(This was originally a link to a post on my blog, A survey of anti-cryonics writing. Eliezer asked me to include the entire text of the article here.)

For its advocates, cryonics offers almost eternal life. To its critics, cryonics is pseudoscience; the idea that we could freeze someone today in such a way that future technology might be able to re-animate them is nothing more than wishful thinking on the desire to avoid death. Many who battle nonsense dressed as science have spoken out against it: see for example Nano Nonsense and Cryonics, a 2001 article by celebrated skeptic Michael Shermer; or check the Skeptic's Dictionary or Quackwatch entries on the subject, or for more detail read the essay Cryonics–A futile desire for everlasting life by "Invisible Flan".

That it seems so makes me sad, because to my naive eyes it seems like it might work and I would quite like to live forever, but I know that I don't know enough to judge. The celebrated Nobel prize winning physicist Richard Feynman tells a story of a US general who spoke to him at a party and explained that one big challenge in desert warfare is keeping the tanks fuelled given the huge distances the fuel has to travel. What would really help, the general said, would be if boffins like Feynman could invent a sort of engine that was powered by sand. On this issue, I'm in the same position as the general; in the same way as a tank fuelled by sand seems plausible enough to him, it makes sense to me to imagine that however your brain stores information it probably has something to do with morphology and chemistry, so there's a good chance it might not evaporate right away at the instant of legal death, and that freezing might be a way to keep the information there long enough for future societies to extract it with their future-technology scanning equipment.

And of course the pro-cryonics people have written reams and reams of material such as Ben Best's Scientific Justification of Cryonics Practice on why they think this is exactly as plausible as I might think, and going into tremendous technical detail setting out arguments for its plausibility and addressing particular difficulties. It's almost enough to make you want to sign up on the spot.

Except, of course, that plenty of totally unscientific ideas are backed by reams of scientific-sounding documents good enough to fool non-experts like me. Backed by the deep pockets of the oil industry, global warming denialism has produced thousands of convincing-sounding arguments against the scientific consensus on CO2 and AGW. Thankfully in that instance we have blogs like Tim Lambert's Deltoid, RealClimate, and many others tracking the various ways that the denialists mislead, whether through cherry-picking evidence, misleading quotes from climate scientists, or outright lies. Their hard work means that denialists can barely move or speak without someone out there checking what they have to say against science's best understanding and pointing out the misrepresentations and discrepancies. So before I pony up my £25 a month to sign up to cryonics life insurance, I want to read the Deltoid of cryonics - the articles that take apart what cryonics advocates write about what they do and really go into the scientific detail on why it doesn't hang together.

Here's my report on what I've found so far.

..fragments of a book that would never be written...

*      *      *

Captain Selena, late of the pirate ship Nemesis, quietly extended the very tip of her blade around the corner, staring at the tiny reflection on the metal.  At once, but still silently, she pulled back the sword; and with her other hand made a complex gesture.

The translation spell told Hirou that the handsigns meant:  "Orcs.  Seven."

Dolf looked at Hirou.  "My Prince," the wizard signed, "do not waste yourself against mundane opponents.  Do not draw the Sword of Good as yet.  Leave these to Selena."

Hirou's mouth was very dry.  He didn't know if the translation spell could understand the difference between wanting to talk and wanting to make gestures; and so Hirou simply nodded.

Not for the first time, the thought occurred to Hirou that if he'd actually known he was going to be transported into a magical universe, informed he was the long-lost heir to the Throne of Bronze, handed the legendary Sword of Good, and told to fight evil, he would have spent less time reading fantasy novels.  Joined the army, maybe.  Taken fencing lessons, at least.  If there was one thing that didn't prepare you for fantasy real life, it was sitting at home reading fantasy fiction.

Dolf and Selena were looking at Hirou, as if waiting for something more.

Oh.  That's right.  I'm the prince.

Hirou raised a finger and pointed it around the corner, trying to indicate that they should go ahead -

With a sudden burst of motion Selena plunged around the corner, Dolf following hard on her heels, and Hirou, startled and hardly thinking, moving after.

(This story ended up too long for a single LW post, so I put it on yudkowsky.net.
Do read the rest of the story there, before continuing to the Acknowledgments below.)

Followup to:  Yudkowsky and Frank on Religious Experience, Yudkowksy and Frank On Religious Experience Pt 2
With sincere apologies to: Mike Godwin

You are General Eisenhower. It is 1945. The Allies have just triumphantly liberated Berlin. As the remaining leaders of the old regime are being tried and executed, it begins to become apparent just how vile and despicable the Third Reich truly was.

In the midst of the chaos, a group of German leaders come to you with a proposal. Nazism, they admit, was completely wrong. Its racist ideology was false and its consequences were horrific. However, in the bleak poverty of post-war Germany, people need to keep united somehow. They need something to believe in. And a whole generation of them have been raised on Nazi ideology and symbolism. Why not take advantage of the national unity Nazism provides while discarding all the racist baggage? "Make it so," you say.

The swastikas hanging from every boulevard stay up, but now they represent "traditional values" and even "peace". Big pictures of Hitler still hang in every government office, not because Hitler was right about racial purity, but because he represents the desire for spiritual purity inside all of us, and the desire to create a better society by any means necessary. It's still acceptable to shout "KILL ALL THE JEWS AND GYPSIES AND HOMOSEXUALS!" in public places, but only because everyone realizes that Hitler meant "Jews" as a metaphor for "greed", "gypsies" as a metaphor for "superstition", and "homosexuals" as a metaphor for "lust", and so what he really meant is that you need to kill the greed, lust, and superstition in your own heart. Good Nazis love real, physical Jews! Some Jews even choose to join the Party, inspired by their principled stand against spiritual evil.

The Hitler Youth remains, but it's become more or less a German version of the Boy Scouts. The Party infrastructure remains, but only as a group of spiritual advisors helping people fight the untermenschen in their own soul. They suggest that, during times of trouble, people look to Mein Kampf for inspiration. If they open to a sentence like "The Aryan race shall conquer all in its path", then they can interpret "the Aryan race" to mean "righteous people", and the sentence is really just saying that good people can do anything if they set their minds to it. Isn't that lovely?

Soon, "Nazi" comes to just be a synonym for "good person". If anyone's not a member of the Nazi Party, everyone immediately becomes suspicious. Why is she against exterminating greed, lust, and superstition from her soul? Does she really not believe good people can do anything if they set their minds to it? Why does he oppose caring for your aging parents? We definitely can't trust him with high political office.

Related to: Is That Your True Rejection?

"If you’re interested in being on the right side of disputes, you will refute your opponents’ arguments.  But if you’re interested in producing truth, you will fix your opponents’ arguments for them.  To win, you must fight not only the creature you encounter; you must fight the most horrible thing that can be constructed from its corpse."

   -- Black Belt Bayesian, via Rationality Quotes 13

Yesterday John Maxwell's post wondered how much the average person would do to save ten people from a ruthless tyrant. I remember asking some of my friends a vaguely related question as part of an investigation of the Trolley Problems:

You are a doctor in a small rural hospital. You have ten patients, each of whom is dying for the lack of a separate organ; that is, one person needs a heart transplant, another needs a lung transplant, another needs a kidney transplant, and so on. A traveller walks into the hospital, mentioning how he has no family and no one knows that he's there. All of his organs seem healthy. You realize that by killing this traveller and distributing his organs among your patients, you could save ten lives. Would this be moral or not?

I don't want to discuss the answer to this problem today. I want to discuss the answer one of my friends gave, because I think it illuminates a very interesting kind of defense mechanism that rationalists need to be watching for. My friend said:

It wouldn't be moral. After all, people often reject organs from random donors. The traveller would probably be a genetic mismatch for your patients, and the transplantees would have to spend the rest of their lives on immunosuppressants, only to die within a few years when the drugs failed.

On the one hand, I have to give my friend credit: his answer is biologically accurate, and beyond a doubt the technically correct answer to the question I asked. On the other hand, I don't have to give him very much credit: he completely missed the point and lost a valuable effort to examine the nature of morality.

So I asked him, "In the least convenient possible world, the one where everyone was genetically compatible with everyone else and this objection was invalid, what would you do?"

He mumbled something about counterfactuals and refused to answer. But I learned something very important from him, and that is to always ask this question of myself. Sometimes the least convenient possible world is the only place where I can figure out my true motivations, or which step to take next. I offer three examples:

Martial arts can be a good training to ensure your personal security, if you assume the worst about your tools and environment.  If you expect to find yourself unarmed in a dark alley, or fighting hand to hand in a war, it makes sense.  But most people do a lot better at ensuring their personal security by coordinating to live in peaceful societies and neighborhoods; they pay someone else to learn martial arts.  Similarly, while "survivalists" plan and train to stay warm, dry, and fed given worst case assumptions about the world around them, most people achieve these goals by participating in a modern economy.

The martial arts metaphor for rationality training seems popular at this website, and most discussions here about how to believe the truth seem to assume an environmental worst case: how to figure out everything for yourself given fixed info and assuming the worst about other folks.  In this context, a good rationality test is a publicly-visible personal test, applied to your personal beliefs when you are isolated from others' assistance and info.  

I'm much more interested in how we can can join together to believe truth, and it actually seems easier to design institutions which achieve this end than to design institutions to test individual isolated general tendencies to discern truth.  For example, with subsidized prediction markets, we can each specialize on the topics where we contribute best, relying on market consensus on all other topics.  We don't each need to train to identify and fix each possible kind of bias; each bias can instead have specialists who look for where that bias appears and then correct it. 

Perhaps martial-art-style rationality makes sense for isolated survivalist Einsteins forced by humanity's vast stunning cluelessness to single-handedly block the coming robot rampage.  But for those of us who respect the opinions of enough others to want to work with them to find truth, it makes more sense to design and field institutions which give each person better incentives to update a common consensus.