Sure. For one, with a short life expectancy you're not being detained where you live. [... stuff about suicide ...]
Okay, I think I'm convinced about that part (partly by what you wrote and partly by realizing that some problems with suicide tourism I was thinking about seem exaggerated after thinking them through).
Unfortunately, this made me realize that this point wasn't really relevant to our disagreement. I still don't think that lack of cryonics-related suicide discourse on the Internet indicates that cryonicists' don't expect cryonics to work (or even that cryonicists' aren't privately considering the possibility of assisted suicide), so it was a bit disingenuous of me to bring it up. Sorry about that.
Upon further reflection I realized that I don't really even care whether people are using cryonics purely as an existential terror management strategy. I don't consider 'look at all those people who already signed up' to be a very important (or even valid) argument for cryonics so even if some of those people turn out to be totally crazy, it won't affect my belief in the possibility of cryonics working. I think my real beef with your post was abusing the concept of belief-in-belief.
Which you're still doing, by the way.
The actual merit of the preservation approach nonwithstanding, how is cryonics not the technological equivalent of a deep-frozen stairway to heaven? The parallels in terms of eschatological topics (including skipping death, chance of skipping ahead in limbo to some kind of death-less future) are easy enough to find.
Maybe. But a very important difference that makes the belief-in-belief concept inapplicable here is that no one claims that believing in cryonics (unlike believing in gods) will by itself affect reality in any way. Believing in cryonics isn't considered important.
If someone takes genuine comfort from the fact that they're signed up, then I'd say that they really believe that cryonics will work. Maybe they started believing it only for this comfort without really thinking rationally. Maybe they believe it too strongly. Maybe they got carried away and convinced themselves that the magical cryonics fairy will take care of everything and they don't have to worry about unpleasant technical details like ischemic damage caused by delayed suspension. But it's not belief in belief if they are actually willing to spend a pile of money on it. (In case of religious activities people can also spend money because of signaling without really believing but right now spending money on cryonics mostly gets you scorn and ridicule so that hypothesis is out.)
It seems to fit the kind of reasoning arguing for the invisible dragon pretty nicely.
Ah, but people are actually paying to have their garages suffused with dragon-killing chemical agents (dracocides?) And you're saying that they don't really believe in the dragon?
(Excuse the tone, no adversity intended. Also, minor typographical edit)
No need to excuse anything, I haven't registered any adversity.
(Title is tongue-in-cheek, "preservation" would've been more appropriate but less catchy)
With [news like that](http://news.discovery.com/history/preserved-brain-bog-england-110406.html), how hard can it be when you actually do want to preserve a brain:
> A human skull dated to about 2,684 years ago with an "exceptionally preserved" human brain still inside of it was recently discovered in a waterlogged U.K. pit, according to a new Journal of Archaeological Science study.
> The brain is the oldest known intact human brain from Europe and Asia, according to the authors, who also believe it's one of the best-preserved ancient brains in the world. (...) Scientists believe that submersion in liquid, anoxic environments helps to preserve human brain tissue.
Unfortunately for the poor guy / brain, we killed his survival prospects. He did go with the cheap option of just saving the head. Speculating, if he got found another few centuries from now, he might've been a patient, not "archeological remains".
On a more serious note, I'd like the perspective of someone signed up for cryonics on this:
With people signed up for cryonics nowadays - I hear it even comes with a necklace! - I wonder what role the signalling aspect (to others, more importantly to oneself, feeling safer from death) plays versus the actual permanent-death-evading.
Having been present for (mouse) brain slice experiments done immediately after extraction, being confronted with the rapidly progressing tissue decay, the most important aspect that could easily be optimised - apart from research into other methods of preservation - was the time from the extraction to the experiments. Each minute made a tremendous difference. Not a surprise: as the aphorism in neurology (stroke therapy) goes, "time is brain".
What leads me to somewhat doubt the seriousness of the actual belief in brain preservation, versus the belief in belief that's based on minimising existential angst, is that the obvious idea of "when death is approaching with an ETA of less than X, commit suicide with cryonics on immediate standby" is not an integral part of the discussion. X may be weeks, or even years, based on how serious you take cryonics.
The above incidentally contains a way of betting to indicate the strength you assign to the actual prospects of cryonics, versus the role it plays for you psychologically. Isn't betting on your beliefs encouraged in this community? (NB: the "suicide" is just included to avoid legal ramifications.)
Regardless of future technological advances, orders of magnitude less brain damage will certainly pose less of a problem than the delay caused even by a couple of hours. A couple of hours = your brain tissue is already a scorched battlefield! Both necrosis and apoptosis get started within minutes.
Measuring your actual belief in the success of cryonics (for someone signed up for cryonics), waiting for death by natural causes doesn't indicate a lot of confidence when even a few weeks of life seem to be measured more highly than a tremendous increase in the actual prospects of cryonics working.
Or do you have above mentioned plans in place for when your life expectancy is less than X months/years (for whatever reason)?