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 time. It really makes one wonder what was going through his head in the original version and feels like a direct critique of Rowling. It made me wonder how I managed to ever take the original seriously (might have something to do with me being 8 at the time).

In Eliezer’s version of the story, Harry is a child prodigy; Highly intelligent and educated well beyond his years in the sciences and the methods of rationality, he is well equipped to handle anything the magical world can throw at him and then some. But this Harry also has a dark side and we get to know him better as he struggles to find balance in himself.

The differences in this parallel universe don’t end with Harry, though. His adopting parents, Petunia and Prof. Michael Verres-Evans, are happily married and treat him as they would their own flesh and blood. Ron and Hermione remain mostly the same, although genius Harry obviously prefers to interact with the hard working book-worm and quickly decides that a boring, average ginger is simply not worth his precious time (speaking of time… no, I won’t ruin the surprise). A cunning and manipulative Draco Malfoy and a powerful yet cynical Prof. Quirrell take on larger roles, in quite unexpected ways. We also see much more of Dumbledore (who’s actually read The Lord of the Rings, seeing as every muggle student ever to come to Hogwarts thought that gifting him a copy was an original idea).

It seems important to note that magic is also treated a little bit differently, especially by a scientific Harry, who sets out to test and understand it, thus restoring order to the seemingly shattered laws of physics. Naturally, things don’t go according to plan and at times he is forced to improvise.

The book started out pretty well, with some laugh out loud scenes as Harry finds out about magic for the first time (see quote below). As I read the first few chapters I kept waiting for the level to drop, for the premise to exhaust itself, for my enthusiasm to subside, but 300 pages in and hungrily reading on, It was clear that I’ve stumbled upon something great and that the story is safe in the deft hands of Eliezer Yudkowsky.

“You turned into a cat! A SMALL cat! You violated Conservation of Energy! That’s not just an arbitrary rule, it’s implied by the form of the quantum Hamiltonian! Rejecting it destroys unitarity and then you get FTL signaling! And cats are COMPLICATED! A human mind can’t just visualize a whole cat’s anatomy and, and all the cat biochemistry, and what about the neurology? How can you go on thinking using a cat-sized brain?”
– Harry, HPMoR

The book is funny, at times hilarious. The premise is well executed as Eliezer draws from his vast experience as a rationalist and lets us take a look at genius minds at work; we all know how hard that is to pull off. Methods of Rationality really hits its stride around chapter 5 and according to the author if you haven’t taken to it by chapter 10, then that’s a good time to call it quits (and rethink your interests).

From the get-go, different decisions create chains of cause and effect that send the book in pretty different directions (like Harry finding out almost immediately that he’s prophesied to battle against the dark lord). Other scenes repeat almost word for word, like the first potions lesson with Snape (only this time, Harry refuses to play the victim and stands up to him, in a rather spectacular fashion).

As the story progressed, I found myself engrossed in the plot, invested in the characters and generally unable to put the book down. It is not flawless and at times Eliezer’s inexperience as a novel writer shows, but overall this is as good as it gets. Come for the premise, stay for the story and along the way let the message of rationality rub off and enlighten you. I’ve rarely been as inspired to study, as in love with science or as driven to succeed as when I’ve read this book.

[Posted on goodreads in 2012 by a younger, very impressionable Eddie. Still one of the most influential books I’ve read and the one that started me on the Rationality path.]