Harry Potter and the Methods of Rationality discussion thread, March 2015, chapter 117

Gondolinian

This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 117.

Plans for next chapter release:

Ch. 118 will post on March 9th, 2015, at 12pm Pacific (7pm UTC).

There is a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)

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Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).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.

This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 117.

Plans for next chapter release:

Ch. 118 will post on March 9th, 2015, at 12pm Pacific (7pm UTC).

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Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).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.

Right, okay, I'm back, and on further reflection, I think I've actually decided that leaving Harry his wand isn't even that bad of a mistake. So, let's get started on why:

it just doesn't make sense to order 37 death eaters to shoot Harry if he raises his wand, rather than order one Harry to drop the damn wand.

If Harry needed his wand to demonstrate something (which he very plausibly might have), it would have made no sense to take it away. From Voldemort's perspective, the threat from letting Harry keep his wand (as opposed to, say, his Time-Turner or a hidden Portkey on his person) is close to none; with the precautions he took against Harry, Harry would have needed to pull off a wordless, movement-free, multi-targeting, incapacitating, direction-neutral attack, which is a tall order even for most grown wizards, much less a first-year at Hogwarts. If the threat is minimal and the benefit is high (demonstrating a secret spell), simple cost-benefit analysis would tell Voldemort to let Harry keep his wand. And so he did. The fact that Harry had an attack that just happened to fulfill all the aforementioned criteria is pure coincidence (I would have called it authorial fiat, if it weren't so brilliantly foreshadowed), and the outside-view probability of such would have been extremely tiny.

strip Harry naked

Again, hidden Portkeys, Time-Turners, Transfigured threats, etc., are all possibilities, and indeed, given Harry's planning tendencies, probabilities. Stripping him naked isn't ultra-paranoia; it's just common sense. Taking the wand, on the other hand, is ultra-paranoia, especially if Voldemort felt there was a benefit to be gained from letting Harry keep the wand; otherwise he'd basically be Pascal's Mugging himself on the off-chance that Harry developed some never-before-seen magical ability off-camera.

But Eliezer wanted it both ways, both to treat Voldemort as super-ultra-cautious AND let Harry keep his damn wand.

Voldemort wasn't "super-ultra-cautious". He was "just cautious enough to succeed". And had Harry not gone and invented partial Transfiguration from Muggle principles back in Chapter 28, he damn well would have.

And actually, thinking more about this has led me to formulate a reply to this as well (beyond my last reply, that is):

and don't give me the "hindsight bias" crap, people were complaining about that in advance

The commenters knew about partial Transfiguration. Voldemort didn't. Also, they had the opening quote from Chapter 1 to guide them. Again, Voldemort didn't. That's a huge informational advantage, and is not to be underestimated. (To see how enormous of an advantage it really is, just look at all of my above arguments, and count how many of them rely on Voldemort not knowing about partial Transfiguration. Answer: all of them.) Hindsight bias doesn't necessarily just apply when you know the answer for a fact; it also applies when you have a bunch of additional information that makes you reasonably confident in a given answer. So yes, upon further reflection, I will "give [you] the 'hindsight bias' crap", because upon further reflection, it's not actually crap.

If Harry needed his wand to demonstrate something (which he very plausibly might have), it would have made no sense to take it away.

So have him drop it and a Death Eater confiscate it, and if he says he needs it to demonstrate something, Voldemort can ask "do you plan to usse it to attack me, sservantss, or to esscape?" before returning it to him. Then as soon as he's done, confiscate it again. That's an extra 10 seconds; which is a small price to pay to hedge against a Black Swan.

Voldemort doesn't know about Partial Transfiguration, but he do... (read more)

8SeekingEternity11y

Voldemort has an absolute truth oracle, or at least a sufficiently good approximation thereof, available too him. If Harry needs his wand to teach V one of his secrets, make him say so in Parseltongue. If H does demand his wand, make him state whether he intends to use it for anything but demonstrating a secret. The wonderful thing here is that this gives all kinds of opportunities for V to screw up without realizing he's screwing up. PT is a secret for which H needs his wand. H is, in a sense, demonstrating PT. Unless V was very careful about making H state his exact and full intentions, we could have had a plausible reason for H to have his wand. There's really no plausible reason for V to just let him have it, though; disarming him (there's even a spell which does exactly that, and one would hope his followers know it...) costs nothing but a small amount of time, and gains V potential defense against "a power he knows not"... the existence of such things being the whole reason V didn't just have H killed immediately!