Harry Potter and the Methods of Rationality

Harry Potter and the Methods of Rationality

George: "And whatever you do, don't think of an elephant."
Mrs Weasley: "George! Ignore him, Harry dear, there's no reason not to think of an elephant."
Mrs Weasley and George at King's Cross Station[src]

Harry Potter and the Methods of Rationality is an alternate universe Harry Potter fanfiction written by Eliezer Yudkowsky, an AI researcher and decision theorist at the Singularity Institute for Artificial Intelligence. The story focuses on a Harry Potter who enters Hogwarts after having been raised with an Aunt Petunia who married a scientist, and thus has two fundamental differences with his canon counterpart: he had a happy childhood, and he is extremely rational-minded. The fanfiction is known for possibly being the most reviewed Harry Potter fanfiction, with over 20,000 reviews on as of 29 June, 2013.[1]

It's 661,619 words in length, about the same as books 1 through 4 and 7 of the original series combined.[2]  For the most part, its reading level is a bit higher than that of Harry Potter and the Deathly Hallows, though some sections about the philosophy of science and logic are more complex.

Though the author is clearly a fan of the Potter books, he takes several satirical pokes at what he regards as weaknesses or inconsistencies in them.  For example:

Moody had once seen an addicted Dark Wizard go to ridiculous lengths to get a victim to lay hands on a certain exact portkey, instead of just having someone toss the target a trapped Knut on their next visit to town; and after going to all that work, the addict had gone to the further effort to lay a second Portus, on the same portkey, which had, on a second touch, transported the victim back to safety. To this day, even taking the drug into account, Moody could not imagine what could have possibly been going through the man's mind at the time he had cast the second Portus.

In this book, Harry and Hermione are in Ravenclaw, and Ron doesn't appear much, as he's not Harry's friend.


The fanfiction's official website can be found here. It features a mirror of the fanfiction, as well as a cover artwork and links to PDF, podcast and other versions. The site also contains notes from the author, background on scientific concepts featured within the series, fanart and an option for update notifications.


Harry Potter has lived for 11 years with the Evans-Verres - Petunia and her scientist husband Professor Michael, reasonably happy but unaware of magic. One day, he receives a letter addressed to Mr H. Potter inviting him to Hogwarts School of Witchcraft and Wizardry. Sceptical, he nevertheless agrees to a visit from Deputy Headmistress Minerva McGonagall for a demonstration of magic. With magic now seemingly a proven reality, Harry now takes his place at Hogwarts, "armed with Enlightenment ideals and the experimental spirit." However, things are not as easy as they seem; while his rational knowledge helps Harry when dealing with most of the student body, one teacher far outclasses him in the realm of plotting — the one whom he knows as Professor Quirrel, and turns out to be none other than a devilishly intelligent Lord Voldemort possessing the body of Quirrel. Feeling a strange kinship with 'Quirrel', Harry develops a close friendship with him despite his friend Hermione's rightful protests that he appears to be corrupting him.

External links

Notes and references

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