It was written:
"I once lent Xiaoguang "Mike" Li my copy of "Probability Theory: The Logic of Science". Mike Li read some of it, and then came back and said:
"Wow... it's like Jaynes is a thousand-year-old vampire."
Then Mike said, "No, wait, let me explain that—" and I said, "No, I know exactly what you mean." It's a convention in fantasy literature that the older a vampire gets, the more powerful they become.
I'd enjoyed math proofs before I encountered Jaynes. But E.T. Jaynes was the first time I picked up a sense of formidability from mathematical arguments. Maybe because Jaynes was lining up "paradoxes" that had been used to object to Bayesianism, and then blasting them to pieces with overwhelming firepower—power being used to overcome others. Or maybe the sense of formidability came from Jaynes not treating his math as a game of aesthetics; Jaynes cared about probability theory, it was bound up with other considerations that mattered, to him and to me too.
For whatever reason, the sense I get of Jaynes is one of terrifying swift perfection—something that would arrive at the correct answer by the shortest possible route, tearing all surrounding mistakes to shreds in the same motion. Of course, when you write a book, you get a chance to show only your best side. But still."
I refer to such a strike as nadegiri; an elegant argument that cuts simultaneously through the opposing claim, its directly-connected confusions, and many layers of indirectly-connected confusion, even if no explicit mention is made of those outer layers. If the blow is realised, bricks are shat as much of the belief network has to be examined in light of the revelation, but often the strike will be of such depth that the target cannot even comprehend the severity of the blow.
Amusingly, after Mike says that Eliezer does not give off the same sense of formidability, Eliezer laments that, "I hadn't thought I'd reached Jaynes's level. I'd only been curious about how I came across to other people." My reaction when I first read this was pretty much, "What the heck are you talking about? Who else can even match your blade?" I'm not sure I'd endorse that reaction, but I would be pretty surprised if I had overlooked someone a level above Eliezer, even if other people matched him (possibly historic, adjusting for standing on the shoulders of giants).
I shall try to update this post with nadegiri candidates:
(1a) http://lesswrong.com/lw/2l/closet_surve
Rings_of_Saturn: "That both women and men are far happier living with traditional gender roles. That modern Western women often hold very wrong beliefs about what will make them happy, and have been taught to cling to these false beliefs even in the face of overwhelming personal evidence that they are false."
Michael Vassar: "How traditional? 1600s Japan? Hopi? Dravidian? Surely it would be quite a coincidence if precisely the norms prevalent in the youth and culture of the poster or his or her parents were optimal for human flourishing."
or equivalently:
(1b) http://en.wikipedia.org/wiki/Reversal_t
Nick Bostrom and Toby Ord: "Reversal Test: When a proposal to change a certain parameter is thought to have bad overall consequences, consider a change to the same parameter in the opposite direction. If this is also thought to have bad overall consequences, then the onus is on those who reach these conclusions to explain why our position cannot be improved through changes to this parameter. If they are unable to do so, then we have reason to suspect that they suffer from status quo bias."
Reversal tests as laid out explicitly by Bostrom and Ord, or alluded to by Vaasar, are—in the situations in which they can be legitimately applied—absurdly powerful. A sufficiently perceptive opponent encountering Vassar's line for the first time would realise not only that they should be suspicious of their conclusion, but also of the fundamental mindset and thought processes giving rise to the arguments for that conclusion, and moreover of an array of other analogous issues and therefore the mindset underlying all of those issues. This is the kind of defeat that's so incisive that everything has to be reevaluated in light of it. (Example of analogous situation: 'Deathists' defend the status quo of human lifespan. But observing that their arguments would generically also support <25-year lifespan if that were the norm or >10^12 -year lifespan if that were the norm and go against ~100-year life span in those cases necessitates at the very least a reevaluation of the entire attitude towards human modification and bioethics that gave rise to the attitude.
(2) http://www.patheos.com/blogs/lovejoyfem
This article runs numbers that conclude that birth control *decreases* the number of abortions. (The gimmick is bodies automatically rejecting fertilised eggs.) Even if we shouldn't take the numbers used at face value, it is plausible enough that bodies might do such a thing that anybody who really cared that much about abortions would be obliged by the high value of information to investigate the possibility, turning a deontological/moral/undecidable debate into a purely empirical, decidable one.
Changelog
2014-02-23 20:00 London time: Added (2).
