Update: Discussion has moved on to a new thread.

The hiatus is over with today's publication of chapter 73, and the previous thread is approaching the 500-comment threshold, so let's start a new Harry Potter and the Methods of Rationality discussion thread.  This is the place to discuss Eliezer Yudkowsky's Harry Potter fanfic and anything related to it.

The first 5 discussion threads are on the main page under the harry_potter tag.  Threads 6 and on (including this one) are in the discussion section using its separate tag system.  Also: one, two, three, four, five, six, seven.  The fanfiction.net author page is the central location for information about updates and links to HPMOR-related goodies, and AdeleneDawner has kept an archive of Author's Notes.

As a reminder, it's often useful to start your comment by indicating which chapter you are commenting on.

Spoiler Warning:  this thread is full of spoilers.  With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13.  More specifically:

You do not need to rot13 anything about HP:MoR or the original Harry Potter series unless you are posting insider information from Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).

If there is evidence for X in MOR and/or canon then it's fine to post about X without rot13, even if you also have heard privately from Eliezer that X is true. But you should not post that "Eliezer said X is true" unless you use rot13.

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While I like that Hermione is getting her own story-arc, there's something about the "Self-Actualization" arc that really doesn't work for me.

It's increasingly seemed as if "bullies" are being portrayed as an interest group or even a subculture: In MoR, it seems like bullies think of themselves as bullies, and stand up for the common interests of their group by perpetuating bullying as a social institution and singling out for attack those who have challenged other bullies. Even if those other bullies are of a different House, year, or social circle.

This makes Hogwarts' bullies out to be an Evil League of Evil, a cross-House union of Bad Guys who know they're Bad Guys. But at the same time we're expected as readers to take Hogwarts bullying to be some kind of mirror of ordinary real-world school bullying, which doesn't exactly work that way.

The idea of bullies standing up for bullying as an institution, or even thinking of themselves as bullies, reminds me too much of the scene in one of Kevin Smith's movies in which it is revealed that streetcorner drug dealers are unionized.

Yeah, the I've enjoyed the arc well enough, and there were some great bits in this chapter, but it's been a bit small-potatoes compared to some of what's come before, and there's definitely a sense of "just how many bullies are there at Hogwarts, anyway?". It's almost like SPHEW is literally grinding bullies for XP.

How about, SPHEW is inspiring bullies to declare themselves, or non-bullies to become bullies, for the challenge of battling SPHEW? (I'd like this hypothesis better if the bullies weren't older, since even acknowledging first-years as a challenge is quite a status hit.)
From the sounds of this I might have to start reading MoR again. So Hermione doesn't start knitting for house elves, instead she goes around beating the crap through bullies? That's awesome.
This seems like what is currently happening in the latest chapter. Neatly sidestepped in Quirell's explanation.

That doesn't sound wildly different from the online troll subculture.

I can agree with your sentiment but there's plenty of evidence from canon that bullying is seriously endemic to Hogwarts, not to mention the Morcanon point of view where slytherins have found themselves gaining status predominantly from racism against and bullying of mudbloods/hufflepuffs. The entire hogwarts system could almost seem to be DESIGNED to generate ingroup/outgroup hostility in huge amounts to layer on top of the basic cliquishness and age-based splitting of regular school.

also, it's strongly implied in this chapter that the enemies hermione is making now are NOT fighting her because they think of themselves as bullies, but because they view themselves as proud slytherins/griffyndors, and see hermione insulting their entire houses.

I don't really think racism is the right word here. Well at least no more than say classism (in general reading HP its very hard to miss the obvious parallels between the divide among muggles and wizards and the class divisions there).
You can have both! Malfoys hate slytherins because they're lower class, but they never claim they aren't even people, because they're pureblood. But they actually want all mudbloods to die, because they're of a mixed breed with the lesser race.
I think its more like hating people with a congenital defect or people of poor breeding who aren't from noble or prestigious families.
Are you talking specifically about the bully whom the SPHEW took out (barely) ? Because I'm pretty sure that particular individual was deliberately proclaiming himself to be a bully in order to provoke Hermione's attack. Hermione figured it out, too, but just a second too late...
My impression was that there wasn't a League of Bullies, but that SPHEW might have brought one into existence. That is, while most of them might not proudly label themselves "bullies", they share a common quality: people who have been embarassed by Granger & co. As it became clear that they would need to band together to redeem themselves, a loose coalition was formed. So I think of it simply as a bunch of otherwise unaffiliated individuals realizing that they have a common problem and goal, and temporarily banding together to achieve it. Which seems at least more plausible.
Right, they're not the league of bullies; they're the league of innocent people slanderously identified as bullies by SPHEW (the LIPSIBS).

I just realized how Wizard negotiations are so far ahead of their muggle counterparts. They accidentally stumbled upon the best possible decision theory.

Take the prisoner's dilemma, except this time add in time tuners. Defection will immediately be punished by defection. The only stable time-loops that can exist are cooperate-cooperate or defect-defect. Actors with mutual access to time tuners will literally have to choose as though controlling the logical output of the abstract computation they implement, includes the output of all other instantiations and simulations of that computation. You don't need to be able to perfectly predict the other person's actions when you can actually observe them and change your own answers to match before negotiations happen.

Two nations going into negotiations will have the Prime Minister wake up, read a note saying "cooperate - agree to concession and gain concession " then go into negotiations and finish in ten minutes. This seems well within the purview of normal time travel and not too far into calculating prime factors with a time-tuner. Although, I'm not sure if Robin Hanson's pie problem would result in "Everybody co... (read more)

I always imagined that wizards are pretty much detached from the muggle world and their technological level and standards of living have been roughly constant for at least hundreds of years. And meanwhile their level of societal organization progressed gradually.

This is contradicted, at least slightly, within MOR if not in cannon. McGonagall mentions in her internal narrative that wizards never invented clocks or any form of magical time-keeping, and only starting using them after muggles invented them. There may will be many other such cases, certainly the extent to which a lot of magical objects superficially resemble their muggle counterparts is quite suspicious.

Ok. The Tonks thing was really clever. And the bit about double-witches was brilliant. It definitely drives home the whole issue of taking joy in the merely real. It is a clever, original, and highly plausible interpretation of what people would likely do if they grew up taking some sort of secret magic for granted.

I aspire to be a doubly aspiring double rationalist.

Yep, double magic is fantastic. Gonna use that when I hear someone wishing they had magical powers.

Double magic may be a reference to Grossman's The Magicians. Warning: While there are many good things in the book, the viewpoint character is depressed and (in my experience) depressing.

I don't know whether Grossman has read HP:MOR, but he heads it off at the beginning of the book. Everyone at the magic school is a good bit smarter than average, but there's no one who's qualitatively smarter than that, and it's stated that enough unproductive research has been done into the roots of magic that it's generally considered to be a dead end.

Grossman's novel was written in 2009. So barring time travel, he wrote his novel before encountering HPMR if he has encountered it.
Thanks. I should have checked that. Extra props to Grossman for thinking ahead in a general way.
Discworld has "Sourcerers..." - the eighth son of an eighth son is a wizard, and the eighth son of a wizard is a Sourceror, who acts as a source of magic and is capable of doing things ordinary wizards can't. Unfortunately, too much magic in any one area breaks holes in reality and lets in Things from the Dungeon Dimensions, so any Sourceror ends up being a walking apocalypse waiting to happen. Which is also why Discworld wizards are celibate. ;)
And here's [http://lesswrong.com/lw/ve/mundane_magic/] the version one level down from regular people wishing they were magic. Note: this information can only be unlocked with the gift of psychometric tracery.
It was great to see a subversion of this [http://tvtropes.org/pmwiki/pmwiki.php/Main/AllMythsAreTrue] trope.

From the Author's Notes:

Update for Ch. 75: Yes, I know this wasn't quite as good as Ch. 74. They can't all be as good as Ch. 74. Also, at some point you have to choose between abandoning the sick baby or spending another three goddamned months trying to rewrite it. I do think I learned something from the experience, anyway.

I strongly preferred Chapter 75, incidentally. Chapter 74 seemed to be another "need a way to top previous chapters" experience, like the underwater battle in Chapter 33. The talky chapters, like 75, are the real soul of the fic; the CMOA, after all, was the casting of a single Patronus, but the long inner narrative made it what it was.

Anyway, I think it's amusing that authors' favorites rarely correlate positively with readers' favorites.

Eliezer has mentioned that he finds dialog hard to write. Maybe authors' favorites don't match readers' favorites because the authors like the ones that came easily and the readers like the ones that took a lot of effort.
Agreed. The chapters were the characters get to really shine are the best. The underwater battle was cool, but the only part I actually CARED about was what happened at the end with Blaise.

To whichever Less Wrong reader has decided to defend Eliezer's honor by trolling the DarkLordPotter forums: Please stop. I know you mean well, but they as a forum are best ignored. Picking a fight with them, creating multiple accounts to avoid bans, etc., is immature and accomplishes nothing positive.

Agreed, I've enjoyed reading the thread though.
So did I, there are some true gems of unintentional humour in there.
My favourite was this attempt at claiming higher status which goes horribly wrong halfway through the post. [https://forums.darklordpotter.net/showpost.php?p=484961&postcount=101]

When I first saw chapter 74, it ended with this line:

You don't have permission to access on this server.

Until that disappeared, I thought maybe Snape's response to the previous line had broken reality.

At the secret inner double-witch school, everyone's most concerned with figuring out who the top-secret super-inner triple-witches are.

The thought had occurred to me. And if you were a double witch, wouldn't you think it was pretty darned plausible that there were triple witches?

I want to be a first-uncountable-ordinal wizard. :)

1Eliezer Yudkowsky12y
You know, the concept of the first uncountable ordinal is actually one of the strongest reasons I've ever heard to disbelieve in set theory. ZFC, or rather NBG, does imply the existence of a first uncountable ordinal, right, or am I mistaken?

Yes, ZFC is quite enough to imply the existence of the first uncountable ordinal.

On the other hand, I don't see what's unbelievable about such a thing; it's just (the order type of) the set of all countable ordinals, and I don't see why it's unbelievable that there is such a set. (That is, if you're going to accept uncountable sets in the first place; and if you don't want that, then you can criticise ZFC on far more basic grounds than anything about ordinals.)

Wikipedia seems to be saying [http://en.wikipedia.org/wiki/First_uncountable_ordinal] that you can prove the existence of the first uncountable ordinal in pure ZF without the axiom of choice. Is that correct?
Yes, and in fact it can be proved in weaker axiom systems than that.
Okay, are there any decent foundational theories that won't prove it?
It is basically the main point of the definition of ordinals that for any property of ordinals , there is a first ordinal with that property. There are, however, foundational theories without uncountable ordinals , for instance Nik Weaver's Mathematical Conceptualism [http://www.math.wustl.edu/~nweaver/conceptualism.html].
Well, that depends on what you take to be decent. In the sibling, shinoteki has pointed (via Nik Weaver) to J_2. As Weaver argues, this is plenty strong enough to do ordinary mathematics: the mathematics that most mathematicians work on, and the mathematics that (almost always, perhaps absolutely always) is used in real-world applications. On the other hand, I find it difficult to work with, and prefer explicit reasoning about sets (but I'm a mathematician, so maybe I'm just used to that). That said, I think that properly limiting the impredicativity of set-based constructions should allow one to create a set-like theory that corresponds to something like J_2. (I'm being vague here because I don't know better; it's possible, I'd even say likely, that other mathematicians know better responses.)
I think the fact that considering the set of all ordinals leads to trouble should make you somewhat uncomfortable with the set of countable ordinals. I'd go a step further and say you should be uncomfortable with the set of finite ordinals. But maybe these are the more basic criticisms you're talking about.
Why not go even further and declare yourself uncomfortable with any finite set of ordinals bigger then what you've personally written down?
Well, I trust well-written computer programs as much or more as I trust my own pen-and-paper stuff, but otherwise that's pretty accurate. I'm uncomfortable with claims about the existence of 3^^^3, for instance. "Uncomfortable" isn't just empty skepticism, it's shorthand for something precise: I think that by reasoning about very large numbers (say, large enough that it's physically impossible to so reason without appealing to induction) it might be possible to give a valid proof of a false statement.
What about something like 10^100, i.e., something you could easily wright out in decimal but couldn't count to?
"Do my ten fingers exist" is a hard question for reasons that are mostly orthogonal to what I think you intend to ask about 10^100. Let's start by stipulating that zero exists, and that if a number n exists then so does n+1. Then by induction, you can easily prove that 10^100, 3^^^3 and worse exist. But this whole discussion boils down to whether we should trust induction. It turns out that without induction, we can prove in less than a page that 10^100 and even 2^^5 = 2^(60000 or so) exists in my sense. In terms of cute ideas involved, if not in raw complexity, this is a somewhat nontrivial result. See pages 4 and 5 of the Nelson article [http://www.math.princeton.edu/~nelson/papers/e.pdf] I linked to earlier. One cannot prove that 3^^^3 exists, at any rate not with a proof of length much less than 3^^^3. What I've called "existing numbers," Nelson calls "counting numbers." The essence of the proof is to first show that addition and multiplication are unproblematic in a regime without induction, and then to construct 2^^5 with a relatively small number of multiplications. But exponentiation is problematic in this regime, for the somewhat surprising reason that it's not associative. It does not lend itself to iteration as well as multiplication does.
Edward Nelson has now announced [http://www.cs.nyu.edu/pipermail/fom/2011-September/015816.html] a proof that Peano Arithmetic (and even the weaker Robinson Arithmetic) is inconsistent. His proof is not yet fully written up, but there's an outline (see the previous link). Terry Tao (whose judgement I trust, since this goes beyond my expertise) reports on John Baez's blog [http://golem.ph.utexas.edu/category/2011/09/the_inconsistency_of_arithmeti.html] that he believes that he knows where a flaw is. Edit: Terry and Nelson are now debating live on the blog! Edit again: I should have reported long ago that Nelson has conceded defeat.
Another term to search for is "feasible numbers". There are several theories of these, and Nelson's theory of countable (addable, multipliable, etc) numbers is yet another.
Why stop at big numbers? Even the numbers you handle in everyday life might lead to a false statement, you are not logically omniscient and therefore wouldn't necessarily know if they did. Why not be uncomfortable with everything?
Scenario 1: I have defined a sequence of numbers Xn, but these numbers are not computable. Nevertheless you give a proof that the limiting value of these numbers is 2, and then another, entirely different proof that the limiting value is 3. Therefore, 2 = 3. But since Xn is not computable, your proofs are necessarily non-constructive, so you haven't given me a physical recipe for turning 2 quarters into 3 quarters. I would sooner say that you had proved something false, and re-examine some of your nonconstructive premises. Scenario 2: You prove that 2 = 3 constructively. This means you have given me a recipe for turning 2 quarters into 3 quarters. I wouldn't say you had proved something false but that you had discovered a new phenomenon, weird but true.
In both cases I would suspect my own mathematical ability, or even my sanity, before suspecting maths. Lcpwing those concerns away, I would observe that a certain set of statements had been proven not mutually consistent which in turn means they do not underpin our physics (granted this would be more surprising in one case than the other).
Something like Scenario 1 has already happened, with Russell's paradox. People did not react by questioning their own sanity but by regarding Russell's construction as "cheating", and reconstituting the axioms so that Russell's construction was forbidden. We're deep into insanity territory with Scenario 2, but people have speculated about such things here before [http://lesswrong.com/lw/jr/how_to_convince_me_that_2_2_3/].
I am fully aware of Russell's paradox. I still think some sanity checks may be worthwhile, as the number of people who have thought they achieved scenario 1 but were in fact crackpots significantly exceeds one.
That there is a set of all countable ordinals is one thing; that it can be well-ordered is quite another. Not to mention that I doubt you can prove omega_1 exists in Z, which has quite a few uncountable sets.
You don't need Z, third-order arithmetic is sufficient. Every set of ordinals is well-ordered by the usual ordering of ordinals.
Only if you accept excluded middle.
That depends on what you mean by "well-ordered". My philosophy of doing constructive mathematics (mathematics without excluded middle, and often with other restrictions) is that one should define terms as much as possible so that the usual theorems (including the theorems that the motivating examples are examples) become true, so long as the definitions are classically (that is using the usually accepted axioms) equivalent to the usual definitions. As the motivating example of a well-ordered set is the set of natural numbers, we should use a definition that makes this an example. Such a definition may be found at a math wiki where I contribute my research [http://ncatlab.org/nlab/show/well-order] (such as it is). Then (adopting a parallel definition of "ordinal") it remains a theorem that every set of ordinals is well-ordered.
I had to look carefully in order to see that it doesn't necessarily contradict itself even though I should have known this from Gödel, Escher, Bach. On reflection this ordinal probably represents something real -- a set of Gödel statements, which we'd regard as 'true' if we knew about them. Or rather, the fact that it seems meaningful to deny the existence of a general formula for producing these Gödel statements that will generate any given example if the process runs long enough. (To get an uncountable set of the right kind I might have to qualify this by saying something like "G-statements you could generate starting from a given system and a given method of Gödel numbering," but I can't tell how much of that we actually need.)
I had to check to be sure, but then saw others noted it: Raw ZF seems quite sufficient [http://en.wikipedia.org/wiki/Hartogs_number] to prove its existence. So even tossing Choice in the bin isn't enough to get rid of it. EDIT: Perhaps this is math's revenge for you having tiled a hall in Hogwarts with pentagons. :)

Perhaps this is math's revenge for you having tiled a hall in Hogwarts with pentagons. :)

But he didn't say regular pentagons. Pentagon tiles shown here. Also, he did say that Hogwarts has non-Euclidean geometry.

Actually, my understanding was that he said it didn't have geometry at all, only topology.
1Eliezer Yudkowsky12y
It's not Choice I have the problem with here, it's set theory.
Do you think that uncountable sets don't exist, or that there is no way to order them such that one is first?
-2Eliezer Yudkowsky12y
The existence of the real number line is one thing. The existence of an uncountable ordinal is another. When you consider the hierarchies of uncomputable ordinals to their various Turing degrees that are numbered among the countable ordinals, and that which countable ordinals you can constructively well-order strongly corresponds to the strength of your proof theory and which Turing machines you believe to halt, and when you combine this with the Burali-Forti paradox saying that the predicate "well-ordered" cannot be self-applicable, even though any given collection of well-orderings can be well-ordered... ...I just have trouble believing that there's actually any such thing as an uncountable ordinal out there, because it implies an absolute well-ordering of all the countable well-orderings; it seems to have a superlogical character to it.
I wonder how much of this is just a function of what math you've ended up working with a lot. Humans have really bad intuition about math. This shouldn't be that surprising. We evolved in a context where selection pressure was on finding mates and not getting eaten by large cats. Speaking from personal experience as a mathematician (ok a grad student but close enough for this purpose) it isn't that uncommon for when I encounter a new construction that has some counterintuitive property to look at it and go "huh? Really?" and not feel like it works. But after working with the object for a while it becomes more concrete and more reasonable. This is because I've internalized the experience and changed my intuition accordingly. There are a lot of very basic facts that don't involve infinite sets that are just incredibly weird. One of my favorite examples are non-transitive dice. We define a "die" to be a finite list of real numbers. To role a dice we pick a die a random number from the list, giving each option equal probability. This is a pretty good representation of what we mean by a dice in an intuitive set. Now, we say a die A beats a die B if more than half the time die A rolls a higher number than die B. Theorem: There exist three 6-sided dice A, B and C with positive integer sides such that A beats B, B beats C and C beats A. Constructing a set of these is a fun exercise. If this claim seems reasonable to you at first hearing then you either have a really good intuition for probability or you have terrible hindsight bias. This is an extremely finite, weird statement. And I can give even weirder examples including an even more counterintuitive analog involving coin flips. I just don't see "my intuition isn't happy with this result" to be a good argument against a theorem. All the axioms of ZF seem reasonable and I can get the existence of uncomputable ordinals from much weaker systems. So if there's a non-intuitive aspect here, that's a reason to update my in
Here is another page [http://singingbanana.com/dice/article.htm] dealing with non-transitive dice that I liked.
Oooh. That page is excellent. I have not seen dice with the order reversing property before. Even being a fan of non-transitive dice and having seen this sort of thing before that was highly unexpected. I'm going to have to sit down and look hard about what is going on there.
The axiom of foundation seems pretty ad hoc to me. It's there to patch Russell's paradox. I see no reason not to expect further paradoxes. We arrived at the axiom of infinity from a finite amount of experience, which seems troubling to me. It's a very cool construction, but it's a finite one that we can verify by hand or with computer assistance. Of the things that ZF claims exist, some of them have this "verifiability" property and some don't. At the very least don't you agree that's a crucial distinction, and that we ought to be strictly less skeptical of constructible, computable, verifiable things than of things like uncountable ordinals?
Also, there's another respect in which foundation doesn't impact Russell issues at all. Whether one accepts foundation, anti-foundation or no mention of foundation, one can still get very Russellish issues if one is allowed to form the set A of all well-founded sets. Simply ask if A is well-founded or not. This should demonstrate that morally speaking, foundation concerns are only marginally connected to Russell concerns.
To make the obvious comment, this is all unnecessary as Russell's paradox goes through from unrestricted comprehension (or set of all sets + ordinary restricted comprehension) without any talking about any sort of well-foundedness... But that's a neat one, I hadn't thought of that one before. However I have to wonder if it works without DC. Edit: Answer is yes, it does, see below.
Sorry. what do you mean by DC?
Dependent choice. Edit: I feel silly, this doesn't use dependent choice at all. OK, so the answer to that is "yes". However it does require enough structure to be able to talk about infinite sequences, unless there's some other way of defining well-foundedness.
There are (at least) three ways to define well-foundedness, roughly: * one which requires impredicative (second-order) reasoning; * one which requires nonconstructive reasoning (excluded middle); * one which requires infinitary reasoning (with dependent choice, and also excluded middle actually). They may all be found at the nLab article on the subject [http://ncatlab.org/nlab/show/well-founded+relation]; this article promotes the first definition (since we use constructive mathematics there much more often than predicative mathematics), but I think that the middle one (Lemma 2 in the article) is actually the most common. However, the last definition (which you are using, Lemma 1 in the article) is usually the easiest for paradoxes (and DC and EM aren't needed for the paradoxes either, since they're used only in proofs that go the other way).
One thing bothering me -- is there any way to define a well-founded set without using infinitary reasoning? It's easy enough to say that all sets are well-founded without it, by just stating that ∈ is well-founded -- I mean, that's what the standard axiom of foundation does, though with the classical definition -- but in contexts where that doesn't hold, you need to be able to distinguish a well-founded set from an ill-founded one. Obvious thing to do would be to take the transitive closure of the set and ask if ∈ is well-founded on that, but what bugs me is that constructing the transitive closure requires infinitary reasoning as well. Is there something I'm missing here?
I know one way; it cannot be stated in ZFC↺ (ZFC without foundation), but it can be stated in MK↺ (the Morse–Kelley class theory version): a set is well-founded iff it belongs to every transitive class of sets (that is every class K such that x ∈ K whenever x ⊆ K); it is immediate that we may prove properties of these sets by induction on membership, and a set is well-founded if all of its elements are, so this is a correct definition. However, it requires quantification over all classes (not just sets) to state.
Sure foundation is by far the most ad-hoc axiom. But it is also one of the one's that is easiest to see doesn't generally matter. For pretty much any natural theorem if a proof uses foundation then there's a version of the theorem without it. Since not-well founded sets don't fit most of out intuition for sets as things like boxes that's not an issue. None of the serious apparent paradoxical properties go away if you remove foundation. Yes, certainly but by how much? If our intuition can go this drastically wrong on small finite objects why should I trust my intuition on objects that are even further removed from my everyday experience? I mean it isn't like I need 30 or 40 sided dice to pull this off. In fact you can actually make much smaller than 6 sided dice that are non-transitive. Working out the minimum number of sides (assuming that each die in the set doesn't need to have the same number of sides) is a nice exercise that helps one understand what is going on.
You're right, I see that it's the "restriction" of restricted comprehension that actually does the work in avoiding Russell's paradox, not foundation. Nevertheless, the story is the same: we had an ambitious set-theoretic foundation for mathematics, Russell found a simple and fatal flaw in it, and we should not simply trust that there will be no further problems after patching this one. This is hardly an argument for accepting that infinite sets exist! There may be a counterintuitive contradiction that one can arrive at from ZF, just as Russell's paradox is a counterintuitive contradiction arrived at from 19th century foundations, and just as all kinds of counterintuitive but non-contradictory behavior is possible in the finite, constructive realm. I am proposing that we remove the axiom of infinity from foundations, not that we go further and add its negation. (Though I see that there has been work done on the negation of the foundation axiom! And dubious speculation about its role in consciousness.)
Also one other remark: Foundation isn't there to repair any Russel issues. You can get as a theorem that Russell's set doesn't exist using the other axioms because you obtain a contradiction. Foundation is more that some people have an intuition that sets shouldn't be able to contain themselves and that together with not wanting sets that smell like Russell's set caused it to be thrown in.
And of course more generally, for those not familiar, you can never get rid of paradoxes by adding axioms!
I'm really tempted to be obnoxious and present an axiomatic system with a primitive called a "paradox" and then just point out what happens one adds the axiom that there are no paradoxes. This is likely a sign that I should go to bed so I can TA in the morning.
How about by legislating? Has that been tried?
2Eliezer Yudkowsky12y
I would be interested in knowing if there is any second-order system which is strong enough to talk about continuity, but not to prove the existence of a first uncountable ordinal.
I can do better. I can give you a complete, decidable, axiomatized system that does that: first order real arithmetic. However, in this system you can't talk about integers in any useful way. We can do better than that: first order real arithmetic + PA + a set of axioms embedding the PA integers into R in the obvious way. This is a second order system where I can't talk about uncountable ordinals. However, this system doesn't let us talk about sets. Note that in both these cases we've done this by minimizing how much we can talk about sets. Is there some easy way to do this where we can talk about set a reasonable amount? I'm not sure. Answering that may be difficult (I don't think the question is necessarily well-defined.) However, I suspect that the following meets one's intuition as an affirmative answer: Take ZFC without regularity, replacement or infinity, choice, power set or foundation. Then add as an axiom that there exists a set R that has the structure of a totally ordered field with the least-upper bound property. This structure allows me to talk about most things I want to do with the reals while probably not being able to prove nice claims about Hartogs numbers which should make proving the existence of uncountable ordinals tough. It would not surprise me too much if one could get away with this system with the axiom of the power set thrown also. But it also wouldn't surprise me either if one can find sneaky ways to get info about ordinals. Note that none of these systems are at all natural in any intuitive sense. With the exception of first-order reals they are clear attempts to deliberately lobotomize systems. (ETA: Even first order reals is a system which we care about more for logic and model theoretic considerations than any concrete natural appreciation of the system.) Without having your goal in advance or some similar goal I don't think anyone would ever think about these systems unless they were a near immortal who was passing the time by
Note that without replacement, you can't construct the von Neumann ordinal omega*2, or any higher ones, so certainly not omega_1. Of course, this doesn't prevent uncountable well-ordered sets (obviously these follow from choice, though I guess you're taking that out as well), but you need replacement to show that every well-ordered set is isomorphic to a von Neumann ordinal. So I don't think that this should prevent the construction of an order of type omega_1, even if it can't be realized as a von Neumann ordinal. Of course losing canonical representatives means you have to talk about equivalence classes, but if all we want to do is talk about omega_1, it suffices to consider well-orderings of subsets of N, so that the equivalence classes in question will in fact be sets. Maybe there's some other technical obstacle I'm missing here (like it somehow wouldn't be the first uncountable ordinal despite being the right order?) -- this isn't really my area and I haven't bothered to work through it, I can try that later -- but I wouldn't expect one.
There's not. The Hartog's number construction gives us the set H(N) of all isomorphism classes of well-orders on subsets of any fixed countably infinite set, and we can prove that H(N) is uncountable and every proper initial segment of H(N) is countable, using power set and separation (but only bounded separation) but not replacement. I verified this just now by looking at Wikipedia's article on Hartog's number [http://en.wikipedia.org/wiki/Hartogs_number] and checking through the proof myself. The next step (step 4 in Wikipedia, ETA: which can be saved for the end, although WP did not do so) is to replace the elements of H(N) with von Neumann ordinals, but this is really beside the point. You already have a representation of the least uncountable ordinal, and this step is just making it canonical in a certain way.
Heh, I'd forgotten how simple Hartogs number was in general.
It's not clear to me that ZFC without regularity, replacement, infinity, choice, power set or foundation with a totally ordered field with the LUB property does allow you to talk about most things you want to do with the reals : without replacement or powerset you can't prove that cartesian products exist, so there doesn't seem to be any way of talking about the plane or higher-dimensional spaces as sets. If you add powerset back in you can carry out the Hartogs number [https://secure.wikimedia.org/wikipedia/en/wiki/Hartogs_number] construction to get a least uncountable ordinal
Hmm, that's a good point. Lack of cartesian products is annoying. We don't however need the full power set axiom to get them. We can simply have an axiom that states that cartesian products exist. Or even weaker do the following (ad hoc axioms) with a new property of being Cartesian: 1. The cartesian product of any two Cartesian sets exist. 2. Any subset of R is Cartesian. 3. The cartesian product of two Cartesian sets is Cartesian. 4. If A and B are Cartesian then A union B, A intersect B, and A\B are all Cartesian. That should be enough and is a lot weaker than general power set I think.
van den Dries, "Tame topology and o-minimal structures," Cambridge U Press 1998 develops a lot of 20th century geometry in a first order theory of real numbers. You can do enough differential geometry in this setting to do e.g. general relativity.
The J_2 referenced in this subthread [http://lesswrong.com/lw/797/harry_potter_and_the_methods_of_rationality/4rov] shoud do the trick. (See in particular number 6 in the page linked to by shinoteki there).
What does "existence" have to do with anything though? Even if the real world, or morality don't "exist" in some sense, you still go on making decisions, reason about their properties. (There appear to be two useful senses of "doesn't exist": the state of some system is such that some property isn't present; or a description of a system is contradictory. These don't obviously apply here.) The trouble is, human value might turn out to talk about complicated mathematical objects, just like mathematicians can think about (simpler kinds of) them, and it's not clear where to draw the line, at least to me while I still have too little understanding of what humane value is. Reasoning about math objects, as opposed to just patterns of the world, seems to be analogous to reasoning about the world, as opposed to just patterns in observation. I don't believe there has to be a boundary around physics, a kind of "physical solipsism". And limitations of representation don't seem to solve the problem, as formal systems might be unable to capture particular classes of models of interest, but they can be seen as intended to elucidate properties of those models.
In set theory there's a formal symbol that's read "there exists", and a pair of formal symbols that are read "there doesn't exist". Do you think these symbols should be understood in either of your two useful senses?
It is possible to read the existential quantifier as "for some" instead of "there exists … such that". I often do this myself, just for euphony (and to match the dual quantifier, read "for all", or better "for each"). But Graham Priest (pdf [http://mail.scu.edu.tw/~phstudies/pdf/no.16/no.16Priest.pdf]) has argued that the "there exists" reading is a case of ontological sleight of hand that should be resisted; in fact, he rejects the term "existential quantifier" for "particular quantifier" (and a web search for this will turn up more on the subject).
I can't think of a situation where I would accept one but not the other of "there exists x such that ---" and "for some x ---". Do you have an example? Godel has a very interesting paper about syntax for intuitionism, where he introduces a new operator read "there exists constructively."
Priest (top of page 3 in the PDF above, numbered page 199) suggests an example: In symbols: Turning this back into English: But not this: One could rescue this by claiming that x exists in the speaker's past thoughts but not in reality, or something like that. But then an uncountable ordinal may also exist in the thoughts of mathematicians without existing in reality.
There are many models of interest in set theory, with different mutually exclusive properties. A logical statement makes sense in context of axioms or intended model. I didn't take Eliezer's comment as referring to either of these technical senses (it's not expecting provability of nonexistence from standard axiom systems, since they just assert existence in question, the alternative being asserting inconsistency, which would be easier to state directly; and standard model is an unclear proposition for set theory, there being so many alternatives, with one taken as the usual standard containing the elements in question). So I was talking about "ontological" senses of "existence" instead.
ZF proves in formal symbols "there exists a smallest uncountable ordinal," and I guess you are saying that it does not mean that in an ontological sense. But then what is the ontological payoff of this proof?
Don't know, maybe not denying that the idea is consistent, and so doesn't "doesn't exist" in that sense?
Like any proof in a formal system, you can conclude that "the idea is consistent unless the formal system is inconsistent." But that's a tautology. If you're not willing to say that ZF refers to things in the real world i.e. has ontological content, why aren't you skeptical of it?
I wasn't saying that. If you believe that a formal system captures the idea you're considering, in the sense of this idea being about properties of (some of) the models of this formal system, and the formal system tells you that the idea doesn't make sense, it's some evidence towards the idea not making sense, even though it's also possible that the formal system is just broken, or that it doesn't actually capture the idea, and you need to look for a different formal system to perceive it properly. ZF clearly refers to lots of things not related to the physical world, but if it's not broken (and it doesn't look like it is), it can talk about many relevant ideas, and help in answering questions about these ideas. It can tell whether some object doesn't hold some property, for example, or whether some specification is contradictory. (I know a better term for my current philosophy of ontology now: "mathematical monism". From this POV, inference systems are just another kind of abstract object, as is their physical implementation in mathematicians' brains. Inference systems are versatile tools for "perceiving" other facts, in the sense that (some of) the properties of those other facts get reflected as the properties of the inference systems, and consequently as the properties of physical devices implementing or simulating the inference systems. An inference system may be unable to pinpoint any one model of interest, but it still reflects its properties, which is why failure to focus of a particular model or describe what it is, is not automatically a failure to perceive some properties of that model. Morality is perhaps undefinable in this sense.)
This is again not the sense I discussed. A claim that an uncountable ordinal "doesn't exist" has to be interpreted in a different way to make any sense. A claim that it does doesn't need such excursions, and so the default senses of these claims are unrelated.
I don't think that it's fair to characterise the B-F paradox this way. The argument of B-F is that, given any collection S of well-orderings closed under taking sub-well-orderings, S cannot be among the well-orderings represented in S itself. There is nothing paradoxical here. (I'm not sure whether this matches the content of Cesare Burali-Forti's 1897 paper, which I haven't read and of which I've heard conflicting accounts, but the secondary sources all seem to agree that he did not believe that he had found a paradox. ETA: After following the helpful link from komponisto, I see that sadly this is not how B-F himself viewed the matter.) Now, if you add the assumption of an absolute collection of all well-orderings, then you get a paradox. But an absolute collection of (say) all finite well-orderings leads to no paradox; we just know that this collection is not finite. And an absolute collection of all countable well-orderings leads to no paradox either; we just know that this collection is not countable. And so on. Of course, none of this shows that such collections actually exist. If you said that you don't really believe in uncountable ordinals (perhaps on the grounds that they're not needed for applications of mathematics to the real world), I would not have commented (except maybe to agree); but calling them incredible (as you seem to do, counting them as evidence against set theory, indeed among the strongest that you know) goes far beyond what I would consider justified.
You can read Burali-Forti's 1897 paper here [http://books.google.com/books?id=v4tBTBlU05sC&pg=PA104&lpg=PA104&dq=burali-forti+1897+paper&source=bl&ots=KOgjeNOkwN&sig=w1EzgD05E4GxA5TGv5EHd1B9Dew&hl=en&ei=HhZtTqChDMOusQKAxJHIBA&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAg#v=onepage&q=burali-forti%201897%20paper&f=false]
There seems to be controversy about "exist" and "out there", can you taboo those? For example, are you saying the you think Ultimate Ensemble does not contain structures that depend on them, or that they lead to an inconsistency somewhere, or simply that your utility function does not speak about things that require them, or what exactly?
This isn't a much simple/weaker claim than other possible meanings for "I just have trouble believing". Their underlying other utility functions would be contagious. For example, if my utility function requires them, then someone of whom it is accurate to say that "His utility function does not speak about things that require them" would't be able to include in his utility function my desires, or desires of those who cared about my desires, or desires of people who cared about the desires of people who cared about my desires, and so forth. Eliezer cares about some people, some people care about me, and the rest is six degrees of Kevin Bacon. The most extreme similar interpretation would have to be a statement about human utility functions in general.
I don't know what it means to care about the existence of the smallest uncountable ordinal (as opposed to caring that this existence can be proved in ZF, or cannot be refuted in second-order arithmetic, or something like that). Can we taboo "smallest uncountable ordinal" here?
well, yea, presumably it implies he believes all humans have that trait, but he could still accept superhappies or papperclipers caring about it say.
In real life, I've had some trouble recently admitting I hadn't thought of something when it was plausible to claim I had. I think that admitting it would/will cost me status points, as it does not involve rationalists, "rationalists", aspiring rationalists, or "aspiring rationalists". Are you sure you chose the phrase "simply that your utility function does not speak about things that require them" to describe the state of affairs where no human utility function would have it, and hence it would be unimportant to Eliezer? If you see the thought expressed in my comment as trivially obvious, then: 1) we disagree about what people would find obvious, 2) regardless of the truth of what people find obvious, you are probably smarter than I to make that assumption, rather than simply less good at modeling other humans' understanding, 3) I'm glad to be told by someone smarter than I that my thoughts are trivial, rather than wrong.
The comment wasn't really intended for anyone other than Eliezer, and I forgot to correct for the halo making him out to me basically omniscience and capable of reading my mind.
I think he actually might intrinsically value their desires too. One can theoretically make the transition from "human" to "paperclip maximizer" one atom at a time; differences in kind are the best way for corrupted/insufficiently powerful software to think about it, but here we're talking about logical impurity, which would contaminate with sub-homeopathic doses.
Well, in that case it's new information and we can conclude that either his utility function DOES include things in those universes that he claim can not exist, or it's not physically possible to construct an agent that would care about them.
I would say "care dependent upon them". An agent could care dependent upon them without caring about them, the converse is not true.
That's even wider, although probably by a very small amount, thanks!
For essentially the same reasons I have trouble believing that the first infinite ordinal exists. Finite ordinals are computable, but otherwise your remarks still apply if you swap out "countable" for "finite." According to ZF there are uncomputable sets of finite ordinals, so you can't verify that they are well-ordered algorithmically.
So what you're saying is that you don't believe the natural numbers exist.
The natural numbers exist in about the strongest possible sense: I can get a computer program to spit them out one by one, and it won't stop until it runs out of resources. It's more accurate to say I don't believe that they're well-ordered, see here [http://lesswrong.com/lw/3aj/exponentiation_goes_wrong_first/]. You might find my reasoning preposterous, I only wanted to point out that it's essentially the same as EYs reasoning about uncountable ordinals.
Set theory is just a made up bunch of puzzle pieces (axioms) and some rules on how to fit them together (logic) so it's weird to hear you lot talking about "existence" of a set with some property P as something other than whether or not the statement "exists X, P(X)" has a proof or not. I thought Hilbert's finitist approach should have slain Platonism long ago.
The following is a comment by John Baez, posted on Google+ where I linked to this thread:

"The Axiom of Choice is obviously true, the well-ordering principle obviously false, and who can tell about Zorn's lemma?"

— Jerry Bona

1Eliezer Yudkowsky12y
This makes it sound like believing in an uncountable ordinal is equivalent to AC, which would make things easier - lots of mathematicians reject AC. But you might not need AC to assert the existence of a well-ordering of the reals as opposed to any set, and others have claimed that weaker systems than ZF assert a first uncountable ordinal. My own skepticism wasn't so much the existence of any well-ordering of the reals (though I'm willing to believe that no such exists), my skepticism was about the perfect, canonical well-ordering implied by there being an uncountable ordinal onto whose elements all the countable ordinals are mapped and ordered. Of course that could easily be equivalent to the existence of any well-ordering of the reals.
No they don't (*). Your saying this explicitly somewhat confirms my brain's natural, automatic assumption that your error here (and in similar comments in the past -- "infinite set atheism" and all that business) is as much sociological as philosophical: all along, I instinctively thought, "he doesn't seem to realize that that's a low-status position". ZFC is considered the standard axiom system of modern mathematics. I have no doubt that if an international body (say, the IMU) were to take a vote and choose a set of "official rules of mathematics", the way (say) FIDE decides on the official rules of chess, they would pick ZFC (or something equivalent). Now it's true, there are some mathematicians who are contrarians and think that AC is somehow "wrong". They are philosophically confused, of course; but, more to the point here in this comment, they are a marginal group. (In fact, even worrying about foundational issues too much -- whatever your "position" -- is kind of a low-status marker itself: the sociological reality of the mathematical profession is that members are expected to get on with the business of proving impressive-looking new theorems in mainstream, high-status fields, and not to spend time fussing about foundations except at dinner parties.) See also this comment of mine [http://lesswrong.com/lw/10q/the_two_meanings_of_mathematical_terms/v6d]. (*) I don't know the numbers, or how you define "lots", and there are a large number of mathematicians in the world, so technically I don't know if it's literally false that "lots" of mathematicians would say that they "reject AC" . But the clear implication of the statement -- that constructivism is a mainstream stance -- most definitely is false.

I think you are stating these things too confidently.

Most mathematicians could not state the axioms of ZFC from memory. My suspicion is that AC skepticism is highest among mathematicians who can.

One piece of evidence that AC skepticism is not low-status is that papers and textbooks will often emphasize when a proof uses AC, or when a result is equivalent to AC. People find such things interesting.

You could make a stronger case that skepticism about infinity is regarded as low-status.

But what do status considerations have to do with whether Yudkowsky's beliefs and hunches are justified?

I don't see why this is even relevant, but for what it's worth, I don't particularly share this suspicion: I would expect those who know the axioms from memory to be more philosophically sophisticated (i.e. non-Platonist), and to be more likely to be familiar with technical results such as Gödel's theorem that ZFC is as consistent as ZF. My own impression is that professed "AC skepticism" (scarequotes because I think it's a not-even-wrong confusion) is most correlated not with interest in logic and foundations, but with working in finitary, discrete, or algebraic areas of mathematics where AC isn't much used. The fact that people find such things interesting is at best extremely weak evidence for the proposition that constructivism and related positions are mainstream. (After all, I find such things interesting!) As I pointed out in the comment linked to above, there is a difference between dinner-party acknowledgement of constructivism (which is widespread) and actually taking it seriously enough to worry about whether one's results are correct (which would be considered eccentric). If AC skepticism were not low-status, you would expect to find papers and textbooks actively rejecting AC results, rather than merely mentioning in a remark or footnote that AC is involved. (Such footnotes are for use at dinner parties.) And also, texts just as frequently do not bother to make apologies of the sort you allude to. A fairly random example I recently noticed was on p.98 of Algebraic Geometry by Hartshorne, where Zorn's Lemma is used without any more apology than an exclamation point at the end of the (parenthetical) sentence. It tends to irritate me when people get something wrong which they could easily have gotten right by using a standard human heuristic (such as the "status heuristic", noticing what the prestigious position is).
This is also my experience.
They're also more likely to know Cohen's theorem that ZF + not(AC) is also just as consistent. And of course, being philosophically sophisticated, it's clear to me that they would be more likely to realise that the axioms of ZFC are fairly arbitrary and no better than many others. They're also more likely to know, and to appreciate the philosophical significance of, that there are many axiom systems that are strong enough to do most mathematics (including all concretely applied mathematics) and yet much weaker (hence more surely consistent) than ZFC (although this has little to do with AC as such). However, when arguing about what philosophically sophisticated people are going to think, we're both naturally inclined to think that they'll agree with ourselves, so our impressions about that prove nothing. You do find such things (but they are mostly published in certain journals, which we can tell are low-status, since such things are published in them).
I'm not sure about that. You and komponisto seem to be using 'philosophically sophisticated' to contrast with Platonism. This use strikes me as similar to how arguing that 'death is good' is sophisticated [http://lesswrong.com/lw/2pv/intellectual_hipsters_and_metacontrarianism/], i.e., showing of your intelligence by providing convincing arguments for a position that violates common sense. In this case arguing that mathematical statements don't have inherent truth value. Remember just because you can make a sophisticated sounding argument for a preposition doesn't mean its true.
Mathematica statements do have inherent truth value, but that value is relative to the axioms. And as far as the axioms go, the most you can say is that a system of axioms is consistent, and beyond that you get into non-mathematical statements. What exactly is sophisticated about this?
Yes, which agrees with my complaint quoted above. Neither of us is a Platonist, so we both assume that philosophically sophisticated people won't be Platonists, although we derive different things thereafter. I'm certainly not trying to show off my intelligence. I just think that the idea of inherent truth value for abstract statements about completed infinities violates common sense!
If that's so, what accounts for your intuition that ZF and other systems for reasoning about completed infinities are consistent?
To the extent that I have this intuition, this is mostly because people have used these systems without running into inconsistencies so far. (At least, not in the systems, such as ZF, that people still use!) But strictly speaking, ‘ZF is consistent.’ is not a statement with an absolute meaning, because it is itself a statement about a completed infinity. I have high confidence that no inconsistency in ZF has a formal proof of feasible length, but I really have no opinion about whether it has an inconsistency of length 3^^^3; we haven't come close to exploring such things. (Come to think of it, I believe that my Bayesian probability as to whether ZF is consistent to such a degree ought to be quite low, for essentially the same reason that a random formal system is likely to be inconsistent, although I'm not really sure that I've done this calculation correctly; I can think of at least one potential flaw.) I cannot speak for komponisto about any of this, of course.
I'm mostly with you. These feasibility issues are definitely interesting. Another possibility is that there is a formal proof of feasible length, but no feasible search will ever turn it up. (Well, unless P = NP). Yet another possibility is that a feasible search will turn it up, I certainly regard it as more likely than most people do. I agree that this counts as evidence, but it's possible to overestimate it. Foundational issues hardly ever come up in everyday mathematics, so the fact that people are able to prove astonishing things about 3-manifolds without running into contradictions I regard as very weak evidence in favor of ZF. There have been a lot of man-hours put into set theory, but I think quite a bit less than have been put into other parts of math. JoshuaZ and I had a discussion about this a while ago, starting here [http://lesswrong.com/lw/5jv/no_coinductive_datatype_of_integers/43uh].
This reminds me of people who argue that, because P != NP, we will never prove this. (The key to the argument, IIRC, is that any proof of this fact will have very high algorithmic complexity.) I'm not sure how to find this argument now. (There is something like it one of Doron Zeilberger's April Fools opinions [http://www.math.rutgers.edu/~zeilberg/Opinion45.html].) Yes, these results should be formalisable in higher-order arithmetic (indeed _n_th order for n a single-digit number). It is the set theorists' work with large cardinals and the like that provides the only real evidence for the consistency of such a high-powered system as ZF.
Yes; that's definitely within the scope of my "such as"! Not quite. Remember that I gave a specific meaning for "philosophically sophisticated": I said it meant "non-Platonist". And what I meant by that, here, is not believing that AC (or any other formal axiom) represents some kind of empirical claim about "the territory" that could be "falsified" by "evidence", despite being part of a consistent axiom system. I claim the situation with AC is like that of the parallel postulate: it makes no sense to discuss whether it is "true"; only whether it is "true within" some theory. What I meant was more like: you would find some substantial proportion (say 20% or more) of textbooks being used to teach analysis (say) to graduate students in mathematics omitting all theorems which depend on AC. Then you would have a controversy on your hands.
Yes, and I was happy to take it this way, as I am certainly no Platonist. Surely only a Platonist could believe that AC is true; we philosophically sophisticated people know that you can make whatever assumptions you want! And so naturally a theorem with a proof using AC is a weaker result than the same theorem with a proof that doesn't, since it holds under fewer sets of assumptions, and thus the latter is preferred. Meanwhile, a theorem with a proof using not(AC) is just as valid as the same theorem with a proof using AC; it's less useful only because it has fewer connections with the published corpus of mathematics, but that's merely a sociological contingency.
Is it often the case that you need to assume the negation of AC for a proof to hold? AC comes up in seemingly-unrelated areas when you need some infinitely-hard-to-construct object to exist; I can't imagine a similar case where you'd assume not(AC) in, e.g., ring theory.
As usual, the negation of a useful statement ends up not being a useful statement. I don't think anyone works with not(AC), they work with various stronger things that imply not(AC) but actually have interesting consequences.
That's intriguing. Do you have any examples of what people actually work with?
Sniffnoy may have more examples, but here are some that I know: * Every subset of the real line is Lebesgue-measurable. * Every subset of the real line has the Baire property (in much the same vein as the preceding one). * The axiom of determinacy (a statement in infinitary game theory). Adding the first two to ZF + DC (dependent choice) is consistent (assuming that ZFC + Con(ZFC) is consistent, as just about everybody believes), and this gives a "dream universe" for analysis in which, for example, any everywhere-defined linear operator between Hilbert spaces is bounded.
This isn't quite right. The consistency of ZF + DC + "every subset of R is Lebesgue measurable" is equivalent to the consistency of an inaccessible cardinal [http://en.wikipedia.org/wiki/Inaccessible_cardinal], which is a much stronger assumption then the consistency of ZFC + Con(ZFC).
Sorry, my mistake. Still, set theorists usually believe this.
Yes, indeed! Yes -- but it needs to be stressed that this doesn't distinguish AC from anything else! (Also, depending on the context, there may other criteria for selecting proofs besides the strength or weakness of their assumptions.) If only people would talk about whether they prefer working in ZFC or ZF+not(C) (or plain ZF), or better yet what they like and don't like about each, rather than whether AC is "true" or how "skeptical" they are.
Yes, indeed, that would be much more sophisticated! But scepticism of the orthodoxy can be the first step to such sophistication. (It was for me, although in my case there were also some parallel first steps that did not initially seem connected.)
Not entirely. If the only known proof for a result assumes choice, then a proof that doesn't use choice will almost certainly be publishable. Using an exclamation mark like that is a pretty rare thing to do. You wouldn't for example see this if one used the axiom of replacement. The only other axiom that would be in a comparable position is foundation but foundation almost never comes up in conventional mathematics. Hartshorne is writing for a very advanced audience so I think putting an exclamation mark like that is sufficient to get the point across especially when one is using choice in the form of Zorn's lemma. This seems to fit my impression as well. Incidentally, for what it is worth, your claim that rejection of AC is low status seems to be possibly justified. I know of two prominent mathematicians who explicitly reject AC in some form. One of them does so verbally but seems to be fine teaching theorems which use AC with minimal comment. The other keeps his rejection of AC essentially private.
Of course it's worth noting that axiom of replacement doesn't come up much either, though obviously the case there isn't quite as extreme as with foundation.
We appear to have misunderstood each other, having something different in mind by words like "skepticism" and "reject." I agree Con(ZF) entails Con(ZFC), and that every educated mathematician knows it. Beyond that I don't have a good handle on what you're saying, or even whether you disagree with Yudkowsky, or me. Are you saying that mathematicians pay lip service to constructivism, but ignore it in their work? Are you additionally saying that there is something false about constructivist ideas? That doesn't sound like such a great heuristic to me...
This seems problematic. Many mathematicians work on foundations and are treated with respect. It isn't that they are low status so much that a) most of the really big foundational issues are essentially done b) foundational work rarely impact other areas of math, so people don't have a need to pay attention to foundations. There also seems to be an incredible degree of confidence in claiming that those skeptical of AC are " philosophically confused, of course".
It's somewhat pertinent to point out that the highest rated contributor at MathOverflow is none other than Joel David Hamkins of 'foundations of set theory' fame.
More than that, I daresay that they'd pick something much stronger than ZFC, probably ZFC with a large cardinal axiom. (And the main debate would be how large that cardinal should be.)
And anecdotally it seems that the AC skepticism that does exist seems to largely come from constructivism, so if we rule out that (since it doesn't seem that Eliezer wants to go all constructivist on us :) ), it's even less so.
I'm not sure what you mean by "constructivism" here; I usually hear that term referring to doubting the law of excluded middle (when applied to statements quantified over infinite sets), but I know several mathematicians who doubt the axiom of choice without doubting excluded middle. I should also clarify the difference between doubting AC and denying AC. If you deny AC, then you believe that it is false, and hence any theorem whose only known proofs use AC is no theorem at all; it might be true, but it has not been proved. (And if AC follows from it, then it must in fact be false.) If you only doubt AC, however, then you simply believe that a theorem with a proof that uses AC is a weaker result than the same theorem with a proof that doesn't, and so the former theorem is still worth publishing but the latter is naturally preferred. This seems such an obvious position to me that I doubt everything in mathematics (although there is a core which I generally assume since mathematics without it seems uninteresting (although I'm open to being proved wrong about this)).
Both AC and its negation can be made sense of in set theory. One or the other can be considered more interesting, or more relevant in the context of a particular problem, but given the extensive experience with mathematics of foundations we can safely study the properties of either. The question of which way "lies the truth" seems confused, since the alternatives coexist. Ultimately, some axiomatic options might turn out to be morally irrelevant, but that's not a question that human philosophers can hope to settle, and all simple things are likely relevant at least to some extent.
Since I found the other replies insufficiently stark here, let me just say that it is not. The details are in this subthread [http://lesswrong.com/lw/797/harry_potter_and_the_methods_of_rationality/4s40].
On the contrary, you need almost the full strength of AC to establish that a well-ordering of the reals exists. Like you say, you don't need it to construct uncountable ordinals, or to show that there is a smallest such. Cantor's argument constructively shows that there are uncountable sets, and you can get from there to uncountable ordinals by following your nose.
0Eliezer Yudkowsky12y
Is this because you can't prove aleph-one = beta-one? I'm Platonic enough that to me, "well-order an uncountable set" and "well-order the reals" sound pretty similar.
No something sillier. You can prove the axiom of choice from the assumption that every set can be well-ordered. (Proof: use the well-ordering to construct a choice function by taking the least element in every part of your partition.) If one doesn't wish to assume that every set has a well-ordering, but only a single set such as the real numbers, then one gets a choice-style consequence that's limited in the same way: you can construct choice functions from partitions of the real numbers.
I'd hardly call a well-ordering on one particular cardinality "almost the full strength of AC"! I guess it probably is enough for a lot of practical cases, but there must be ones where one on 2^c is necessary, and even so that's still a long way from the full strength...
I just have a hard time imagining someone who was happy with "c is well-ordered" but for whom "2^c is well-ordered" is a bridge too far.
Hm, agreed. I guess not so much "the full strength" but "the full counterintuitiveness"? Where DC uses hardly any of the counterintuitiveness, and ultrafilter lemma uses nearly all of it?
Uh, that's a lot more than "Platonism"... how was anyone supposed to guess you've been assuming CH? Edit: To clarify -- apparently you've been thinking of this as "I can accept R, just not a well-ordering on it." Whereas I've been thinking of this as "Somehow Eliezer can accept R, but not a cardinal that's much smaller?!" Edit again: Though I guess if we don't have choice and R isn't well-orderable than I guess omega_1 could be just incomparable to it for all I know. In any case I feel like the problem is stemming from this CH assumption rather than omega_1! I don't think you can easily get rid of a smallest uncountable ordinal (see other post on this topic -- throwing out replacement will alllow you to get rid of the von Neumann ordinal but not, I don't think, the ordinal in the general sense), but if all you want is for there to be no well-order on the continuum, you don't have to.
That's how I remember it, although I don't know a reference (much less a proof). All we know is that omega_1 is not larger than R.
I thought that could be proven without reference to the existence of a set of them, just from general facts about well-ordering? And then the only question is whether the class of all countable ordinals is set-sized. Which it must be since they can all be realized on N. As long as you accept the continuum, anyway! I don't see how the continuum can possibly be more acceptable than omega_1.
-1Eliezer Yudkowsky12y
I think we may have something of a clash of backgrounds here. The reason I'm inclined to take the real continuum seriously is that there are numerous physical quantities that seem to be made of real or complex numbers. The reason I take mathematical induction seriously is that it looks like you might always be able to add one minute to the total number of minutes passed. The reason I take second-order logic seriously is that it lets me pin down a single mathematical referent that I'm comparing to the realities of space and time. The reason I'm not inclined to take the least uncountable ordinal seriously is because, occupying as it does a position above the Church-Kleene ordinal and all possible hypercomputational generalizations thereof, it feels like talking about the collection of all collections - the supremum of an indefinitely extensible quality that shouldn't have a supremum any more than I could talk about a mathematical object that is the supremum of all the models a first-order set theory can have. If set theory makes the apparent continuum from physics collide with this first uncountable ordinal, my inclination is to distrust set theory.
How can you say this after having read this thread [http://lesswrong.com/lw/3aj/exponentiation_goes_wrong_first/35hz]? If you believe in second-order model theory, then you believe in set theory. (However, by limiting it to second order over the natural numbers, without going on to third order, you are not obligated to believe in uncountable ordinals.) ETA: It is very imprecise to compare second-order model theory and set theory like this. Already model theory is set theory, of course, albeit (potentially, not in practice) set theory without power sets. I should just leave the model theory out of it and say:
I have my problems with the other two, but this is the only one I don't understand. What do you mean? You seem to accept the notion that all finite numbers have a supremum. Why not just iterate whatever process accounts for that?
-2Eliezer Yudkowsky12y
http://en.wikipedia.org/wiki/Second-order_logic#Expressive_power [http://en.wikipedia.org/wiki/Second-order_logic#Expressive_power] - you can't talk about the integers or the reals in first-order logic. You can have first-order theories with the integers as a model, but they'll have models of all other cardinalities too. http://en.wikipedia.org/wiki/L%C3%B6wenheim%E2%80%93Skolem_theorem [http://en.wikipedia.org/wiki/L%C3%B6wenheim%E2%80%93Skolem_theorem] First of all, I've never seen an aleph-null, just one, two, three, etc. Accepting that the integers have a supremum is a whole different kettle of fish from accepting that the collection of finite integers seems to go on without bound. Second, taking a supremum once, using a clearly defined computable notation and a halting machine that can compare any two representations, is a whole different kettle of fish than talking about the supremum of all possible ways to define countable well-orderings to and beyond computable recursion.
It's more accurate to say that you can't talk about arbitrary subsets of the integers or the reals in first-order logic. I agree. This is the difference between completed and potential infinity. Nelson [http://www.math.princeton.edu/~nelson/papers/e.pdf]. I'm not so sure. Everything you've ever talked about, uncountable ordinals and all, you've talked about using computable notation. Computable, period is a whole different kettle of fish.
OK, you say you don't accept that sort of uncomputable leap to the end. The problem is that, AIUI, you're already accepting it as soon as you accept the power set of N. (Of the various "axioms of power" of ZFC, power set is the only one needed here. And if you just want omega_1, you don't need arbitrary power sets, just that of N. I mean really you want P(N x N), but since N is in an easily-described bijection with N x N, it shouldn't make a difference; just use a pairing function instead of proper ordered pairs.) The construction of omega_1 from P(N) is pretty straightforward, really, and doesn't use any of ZFC's other powerful axioms. Maybe you can somehow have the reals without P(N)? I.e. without binary expansions? shrug This is getting rather far away from what I know. Constructivists -- well, not the milder ones who just reject excluded middle, but the stricter ones who don't like impredicativity (whatever that might be, don't ask me) -- don't accept the axiom of power sets; they consider it just as much an unjustified leap to the end. Of course you could always try summoning TobyBartels and ask him how the constructivists do it. When you say these sorts of things I'm a little of surprised you haven't gone constructivist already. But I guess you like classical logic. :) (By the "axioms of power", I mean replacement, power set, and choice; the ones anyone might object to. Well, foundation is objectionable too, but it's more of an axiom of weakness. Healing Salve as opposed to Ancestral Recall. :P Also looking things up apparently the no-impredicativity constructivists insist on weakening axiom of separation as well? Well, I think their weaker version should suffice here. Again, I am saying these things without carefully checking them because hopefully TobyBartels will show up and correct me if I am wrong. :) )
You either need P(P(N)) or something like an axiom of quotient sets [http://ncatlab.org/nlab/show/quotient+set] to take the equivalence classes that are the actual elements of this version of omega_1. I presume (but haven't checked) that this is why J_2 has R but not omega_1 (although J_2 is not written in set-theoretic language, so you have to encode these). Assuming you accept classical logic, then P(N) may be constructed as a subset of R: that famous fractal the Cantor set. Just about everything that I know about predicative mathematics is distilled here [http://ncatlab.org/nlab/show/predicative+mathematics]. There I describe two schools, and the constructive one (which is less predicative than the classical one!) is the only one that I know well.
Crap, looks like I should have checked that after all! OK, I guess if Eliezer accepts R but not P(R) then there's less of a problem here than I thought. :P Edit: Nevermind, this line was asking what J_2 was, you've given a reference elsewhere. Oh, that works. Should have thought of that. Huh, so there's two separate things going on here. Constructivism in the sense of no-excluded-middle, and I guess "predicativism" in the sense of, uh, things should be predicative? I probably should have realized those were largely independent, but didn't. How is the constructive version less predicative? Is it just the function set issue?
Would Chaitin's constant also be one of these "superlogical" things that cannot "exist" "out there"?
I know that you rescinded this question, but intuitionists (at least) would answer it affirmatively.
I'm reminded of the concept of information cascades: With every new level of witchness discovered, the probability of the next one increases.
There's a limit though since we have a decent estimate for how many wizards and witches there are in the world. That gives a strict upper bound on the total number of levels unless some of the levels are completely empty, tthat is something like every 12th level witch is also a 13th level witch. And if that's the case it isn't clear why the levels are being countered separately.
If there are much more powerful levels of magic, our estimate of the number of witches could be wildly off.
How do you figure that? The double-wizard idea doesn't seem to be that there are apparent Muggles with some form of magic. It seems to be that that there are people who seem to be ordinary wizards but really have additional powers. So levels of wizardry should be strictly ordered.
In canon, it sounded like some witches pretended to live ordinary lives, and others lived "off the grid" in the middle of nowhere. The same mix might happen with higher-order witches, with some attending Hogwarts, some pretending to be muggles, and others going unnoticed by anybody. If there are an arbitrarily high number of witch-levels, then the limit is the earth's population, not the magical population. But that's only a potential limit, as witches of arbitrarily high level can support an arbitrarily high number of themselves on one planet (or go to other ones).
regular wizards have little trouble concealing the existence of their entire culture from every muggle, so presumably double wizards could have similar levels of control over whether or not regular wizards can perceive them. Double witches might be a group that's separate from as well as a subset of regular witches
So the Witches (when compared to Double Witches) aren't analogous to Muggles (when compared to Witches); they're analogous to people. Although we have heard rumours to the contrary, we Muggles tend to just think of ourselves as people, and any Witches that there may be are a special class of people; however (according to some versions of the rumours) there are actually quite a few Witches whom we would never perceive and therefore never even count as people. Similarly, although Witches have heard rumours to the contrary, they tend to just think of themselves as Witches, and any Double Witches that there may be are a special class of Witches; however (according to some versions of the rumours) there are actually quite a few Double Witches whom they would never perceive and therefore never even count as Witches.

77: I didn't read the title in full before I read the chapter. I must admit that "Sunk Costs" weren't a lesson that sprung to my mind as I read. Since sunk costs are such an important lesson to convey I rather hope there is another chapter on the subject. It strikes me as something that is easy to contrive scenarios to illustrate.

I was actually wondering more about the “Interlude with the Confessor” part. Is it non-obvious only to me? There’s a chapter with that name [http://lesswrong.com/lw/y8/interlude_with_the_confessor_48/] in Three Worlds Collide, but other than both containing a private dialogue between two people of different ages I don’t quite see the relation.
Similar reaction here.
I also was left thinking at the end "Where are the sunk costs?"
The sunk costs are what Snape has done and the costs to him and his life.
So, it's that Snape isn't fixing his life because he's bummed out about sunk costs?
That does seem to be the implication. However, he may actually decide to fix it.
Where 'he' hopefully means 'Eliezer'.
Huh? He means the fictional character Snape. That is, I hope that in the narrative Snape will decide to fix it.
Whereas through playing on ambiguity I am hoping that Eliezer will put something in the story about actual sunk costs, which Snape's story does not currently qualify as! As of right now the story is broken.
Ah yes. This makes sense. In that context I agree with your statement as well.
Or alternatively, the title is broken.
Yes, a two word fix right there!
That's the closest thing to a sunk cost in the chapter but it just doesn't quite fit. It's somewhere just outside the borders of sunk costs and sour grapes.

From Author's Notes 69:

Also, this thing with S.P.H.E.W.? You're thinking I've been working up to that for a while, right? You're wrong. It just happened, just now.

I'm slightly concerned after reading this post about how serials go off the rails.

Has there yet been any Word of God on firearms in the Methods of Rationality? I know that the other Word of God has the famous quote, "In a fight between a Muggle with a shotgun and a wizard with a wand, the Muggle will win." I'm curious if this sort of thing still holds for MoR.

Hogwarts, being a school, wouldn't have narrative need to involve any guns directly. Fights between bullies and students rarely end with gunshots even in the real world afterall. But the mere existence of such objects casts ripples on everything else. Just like modern warfare is dominated by the existence of nuclear weapons even when not deployed, guns remaining effective would dominate the shape of all wizard conflicts. Home invasions go from safe for the better wizards to potentially lethal any time. Public takeover (as in Deathly Hallows) becomes impossible. Support from demihuman races become pointless if open battlefields are impossible. Hell, all the death eaters in total seem almost comically weak against a single battalion of trained soldiers loaned from a friendly country and supported by a wizard or two. Death Eaters might be an effective terrorist organization, but could not b... (read more)

Since magic in the HP universe has the property of not having to make sense, one could imagine a spell that simply makes guns not work, or that makes all projectiles move slowly, or that causes everyone within the area to miss what they aim at.

The ending battle of Deathly Hallows pretty much treats wands as if they were guns. You could edit the film to replace all the wands with guns and have very few instances where anything looked wrong. So far HP:MoR has made the magic feel more magical than that.

A gun might top a wand for a lethal quickdraw, but magic has a ludicrous number of tactical advantages. A home invader with a gun, for instance, is no longer a threat when you can use charms to make it impossible for them to be aware of the existence of your house.

But still, knowing that you can pull off an assassination at literally zero risk to yourself at any time (Invisibility Cloak + Sniper Rifle + Portkey + Time Turner) has to do something to an actor's willingness to compromise with rivals.

The sniper rifle doesn't make this much easier; it's loud (although it might be quieted magically) and Avada Kedavra is a surer kill. Anti apparation spells probably cover portkeys, or if they don't, there are probably other spells to deal with them. Plus, you can't pull it off "at any time" given that it can be stopped by a standing anti-apparation spell and a closed door, which are pretty minimal precautions for a high profile political leader.

If you're really creative, you could probably assassinate just about anyone, but this is more or less true in real life, and prevented largely by the extremely small overlap between people with that kind of creativity and people who want to pull off assassinations.

I was considering more a wizard vs wizard+technology situation. Presumably wizards already figure out ways into charmed houses; the addition of guns just make it easier once you've already located it.

The benefit of a sniper rifle is the range. Harry Potter magic seems to be effective at about a dozen yards at most. The longest confirmed sniper kill is over one and a half miles without any aid of aiming magic; the sound of the bullet arrives about 5 seconds after you're already dead. That should leave you well outside of the range of any anti-apparition wards, and require knowledge of ballistics to even track you to your shooting spot. Lee Harvey Oswald would have gotten away easily if he could apparate or portkey; as it was he was able to walk around for an hour until police were tipped off to his suspicious activity. Voldemort specifically seems to have an odd thing for meeting in the outdoors, and Dumbledore is fond of watching Quiddich. It's not like there would never be an opportunity.

Voldemort met outdoors in a graveyard in the series, once, and that was at a point where nobody but his servants ha any idea he was alive. Secrecy was the Death Eaters' main weapon. As for assassinating someone like Dumbledore, you could probably do it if he weren't already suspicious enough to take precautions against it, but you could do that with magic as well. Warfare technology would certainly have uses in the wizarding world, particularly for a smart individual, but it's not like any particular combination of technologies and spells is simply uncounterable, it just makes things much more complicated and forces everyone to become more paranoid. Aside from raising standing shields, taking undisclosed routes or teleporting to safe destinations and all the other precautions one might take, magic might take bullet tracing to entirely new levels. "Find the gun that fired this bullet" and "Find the person who fired this gun" spells may very well exist, or be easy to invent once they're needed.

I'm thinking McGonnagal could set up a decent nuclear defense system too. Charms that detect incoming airborne objects and transmogrify then into pigs seem right up her alley.

In general it seems that magic gives far more defensive options than technological weaponry. These days our defensive options are pretty much MORE ATTACK! But magic has invisibility, shields, teleport, (extra) secrecy and flipping time turners!

Right after the Azkaban mission, McGonagall, Snape and Dumbledore hold council together. I remember that after Dumbledore shows terror at the idea of a Harry vs. Voldemort war fought with Muggle weapons (he's thinking of nukes), McGonagall thinks something like "firearms aren't that dangerous for a prepared witch".

Part of the time when I was reading Deathly Hallows, and all of the time I was reading MoR I always expected Harry or at least SOMEONE else to act like Kiritsugu from Fate/Zero. Imagine: Enchanted portkeys with no destination yet programmed in attached to home made bombs, flash-bang grenades as a staple in wizarding duels to disrupt aiming/concentration, to say nothing of the videogameesque ability to actually carry around an entire armory with you or heal yourself much quicker EVEN IF YOU DON'T USE MAGIC.

(For those of you who don't know, Kiritsugu is a mage assassin who takes advantage of the Magic Association's technophobia and uses weapons as a regular part of the kit: Mages aren't going to defend against you if you're a mile off with a sniper rifle and they aren't going to defend against landmines if they don't know they exist!)

Edit: Actually, scratch the Kiritsugu idea I just want Neville to cast a shield charm of some sort at his feet so he can rocket jump from staircase to staircase at some point. Pity Quake 2 is five years in the future.

7Eliezer Yudkowsky12y
"It would be silly if anyone could win the whole war at any time just by owling him a hand grenade," Harry thinks in Ch. 37. A Fate Zero style conflict between a sane and a non-sane wizard ends very quickly, and if two sane wizards ever fight each other...
I sort of assumed that's what we were expecting in the eventual Harry/Quirrel showdown...
Rowling said somewhere in an interview that there were ways of making yourself impossible for an owl to find; whether this is a blanket affect or could be lifted for select targets is unclear. Otherwise, the Aurors could have just owled the Death Eaters something and then followed the owl to their hiding spaces.
Yes! Rocket jumping Neville please! In fact, the more of Neville fighting stuff the better.
I have to say I find the notion that rocket-jumping would be better than existing magic pretty suspect.

See "Secrecy and Openness". I directly contradicted Rowling in that chapter for exactly that reason. Roughly, a good wizard or witch who knows what's coming can easily raise a shield against bullets. Bombs are more difficult, although e.g. the Castle Hogwarts would just shrug them off. And there are ancient devices and certain old structures that could stand up to point-blank nuclear weapons, but they're rare.

Is the Castle of Hogwarts one of the structures which is nuclear weapon proof?
4Eliezer Yudkowsky12y
That was hard to decide. I eventually figured on "No" - the Four Founders are too recent, and shouldn't have the magic level necessary to produce large-scale nuke-proof structures.
Hmm, that gives us some interesting data about the decline of magic. We now know that the power decline included a decline in defensive magic, and this may be the first explicit statement of a type of magic that was capable at some point in the past that the Founders could not use. I'm sure this would be quite useful for Harry. Also, I think this sort of thing might depend on practice on the size of the nuke by a lot. Some stone buildings in Nagasaki survived relatively intact and are still in use. On the other hand, that bomb had a yield of only around 20 kilotons of TNT. A lot of modern bombs are in the megaton range. So Hogwarts should be able to stand a chance to partially survive a small nuke simply due to the fact that it is a big castle with very thick walls. It shouldn't take that much magic to make that size nuke completely survivable. So even if Hogwarts can't survive a direct strike from a megaton weapon, maybe it should be able to survive a small nuke? Edit: Another thought, if Dumbledore is now worried about the possible use of nukes wouldn't he try to upgrade the castle's defenses against specifically that sort of attack? It might be that very ancient powerful structures would survive a nuke because they are just that powerful, but even if that sort of general power doesn't exist in the modern time, there are still specific anti-nuke strategies that one could do. If for example one had a spell on the Hogwart's grounds which prevented explosives from detonating that would force a minimum distance for nukes to be used (since nukes need a conventional explosive to make the fission core go critical). One could get around that by having a gun type fission bomb [http://en.wikipedia.org/wiki/Gun-type_fission_weapon] with something other than explosives to launch the bullet (say compressed gas). This would put a severe limit on the maximum yield of the nuke and would mean that no pre-existing nuke would work. Another option would be to have some sort of pre-

One could get around that by having a gun type fission bomb with something other than explosives to launch the bullet (say compressed gas).

You're making this too complicated. As evidenced by the levitate-slowly-to-the-ground spell, they've already got magics in-universe that impede the maximum kinetic energy of an object.

Just surround the entire area with a field that inhibits maximum relative velocities to something an arrow could achieve. No more guns, no more bombs, no more nukes. Problem solved.

I assume that at a certain power level, even magic can't protect you. Atlantis at full power probably couldn't defend itself against, say, a gamma ray burst, a black hole pulling the solar system into it's gravity well, our sun going supernova, or heck, the sun just expanding due to old age. A spell to protect against incoming shockwaves would probably require vastly more energy than a spell that targeted and halted igniting charges. Although ironically it seems much more muggle thinking to halt a theat with through intricate understanding of the mechanisms than to just pump more power into it.
Not to mention whatever it was that destroyed it.
I was just thinking that while the Cloak of Invisibility shouldn't protect its wearer against nukes -- intuitively, nukes can kill you without anyone knowing your precise location -- the job shouldn't require a greater level of magic than it took to make this artifact. And Harry believes he knows an important piece of the spell that made the Cloak. Let's see if he got that right, and if he can generalize correctly (using only the new info that Quirrel gave him).
Sorry, where was that stated?
Ch. 56:
Ah, I see. I misunderstood you; I thought that you meant that Harry knew how to replicate an important piece of the spell that made the Cloak, not that he understood part of how the Cloak functioned.
...I don't know what you mean by "important part of the spell" if you exclude secret ingredients, physical motions like drawing a symbol, or the vague-but-intuitive general procedure behind these.
I'm saying "an important piece of the spell" because you used that phrase. My point is: Harry knows that the Cloak keeps him hidden, not just invisible; this is similar to Thestrals; there's Thestral blood painted on the inside of the Cloak. None of that indicates that he knows how to replicate this effect, which is what I thought you meant when you said:
Yeah, I wrote the grandparent hastily and badly. I felt confused about the difference in interpretation. But it doesn't seem like an interesting difference; looks like you just took "spell" to mean the effect rather than the cause. I hope you'd agree that knowing part of the cause should increase the chance of successful replication.
I do agree that knowing part of the cause should increase the chance of successful replication. I just think that there's still a long way to go. We're probably both reading more into each others' posts than we should.
I believe that the implication here is that the cloak's behavior around Dementors is very similar to some of the behavior of the Patronus 2.0.
Stopping nukes specifically with magic would be simple. Just gate all the free neutrons in a radius to a hundred miles vertically up. Nuclear bombs might as well be fuelled with toffee.
Magic seems to operate on a human level intuitive scale. Doing something just to free neutrons wouldn't fit that pattern.
So turn the fuel to toffee.
At least one wizard (Harry) can go deeper than the human level, so it might be possible.
Is the cloak of invisiblity one of the devices that would stand up to a nuclear weapon?
Well, if the final movie is anything to go by, then it shouldn't be. Harry breaks the Elder Wand into pieces at the end of the film, which shows that the Deathly Hallows clearly aren't indestructible. (In the book, Harry returns the wand to Dumbledore's grave instead of destroying it, which doesn't tell us anything about whether he could have destroyed the wand.)

HP:MoR does imply however that one needs extra-special power to destroy artifacts -- e.g. the FiendFyre which in canon is one of the few things that can destroy a Horcrux, is also mentioned (not by name, but implicitly as a type of cursed fire) in HP:MOR by Quirrel as what would be used to destroy an artifact like the Sorting Hat.

So I don't think Harry just snapping the Elder Wand in two could happen in the 'verse of HP:MoR.

It really shouldn't have been allowed even in the movie. (NB: I haven't seen the movie; I'm only relying on CronoDAS's description.)

Possibly the reason he could destroy the wand was that he was its 'master,' (for those who don't know a large plot point in the final canon book and movie was that wands have particular masters that they are bonded too, and so can only be wielded fully by them or someone who defeats them. Hence why Voldemort couldn't use the elder wand properly. ) Presumably having access to all the wands power as harry did at the end would allow one to override the safeguards against destroying it?
Gah? Seriously? WTF did they change that? That's arbitrary. I somehow lost interest in the movies after about 3 or so. Not sure why. Possibly because Ginny wasn't nearly as cute or as sane as in the books and possibly because I just didn't want to see Ron's face or hear him say stupid, stupid things. Well I suppose destroying it is possibly less insane than leaving it with Dumbledore where anyone would look. Just not as sane as keeping it, being badass and cough "optimising" the world.
Because he wanted nobody else to have it, and frankly the book solution of "I'll hide it, and hope nobody finds it again" was extremely inadequate; especially after dozens of people had heard Voldemort and Harry discuss its existence. The movie version of snapping it in two and throwing it away made the point much louder and much more finally.
They, not he. The changes to the magical world regarding the casual destruction of magical artifacts are far more significant to changes to irrational!Harry's decision making. (See third paragraph.)
The concept of "artifact" isn't nearly as neatly delineated in Harry Potter canon as in the MoR!Verse. In canon, it's Horcruxes that are very hard to destroy -- other magical objects not necessarily so. I don't believe there's anything even in canon that would have prevented Harry from snapping the Elder Wand in two.
While never being explicitly discussed either way casual destruction of artifacts as powerful as the deathly hallows doesn't happen in Harry Potter. It occurring in the movies is something new and I am comfortable with my initial reaction [http://lesswrong.com/lw/797/harry_potter_and_the_methods_of_rationality/4rfh] of surprise and disappointment. I hope MoR doesn't base its own magical reality on the one evidently depicted in the movies because it just wouldn't be either as appealing or as coherent.
As I mentioned in another comment, in the MoRVerse it's strongly implied that all artifacts (which as I said are more clearly categorized as such in MoR than in canon) have some extra durability in them (as Quirrel says the FiendFyre would be used to destroy an artifact like the Sorting Hat) -- so I don't think you need worry about this.
What's wrong with having powerful objects that are easy to destroy? I mean most advanced pieces of technology in our world aren't that hard to destroy, or at least render inoperable.
Personal preference and internal consistency. It's ok if the elder wand is just a stick but I don't have to like it.
Of course, the castle can be nuke-proof in other meanings than just “a point-blank nuke wouldn’t destroy it”, I imagine.
A muggle could easily shoot an unprepared wizard. However, shouldn't there be magical protections against firearms?

The most recent update would suggest that fairly standard shielding charms can stop blunt impact.

"Daphne could hardly see the movement as Susan seemed to hit the corridor wall and then bounce off it like she was a rubber ball and her legs smashed into Jugson's face, it didn't go through the shield but the sixth-year went sprawling backward with the impact"

There appears to be conservation of momentum, but the momentum from typical firearms spread out over your entire body isn't even going to leave a bruise, assuming said charms are up to dealing with something with as much sectional density and velocity as a bullet.

IMO a good model for wizard duels vis a vis muggle innovations and creative thinking is the ritualized warfare practiced in the Americas in pre-Columbian times. Lot's of punches pulled, lots of unstated mutual agreements not to escalate, and a general low-intensity level of aggression that doesn't get too many people killed.

Just not partially motivated by the need to capture opponents for sacrifice?
Perhaps sacrifices are the real source of magic. Not really equivalent exchange, given the trivial uses magic is usually put to, but that's thermodynamics for you - 'you can't win, you can't break even, and you can't quit'.
I'm immediately reminded of discworld where technical improvements in magical theory have gotten to the point where a spell that originally required the sacrifice of a human being can now be performed using a few ccs of mouse blood. Hmmm, what if the practice of magic is weaker in the present of MoR because ritually sacrificing a few dozen peasants for purely experimental ends is considered in bad taste? I can see Dumbledore BSODing over the discovery that Hogwarts is actually powered by the hearts of ten thousand orphans somewhere down in the foundations.
I think we can rule that out on the basis that Godric Griffindor wouldn't have stood for it.
Hm. In Chapter 74, we learn that all ritual magic requires a sacrifice, and Harry muses about all the pulled punches in wizard warfare. Iiinteresting. This is one of the few speculations that I would actually like to see confirmed-- I find it very satisfying, for some reason.

Hm. In Chapter 74, we learn that all ritual magic requires a sacrifice, and Harry muses about all the pulled punches in wizard warfare. Iiinteresting.

Especially since Quirrell/Voldemort specifically mentions that it is possible to sacrifice "a portion" of one's own magical power -- permanently -- to achieve 'great effects'. I imagine a nefarious individual could conceive of a rite whereby the sacrifice of another wizard's life -- and by extension, his magic -- would cause at least some portion of that magic to be transferred to yourself.

Perhaps older wizards were more powerful because... they had more power? One could easily conceive of Godric Griffindor using this method of execution upon potential Dark Lords in order to combat more-powerful ones.

That seems like an effective method of imprisonment. Force the wizard to expend their power permanently in rituals (or just one powerful ritual). Such a prison would be significantly safer than Azkaban, since any wizards which escape would be effectively useless. They would be permanently helpless; some might consider it an even worse fate than dementors.

On further thought, perhaps that is why the public accepts dementors. Imagine what the prison system could have been before dementors were harnessed for prison work. The state would have an incentive to label people as criminals, so that it could burn their magic. The entire situation would degrade into an ever worsening police state. The discovery of dementors for prison use would be a humanitarian breakthrough akin to the abolishing of Capital Punishment.

I'm impressed. That's WH40K-level crapsackiness.

It's also straight out of Vampire: the Masquerade - Vampires can become stronger and more vampire-ish by eating the "souls" of other vampires. This is considered a heinous crime in vampire society and is punishable by Final Death.
Which means you'd better make sure you drink a lot of vampire souls before they catch you. All of them if possible.
Huh, I thought the obvious precedent was Larry Niven's story about a world where even minor crimes are punishable by death so that your organs can be harvested for transplantation...
Well, that too. ;)
Apart from, y'know, still being humans, right?
If any of those previous Dark Wizards were dangerous even as ordinary humans, they wouldn't've lost in the first place.
Unless they had some kind of really cunning plan.
If they had such a plan which really truly required them to be non-magical* and somehow was superior to all magical plans, they could just burn their power themselves... * This makes me very wary as it sounds perilously close to conjunction fallacy. The set of 'non-magical \/ magical plans' ought to be larger than either subset...
Example: Have your enemy burn your magic. Your enemy thinks you are safe and lets their guard down. Your minion sacrifices themselves and you absorb their magic. You win. Admittedly this plan will involve more than three things going right in a row.
I was going to say that this step seems like an assumption, except Eliezer just made Dumbledore say that was the secret to Grindelwald's success, so...
He never said that his Muggle allies were killing themselves; the blood sacrifice mentioned could easily be from those who were killed in the Nazi extermination camps.
Is there a difference, from the magical point of view, between Muggle allies slaughtering each other to fuel Grindelwald, and slaughtering non-allied Muggles to fuel Grindelwald?
Arguably, his Muggle allies (assuming, as usual, that these are the Nazis) were indeed sacrificing themselves: they started a war which they lost, leading to their deaths (in many cases) by war, hanging, or suicide (the last including the Muggle Fuehrer himself). However, I interpreted this as Sheaman did; sacrificing others may be less powerful, but it was a lot of others.
In a number of magic systems, the willingness of a sacrifice can have a huge impact on its effectiveness, ranging anywhere from a willing sacrifice granting significantly more power than the unwilling to requiring the sacrifice to be willing for it to work at all. I'm uncertain where Potterverse stands on this, let alone MOR!Potterverse. Assuming Voldemort's ritual in GoF was more than empty words, willingness is important, or at least notable, given: Italics added to emphasize parts concerning consent.

Also, many parents in the holocaust were forced to either leave there children or die. Many were forced to sacrifce themselves for their significant other or watch them both die. Consent (as wormtail shows) can be based on a wide variety of factors that might not involve you being truly aligned with how you feel about the ritual itself. A muggle might walk into the gas chamber willingly to save his/her spouses life but the harry potter verse never deals with "how much consent is consent".

I wish that this comment weren't buried behind "continue this thread"; I don't want to be the only one who votes it up.
Sure. So in one ritual we know of, consent and lack of consent matters. But that doesn't argue much one way or the other about the proposed scheme for how burning your magic might be a winning strategy.
My point in bringing it up was that we don't know if his minions were sacrificing themselves or others, so the last step is still an assumption. Even if Grindelwald managed to have minions loyal enough to sacrifice themselves, though, there's no guarantee that anyone else's minions would be that loyal. I'd say that it's a gamble pretty much no matter what.
Perhaps there is a charm in MoR. Although in cannon there were arrows killing wizards. I'm not really concerned about muggle vs wizard, but rather wizard vs wizard. As was mentioned earlier in the story, any spell you can throw out requires them to expend effort to negate. And guns can spit out quit a few 'spells' per second as well as from beyond unaided sight range. Even if a shield existed, guns would still be changing things by forcing enemies to keep up that shield at all times. Plus there's also the question of IEDs. They pump out enough damage that I doubt any wizard could withstand one. The IRA was active during the time period, and made use of carbombs; it would be unusual if someone like Seamus Finnigan didn't know about them.
There might be a spell for inactivating guns and/or destroying them. It's odd that wizards are immune to flame (couldn't be burnt as witches) and yet they're so vulnerable to impact. It would be interesting to throw a Spell of Coherent World-Building.
They didn't have an always-on immunity to flame, they cast a Flame-Freezing Charm. Deadly impact is usually too sudden to prepare against, whereas you can see them building the fire minutes in advance.
Well, a number of schools in the real world have gangs that do shoot each other with guns, oftentimes in the school's parking lot.
That's not how I remember the quote at all. What I remember was more along the lines of "a pure-blood fanatic versus a competent Muggle with a gun would lose," with italics added to indicate which part I'm unsure of the wording on. Which, of course, has completely different implications. I searched for the original quotation for what I remembered and for the quote that you posted. I couldn't find mine, irritatingly enough, but I couldn't find an original quotation of yours, either. Do you have it?

Why has no one advanced the hypothesis that Harry is a double wizard?

Possible in-universe explanation: I would guess people suspect that barring emergencies double-wizards keep their abilities secret. So Susan can use her double-wizard abilities just that once when she really needs to. A double-wizard would get in trouble for using their abilities all the time just as a wizard would get in trouble if they used magic around Muggles all the time. Also, what Harry does is so weird that it doesn't even fit what they think a double-wizard might do.

Probable actual explanation: Eliezer didn't think of the double-wizard initially.

The obvious conclusion is that Harry is a triple wizard pretending to be only a double wizard pretending to be a wizard (who sometimes pretends to be a muggle). Twisted indeed are the minds and deeds of triple wizards.

Considering that Harry is being taught Legilimency behind the scenes, was given an invisibility cloak and time-turner, has lunch every week with Quirrel, researches the science of magic with Hermione, and probably a bunch of other things I can't think of, I think it's safe to say that he IS a double wizard.

"What's your name?"

The black cloak rotated slightly, back and forth, it didn't look like shoulders shrugging, but it conveyed a shrug. "That is the riddle, young Ravenclaw. Until you solve it, you may call me whatever you wish."

The ... riddle, eh? Hmm. What with that, and the "Tell them I ate it" describing an avatar of Death earlier, I can't help thinking that Tom has failed to pay full attention to that Evil Overlord list of his.

(Assuming, at least for the sake of argument and perhaps for other reasons of which I shall not speak here, that both Quirrell and Hat&Cloak are Voldemort.)

Is this partly a practical in updating estimates? * I guessed Quirrell for Mr-Hat-and-Cloak after Zabini's interaction and obliviation Since then * Snape has been shown to be a player * I think Quirrell has never been shown using obliviation * Quirrell comments on Snape's 52 obliviations after the ambush * Quirrell has been shown to have a very good model of Harry. Assuming that is of importance to him, he would have needed a better model of Hermione that Hat&Cloak has shown and "I do permit myself to read faces". * House Slytherin Marauder's Map equivalent to simplify logistics? Though thinking about it, Quirrell's knowledge of the 3rd floor corridor corridor could have been Legimens and Obliviation of the more astute Gryfindors - like Fred & George with their ward breakers monocles...
I would add as weak evidence the need each person has for being Mr-Hat-and-Cloak. * Hermoine Granger recognizes the true face of Mr-Hat-and-Cloak. This should rule out proxy agents or Sirius Black. * Mr-Hat-and-Cloak does not understand girls. Dumbledore or Lucius would understand the need for appearances immediately. Quirrell would get it very quickly. Which leaves... * Severus Snape does not understand girls. Until Sunk Costs, he'd never kissed a girl. He does not have a good model of relationships or seemingly girls in general. * Mr-Hat-and-Cloak is emotionally invested in converting Hermione Granger. This implies that it is important to Hat's plans that it succeeds. Quirrell and Dumbledore have a multitude of options to influence the outcome and shape of Harry's life; Snape has effectively zero.
I don't think Sirius Black can be ruled out. It's quite possible that Hermione has seen pictures of famous past criminals, including Sirius and Bellatrix. Also her sudden terror at recognizing him seems way bigger than if it had been someone like Severus or Quirrel, so this recognition made me update upwards the probability of him being Sirius Black, not downwards.
Yes. Also, "she saw the face beneath, and recognition sent a jolt of terrified adrenaline bursting through her" - 'recognition' doesn't read to me like the person she saw was a personal acquaintance of hers. Grindelwald? He's been mentioned so many times, and his connection to Dumbledore explored in such detail, that it'd be surprising if he didn't play a role in the story. If you grant that, then his motivation for returning was aggressively foreshadowed by Chapter 42 ("Courage"). He'd be a strong candidate for opposing and manipulating Dumbledore as Hat & Cloak is doing. But not much in Hat & Cloak's appearances points to Grindelwald specifically. The sibilance of his speech and the ambiguity around his gender might be nods toward stereotypically gay characteristics. And might not be. It'll be clearer once Eliezer's told us more of what Grindelwald was like as a person.
Not to discount the other suggestions, but 'recognition' did read as someone she knew to me. The mist dissipated, and she recognized the face beneath. Though I'll admit, the "jolt of terrified adrenaline bursting through her" doesn't necessarily fit with all of the possibilities.
I dunno about that. Suppose H&C is someone Hermione was previously disposed to like and trust; then finding that s/he had been behaving like that would be quite a shock. On the other hand, anyone whose past behaviour rendered H&C's actions not-shocking is probably someone she'd be unhappy finding herself face to face with even in the best circumstances. (FWIW, I too read "recognition" as probably indicating someone she already knew.)
How do either Black, Bellatrix, or Grindelwald pass the observation about the wards screaming on Obliviation by non-professor?
We didn't know about this restriction back then. But yeah, that restriction effectively eliminates the possibility of a non-Professor like Sirius being Hat & Cloak.
Yeah. Which, as the example of Skeeter teaches us, means that we could look for a weaker link in the chain: the professors themselves. Imperius/Obliviation strategies have been discussed in the past, but Polyjuice Potion hasn't. Would that work? Dunno. Moody fooled the wards in canon, but that was probably because the fake was the only one to ever get keyed in as a Professor in the first place. Would Polyjuice let Flitwick or one of the others be replaced?
So Snape heard the prophecy from...someone with a Slavic or Germanic accent. The only candidates from canon that I can think of are Grindelwald, Karkaroff (who doesn't have a strong accent, at least not in the movies), and Krum (who may not have even been born yet.) Could Snape have visited Grindelwald in Nurmengard at some point? Hat & Cloak seems like Quirrell to me. Who else stood up for Hermione, even a little bit, at the Head Table? Though he must have a lot of faith that multiple Obliviations don't cause permanent damage. Hermione is way too potentially useful, both in her own right and as a lever on Harry.
Chapter 46 [http://www.fanfiction.net/s/5782108/46/Harry_Potter_and_the_Methods_of_Rationality] has McGonnagal think of Trelawny as the origin of the prophecy, and she seems to remember it in its original voice. The sequence of events then seems to be that Trelawny went into her trance with McGonnagal in the room, but the destined recipient of the prophecy actually being Snape just outside it. Snape thought he was overhearing a prophecy meant for McGonnagal, when in reality McGonnagal overheard a prophecy meant for Snape. Edited to add: Chapter 28 [http://www.fanfiction.net/s/5782108/28/Harry_Potter_and_the_Methods_of_Rationality] is the one that gives the most detail.
If (as in canon) the prophecy was made (1980) shortly before Harry's birth, then Krum had been born (c. 1976), but I don't suppose that he was talking yet. (ETA: Sorry, of course he was talking. But he would have sounded odd, an adult prophecy from the mouth of a child. That doesn't really prove anything, I guess.)
Sirius Black also might not know much about girls. I can't recall his knowing much in canon (as that was more James Potter's department), and of course here he seems not even to be interested in them, as they say. (On the other hand, it is a bit of a cliche in our culture that gay men turn out to understand women better than het men do.)
Bellatrix is the first theory I've heard that seems to adequately explain "jolt of terrified adrenaline", to me. I hadn't thought of that possibility. And we should be expecting Bellatrix to appear somehow, which seems less true for Sirius.
My mentioned idea about Sirius isn't workable anymore -- and neither is the one about Bellatrix. Because we now know that only professors can obliviate people at Hogwarts without being detected -- so Hat & Cloak has to be a professor.

This may have been pointed out before, but not where Google and I could find it.

Harry, speculating in Chapter 25:

Some intelligent engineer, then, had created the Source of Magic, and told it to pay attention to a particular DNA marker.

The obvious next thought was that this had something to do with "Atlantis".

Harry had asked Hermione about that earlier - on the train to Hogwarts, after hearing Draco say it - and so far as she knew, nothing more was known than the word itself.

It might have been pure legend. But it was also plausible enough that a civilization of magic-users, especially one from before the Interdict of Merlin, would have managed to blow itself up.

The line of reasoning continued: Atlantis had been an isolated civilization that had somehow brought into being the Source of Magic, and told it to serve only people with the Atlantean genetic marker, the blood of Atlantis.

Chapter 61:

"Worse than any peril I know," said Albus. "But probably not worse than whatever erased Atlantis from Time."

The Friendly AI Critical Failure Table:

34: The programmers and anyone else capable of explaining subsequent events are sent into temporal stasis, or

... (read more)
It's a reference to Harry Potter and the Wastelands of Time [http://www.fanfiction.net/s/4068153/1/Harry_Potter_and_the_Wastelands_of_Time]. Ancient magic, unlimited timetravel, and correspondingly more powerful opponents.

There seems to be an inverse correlation between how much Eliezer likes his chapters and how much I like them. (My favorite chapter is 47)I thought 75 was great. No, it wasn't as funny. It was chapter 74's job to be funny, and chapter 75's job to touch on some serious issues, and that doesn't make it worse.

I really liked Hermione and Harry sitting and talking through their issues in an adult manner. Literature could use more of than and less indignant yelling like the fourth-year-girls recommend.

(In general I also like chapters with lots of dialog. I feel like we get the most character-development-per-pound that way.)

I just like how often not communicating is used in fiction as a false way of creating conflict, but Eliezer shows that you can still have a story (with conflict!) when people try and understand each other.

This is something I hadn't realized explicitly until you pointed it out. But yes, lazy authors don't bother to give their characters conflicting goals or personalities or deep beliefs, so they give them conflicting surface beliefs and then come up with bad excuses for them not to communicate.

But people do hold conflicting surface beliefs and refuse to communicate...

But people do hold conflicting surface beliefs and refuse to communicate...

Certain kinds of stupidity may be common and yet too stupid to be a source of interesting conflict in fiction.

Real life isn't a coherent narrative. Realistic fiction would look and sound something like this [http://www.youtube.com/watch?v=qmGVYki-oyQ&feature=fvst]. Good authors avoid doing that, except in parody.
O RLY? [http://en.wikipedia.org/wiki/The_Mezzanine]
That too!
Defnitely. What is the point of getting into yelling matches when the physiological arousal that comes with it cannot even be then channeled into makeup sex?

I could have sworn that somewhere I saw a comment expressing surprise or disappointment at Snape being taken down so easily -- but I now can't locate the comment.

In case it was someone from here: It seems clear to me that it was Quirrel who both chose to reveal Snape's location, and of course he'd have also contributed to the volley of spells that quickly took down Snape's shield as well. It seems that Quirrel really didn't want Snape getting the situation back under control - and his presence was what Snape didn't anticipate.

You can't raise and strengthen very much in the way of advanced shielding and be invisible at the same time, and massed fire from forty-four fifth-year through seventh-year wizards is nothing to sneeze at. Snape would have noticed Quirrell taking him out, but it wasn't necessary for Quirrell to do so.

That makes sense. Additionally, it seemed to me as if the volley of spells hit snape before his sheilds had even formed completely.
Timing his disclosure spell so that Snape is stunned by the massed fire of his own proteges, would be a more satisfying move in his game against Snape. Plausible deniability again, once the disciplined educated adult observer is removed? What are the longer term goals here? Increase pressure within Hogwarts so Harry feels his confinement more?

I'm a bit surprised that nobody has started talking about one of the most important things revealed in this chapter. Quirrell knows that Snape is on Dumbledore's side. The fact that they had a double agent working against Voldemort in the original canon was quite possibly the Order of the Pheonix's single biggest advantage, and in this canon I would say that it was one of the two most important pieces of information Quirrell might not have known (the other being that Harry knows about the prophesy.) This solidifies Quirrell's position tremendously; there are few liabilities greater than an uncovered double agent.

He's Quirrell [http://abstrusegoose.com/384]. I more or less assume Quirrell can deduce at least a cynical caricature of any player's motives, resources and actions with a glance or two. Snape trying to double agent Quirrell and Dumbledore just seems absurd! I'm also not sure I would quite have assigned Quirrell as the guy who needs to know about Snape's loyalties. It seems like it is Lucious who is going to be the Death Eater Lord in this one. Quirrell has a whole other game. This means that Snape still has a chance to be a double agent, so long as Quirrell doesn't meddle for fun and/or profit.
He may still be able to be a double agent in Quirrel's organization. In canon, Voldemort knew Snape reported to Dumbledore, how could he not when Snape was spared Azkaban on Dumbledore's word that Snape was a spy. Voldemort however thought that Snape reported to Dumbledore only for the advantages it gave him, personally and in the form of information to be used for the Death Eaters, and not from any true loyalty to the Light or opposition to the Death Eaters. Similarly, Quirrelmort knows Snape serves Dumbledore, but thinks (perhaps even correctly) that Snape is also plotting and acting on his own, presumably because of some difference of opinion with the Headmaster. Quirrelmort obviously won't think him a loyal Death Eater like Voldemort did, but for that matter I doubt Quirrelmort trusts anyone who hasn't been put through what Bella has to be truly loyal. Spying on him was always going to be harder than spying on canon Voldemort, but he still may relay important information to Snape in the course of asking him the 'favors' that he wants in exchange for not informing on him to Albus. Particularly if Snape's actions weren't actually against the headmaster's orders, or if he decides to come clean about them while still pretending to Quirrel that he wants his plot to remain secret.
Obviously. And this isn't because of their recent conversation, or because of the Battle of Forty-four Bullies, or because of any other difference between MoR and canon deeper than that MoR!Voldemort is not stupid.

So, what are the chances that Harry and Hermione start talking about their encounters with creepy stalkers? Harry could even say something smug and about how crazy it would be if he kept that sort of thing to himself. Or do we have to wait and watch it go bad first?

Low, since Hermione likely won't remember any creepy stalkers (or the one particular stalker you seem to be thinking of, at least). C&H will continue obliviating her each time until he either succeeds after presenting himself in a way she does not find creepy, which then would be the only encounter she remembers, or gives up.
Now, having made the observation that people are unlikely to talk about things that have been obliviated from their memories, propagate that insight through your belief network in combination with the assumption 'wedrifid is not stupid'. This will hopefully cause an update in your belief "the one particular stalker you seem to be thinking of, at least". I really do refer to stalker after he cleans his (or her) act up. Even once he gets his performance right after n attempts and Hermione listens to him with an open mind he is still someone jumping out of a corridor he had no right to be in giving her personal advice. Harry's stalker(s?) which may or may not be the same as Hermione's stalker is in much the same category. Even when Harry and Hermione are willing to take interest in what their anonymous advisers are saying they should be comparing notes with each other and finding ways to verify the identity, intentions and reliability of the strangers. It doesn't matter how pretty, charming and respectable he can make himself, he is still a creepy man (or woman) jumping out of corridors, causing unaccounted for fight or flight responses and leaving messages in bedrooms. You don't just keep that sort of thing to yourself. For similar reasons to Harry thinking it would be insane for him to keep the sorting-hat whispering to himself. This is exactly the sort of thing that Harry ridicules.
I'm simply saying that H&C likely won't succeed while being thought of as "creepy" by Hermione (actually creepy, not "that sort of behavior usually would be creepy, but somehow I trust him/her anyway"). If you think that ambushing her like he does will inevitably creep her out, well, I'm not sure I disagree since I'm a bit dubious on whether he can actually succeed with that approach. If the descriptor "creepy" wasn't supposed to carry any weight that already happened, more or less, and Hermione stopped the conversation at the word "Santa".
I'd think the chances are fair that Harry passed his Chap 6 obliviation signaling method onto his allies. If she is paranoid enough to key it for disorienting encounters with powerful wizards, the chances are high they might end up talking about encounter N. What would signal would Harry think best? Something you could detect at the time of signalling, like a broken toothpick in your pocket, or a signal detectable safely in the future, like a penmark on the inside of your pocket? Probably both.
A rememberall. Surely this would also be a relatively high priority for his research too. In fact Harry explicitly made a note to himself to research mental magic near the top of his todo list. That should have turned up a device or spell that detects obliviations and he should be in the habit of using it on himself regularly. Which reminds me about the research he is supposedly doing. What has he discovered? What useful spells has he learned? He's supposed to be a genius of near-Hermione level academic skill and far more strategic thought. When are we going to start seeing him pull out awesome, practical magical knowledge or skill?

What has he discovered? What useful spells has he learned? He's supposed to be a genius of near-Hermione level academic skill and far more strategic thought. When are we going to start seeing him pull out awesome, practical magical knowledge or skill?

And somewhere, someone begins thinking paranoidly, 'yes, Harry has made very little practical progress, compared to how much time he has put into scheming against bullies, breaking into Azkaban, and fighting Ender's Game - and isn't it interesting that all 3 seem traceable back to one particular person?'

I was about to respond to wedrifid in agreement, suggesting that were actually several loose ends where Harry ought to have interesting research results, which I would very much like to read about. And yet it's already April! So I was feeling a bit disappointed. But your explanation has cheered me up immensely.
I doubt the Ch. 6 signal was magic, since he'd invented it and the recognition code before knowing about magic, and implemented during his first shopping trip. I don't think you'd need magic to signal obliviation or a full-on groundhog day attack. Magic-wise, I'd suppose that obliviation would make a rememberall signal permanently, but then it seems like that would be important to for obliviators to counter somehow. Magic leaves an armory worth of potential Chekov guns laying around. If owling hand grenades isn't enough to win the next war, it should be something interesting.
Oh, I agree. I speak of upgrades to his precaution measures which I would expect him to have by now. Your point regarding countermeasures is important. Particularly savvy wizards can be expected to think of that. For this reason I would expect harry to maintain his mundane tactics as well. This exploits the known blind spot of nearly all non-Quirrell wizards. Improving his mundane signalling system has also been raised in importance now that Harry is aware of the possibility of Obliviation and has more reason to expect enemies to be motivated to use it. An example being the money earning scheme. I would probably enjoy reading about other tactics that Harry considers even if they do not end up being Chekov guns!
This was brought up before: Of course, there still hasn't been any sort of resolution from that, though there are a number of interesting theories...
But we know Hermione didn't send herself a signal. Anything simple and quick enough to do unobtrusively (like biting her lip) would have been instantly noticeable to her on the second iteration.
We know Hermione didn't send herself a signal she could notice instantly on a second iteration. As of ch76, we do not know if she sent herself a signal not instantly noticable. You might not want to use a signal that could be detected by yourself during an obliviation event in order to make sure the signal isn't telegraphed to the obliviator. Harry might think that if one needed to signal obliviation, it might be best to detect it safely in the future, unless he thought he could make use of an instantly detectable signal and a tactical response would be worth risking interception. In Ch. 6 he risked interception of the signal (he told the potential obliviator McGonnagal about it) in order to forestall obliviation. I doubt that that tactic would work with Mr. Hat and Cloak/Ms. Veil/...
Unfortunately that strategy only works if you suspect you're about to be obliviated. Which makes it mostly ineffective except against people who play fair and ask before mucking with your memories.
Or people like canon!Lockhart, who bragged but didn't ask, though that might be a petty distinction. Or like it was first revealed in chapter 6, as stated above, or again in chapter 17, when one is in a situation wherein there's a high likelihood of Obliviation. Honestly, unless someone springs out and sneak-attack Obliviates you, you'd probably have an inkling that someone trying to keep their secrets is either about to kill or Obliviate you, which should be enough time to chew your cheek or lip.

Ok. Wow. New chapter up.

The ritual references Doctor Seuss (explicitly), Lovecraft, Slayers, Hellraiser, and Warhammer. Edit: And Zelazny. Did I miss anything else?

And the example ritual which Quirrel references is if I'm not mistaken the failed attempt to summon Death in The Sandman. (Is that correct? I don't have a copy on me, but the ingredients certainly sound similar to that. If not, what is this referencing?)

That was an amazing mix of seriousness, darkness, humor (especially the way end), and with a bit of rationality and psychology thrown in also. That chapter was amazing.

Edit: I'm a little worried. We know that a lot of fictional stuff in non-HP fiction turns out to be real in this universe. I hope Harry hasn't accidentally triggered something.

Edit: Also, this does raise a serious question: Since Harry has read Lord of the Rings and Lovecraft and a fair bit of other stuff, how much of what he is making up is made by him from fiction he knows and how much is stuff that he happens to write that sounds good that happens to (at a meta level) reference fiction in our universe? For example, it is extremely unlikely although just potentially possible for Harry to have seen some version of Slayers. But this seems unlikely.

This chapter was great. I especially loved the following line: I'm so glad we'll be seeing regular updates for a while.
I think you can add Buffy the Vampire Slayer to the list. "Acathla" was the name of the demon that the big bads were attempting to summon (or reawaken) at the end of Buffy season 2.
I don't think the part about summoning Death is a reference to anything. After all, we already know what the incarnations of Death are in MOR. And it looks like the conterspell to dismiss Death is lost no more thanks to Harry...
It's a good thing Harry didn't follow that line of conversation; if it were me I could picture wondering out loud why nobody had tried the ritual, suddenly breaking off in realization and thereby giving myself away.
I immediately went to check when I read that passage and no, the sacrifical items don't match at all (although the style is the same). Next I thought it might be from Terry Pratchett's Mort, but it wasn't that either, although this passage is strikingly germane:
I'm having difficulty parsing this. The only interpretation I can come up with is that people have often written (fantasy?) fiction which turns out to come true, and that doesn't seem accurate.
The worry is that in the HPMR universe a lot of things which are fictional in our universe have turned out to exist. For example, McGonagall's references to prior Defense Against the Dark Arts teachers included Professor Summers [http://en.wikipedia.org/wiki/Buffy_Summers] and Professor Blake [http://en.wikipedia.org/wiki/Anita_Blake]. In some cases the situation looks even stranger since Harry has played Dungeons and Dragons (we found that out in the visit to Diagon Alley) but Draco has heard about creatures called mindflayers [http://en.wikipedia.org/wiki/Illithid] which are from D&D. Making things worse, we also know that Harold Shea [http://en.wikipedia.org/wiki/Harold_Shea] is a real world wizard in Harry's universe and his entire MO is to go into fictional universes from "our" universe. The concern therefore is that there might be a creature or terrible thing that Harry thinks is fictional but actually exists. Thus it might well be that the Chaos Gods or Cthulhu or Yog-Sothoth actually exists. If so, Harry using them in a chant could have some very bad consequences.
Ah, much clearer.
1Eliezer Yudkowsky12y
Well, I'm glad someone got Zelazny, but that leaves at least three references I haven't seen anyone decrypt yet, two obscure and one much more mainstream.
May have got another- Dragonlance?

We know that Hogwarts changes itself and has a mind of its own. We also know that Eliezer had pointed out to him in a completely distinct context that doorknobs were not invented until the second half of the 19th century. (In this thread.) In chapter 71, Eliezer explicitly mentions a door in Hogwarts having a knob. Am I overthinking or has he just given us evidence that Hogwarts is smart enough to adopt new technologies to itself?

This may not be the case since the Wizarding world does on a rare occasion adopt Muggle technology (such as the use of armor by medieval wizards). But either way it suggests that either a) wizards adopted a very late technology or b) Hogwarts has a lot of flexibility in how it behaves and can even upgrade itself. So we either have a useful sociological data point or we have a data point about what Hogwarts is capable of doing.

Hogwarts also has modern plumbing, which was presumably not put in by hand considering whoever did it would've found the chamber of secrets in that one place they put a bathroom. I think we can safely assume it will grow new features.

The magic level of the Chamber is sufficiently high that one could conceive of it using an equivalent of a high level Confundus charm on people so that they could install plumbing and yet not notice. But you have a good point and your explanation sounds simpler.
Doesn't McGonnagall mention that the clocks in Hogwarts were most definitely invented by Muggles? That would be an additional datum in favor of this interpretation.

RE: Chapter 75.

Harry is usually rather good avoiding making reckless commitments but he seems to have thrown that caution away. I refer here, of course, to the non-interference treaty he proposed with Hermione. When it comes to things like becoming a ghost-whispering Hermione's rivals that is all well and good. That's Hermione's business. But if there is one scenario we can expect the treaty to cover - informally specified as it is - is that which prompted its very creation.

  • Asking the other girls if they wanted protection was more than just an excuse. If
... (read more)

Led by Snape? I relatively certain that Snape engineered this entire scenario from the get-go to cause the situation to escalate to the point that the school would have to crack down hard on bullying. Snape just arranged it in such a way that he could get what he wanted and still come off looking like the bad guy. Snape is, in fact, fanatically anti-bullying.

Good point. I have no idea what Snape is thinking (to be honest I glaze over at Snape parts). I guess he is anti-bullying except when done by people he likes to people he doesn't like?
I'm probably missing an tag, but consider the evidence. * Dumbledore told Harry that Quirrell intervened so Daphne could take down Astorga * As I understand it, all the bullies have been under Snape's tutelage, their entire Hogwarts careers, with the Slytherin bullies having had him as head of house. * Prof. Sprout was warned off after dealing with Slytherin bullies on Harry's first day Quirrell's "they have tolerated worse in their hallways" and give a finger from my wand hand, suggest that bullying has been tolerated for a long time. What are Snape's adult motives and goals? How much of a panopticon is Hogwarts or House Slytherin there? When he tasked 7th-year Rianne Felthorne, presumably with sending the message back via Bullstrode, she lost count of the charms cast and didn't show recognition of them. Harry would have recognized them from Bester and Quirrell. Hogwarts is a centre of power, perhaps funds his Potions research and precautions againts Voldemort's return. Is conditioning Hogwarts students to fear him defending his future position or building a power base. Are Dumbledore & Snape treating Quirrell as a bird in the hand, under close observation - Bellatrix's escape is still under investigation after all. Who set up the ambush outside the library? Snape or Quirrell? 2PM is too early for Harry's Time-Turner unless the shield was circumvented. Was testing for The cloak of Invisibility a hint from Snape?
That's how I'd characterise his attitude in canon. ETA: This includes, in particular, his own bullying of students.
But wasn't the point of the chapter's end that didn't crack down on the bullying, but just on SPHEW? I don't know what Snape gained by all the escalation he engineered.

My pet theory is that every display of anger Snape ever makes in MOR is part of his act. In fact, the only two genuine displays of emotions we've seen have been his private smile after chewing out Jaime Astorga and his involuntary smile when Harry accused Dumbledore of being a Nazgul. (Snape is the secret Xanatos behind Self Actualization, which is why both Dumbledore and Quirrel keep acting surprised when people assume they're involved.)

Everything actually went according to his plan, except, possibly, being revealed from his Disillusionment as he shadowed the SPHEW members to the ambush. And he DID crack down on all the bullying, he threatened the Slytherins with horrors in private before he publicly punished Hermione.

This is a masterstroke on his part because it removes all incentive the Slytherins and bullies at large might have to seek vengeance against Hermione; she's already being punished severely. The bullies are shamed and fearful, and the one who shamed them is cowed as well. Equilibrium is restored. Hermione pays the price, but it is a fair price, as far as Snape is concerned.

It was Snape that Harry called a Nazgul.
In your theory, what was Snape's original plan with the 44 bullies before Quirrell interfered at Harry's request?
Snape's original plan was to let the bullies beat the crap out of the girls, then Dumbledore would be forced to confront the issue directly. Quirrel may have even been the one who revealed Snape's invisibility just to embarrass him.
Thanks, that makes sense. Personally, I'd be very suspicious of any plan that required Dumbledore to react reasonably, but Snape trusts D more than I do. (And I always assumed, once his involvement became clear, that Quirrel was the one who revealed Snape.)
Harry trusts Hermione. Or Harry finds the idea of failing to signal trust in Hermione even more abhorrent than possibly abandoning the girls to their fates. He needs Hermione to keep his ego sane, whether or not she's guaranteed to be able to keep her ego sane. Saying "I will override you rather than ask you for your opinion" is saying "I will be right and you will be wrong, when we disagree." That's a foolhardy claim for him to make. Hermione stopped him from doing Mad Transmutation Science without so much as doing the magical equivalent of wearing safety goggles, she's an important check to keeping his ego from driving him straight off a cliff.
Exactly. Now he should begin to see why most people in magical Britain allow Azkaban to go on, without protest. I suggest that Harry could perhaps have managed to send a good signal - possibly even a better and visibly more sincere signal - by making his commitment with something like his typical discretion.
Well, the deal certainly seems risky. And his judgement is suspect -- we know he's already risked his life in a stupid way (at least once) to prove his 'intelligence' to Hermione. But on that occasion, Hermione with her trust in authority pointed out the flaw. Later Harry correctly decided that her advice (or at least, the act of thinking about what she might say) would have saved him from making a big mistake with Azkaban. Since she now appears capable of listening, asking her could yield a net increase in expected value. I don't even know if Harry made the right decision by protecting her and her friends. We'll see if Quirrell merely increased Harry's reputation or if, thanks to his action in ch. 75, the events of these chapters will ultimately make staying at Hogwarts unsafe. (I'm embarrassed to admit I missed this possibility until I saw an FF.net reviewer make a related point.)
* Asking seems valuable any time there is time for information-gathering. Hermione is smart (and even more valuable than Harry's inner Founder personas.) * Asking for permission seems appropriate when it applies to interfering with Hermione specifically. * Asking Hermione for permission when other people's lives are at stake and Hermione happens to be in the room is not appropriate. * Asking Hermione for advice and preference when other people's lives are at stake and Hermione happens to be in the room is basically essential. * When the decision is already obviously determined without even needing Hermione's input warning her is obviously essential. * I don't believe Harry explicitly said he will do what she says whenever he asks her. It isn't quite asking for permission, even though that is the implication. Non-compliance would not be a technical breach but a real insult. * As it stands Harry saving Tracy and Hannah after Hermione said not to would be way, way more disrespectful than just doing it without asking. * With a simple disclaimer that represents even a tiny fraction of what Harry usually considers when making commitments Harry saving Tracy and Hannah despite having a negative response would be frustrating to Hermione but not a defection on an implied agreement and probably far less insulting than if he had just not asked at all. * Hermione knows Harry well enough that a mild when-it's-not-about-you disclaimer should be expected from Harry - even reassuring. People doing things that are totally out of character and sabotage their own goals just to please you is (usually) creepy. * I don't think this is in-character for Harry - or at least it isn't unless in-character Harry is totally whipped and this is a flaw he needs to overcome. * Eliezer saying "No, that's what Harry meant to do and he was Right to do it" would make me sad.
I, for one, take it as a sign of Harry's growth that he's willing to put his alliances ahead of his utilitarian calculations, and him doing that appears to be cementing his alliances nicely.

I would've thought that he is increasing the influence of his "alliance" term in his utilitarian calculations.

Harry made the right decision by protecting her and her friends. Given what he knows and even given human (and Hogwarts) behavior it gives the best expected outcome. Yes, Eliezer may construct negative consequences for Harry and try to teach a Deep Lesson but I basically wouldn't buy it[1]. You can't get much better bullying deterrent than seeing them visibly humiliated by first year girls. Add in some naked wall sticking and nobody would want to affiliate with such a degraded role. (They'll move on to more successful dominance displays.) [1]ETA: Unless the Deep Lesson was one about decisions still being the correct decision at the time even if hindsight revealed an unpredictable outcome. But there are easier ways to communicate that.
You're addressing the wrong question. We know that at least one apparent sociopath (Belka) wanted to hurt/kill Harry and Hermione before Snape's angry intervention. So we have to ask if likely Legilimens Q. Quirrell, who interferes with Snape's damage control in ch. 75, wants Belka or someone else to commit murder. More broadly, we have to ask if it made sense for Harry to get help from Quirrell or to try and cheer up the unFriendly AI.
Now that you mention it, that promise does seem rather off-balance compared to Harry's usual standards. Boring hypothesis: He's falling in love with Hermione. Interesting hypothesis: He started out very isolated. His family wasn't abusive, but he didn't connect to anyone. Now he's having to navigate having personal connections, and it's harder for him to make abstractly good choices.
Really? His commitment to Draco regarding Dumbledore is at least as reckless.
That is exactly what springs to mind as an example of how Harry usually goes about making commitments. In that case he was sane enough to mention all of 5 disclaimers, and at a time when Draco was more emotionally destabilized than Hermione is here. I suggest he could have managed to casually include just one this time.
7Eliezer Yudkowsky12y
Wrote the quadruple-disclaimerized version of that conversation, deleted the disclaimers because it didn't flow as writing. Justification: Harry finds it very easy to imagine that Hermione is just as terrified of losing control as he is, even though that's not quite what's going on at the other end.
Should I vote this comment down because I wish you really had put the disclaimers in there and don't find the justification satisfying? (Answer to my own question: no.)
I voted it up because at least he acknowledged he tried. I'm going to pretend I didn't read the justification - it's terrible!
Yes, this alone (just the part that I quoted) is enough to vote it up, on the principle that one votes up what one would like to see more of. Thanks for reminding me to do that!
Glad to hear that! And I can certainly imagine 4 disclaimers not fitting there at all. (One, on the other hand, mentioned as an afterthought...)

One more thing to like about Chapter 75: It really is that much work to change a basic belief.

When I commented at fanfiction, I described Hermione as (previously) obeying rules, but it probably is more accurate to describe her as having trusted authority.

She may be trusting Harry too much-- does it really make sense to take total responsibility for the outcomes of your actions, considering that you can't know everything that's going on? Harry can take that stance because he's smarter than just about everyone around him, but what happens if he has a definitive failure-- not just losing, but a failure?

On the other side, are there authorities worth trusting, and if so, how do you recognize them?

Indeed, Hermione is practically the embodiment of the Authority/Respect [http://faculty.virginia.edu/haidtlab/mft/index.php] intuition.

Dumbledore says that there are only three wizards in Hogwarts powerful enough to pull off what happened in chapter 74, and names Snape among them, but my impression from the original novels wasn't that Snape was exceptionally powerful among the professors of Hogwarts. He was definitely extremely formidable compared to the average wizard (one thing that I thought added verisimilitude to the books was that it was frequently shown that ordinary adult wizards frequently aren't very competent at magic aside from the few things they use regularly; think how many... (read more)

Let's not forget that Cannon!Snape was writing instructions for sectumsempra in the margins of his potions textbook when he was a child - a textbook he incidentally rewrote while he was taking the class. Since then he has been rubbing shoulders with Voldemort and Dumbledore. That said he is more powerful than McGonagall then something has changed rather drastically. That girl is badass.

I have to agree that 'only three' is surprising. Dumbledore himself and Quirrel leave only one extra spot...

Cannon!Snape is definitely badass, but I always figured that given Hogwarts' eminent reputation and the size of their faculty, their standards for anyone holding a professorship are probably extremely high, barring positions people don't want to fill (Defense Against the Dark Arts and possibly Care of Magical Creatures) and pity jobs like Trelawney. In a setting where the academic and practical are so closely intertwined, I imagine holding professorship at Hogwarts as being something like being a member of the National Academy of Sciences and Green Beret combined, probably topped off with an Eagle Scout.
It is a damn high bar and I think you mentioned the big players. Dumbledore -> McGonagall is easy. Then it is Snape vs Flittwick for No.3. It wouldn't seem unreasonable to place Snape higher than the gnome illusionist given that Snape is the one with dark secrets that no doubt include all sorts of badass juice. The problem with the '3' figure in MoR is that Quirrel comes in as a wild card and you would be reckless place him anywhere below second. And as you say, Snape > McGonagall doesn't seem right!
This. I feel like Quirrell would never fight completely fairly against anyone and so he basically can only lose against the unbeatable power of the elder wand. In a fair fight Snape and McGonagall together might be able to take Quirrell but doesn't fight fair.
I don't know -- even in canon, Snape didn't want to win that fight. But this does leave me slightly confused about his apparent stunning just now.

Right. In canon, Snape didn't want to win that fight. Also in canon, Snape is the only wizard besides Voldemort who can fly without a broomstick, although the movie subverts this. One also notes that a half-blood was accepted into the Death Eaters and presumably not for his wealth or family connections. More to the point, in MoR there's a sharper distinction between powerful wizards and non-powerful ones; powerful wizards have taken an interest in ancient riddles, they have delved into secrets, they have found sources of lore that cannot be learned from books. Professor McGonagall knows a hell of a lot about Transfiguration, but she hasn't gone down that road.

Even so, the gap between a "powerful wizard" like Snape and, say, Dumbledore, is rather large. Dumbledore strolls through Amelia Bones's wards like they were water, and Bones, in this fic, is an ancient and experienced witch. Forty-four simultaneous strikes from upper-year Hogwarts students will definitely bring down Madam Bones, maybe even if she does have time to reinforce and strengthen her shields. Dumbledore would wave the Elder Wand, once.

Is Snape as powerful as Dumbledore was at his age?
Almost definitely not. Dumbledore is, in canon (and I presume in MoR), probably the most powerful wizard in centuries. He defeated the holder of the Elder Wand in a duel (which was believed to be impossible) at 64. While Snape is in his early thirties, it seems unlikely the extra three decades would make all that much of a difference.
Keep in mind, in HPMoR, it's heavily implied that AD's artificially aged because he's been overusing time-turners, possibly since his Hogwarts days.
Assuming he's been using the full 6 hours since age 18, that would only give him an extra decade on Snape.
We're not comparing Dumbledore in his thirties to Snape in his thirties, but Snape in his thirties to AD at "64". If we assume that he's been using his time turner since age 11, like HP (though based on his backstory, it seems he got a large intelligence boost at 10, so that might be where he started), he's effectively over 77 when he fought Grindelwald, giving Snape upwards of 4 decades (longer than he has lived thus far) to reach Grindelwald-defeating levels of power. In addition, we know that Snape has good reasons to hide how powerful he is (especially in MoR) and has a substantial amount of muggle knowledge. These all indicate that he's in the same league as Dumbledore, but benefits from not broadcasting the fact. This would also explain the way he was described in MoR.
Right; by 'extra decade' I meant another decade above the three Dumbledore was already older than Snape. It seems unlikely to me that what made Dumbledore able to defeat Grindelwald at ~78 was that he was 78, rather than that he was Dumbledore. From EY several comments above [http://lesswrong.com/lw/797/harry_potter_and_the_methods_of_rationality/4q99]: We do know now that Dumbledore had a phoenix to help him out in the duel with Grindelwald, and so we might suppose that the equipment advantage was balanced between the two instead of heavily favoring Grindelwald. (My impression is that the Elder Wand is better to have than a phoenix in a duel, but that's just an impression.) But I don't know what Dumbledore looked like in his early thirties. We see him at 18 and then at 64, and perhaps he passed through where Snape is now at about thirty. My guess is not.
That duel was a faked show, it never really happened, at least not in the way people were led to believe it did.
You know, I didn't realize until just now what it was that seemed off about Draco's account of the duel with Grindelwald. He said (quote) "there’s no way two wizards would be so exactly matched that they’d fight for twenty whole hours until one of them fell over from exhaustion", and used this improbability as evidence that the fight had been staged. Fact from canon that I don't believe has been mentioned in MoR (and thus may not be MoR canon): Gur Ryqre Jnaq unf gur negvsnpg-yriry cebcregl bs 'haorngnoyr va pbzong', ohg jvryqref pbhyq or xvyyrq ol, sbe vafgnapr, nffnffvangvat gurz va gurve fyrrc. Speculation: Qhzoyrqber pbhyqa'g npghnyyl qrsrng gur Ryqre Jnaq va n qhry- ur whfg bhgynfgrq vgf jvryqre. It seems obvious in retrospect, but since I didn't think of it until now maybe others haven't either. Unless you have some other reason to think it was faked...?
Is this fact in canon? That seems to be the legend but I don't think it was ever explicitly confirmed. I don't have my copy of HP7 or Tales of Beedle the Bard, but the Elder Wand article [http://harrypotter.wikia.com/wiki/Elder_Wand] in the Harry Potter wiki seems to cite Dumbledore disagreeing with this statement in his commentary on Bard.
Yes, but it's not clear that this means the same thing. Killing in their sleep somebody who relied on the Elder Wand for protection makes you the new master of the wand, but you didn't defeat them in a duel.
That does fit really well.
It turns out that you were right about the concept but wrong about the source. Not bad. Unless Dumbledore is lying, of course.
It is strongly implied by canon and Word of God (JKR) that: Qhzoyrqber naq Tevaqryjnyq jrer ybiref.
I believe she stated that Qhzoyrqber jnf vasnghngrq jvgu Tevaqryjnyq, naq Tevaqryjnyq xarj vg, ohg qvqa'g erpvcebpngr. I think that the whole thing about the wielder of the Elder Wand being unbeatable in a duel was mythic exaggeration in the original canon; it was just a lot more powerful than ordinary wands.
You are correct about their relationship. Notice also that Ariana died when Dumbledore was 18 and Grindelwald was 16. (The whole Dumbledore-Grindelwald timeline is sort of screwy, since they part ways and then fight 46 years later, and yet the duel isn't really separated from their impetuous youth in most of the descriptions I've seen.) Very possibly, especially given that the Deathly Hallows are seen as mythical rather than real by most wizards. Even so, beating someone with a strong equipment edge (and presumably a strong Dark ritual edge) through virtue of superior talent, intelligence, and endurance is remarkable. It would be one thing if, like Grindelwald, he stole the wand from its previous owner, or like the second owner he murdered Grindelwald in the middle of the night. Instead, he stood up to a oblubbq pehfu for 20 hours, waiting for his opponent to surrender through exhaustion.
Which explains why Dumbledore might wait (ETA: wait to fight Grindelwald, I mean, not draw out the fight once it started), without wanting to deceive the world or having the motives Draco ascribes to him. It makes Albus look bad in a different way, but given our other knowledge I think it counts as evidence against your interpretation.
Malfoy, are you strong enough as a rationalist that you believing that should be strong evidence for us?

I'd like to warn of a slight ambiguity in the stated commitment Eliezer made in this latest chapter. I'm especially worried that since money are involved, some people may feel cheated if the pledge isn't clarified ASAP and it ends up being the weaker form of the pledge.

"I will release completed chapters every X days" -- does it mean that the chapters that are currently completed, will be released one every X days? How many chapters are those? Or does it mean Eliezer pledges to complete and release a chapter on such a schedule for the remaining du... (read more)

I donated, because it was a good reminder that I should be donating anyway, but the reward kind of leaves me cold. If Eliezer writes new chapters after 78 at a constant rate while publishing existing chapters, then if he publishes all his existing chapters really quickly he won't get many new chapters done in the interim and we'll have to wait a longer time after 78 for 79. If he publishes existing chapters slowly, he'll have 79 done by the time he gets to 78, and can publish those at a steady rate while working on 80+.

So instead of donating to get more total HPatMOR, donations change the pacing away from "slow and steady" and toward "quick burst of chapters now, then a longer interval", with the end date of the fic not changing at all. Personally, I would prefer the steadier pacing.

The obvious solution is for Eliezer to set up a second fund, donations to which slow down the release of chapters.

Perhaps a fund which actually increases the net MoR chapters written. For, you know, the MoR readers who actually picked up some hints of rationality during their reading.
If that existed, it'd be more work, and it would siphon money from the first (two) fund(s).
Err... yes. But the current fund is insulting by its very existence. A 'reward' of something that provides no value (slightly altering a release schedule?) is a discouragement to donation, relative to just 'please give money if you liked it'. More MoR for money, on the other hand, would be following that glorious principle of exchanging money for goods or services.

More MoR for money, on the other hand, would be following that glorious principle of exchanging money for goods or services.

As his author notes in the profile page mentioned, there's at least some people who argue that Eliezer went too far by even the mere offer of an altered schedule in exchange for donations -- right now I think their argument is extremely weak, however Eliezer would probably be treading actually murky waters if he had people give him money for the fanfiction itself (instead of the minor convenience of a quicker schedule).

Oh, right. Laws. They totally slipped my mind. Yeah, he should have gone with just accepting donations.

Ever been addicted to anything?
Insert ceteris paribus into the grandparent.
Ceteris is not paribus. Several readers complained of withdrawal symptoms during the hiatus.

If Eliezer writes new chapters after 78 at a constant rate while publishing existing chapters

For human-psychological reasons I expect that "the drive to complete more chapters" will become appreciable pretty much the moment 78 is published (and not much before).

Even if I am wrong, I don't think "writes at a constant rate" is a safe assumption to make about Eliezer's fiction writing. (This is, of course, tongue in cheek.)

Oh Yvain, thank you for posting this so i didn't feel the urge to nitpick.

I thought the part about "hopefully Ch. 78 will be finished by the time the Interlude is posted" ought to clearly imply that the schedule only applies until I run out of completed chapters.

I just recommend that you edit the text of the promise to make it crystal clear. It's best not to leave any ambiguity in such matters.

I had interpreted it literally, as meaning "indefinitely", and had even reread the sentence to make sure. I'm probably not the only one.
5Eliezer Yudkowsky12y
Duly noted!
For some reason I interpreted the commitment as lasting until the Singularity Summit. I have no idea how that happened though, there's not really anything in the language to suggest that.
Eliezer has had success with imposing such commitments on himself in the past (OB sequence). Given that the money involved puts the endevour on the path to his save-the-world mission I expect Eliezer would pull off the commitment. (That said I wouldn't necessarily contradict an unwise claim.)

In recent chapters I've been agreeing more with Dumbledore overall than with Harry. Not on everything (Dumbledore probably should do more to prevent bullying), but Harry's general attitude seems pretty foolish. It might work out ok for him - he's got the author on his side and lives in a world with extraordinary quantities of low-hanging fruit. But I'm not sure if he's a good role model for those of us stuck in the real world.

It might work out ok for him - he's got the author on his side

I say the opposite. The spiraling negative consequences for standing up to petty bullying are utterly absurd in scope and even in direction. And either Dumbledore is totally miscalibrated regarding the importance of house points or the world is even more artificially hostile. A civil war because an 11 year old girl didn't lose fifty house points as well as the detention she got as punishment for being attacked by 44 students? When, mind you, Lucious's son had been backing Hermione himself? That's just absolutely absurd.

I don't necessarily agree with Harry's eagerness to start targetting powerful non-Hogwarts adults with schemes but the "ask teacher to stop girls being severely beaten" was a no-brainer.

Smartest thing said in the entire chapter:

"You shouldn't be Headmaster," Harry said through the burning in his throat. "I'm sorry, I'm so sorry, but you shouldn't try to be a school principal and run a war at the same time. Hogwarts shouldn't be part of this."

"utterly absurd" except that someone was plotting behind the scenes. It was spiraling out control only because somebody kept pushing it around in a circle. I guess the question is "who". We know that Snape was involved in this scheme somehow, so he'd be the parsimonious choice, but it doesn't seem to fit his goal system.
Note the implications of the obvious analogy for EY, although not everything an author sets up his characters to say has to be an allegory.
I didn't notice that one at all but now that you point it out it's all too true!
I tried to say this before, but apparently it got lost in my bad expression: civil war and other bad outcomes seem vastly more credible if they happen to serve Quirrell's goals. And some of them would. Harry's mistake doesn't lie in going against Dumbledore, I think. It lies in failing to update the probability of Quirrell indirectly killing someone to manipulate Harry, based on Azkaban.
He's Quirrell. Quirrell doesn't even need to snap his fingers to make that sort of thing happen. No doubt from me. He does seem to trust Quirrell an awful lot.
I don't think Harry is used to having friends [http://lesswrong.com/lw/797/harry_potter_and_the_methods_of_rationality/4roq]
The wizarding community in Magical Britain is pretty close to civil war in general. The community is small so small scale results can have larger impact, and Hogwarts is the only magic school in Britain so people pay more attention. Moreover, the wizarding world has a lot of values based on medieval ideas. In Roman times people fought wars over chariot team winners. In modern times that's translated into wars about football [http://en.wikipedia.org/wiki/Football_War]. The idea that discipline issues could be a significant enough dispute to push them over the brink is not implausible.
The recent conversations Harry has with Dumbledore seem to imply that Harry is becoming what tvtropes calls a Knight Templar [http://tvtropes.org/pmwiki/pmwiki.php/Main/KnightTemplar]: a zealot who is willing to burn villages in order to save them. Such a person will very easily commit great evils in the name of "The Greater Good" (whatever that may be). I agree with Dumbledore on this. Harry has no brakes; he is willing to escalate his counterattacks without limit, collateral damage be damned. This may not technically count as "Dark" according to the dichotomy set up in the narrative, but it's still a completely evil way to act.
Or a Totalitarian Utilitarian [http://tvtropes.org/pmwiki/pmwiki.php/Main/TotalitarianUtilitarian].
Dumbledore's depiction reminds the confessor in three worlds collide [http://t.co/hiyj4mI]. He mentions that there are very few humans who need help to be more optimistic, and his experience leads him to see all the ways that things can go wrong, so makes him suited for being rational. Similarly with Dumbledore, his experiences have made him highly risk averse, often to good, but it does result in him being unwilling to change things. (As a contrast to the more reckless/innovative Harry).

Ah, so that's why her arm was aching. I could have got that, if only I were better at noticing my own confusion. Tsuyoku naritai!

I completely missed that looping thing too - I had assumed the aching thing was the usual fight-or-flight response ('the gun felt like it weighed a hundred pounds and shook like a sick puppy as I pointed it at him'). I do, however, give myself credit for thinking, 'surely Hermione isn't stupid enough to buy that Merlin story based on a shapeshifter changing their appearance immediately after telling that someone they were distrusted because of their appearance.' The interesting thing to me is that Cloak-and-Hat's claim he can make arrangements at other schools ties in with Harry's standing offer from the letter-leaver to take a Portkey to that American school, which sounded like a Quirrel thing to do, and that odd bit about 'time' - well, wizards already have time travel on the scale of hours, why not years? Quirrel being a time traveler (I am sure someone must have thought of this before) would explain a lot. His sickness could be due to the time travel (maybe sharing with an uncooperative body?), it'd explain his power, it'd also explain his very good priors for what is going on, and out of universe, Eliezer has recommended time travel Harry Potter fanfiction. Whether Quirrel is a time-traveling Harry himself, I'm not sure. That may be a step too far, although it would explain the 'don't cross the streams' stuff with HarryxQuirrel.

Ugh, several points of bad logic.

His sickness could be due to the time travel (maybe sharing with an uncooperative body?),

There's nothing about Harry Potter-style time travel that causes sickness or bouts of weakness, even short ones. This is evidence against Quirrel's central mystery being long-distance time-travel.

it would explain the 'don't cross the streams' stuff with HarryxQuirrel.

It would NOT explain it! There's nothing in Harry Potter-style time travel (either canon or MOR!verse) about not touching or interacting with past versions of yourself. This is again evidence against Quirrel's mystery being long-distance time-travel, not in favor of it.

You're making false assumption based on other movies and series that have nothing to do with the rules of time-travel as established in Harry Potter!

It'd also explain his very good priors for what is going on

That's the only thing it would explain. But all your other points actually point against time-travel.

Travel often involves danger in Harry Potter; Floo ports can be unpleasant, likewise Port keys, and when apparating, one can 'splinch' oneself. Time travel with the heavily restricted Time turners is quite complex and hence possibly dangerous, as MoR has already shown. In the HP time-travel fic Eliezer recommended, each instance of multi-decade time travel damages the protagonist ever more, until during its settings, one more travel back will probably kill him upon arrival. (And logic? In a fiction universe where we can trust nothing?) I must have missed this. Where is it written that you can touch your past self, mingle magics with your past self, cast spells in your past self, etc.?

Eliezer has said that Tom Riddle (aka Voldemort aka Professor Quirrel) taught himself occlumency in his third year by getting a time turner and leglimizing himself.

Oh. Hm. That's a good point then.
Cool! (Where did he say that?)
http://lesswrong.com/lw/30g/harry_potter_and_the_methods_of_rationality/30d1 [http://lesswrong.com/lw/30g/harry_potter_and_the_methods_of_rationality/30d1] (Took me a long time to dig that up.)
Thankyou! My googling didn't turn anything up and I've reread all of MoR itself in the last couple of days (except the bits I didn't like) so I was failry sure it wasn't in the story itself. I notice that I myself replied to Eliezer in that thread. Over the last five years or so I seem to have lost the ability I once had to remember nearly perfectly every conversation I participated in. Shame. :)

(And logic? In a fiction universe where we can trust nothing?)

This is Harry Potter and the Methods of Rationality. If we're not supposed to use our logic here, then the whole thing is pointless.

There's nothing in Harry Potter-style time travel (either canon or MOR!verse) about not touching or interacting with past versions of yourself

I must have missed this. Where is it written that you can touch your past self, mingle magics with your past self, cast spells in your past self, etc.?

Absence of evidence is evidence of absence. You have a number of time-travel interactions in both canon and MOR!verse where you could attempt to find any such hint of a prohibition, sense of "Doom", bouts of sickness is relation to time-travel, etc, etc.

If you can't find such evidence of a prohibition, or the other phenomena you describe, then that is evidence against there being such a prohibition or such phenomena.

You don't use logic because you're "supposed to".
I won't downvote you, but I was tempted to, for seemingly intentional lack of clarity in your objection. Making us guess at what you mean seems a waste of our collective time. By the phrase "if we not supposed to use our logic" I meant "if we can't apply our logic to make testable predictions about plot-points and revelations in subsequent chapters". Is that more agreeable with you?
If we're going to divert to this tangent then I'll say that yes, in fact, often people do use logic because they are "supposed to". You could make the normative claim that you're not "supposed to" use logic because you're "supposed to". But the descriptive one is as false as the normative one is arbitrary.
And wasn't intended meaning.
And intended meaning of ArisKatsaris fits perfectly well in context [http://lesswrong.com/r/discussion/lw/797/harry_potter_and_the_methods_of_rationality/4rgb].
I don't think it was. If there is any notion of consequences at all, there are methods to be developed for steering consequences where you want them to go, it's not a matter of social or genre convention to break this principle.
I don't believe you parsed the context correctly.
Yes. I dislike connotations of "supposed to", since it equivocates between laws of thought and social expectations, but this distinction doesn't map to the context, because two worlds are involved instead of just one. In context, the intended distinction is between the author following or breaking in-world laws of nature, filtering the evidence essentially.
Non sequitur
Privileging the hypothesis - that mingling with your past self is harmless. It's the rare timetravel fiction (fanfiction or otherwise) where such interactions are harmless; usually, it's disastrous in some respect. In the absence of an actual example that it is not disastrous, like the Tom Riddle citation, our priors are not 50/50 or outright assuming it's harmless.
No. Please read the grandparent again. I cannot explain more clearly without explaining basic logic itself. The reply simply does not follow. The remainder of what you say here could be made as a reply to the great grandparent where it would at least fit (even if I would still disagree based on priors).

Chapter 75 was sad but did have its funny parts.

I really liked:

Nice well-groomed boys get girls, and Dark Wizards also get girls, but nice well-groomed boys suspected of being secretly Dark get more girls than you can imagine -"

I do think that there is a serious problem with the scale of the problems that Harry is dealing with as opposed to those Hermione is dealing with it. It almost comes across as token feminism. The actual books have been criticized for that same thing but at least there Hermione got to actually deal with the same life-threat... (read more)

I've been pondering this. I was really glad when Hermione started getting to take the spotlight, and a lot of my appreciation was from a straight-forwardly-feminist perspective. I posted a mini review talking about how Hermione had been lacking as a character, the hints Eliezer had dropped about her future development, and my appreciation for the way he eventually handled it. Apparently this comment played a role in Eliezer coming up with the SPHEW acryonym. I'm not sure if it ended up otherwise shaping the arc. He also noted that the initial setup (where Dumbledore basically tells Hermione she can't be a hero because she just can't) was intended to be a critique, but not about feminist issues.

A few months later, I think this section is an interesting case study in meta-token-feminism. I think that Eliezer in general agrees with most goals of the movement, but is probably actually opposed to token feminism. (This is based off of a few vague statements he made, I'm only 65% confident). I also think that SPHEW was originally intended to sort of lampshade the issue, addressing some real issues but in a tongue-in-cheek way. (The issues - mostly about the power imbalance that he created... (read more)

Absolutely not. Draco will be in between them.
I'm pretty positive Draco and Hermione will be flanking him.
Dramiorry: OT3 for lyfe.
I'm totally shipping that threesome. And wondering just what their parents would say about it.
Huh. My first thought was simply to argue that a work of fiction is rarely improved by attempting to make it meet certain moral standards; The Kreutzer Sonata isn't any less great for espousing despicable beliefs, and plenty of terrible novels inspire laudable ideas of human society. So, if artistic quality and moral quality are unrelated, better that an author write what comes from their heart rather than attempt to teach what they haven't yet interiorised themselves, and risk coming off as insincere or overzealous. However, MoR is ostensibly meant to be an educational and inspirational story as much as an entertaining one, so in that particular light the suggestion carries more weight. Even so, it wasn't Eliezer's decision that the fated hero be male and the well-meaning-but-over-her-head companion be female. Perhaps more importantly, had Ron kept his canon role instead of being replaced by Draco, there would have been a second, male WMBOHH companion, Hermione's frustration would not have been framed in terms of perceived sexism in the first place, and there probably would not have been a S.P.H.E.W..

However, MoR is ostensibly meant to be an educational and inspirational story as much as an entertaining one, so in that particular light the suggestion carries more weight. Even so, it wasn't Eliezer's decision that the fated hero be male and the well-meaning-but-over-her-head companion be female. Perhaps more importantly, had Ron kept his canon role instead of being replaced by Draco, there would have been a second, male WMBOHH companion, Hermione's frustration would not have been framed in terms of perceived sexism in the first place, and there probably would not have been a S.P.H.E.W..

I mostly agree with this. But with an extremely lengthy qualifier:

My take, as a storyteller, is that your collective work should meet your moral standards. (I mean, they're YOUR standards, your work should be meeting them, whatever they are). That doesn't mean jamming morals down people's throat, it doesn't mean making sure each work conveys every single positive thing you believe in. But I think it does mean that you should consider what impact your story might have on the people who read it, and given the chance, you should try to make that impact positive.

Some of my favorite stories are ones... (read more)

What's wrong with completely shutting up about morals? Gustave Flaubert's Salammbo is also about an alien crapsack world where the only character who disagrees with common morals is even worse than everyone else, and it's wonderful. Except the parts where the book cuts itself off during a description of mass murder, torture, human sacrifice, or male-male couples, to remind the reader that they are wrong and abnormal. Yes, Gus, that's nice, but will you be quiet and let the grown-ups read? I guess you could make the argument that it teaches you that the typical mind fallacy is false, or to question your own society, or something, but that looks dubious. It's just a pretty thing, and it doesn't have to meet moral standards any more than gastronomic ones.
You're still conflate "be a moral work" with "shove morals down your throat in a hamfisted way" which is exactly what I was saying you DIDN'T have to do. If Salammbo does this in a clumsy way, well, then yeah, maybe that book could be written better. (If it says male-male coupling is bad, I disagree with it on a moral level anyway, although that's different than disagreeing about how that morality was dealt with). When I say "works should be moral" I mean that, all else being equal, I prefer art works to produce a positive effect on the world. Sometimes by directly inspiring people, sometimes by subtly shaping them.
Actually, insofar as he decided not to gender-flip everybody or change the prediction, he did decide to make the fated hero male and the companion female. Not that I think he should have done otherwise, all things considered, but this kind of argument annoys me in general.
Harry isn't dealing with any life threatening issues now, except internally. I'd be surprised if the story reaches its conclusion without her being made aware of the issue of Voldemort and playing an active role in the conflict.
And he has dealt with bullying in past chapters (though he focused most on Snape's bullying). Harry and Hermione learned almost directly opposed lessons from the experience, both of which seem correct.

What do people think about the interaction with Dumbledore? I got the sense that this was a chapter where we (the reader) are supposed to consider that Dumbledore may very well be wiser than Harry because he's got a century+ experience on fighting evil, but that because the chapter is from Harry's POV it doesn't read that way.

I'd been meaning to raise that question, too. Dumbledore is talking like a typical administrator from Mediocristan [1]. It's easier in the short run, and the medium run, and sometimes the rather long run, to tolerate bullying if you aren't subject to it. However, every once in a while, you get a civil rights movement or an Arab Spring. On the other hand, Harry isn't exactly dealing in non-violence, and it's possible that his faith in the effectiveness of punishment is naive. I await further chapters. [1]Nassim Taleb's name for the condition of being able to make pretty good predictions about tomorrow by simply saying that it will be like today.
I don't think bullying is qualitatively different from normal social interaction, merely quantitatively different.

Sometimes quantity has a quality all its own.

I didn't mean to imply that it wasn't a bad thing. My point is that the standard discussion seems to be about detecting bullies, as if they were a type different than other people. Even when the similarity of bullying to regular behavior is acknowledged, I have heard appeals to magical categories along the lines of "how can we distinguish regular behavior from bullying", as if they were different in kind.

The flawed question of asking how to detect bullies prevents people from having to admit that their own normal children may contribute to social problems, as does pretending that normal social grouping is perfectly fine, zero percent bad, and unrelated to bullying.

It's also an anti-consequentialist focus on behavior rather than its effects.

I think the current debate around bullying is designed to make participants feel self-righteous and as if they were doing something, but not asking the right questions and not able to trade the benefits and lack of costs to the participants for benefits for children.

Could you expand on your idea that there's no well-defined difference between bullying and normal social behavior?

Definitions from wikipedia and http://www.stopbullying.gov, with emphasis added:

Bullying is an act of repeated aggressive behavior in order to intentionally hurt another person, physically or mentally. Bullying is characterized by an individual behaving in a certain way to gain power over another person.[14] Norwegian researcher Dan Olweus defines bullying as when a person is "exposed, repeatedly and over time, to negative actions on the part of one or more other persons." He defines negative action as "when a person intentionally inflicts injury or discomfort upon another person, through physical contact, through words or in other ways".[15]


What is Bullying?

Bullying is a widespread and serious problem that can happen anywhere. It is not a phase children have to go through, it is not "just messing around", and it is not something to grow out of. Bullying can cause serious and lasting harm.

Although definitions of bullying vary, most agree that bullying involves:

Imbalance of Power: people who bully use their power to control or harm and the people being bullied may have a hard time defending themselves Intent to Cause Harm: actions done by acc

... (read more)
That's an interesting angle, but I think the worst dominance-establishing behavior does enough damage that trying to snip that tail off the bell curve could be worth the trouble. Moving the center of the bell curve towards decency is also a worthy project, but perhaps more difficult.
That's not how the project is perceived by people involved in it, at least that's what I presume granted the media they emanate. They don't talk about, and I am guessing they don't think about, what causes normal dominance behavior to progress into the most affecting kind, and the focus is on getting normal people to report rather than change their social behavior. Quoting the first three paragraphs of the front page NYT article from August 30, which I didn't see when I wrote anything above: So the focus seems to be convincing normal people to report, rather than suggesting that they are doing anything at all wrong or that they might, by increasing the severity of normal behavior they are already doing, become targets under the new law. There is no push for introspection nor for considering the feelings of others, the worst people are asked to consider of themselves is that they had not been reporting the bad behavior of others often enough - a small sin. Does anyone have a guess as to when the first article about the use of this law (taking effect September 1) to bully someone will be written? Delusional descriptions of a problem generally can't be justified by claims that the description is targeted at the worst behavior or designed to get the most return out of a small investment because an accurate picture of reality is usually the first step to implementing any strategy well, regardless of its resources and scope.
It looks as though I was thinking about anti-bullying programs the way I think they ought to be done, and you had the specific example in mind of how current anti-bullying programs are being described.. Anti-bullying programs don't seem to have done a lot of good. [http://boston.com/community/blogs/crime_punishment/2010/08/why_anti-bullying_programs_fai.html] I've read an account of a school-- Great Walstead, a British boarding school in the 60s-- which really didn't have bullying. The head of the school wanted his students to do well, and hated bullying-- it wasn't a pasted-on anti-bullying program. (This is from Frank Schaeffer's Crazy for God, a memoir which is mostly about growing up in a family which was at the top of the early Religious Right-- the description of the boarding school is a minor episode.)
That all makes sense.
The fascinating thing is that high quality only comes from cluefulness at the top of the hierarchy, and it's hard to transmit clues. It seems to me that the anti-bullying programs you describe are an effort to mechanize a process which requires consciousness. Even so, they may be of some use if they limit overt violence. One of the things which is hard on victims is for them to be injured publicly, and for everyone to behave as though it doesn't matter. An account from fiction of consciousness-based top-down anti-bullying: One student starts calling another "Stinky", and an upperclassman shuts it down by saying "nicknames should be endurable". (Sorry, cite forgotten.)
What I want to know is why Harry didn't accuse Dumbledore and his staff of not doing enough to prevent bullying. I know I would have.
He came fairly close back in the early chapters. He was going to start a PR campaign on the subject...
Ah. I guess its been too long. Which chapter was this?
This was bullying by Snape, not by students. See here [http://www.fanfiction.net/s/5782108/18/Harry_Potter_and_the_Methods_of_Rationality].
The interesting question is whether it didn't occur to Eliezer or it didn't occur to Harry. I can see it either of them not thinking of it because at this point, Dumbledore is well established as not caring about bullying. It's pretty clear that Harry would have to start from scratch to convince Dumbledore that bullying is something to oppose.
I think any reader with a few ounces of rationality should be spotting the obvious false dichotomy between Harry's "fight bullies" and Dumbledore's "don't fight bullies". I predict that by the end of the Self-Actualisation arc, Harry will have come to this realisation, potentially through discovering a third way to deal with bullies.

Agreed. Harry's present approach seems to be turning bullies into a self-aware interest group.

Hermione's present approach (and perhaps, more importantly, Snape's involvement) seems to be turning bullies into a self-aware interest group. It remains to be seen whether Harry's help made things worse or better.

He could make them into a self-aware interest group that is scared of him. Bullies understand force. What's that spell when you lift them upside down by the leg? I'd start by talking to Fred and George and seeing if they could get spells like that into a pre-packaged consumable form. And get some serious self defense training happening. Have there been any chapters so far on actual research based training methods for building skills? Or has Harry just been trying to 'clever' his way out of stuff? A little crowd control doesn't seem like something Harry should have difficulty arranging.
I don't quite understand why Harry didn't suggest to Dumbledore that if he's so concerned about further escalation by the bullies he should expel them. It's not as if that would be so difficult to justify. (Though there are a number of possible downsides.)

Does it say anywhere in HP:MoR that Tonks is a metamorphmagus? I can't remember if it does and there were some reviewers (presumably who didn't read the original series) confused by her ability to imitate Susan without polyjuice poison.

She's not definitely called out as Tonks, and I'm not sure the years match up, but from chapter 29: "Did you know there's a fourth-year girl in Hufflepuff who's a Metamorphmagus?" said Hermione as they headed toward the Great Hall. "She makes her hair really red, like stopsign red not Weasley red, and when she spilled hot tea on herself she turned into a black-haired boy until she got it under control again."

I've just decided to eliminate the "fourth-year" qualifier. I'd previously meant Ranma to be separate from Tonks, but on reflection it's kind of funnier if she is Ranma. More importantly, I want Metamorphmagi to be rarer and more unexpected than if two different ones are attending Hogwarts at the same time.

I think that's supposed to be a Ranma 1/2 [http://en.wikipedia.org/wiki/Ranma_%C2%BD] reference.
Huh, I missed that. I thought it was EY's way of dropping in a cultural tidbit about the wizarding world, where a transsexual girl is naturally thought of by everyone as a girl, though they all know that she makes her body the way it is by being a metamorphmagus, and she reverts to her non-metamorphed form when she's startled. Then I started wondering what non-metamorphmagus trans people would do. Maybe there are permanent sex-change potions. Or perhaps temporary ones that you have to keep taking, like polyjuice but without copying anyone. Or maybe all trans wizards are metamorphmagi, but I doubt it.
My understanding is that Tonks is a seventh year. Edit: And what Zack said.
Definitely a seventh year: "Miss Granger is selling them for two Sickles, and tells me that she has so far sold fifty of them. I believe that Nymphadora Tonks, in seventh-year Hufflepuff, is enchanting them for her." Ch 70, referring to the SPHEW buttons.
Edit: And what Zack said.
I just did a quick search. She's been mentioned once before, but there was no mention of her ability.
Thanks. It's just when they mention her making the buttons, right? He really should clarify that for these people.

I always wondered when/if Harry would figure out that the way magic works is evidence for the simulation argument. I just started rereading the old chapters, and found this in chapter 14:

You know right up until this moment I had this awful suppressed thought somewhere in the back of my mind that the only remaining answer was that my whole universe was a computer simulation like in the book Simulacron 3 but now even that is ruled out because this little toy [the time turner] ISN'T TURING COMPUTABLE!

I think his assumption that this rules out the simulati... (read more)

It's also an invalid conclusion for other reasons. Harry hasn't actually done anything uncomputable with a time turner, and the one occasion that he came close (trying something computable but slow), all that he got for his pains was ‘DO NOT MESS WITH TIME’. It's very easy to compute this. Even if Harry does something that seems uncomputable, that proves nothing [ETA: although of course it is evidence and Harry's estimate of simulation should go down in accordance with Bayes's Rule], since he only observes finitely many experiments, and any finite result is (trivially) computable. It's always possible that the system could break down when you push it further. (Presumably it has an error catcher that outputs ‘DO NOT MESS WITH TIME’ when this happens.) As far as we know, the real world is computable, and it's computed this story. Therefore nothing in it is definitely uncomputable.
That message came from Harry, not from physics. Roughly speaking it indicates that a stable loop where Harry gets hysterical is easier to arrive at than a stable loop where the problem is solved. ie. In one of the instances something surprising and dangerous but non-fatal (would have) happened so that (potential) Harry would have set up a stable time loop that prevented that branch from ever happening. (Or maybe Harry just went paranoid for no reason - hard to tell with him.)
Everything that comes from Harry comes from physics! But of course I really mean that it outputs something to deter the agents in question from trying to push things that far. In Harry's case, that's ‘DO NOT MESS WITH TIME’ in scratchy letters; in somebody else's case, that's something else. But the simulation should be able to calculate whatever is needed.
The thing is we don't need to hypothesize this extra mechanic in order to explain the observations we have seen. It is like, say, hypothesizing a new force in physics called the 'siphon' force when siphoning is explained perfectly well by gravity and pressure differences in the fluid.
We do if we want the universe to be computable. To calculate our posterior probability of the simulation hypothesis, P(A|B), using Bayes's Theorem, we first find (among other things) P(B|A), the probability that we would have observed the new evidence if the simulation hypothesis were true. I'm arguing that this is higher than Harry thinks (hence so is P(A|B)), since it's easy to come up with ways that it could happen (contra Harry's claim quoted above). I'm not claiming that P(A|B) is actually high. More generally, people need to be open to hacks and kludges when considering the simulation hypothesis.
Hm... that is also true. Sufficiently restricted time travel should be computable. Not sure how restricted it would have to be. A sufficiently good computable approximation could conceivably have fooled a wizarding society that did not use the scientific method.
There's actually, unless I've made a stupid mistake, an even better algorithm that is Truing computable, if very slow: every time the value of a bit may depend on future events, split the universe and calculate both possibilities. If a branch ever implies a paradox prune that branch and pretend it never happened. Actually, while this indeed would require a ludicrous amount of branching for an universe where arbitrary chunks of matter can be transported back to any given plank time, all those branches would need to be computed anyway for MWI quantum mechanics. So all you're really doing is tweaking the MEASURE of each branch.
Hm... sounds right. This also has the fairly disturbing implication that, while people only ever remember consistent time loops, the distribution of mind-moments currently experiencing time loops is not weighted towards consistency, and thus most of them cease to exist as soon as the time travel event fails to happen in a way that would have formed a consistent loop.
Yea, hehe. Reminds me of Mangled Worlds Quantum Mechanics: http://hanson.gmu.edu/mangledworlds.html [http://hanson.gmu.edu/mangledworlds.html] Basically the same thing, but with the born probabilities instead of temporal consistency. And the fact that it may very well be real. O_o

Two ideas that came to me overnight:

  • Fred and George convinced Rita Skeeter by... not convincing RIta Skeeter. Someone polyjuiced as her went to the Daily Prophet offices announcing their amazing new story.

  • Eventually someone will be an animagus who turns into a human. Probably not Harry, as it would seem repetitive for him to have both a human patronus and a human animagus form.

Eventually someone will be an animagus who turns into a human.

That seems like it would just be a much weaker form of Metamorphmagus; and as such, largely uninteresting.

Possibly, although I think EY might well go for it as a good abuse of the rules, and I'm sure he could find a way to make it interesting.
"I'm not serious!"
On the subject of abuses of the rules, I briefly considered the idea of a Patronus that could cast Patronuses, before remembering the bit about it draining Harry's magic.
Or it was Tonks or another metamorphagus?
Fred and George didn't do it. They planted a story about Quirrel. Quirrel read the story and, seeking a way to get back at Skeeter, found out that Fred and George were trying to get back at Skeeter on Harry's behalf – but not that they had planted the story about Quirrel. So he offered to help them, and set everything up for Skeeter, then wiped their memory of everything they'd done to plant the story, which included the memory of planting the story about Quirrel.
Not convinced - Quirrel said he'd have trouble arranging a small portion of the evidence Skeeter saw. Obviously we don't have to believe that, but EY's general setup makes me think it's something Fred and George did.
I wouldn't take at face value anything Quirrel says that's not in Parseltongue. And even then with a pinch of salt: it might be that it's simply harder to lie in such a non-human language rather than there being any actual magical constraint.
I still can't see how publishing a stupid and incorrect story would have been reason enough to make people assume that Rita Skeeter had gone into hiding lest she faced Malfoy's punishments. Canon!Skeeter would hardly flinch at publishing bullshit stories, and I don't recall hints in MoR that that trait was different - hell, she says her paper regularly throws around empty accusations of Death-eating, which sounds like a much more dangerous thing to do for a publication than fake marriage tales.
Been a while since I read it, but I got the impression the danger came from offending the Goblins and other major magical institutions. (As far as death-eating goes, both in MoR and canon, the paper is connected to Lucius Malfoy, who would like all accusations of death-eating discredited and made ridiculous conspiracy theories - so he might even encourage obviously false stories. The danger would be libel suits, and those are healable with Malfoy funds.)
The problem with libel suits is that as far as I could tell, there aren't any in the canon wizarding world, as evidenced by Rita Skeeter writing whatever the heck she wanted. I also thought that her going into hiding seemed like an overreaction, though it could be another example of wizards believing anything. As for legitimate reasons for her running, though, what I got from the story is that the problem is not that this is a bullshit story, or even a really high-profile bullshit story, but that it's a demonstrably false high-profile bullshit story. If she is used as a social weapon and to spread disinformation, being openly proven to lie--or be overly credulous--would be a liability, albeit one I wouldn't think would warrant assassination.
It's a sticky inference to make. Maybe there are no libel laws as you say; or maybe: 1. Malfoy has enough money to hire lawyers who successfully beat even the magical equivalent of England's plaintiff-friendly libel laws 2. Variant of above; it is known that attacking the Prophet/Malfoy will be a poison pill for the attacker as the legal fees are too high to be borne and/or discovery will be abused to dig up all sorts of dirt and private information. 3. People fear the behind-the-scenes retaliation of the Malfoys and their alleys 4. Variant of above; fear retaliation by the Daily Prophet (monopoly paper) which doesn't rise to the level of legal actionability - constant mocking and negative references. 5. Death-eating in particular is not good grounds for a libel suit; perhaps magical England has a factual defense like the US, and all the accused are in fact former Death Eaters. 6. Variant of above; Magical England has libel laws, just they are in general like American libel law and it's awful hard to win such a lawsuit. 7. The Prophet carefully writes too vaguely to be sued in the first place. 8. Rowling just didn't think about it; the British press is scurrilous, so the magical press is scurrilous. The various economic and legal incentives are too far to the background to be even thought about. Eliezer borrows this assumption, and in keeping with his medieval evil Magical England interpretation, it doesn't matter why the press is evil and freely accusing people of Death-eating. Given the uncertainty of the libel suit point, and the canon that goblins are touchy murderous nasty customers, I'd rather point to powerful factions rather than a big libel suit as why people would accept Skeeter hiding or going into exile.
The Malfoys' alleys are people I really wouldn't want to meet in a dark ally.
And Daigon Alley in particular.
(I think wedrifid was suggesting that "alley" should be "ally")
Well yeah, but it's a lot funnier to pretend it's deliberate.
Rita Skeeter says that if Quirrel was a real Death eater, the paper never would have actually printed it.

Hah, the little details you catch on a re-read:

the bolts struck and vanished upon a dark red octagon that appeared in the air


6Eliezer Yudkowsky12y
A.T. Field. What do you mean, Hammertime?


... you know, it's kind of impressive that you meant to make a nerdy reference through something which could have been so utterly everyday and mundane that it would still have been funny precisely because of how everyday and Muggle it is.

On at least three occasions in this fic that I can think of offhand, people have confidently identified references which seemed very clear and obvious and fitting after I looked them up, despite the fact that I hadn't the slightest idea of what I was "referring" to at the time. It is enough to expand my concept of coincidence.

What's your current concept of coincidence?

Quirrel is starting to get antsy... things are going to become very interesting once his term as Battle Magic professor is over. The Tracy girl... I don't like her. This is not to say I don't like the writing associated with her (great for comic relief, I'll EAT YOUR SOUL), it may have to do more with her being a vapid girl character in "competition" (within her own mind, anyway) with a smart, eminently likable Hermione Granger... I believe I may be in serious danger of becoming one of those shipper people.

This isn't necessarily a "competition" that anyone has to lose. Harry could always take a third option and attempt to make a rationalist polyhack on the problem. He's shown the ability to get along well magically with more than one different person and it doesn't seem likely that he would distance himself from one if history had shown he could use their help for important tasks. Also, my understanding is that Harry hates disappointing people. Considering that, it's a little hard to imagine him turning down Tracy without at least considering a way to keep them both her and Hermione happy simultaneously. It would also come in handy in the future if the story extends long enough for him to meet Luna Lovegood. And the fact that I think this would be an idea that I would really like to read now that I have thought of it seems like pretty good evidence that I am shipping.

I just read all the chapters from 1 before Azkaban until the end. Have to say I loved them. Either that which had pissed me off about the chapters immediately preceding that one was not present or I have lower standards now. From what I recall the irritating bits were Harry being inexcusably stupid in ways that are later fully endorsed by Eliezer. But everything Harry has done since then has been either a good decision or revealed to be a bad decision. Like going to @#%@# Azkaban. I particularly like this scene:

"...and Professor Flitwick says her de

... (read more)
I reread it a lot recently and once SPHEW got attacked by the whole huge army of bullies and Harry pulled that ritual awesomeness i enjoyed the arc much more in retrospect.

The play referenced in Chapter 75 refers to the webcomic Ow, My Sanity!.

The relevant paragraph of Chapter 75, for convenience of comparison and search:

"Oh," said the third-year girl, "I was thinking of that really romantic one where there's this very nice, sweet boy who makes a Floo call, only he mispronounces his destination and stumbles out into this room full of Dark Wizards who are performing a forbidden ritual that should've stayed forever lost to time, and they're sacrificing seven victims in order to unseal this ancient horror which

... (read more)

When I read that passage I would have bet a non-negligible amount of money that the work referenced was an anime or manga. Good thing I didn't.

edit: bloody hell is that webcomic terrible

It's frustrating. I read the trope page before checking it out, and thought it sounded really interesting. But it took me almost no time to give up on it. What good is a story that's supposed to be about the relationships between people and beings that look like but don't think or act like people when the people don't think or act like people?
Well, Stephenie Meyer's bank account balance says it's worth something.

So does Dumbledore know that Snape is putting the Sorcerer's Stone back into Gringotts?

Okay, chapter 76.

"But do you know how many licks it takes to get to the Tootsie Roll center of a Tootsie Pop?" is Hermione's best line so far. That part of the story felt slightly unrealistic, as a result of how ballsy Hermione was being. She's an eleven year old girl, confronted by some unknown person. I am surprised she is that confident.

As always, I love how the theme of "surface appearances" is placed throughout in so many ways, in every one of the scenes.

I thought it unrealistic more because it's an accidental Americanism in something supposed to be set in Britain.
I was a little surprised by Hermione's lack of curiosity. Just because it would be unwise to trust Mr. Hat-and-Cloak doesn't mean that she should completely ignore him instead.
I was also surprised about how out of touch Mr. Hat-and-Cloak seemed to be. Where is he getting his information? He seems to have an absolutely abysmal model of both how Harry thinks and how Hermione thinks Harry thinks. He hasn't been much better in previous cases. It wouldn't have taken much snooping around to get better informed than he seems to be.
I'm fairly confident that Mr. Hat-and-Cloak is well-informed but aiming to miss-inform. Why he wants to make Hermione suspicious of Harry, I'm not sure.
The point is more that he's not very good at making Hermione suspicious of Harry.
I'm wondering if Mr. Hat-and-Cloak is someone who's stupid, or at least stupid compared to the main characters. With all the layers of intrigue, it could take a while to be sure.
At the very least, the dictionary obliviation attack is pretty clever. In retrospect, it's kind of obvious - but no one else in canon or MoR does it. (Harry could think of it easily based on his experiences with his occlumancy instructor, but hasn't yet, probably because it's a very Dark technique or because he can't yet obliviate.)
It is clever, although if he has to make enough attempts in a row, Hermione may notice the missing chunk of time. That wouldn't be enough info in itself to reveal what's been going on, but it should make her suspect something malicious, and possibly even that she's had her memories tampered with.
This will not happen if Hat-and-Cloak has access to a Time-Turner.
Time-Turners are locked onto a single person's use and cannot normally be used to transport more than one person back in time (Harry and Quirrell had to go through some trouble to travel back in time together using a single time turner, although now I am wondering why they didn't just use simultaneous rotations to meet with each other in the past; surely Quirrell has his own time turner?)
Time-Turners are not normally locked like Harry's is (which also has the restriction on the time of day when it can be used). For instance, in Prisoner of Azkaban, Hermione uses her Time-Turner to transport her, Harry, and Ron back in time simultaneously. If Quirrell had his own Time-Turner, then they could have avoided using Millicent's, unless Quirrell wanted to keep his possession secret from Harry. In any case, using two Time-Turners is silly, because that uses up the 6-hours-per-day limit of both Time-Turners instead of just one.
Pedantic technicality: not Ron.
Then how did Quirrell figure out the restrictions on Harry's Time Turner without so much as laying eyes on it? All he should have known from Harry's temporal discrepancies was that the thing existed. That implies to me that the set of locks Quirrell mentioned are a standard operating procedure, and the only extras that Harry's turner has is the protective shell / locked before 9 PM combo. See also posts 1816 [http://tvtropes.org/pmwiki/posts.php?discussion=722rasd1fu9p8mn5fdcbp572&page=73#1816] through 1822 [http://tvtropes.org/pmwiki/posts.php?discussion=722rasd1fu9p8mn5fdcbp572&page=73#1822] in the TVTropes Methods of Rationality thread.
So the quote is Nevertheless, it seems possible that if Mr. Hat-and-Cloak has a Time-Turner, he would be able to break the wards on it (Quirrell only avoided doing so because it would be noticed upon inspection of Harry's Time-Turner, and Mr. Hat-and-Cloak is not likely to have that problem).
Very true; I've forgotten whether wizards can create false memories to cover up big time gaps. If they can, it's a much smaller problem than it looks. But we have reason to believe that Cloak-and-hat was not expecting to have to make very many attempts, that he either is usually very good at the dictionary attack or he's that Dunning-Kruger - he got so frustrated he exploded and asked a revealing question outright. And then, the writing seems to imply, he only needed one more try to crack Hermione's code. So, this reads to me like an expert using an effective tool who happened to run into an extremely unusual girl/problem, not a only-modestly-clever-or-perhaps-even-stupid person. (Also, thinking again on my remark that it's a very Dark technique, I'm even more confident that this is not Lupus or Sirius - neither of them seems like the kind of character to pull such a Slytherin technique.)

I'm even more confident that this is not Lupus or Sirius

It's never Lupus.

I walked right into that one.
Are you sure about that? Hermione firmly denies being suspicious of Harry while talking to Mr. Hat-and-Cloak, but that doesn't necessarily mean that this won't make her more suspicious of him on at least a subconscious level. If Mr. Hat-and-Cloak is Professor Quirrell, as is strongly suggested in both of his appearances, then we should expect that this is fairly likely to be the case, as I would expect Quirrell to be fairly good at this sort of thing.
Yes. If Mr. Hat-and-Cloak is Quirrell, then either: a) He will sucessfully make Hermione more suspicious of Harry, or b) He will make Hermione less suspicious of Harry and that will be what he wanted.
I would expect Quirrell to know better than to appear to Hermione as Hat-and-Cloak in the first place.
Yes, this particular episode has greatly increased my confidence that H&C, whoever it is, is not Quirrell.
I'm not entirely convinced. If Quirrell has a weakness (note, I did say "if"), then it's his lack of empathy with children, and especially Muggle-born children. Harry is able to consistently surprise him (f.ex. in Azkaban, or by cheering him up at the end of the bully saga, etc.), and I didn't get the impression that this is because Harry is some sort of an uber-outlier. He's an outlier, yes, but he's still a human kid. This weakness probably stems from Quirrell's cynicism, which a few characters have already commented upon. Qurrell subconsciously assumes that everyone is acting like a perfectly rational agent that attempts to maximize its own expected utility by enhancing its power to manipulate external reality (which occasionally includes other actors). In Quirrell's subset of the world, this assumption is quite often correct, but most real people -- such as Hermione -- do not, in fact, act that way all of (or even most of) the time.
He definitely doesn't think so consciously; one of his more memorable quotes is something along the lines of "The main thing ordinary people do, Mr. Potter, is nothing".
Ok, that's true. Instead of saying "everyone", I should've said "everyone who is not beneath his notice, except perhaps in aggregate". I doubt that Quirrell counts Harry or Hermione as members of the "ordinary people" set.

Is it just me, or is Hermione getting Flanderized into irrelevance ? Her initial role was to act as Harry's partner and foil, but lately it seems that she'd become just another typical Gryffindor-style heroine... Utterly predictable and ultimately ineffectual.

Edit: fixed markup

During this "Self Actualization" story arc, yes, she's going in that direction. I strongly suspect, however, that this will not last, and that lessons learned during her Gryffindor phase will help her grow as a character once she gets over it.

By the way, I want to pay Eliezer the high compliment of stating that the mysteries of Chapters 71 through 76 are perfectly obvious in retrospect.

Wait... there's mysteries?

Did Chapter 77 change title from "Interlude with the Professor" to "Interlude with the Confessor" or was it always the latter and I just misread it terribly the first time?

I just checked my email alert: 'Chapter 77 Title: Interlude with the Confessor: Sunk Costs'. So I think you misread it.

Just finished 76. This might be crazy, but...

I predict that Harry just went Dark. He discovered that wizards can be imprisoned without torturing them to death via Dementors, and yet people still tolerate Azkaban. The majority of the adult wizarding world has now given up their right to moral consideration in his eyes, a simple extension of the Death Eater: "His life is already bought and paid for, then, and I can do anything I want to him without ethical problems."

Unless something drastic changes his course, he will impose his will upon the wizar... (read more)

I doubt it. If Harry simply told himself, he'd probably listen.
Dunno, depends on how far they've diverged. I know if I went back 10 years and told my past self not to do a certain thing I'd have even ignored myself, much as I ignored everyone else in my life that tried to warn me away back then. If Harry really wanted to do something he could conceivably (and possibly even correctly) reason that his future self has had such a radical shift in values that they are antagonists now, and his future self is yet one more obstacle to overcome.

Well, whats the point in super-secret self-recognition codes (Recognition code 927, I am a potato) when you then do not listen to your time-traveling self? Especially a rationalist of Harrys Level would have to be holding an entire idiot globe to ignore such advice.

But now Harry knows that mind-reading is a thing.
But he also knows that he has the rare potential to become a perfect occlumens, and also that "defense" is far superior to "offense"- setting new recognition codes after aquiring immunity to mind-reading seems a trivial thing to do.
... which means there's no point in talking to him until becomes a perfect occlumens.
Harry actually says that can't trust something simply because it mentions the recognition code in the chapter that mentions it:
OK, but Harry is not as stupid as you were then. (^_^) More generally, people are focussing on Harry would know recognise Future Harry for certain, whereas Future Harry should be able to give rational arguments sufficient for the cause. Only terrible coincidence will make dissuading Harry depend on specific knowledge unavailable in the past.
This would seem to indicated that something happened to Harry from the past-future that caused him to lose about 80 IQ points or possibly most of the details of his memory. He doesn't strike me as incredibly brilliant or astoundingly well informed.
Quirrel is a much more plausible time-traveling Harry. (Still not that great though.)

The authors notes for 76 imply that the ending was changed, could someone enlighten me to what it was originally?

Anyone care to speculate about the figure at the end?

The authors notes for 76 imply that the ending was changed, could someone enlighten me to what it was originally?

It was this:

"Hello again, Hermione," the kindly whisper emanated from the white glow behind the veil. "I've been sent to help you, so please don't be afraid. My name is Myrlirrien, and I am your servant in all things; for you, my Lady, are the last magical descendant of Merlin."

There were a couple other minor edits throughout the chapter -- basically red herrings that Eliezer removed. Draco had jokingly speculated whether Hermione was the Heir of Ravenclaw. Cloak-and-Hat had urged Hermione to flee -- to Beauxbatons, or Salem's Institute, or Durmstrang, or even "the Secret City of Australia", anywhere but Hogwarts.

Anyone care to speculate about the figure at the end?

Nothing much to speculate I think: The figure at the end was Cloak-And-Hat taking a nicer form after obliviating Hermione, because she incautiously revealed to him the chief reason she hadn't been trusting him in all the previous iterations of their encounter.

I think if there's confusion in the readership about this, it's because not everyone realized that Hat-and-Cloak had this discussion more than once with Hermione, each time changing it somewhat in order to convince her until he frustratedly snapped at Hermione about her not trusting him no matter how many ways he tried to convince her...

Ah I see. I hadn't realised that was meant to represent her being obliviated and the conversation restarting I thought cloak and hat was revealing a 'true form' as the silvery lady.
One more small issue: ""What?" hissed the Potions Master" is problematic because "What?" lacks s sounds. I don't think Quirrell knows Parseltongue.
You mean Snape, of course?
No, I meant Quirrell. Could Quirrell understand Parseltongue without being able to speak it?
But Quirrell (1) is not the Potions master and (2) is commonly reckoned to be possessed by Voldemort, who is a Parselmouth even though Q. has told Harry he isn't. (Of course he would feel no compunction about lying to Harry.)
My point was that there'd be no point in Snape speaking in Parceltongue to Quirrell unless Quirrell could understand it. Your point about Quirrell plausibly having Voldemort's ability is good. I don't know whether there's any reason they'd have been using Parceltongue.

Now I am imagining a secret language spoken only by postal workers. :)

In general? Security - same reason morphed Quirrel and Harry use Parseltongue. That's why they are in the forest in the first place.
I believe that you are overthinking this. Look at other writings, that have nothing to do with snakes, and you will find examples such as "'How dare you speak to me that way!' she hissed" as a way of speaking when angry. I seriously doubt that it has anything to do with Parseltongue. Yes, because Dumbledore canonically could. edit: Here's the link: Just search for 'Parseltongue' [http://www.accio-quote.org/articles/2007/0730-bloomsbury-chat.html]
8Eliezer Yudkowsky12y
Dumbledore does not understand "Parseltongue" in MoR and Ron could not have memorized a phrase in it. Parseltongue is not audio structure. Snakes can't talk.
Despite knowing that snakes can't actually hear and thus could not possibly have a verbal language, I've always thought that Parseltongue must have have some sort of correlation, however rough, between what they were saying and the kinds of hissing they produced. How else would you use a password-recognition spell--similar to the one for Dumbledore's office--to lock the Chamber of Secrets?
I believe that this, right here, is a difference between MoR and canon. (Not that I disagree with it!)
I was responding to the 'why would anyone ever use Parseltongue' comment. It's interesting that Dumbledore understands Parseltongue, and he is the major person to keep the conversation secret from, but note that Parseltongue would protect against many other factions, and unless the agent had a taperecorder handy or something, it'd also protect against any agent/ally of Dumbledore (if not the man himself), of which there are many. (I personally don't think 'hissing', for Snape or Quirrel, indicates Parseltongue use - that's a major secret and would be indicated more strongly.)
I wasn't referring to you specifically, so much as the train of thought extending from: That definitely seems like overthinking to me, considering how commonly someone hisses in literature. Though I admit, it would be a great security precaution--which is precisely why Quirrel and Harry do so when the topic is sensitive, as has been said.
I don't remember that. Which chapter did this take place? I assumed that the question referred to the true identity of Mr. Hat-and-Cloak. I do remember that he appeared before in a conversation with Blaise Zabini, and in both that conversation and his recent one with Hermione, it was strongly suggested that he was Professor Quirrell, although I'm very confused about what Quirrell is up to.

I don't remember that.

I'm referring to this latest chapter.

It's not stated outright, but evidence to that effect are

  • The figure both times says "Hello, again"

  • both encounters (with Cloak-and-Hat and Shining-Lady) start with "her body jerked around so fast it was like she had Apparated, she found that without any thought or any conscious decision her wand had leaped into her hand and was already pointed at..." (basically she has forgotten turning and forgotten lifting the wand and pointing it)

  • "Hermione's heart was already pounding hugely inside her chest, her witch's robes felt already sweat-dampened against her skin, there was a taste of fear already in her mouth"

  • "she felt like she needed to grab her right arm just to keep it up, her head ached like she'd been staring at the black mist for days; she didn't know why she'd gotten tired so quickly."

  • At the beginning of the encounter: "she didn't know why she was so suddenly filled up with adrenaline but her hand gripped harder on her wand. " At the end of the encounter "recognition sent a jolt of terrified adrenaline bursting through her"

Gah, that's what I read. He took that out? Bah. The new version his trite.

My memory of anything before around chapter 50 is starting to get pretty fuzzy. Assuming I'm not alone, I'd like to request that Eliezer post some kind of catch-up summary or outline of important events before the beginning of the next story arc.

Previously, on Harry Potter and the Methods of Rationality...

... and then it segues into a full-blown recap episode, the kind that betimes makes anime audiences scream with anguish.
I recommend just rereading. It goes a lot faster than the first time you read it, especially if you skim.

My testing recommends a slow reread, there's a lot I missed the first time around that I found later.

Well, there's always the audio. It'll be a while before it gets to chapter 50, but it's going fairly steady. http://itunes.apple.com/us/podcast/harry-potter-methods-rationality/id431784580?ign-mpt=uo%3D4 [http://itunes.apple.com/us/podcast/harry-potter-methods-rationality/id431784580?ign-mpt=uo%3D4]
I know there are other ways to solve my predicament, I just don't like them quite as much. It didn't hurt to ask, right?

Ch 78:

"No, not you, Miss Felthorne!" Snape said. "Not you! We really are talking about a boy. One who attends your Potions class, in fact."

Maybe I'm misunderstanding this part of the conversation (possibly because Miss Felthorne's private thoughts have contaminated my idea of what Snape's model of her is likely to be), but it seems to me that Snape ought to have said here ‘Not me!’. Because (as he claims next) he is really talking about a boy, a student in the same class, rather than himself.

But the reason that he slips up is that ... (read more)

There are 3 possible interpretations of the boy-Felthorne conversation. One is taking it at face value, one is thinking of it with Felthorne as the boy and Snape as the girl, and one is having Snape in the role of the boy and Lily in the role of the girl. Snape was using the face value conversation as a front for talking about the third one, but Felthorne misrepresented it as the second one, and once Snape realized that (presumably by using legilimency, since he catches Felthorne's gaze) he made it clear that it wasn't the case (though he did hint that he was really talking about himself by mentioning that the "boy" in question was in her potions class).

The boy in the face value conversation probably doesn't exist, since there would be no point bringing him to Felthorne's attention minutes before she is going to be obliviated (and it would be too much of a coincidence to have three real life situations correspond to each other instead of just two).

I missed that one! Now it all makes sense.
Possibly not. He may be talking about an actual boy just like that who he happens to see acting just like he did. He seems to be saying "not you" to mean that he knows that she has a crush on Snape and that Snape isn't talking about that.
It seems to me that Snape is being silly and honest at the same time, stumbling over how to express his thoughts — very much in the "So, my friend has this problem" vein, but with a twist. It's kind of like the old riddle, "I have two coins in my pocket that add up to fifteen cents. One of them is not a nickel. What are they?" "Not you" means "No, I'm not saying that I have a crush on you." However, he is talking about a boy who attends her Potions class, namely himself.
No, I'm pretty sure his "not you" is almost entirely literal; you seem to be missing the analogy. In the hypothetical he's considering ("suppose that boy had helped you"), the situation of the boy with respect to her is analogous to the real situation of her with respect to Snape. Hence when he points out that she would probably consider him bothersome... well, you see. "Not you!" indicates that, though the analogy is present, that wasn't what he was going for; he is simply considering a hypothetical about an actual boy, not making a jab at her by means of analogy. (Or in short, JoshuaZ is right. Added: See also jaimeastorga2000's comment.)
To explain the stumbling, keep in mind that he's probably never kissed anyone before, ever. We understand this because he fell in love just on the cusp of puberty and carried the torch up until Harry disillusioned him in the wallway after saving Lesath. Felthorne doesn't have the context we do to know the depth of the situation, but she realizes that she is his first kiss just before being obliviated, simply from the physical details.

Real scientists hypothesize the genetic nature of magic inheritance;


I hope there is far more Harry doing chuu2 (third definition) things in the story. At the very least I find it completely awesome when developed characters that I like start doing utterly chuu2 things like making up chants, pretending they are in contact with mysterious entities, laughing insanely for no reason or trying to topple the status quo with mad scientist powers

...I mean come ON they even share the same tendency to evilly laugh. Although, yes one is an obvious parody of chuu2 actions and one is just pretending to be one for laughs. I wonder if Ha... (read more)

Nitpicking on chapter 74: (1) No one in the UK would be likely to use the word "gotten". (2) Surely Tracey should say "mundata sum" rather than "mundatus" since she's female? (Yeah, it's a quotation. But the person being quoted was male, no?)

This fic is written in American English, Eliezer isn't even remotely trying to be British (look t.e. at all the -ize verbs). I do think it was a wiser choice than attempting to fake Old World speech, but now that HPMOR has become extremely popular I REALLY wish he would enlist some native fans to Britpick [http://www.mugglesguide.com/modules/articles/article.php?id=12] the chapters. I'm not even British and I still found it quite jarring when Quirrell retorted "Fire me" instead of "Sack me". (I understand that nowadays there is a lot of cross-Atlantic mingling between the two dialects, especially eastwards, but firstly, Harry Potter is set in 1991; and secondly, a medievalesque public school is such a stereotypically British environment that one expects the language to match.)
During the Revolution, Salem witches were considerably more adept at battle magic than those taught at the institution that had been sucking magical knowledge out of the world for the previous 600 years. They also had the advantage of being able to train in the open since most Puritans were self-obliviating. It wasn't until the 1890's that the school returned fully to Ministry control after the retirement of Headmaster Teetonka. Over a century of American control left its mark on the language and culture of Wizarding Britain, unfortunately the basis of powerful aboriginal magics remains restricted by edict to the students of the Salem Institute, El Dorado, or the University of Phoenix®.
There's nothing wrong with -ize verbs in British English; that's the preferred form of the OED, for instance. But yes, MoR could do with a bit of Britpicking. (I didn't find "Fire me" jarring; it certainly would have been weird in BrE in 1991, but it isn't in present-day BrE -- not for me, anyway -- and that's what governs my wrongness-sensors.)
That assumes Harry has actual familiarity with Latin rather than just grabbing a bunch of references.
I think it's been mentioned before that he sees personally learning Latin as the obvious way to find out what Bacon's diary says.
Yes, it does. (Though ... this looks to me like an Eliezer-reference rather than a Harry-reference; the thing being referenced is a year or two too late for Harry to know it.) I'd expect MoR!Harry to get something like this right -- but then I'd have expected realworld!Eliezer to get it right too, so maybe I'm unrealistic.