry Potter series, rewritten portraying Harry as a hyperrationalist.

Not worth five stars as a work of fiction per se, but fascinating enough to get bumped up to amazing because of several other factors:

• Folks with mildly compulsive rationalist and/or scientific leanings often have trouble with the nonsensical goings-on of magical worlds. Occasionally Yudkowsky nails this so well that I was laughing convulsively. The author sometime
Feb 26, 2021 rated it it was ok
Give it time... Maybe the next chapter will be better... I'll try the next day... Still I just want a peak, maybe the next chapter is better... Then, I give up...

Want to give it 1⭐️but the too long pages of the book seems to be an effort, so I just added a star. No more, nothing less...
Nov 25, 2012 rated it it was amazing
HPMOR (as it's known to fans) is the perfect book for nerds: funny, clever, rife with allusions to other great nerdly works, and yet seriously capable of teaching something real. In this case, the real value-add are principles of reasoning that can lead to better decisions by genuinely emotional, non-Spockian humans in real life.

Shockingly, this story also has a plot. It runs roughly parallel with the HP canon, but the relationships are different and the entire arc of the Potter stories seems d
Andrej Karpathy
Aug 13, 2015 rated it it was amazing
Wonderful alternate Harry Potter timeline story. In many aspects I prefer it to the "real" Harry Potter books. It is kind of like hard sci-fi, but in Harry Potter universe. It starts strong, then drags a bit for a while, but then it ends very strong. Very enjoyable read overall! ...more
Alliana Vivares
Mar 20, 2012 rated it it was ok
Alright, my first complaint is that it should warn readers that it contains sensitive issues. I almost choked on the chocolate I've been eating when I read Draco's nonchalant threat of rape. I mean, hello? Isn't he still eleven? And okay, maybe there are lots of open-minded eleven-year-olds in the world but saying that to an almost complete stranger is too much! Harry was very close to being bad here; it made me wonder what that idiot Petunia had been teaching him. He is rude to his elders, whic ...more
Jan 20, 2012 rated it really liked it
Shelves: fantasy
Eliezer has completely turned the story around with a fabulous mixture of real science and JKRverse. The book is peppered with real life use of rationality , Bayesian Logic and psychology. It’s quite a learning experience, especially if you look up the bits you don’t understand.
May 30, 2012 rated it did not like it
This review has been hidden because it contains spoilers. To view it, click here.
Jul 20, 2012 rated it it was amazing
Harry Potter + science + philosophy = slightly mind boggling + very entertaining

All of the above is true.

However, whether or not I have truly read this fan fiction is a different question. In one sense, I have read it. In another, I have not. The reason for my discontinuity can easily be explained. I have read all of this work that exists up to this point in time. However, this book is far from complete.

In any case, though, I will accept that I have "read" this book because I can't be "current
Faysal Subhani
Aug 09, 2013 rated it it was amazing
Shelves: favourites
Simply Brilliant. Arguably one of the best books I have read so far. Definitely better than the original Harry Potter itself. It's not meant to be a spoof, but an espousal of the author's philosophy of rationality. This book is so realistic, even though it's based on magic. It makes you reflect on life. Above all, it keeps you guessing till the very end because the author refuses to categorize characters in the book as being good or evil. And the best part is, the book is free to download from h ...more
Mar 26, 2014 rated it it was amazing
I will keep this review brief and to the point. First off, all the negative reviews come from people who are either too stupid to understand it or are too in love with the Potterverse to accept something better. Keep that in mind.

Written with a magical version of Ender Wiggin, Harry Potter is a child genius who is skilled in the ways of science and (Yudkowsky's brand of) rationality. Naturally, Eliezer toys with all the loopholes of Rowling's original works, and adds far more depth to the chara
Sep 03, 2013 rated it really liked it
Okay, so this gets tricky.
The first, say, ten-fifteen chapters were AMAZING. I was cracking up (I snorted my soda at pretty much the same times Harry hacked up his Comed-Tea) at the many absolutely hysterical moments that come up when Harry is a complete brilliant jerk with negligible people skills (he has them in theory- probably because he read about them- and he can manipulate, but otherwise...).
Then, by about chapter 15 (maybe not til chapter 20) I just started getting bored. The writing wa
Chris Mulligan
Jun 24, 2013 rated it did not like it
Many of my friends love this book, but after giving it through ~chapter 10 I was incredibly relieved to put it down. It's truly dreadful. Every character is horrible and unpleasant. The "rationality" is mostly Harry being a smug and cruel jackass. I found no humor, and little insight. ...more
Adam Smith
At the time of this review the story is 103 chapters, and counting, long (longer than the actual books), and still within the timeframe of the first book. Set to end March 2015.

An alternate world where the role of Harry Potter is played by a somewhat sociopathic Sheldon Cooper. Instead of marrying the repugnant mr. Dursley, Harry's aunt Petunia married a respected physicist resulting in Harry being raised in a loving environment where knowledge is praised and making the most of your life an acce
Eric Herboso
Not only is this the best fanfiction I've ever read, it is among my favorite novels of all time, and so far I've only been able to read up to chapter 85.

This is a reimagining of the canonical novels of Harry Potter where the main character is extremely rational. Although he is a preteen, this version of Harry Potter has a mind on par with an extremely gifted 18 year old, and it shows. His nemesis, Voldemort, is similarly increased in intelligence by a dramatic amount. The Tom Riddle of this fanf
Jun 05, 2011 rated it liked it
Shelves: fantasy
A fun take on the Potterverse from someone obsessed with all the ways that humans fail to behave in ways that make sense - for a rather strict meaning of "make sense". Leaving aside the usual fights over the legitimacy of fanfic in general, the big question is how much Yudkowsky's Potter is an idealized author stand-in (a "Mary Sue", or "Marty Stu" in the parlance). My answer: Quite a lot, but not fatally. On the minus side, this Harry Potter talks and thinks quite a lot like someone in his late ...more
Utkarsh Kumar
Jul 01, 2016 rated it it was amazing
Shelves: magic-mayhem
6/5 stars!
The book is an absolute treat for HP fans. Set in the alternate universe where Harry's aunt Petunia Evans-Verres married a scientist Michael Verres-Evans instead of good-for-nothing Vernon Dursley, Harry James Potter-Evans-Verres turns out to be a child with a critical logical and scientific thought process. His experiments to understand the underlying secrets behind magic lead to interesting insights. The book on the whole is hilarious. You might not have thought of the original Harry
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From Wikipedia:

Eliezer Shlomo Yudkowsky is an American artificial intelligence researcher concerned with the singularity and an advocate of friendly artificial intelligence, living in Redwood City, California.

Yudkowsky did not attend high school and is an autodidact with no formal education in artificial intelligence. He co-founded the nonprofit Singularity Institute for Artificial Intelligence (

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