I imagine it should be terrifically hard to let go of your child and 'kill' them preemptively, for them to have a hope of later life. Even if the parents did even consider that option.
As far as I see it, cryopreserving a person that is not legally dead ('cryothanasia'?) might be possible, but no cryonics company has procedures in place to arrange for it and I am not aware of anyone that has been preserved this way. At least, it is necessary to move to a country where voluntary euthanasia is legal and the associated autopsy is not mandatory, and you are on your own with this. [1] This is another issue that cryonics companies and advocates prefer to overlook.
Cryonics is still very niche as it is. People are still very reluctant to arrange for cryopreservation beforehand, as it is. Cryonics companies have their hands full with just continuing to operate and convincing people to use their services. For there to exist people that are fully rational about their own or their loved ones' death, and think about it more deeply than the cryonics companies and advocates, is a whole next step entirely: I am unaware of such people yet.
You seem to be arguing that death is a binary state, but I don't think this is particularly well established. There are all sorts of arguments over what constitutes definite proof of death [1]. It seems more likely to me that the process of dying is a transition, and that the exact point along that transition where someone is irreversibly gone depends on our current level of medical technology – which is exactly what cryonics is betting on.
As an analogy, when RAM loses power, the data on it doesn't vanish instantly, but rather degrades over some period of time [2]. Depending on how the information is stored, what you're willing to do without, and what you can piece together, you can declare the data in RAM "gone" at different points throughout that process.
[1] https://en.wikipedia.org/wiki/Medical_definition_of_death
[2] https://www.usenix.org/legacy/event/sec08/tech/full_papers/h...
Yes, death is not a binary state physically, but it is legally. This is what cryonics counts for.
Also, conscience is not binary; there is plenty of evidence that it is uneven and noncontinuous. People lose conscience and then regain it and live on all the time. Many people live in reduced states of consciousness most or all of the time. Our mind tries to maintain illusion of continuity of consciousness for our convenience. Sometimes people survive ridiculous amount of brain damage (men living with a hole in their head). All this is evidence that whatever forms our conscience is very redundant and just might survive the damage of what today is considered death and future restoration. Especially with the help of whatever medical technology will be available in the future (nanotech, hi-res brain scanning, etc.); especially if it would be needed anyway to counter the damage sustained during cryopreservation.
Do you mean "consciousness" here? I assumed you actually meant conscience at first but this sentence doesn't seem to make sense with that word but then you use consciousness later which means it isn't just a spelling error. I'm not asking to be pedantic, but because I'm now getting confused about what you're trying to say in parts of your otherwise interesting comment.
[1] http://chronopause.com/chronopause.com/index.php/2012/05/20/...
[2] http://www.brainpreservation.org/preservation-rights/
[3] http://www.oregoncryo.com/aboutCryonics.html
[4] http://www.huffingtonpost.com/zoltan-istvan/should-cryonics-...
Perhaps one way to think about it is that cryopreservation is a modern alternative to a grave burial, and the thing most salvaged is the hope and memories in the family and friends of the deceased.
http://www.alcor.org/cryomyths.html#myth2
We can debate the degree to which cryoprotectant perfuses the brain outside a laboratory test of tissue, but vitrification appears to preserve the fine structure of tissue very well:
http://www.brainpreservation.org/competitors/
There is evidence of synaptic preservation in preserved and restored nematodes:
Her personality and memories, of course. Most of the brain is back-office, keeping the body alive and doing low level processing. The parts containing "her" could easily be untouched by cancer. Keeping just her brain frozen is a bit of a stretch, but all the hurdles are strictly technological in nature. Make a clone (or a partial clone, if you have ethical concerns), cut and paste the good parts into the clone and you've healed her completely.
It may seem a lot right now, to fuse brain parts together or to do head transplants, but they aren't really that far-fetched. Barely 100 years ago we were still arguing whether heavier-than-air flight is possible, and weren't even dreaming concepts like radiation or turing computability. Compared to that making nerves grow back together is just elbow grease.
(1) Resuscitate cryo-preserved (vitrified) brain tissue.
(2) Re-create a body and somehow transfer this brain or mind into it (or upload consciousness)?
... then it is likely that we would have such a deep understanding of consciousness and mind that we could repair or scan-around the damage. I think we're talking about "singularity" levels of both technology and philosophical comprehension here. It's all total sci-fi for the time being.
I don't fully disagree with you, but this is sort of begging the question, since cryonics seems to rely heavily on the chance of unforeseeable advantages.
On top of that, you seem to be committing the common fallacy of equating every minute of life as the same, whether you're suffering terminally in a hospital bed or watching the sunset with friends (this is also why people choose to be taken off the respirator or have DNRs). Using something like QALYs makes infinitely more sense (though switching to QALYs may not quite invalidate your point).
The last thing advocates of euthanasia and DNR for the heavily-suffering should want to see is their ethical arguments muddied by cryogenics salespeople hanging round hospitals persuading people that they'd be better off dying shortly after diagnosis...
I'm somewhat inclined to agree with you but I don't think misrepresenting the arguments made by proponents is the same thing as rebutting them, like you did in this second comment.
> The last thing advocates of euthanasia and DNR for the heavily-suffering should want to see is their ethical arguments muddied by cryogenics salespeople hanging round hospitals persuading people that they'd be better off dying shortly after diagnosis...
Uh, that's great and everything but it's not even remotely relevant to the point of whether QALYs are a more appropriate measure than raw years of life for measuring the effectiveness of cryogenics. Sorry if that sounded a little caustic, but I find enormously tiresome the cynical tactic of appealing to "that argument is dangerous, what if someone down the road abuses it?" when one is unwilling or unable to address a point. Particularly because you could come up with some scenario in which pretty much every assertion could be used for ill.
If patients are making decisions to shorten their lifespan it should be on the basis of suffering less pain rather than subscribing to pseudoscientific twaddle about unforeseeable sufficiently advanced technological magic. The OP seemed to think the latter should have been prioritised if legal.
Its rather tiresome when people accuse me of being "unwilling or unable to address a point" after they've already parenthetically acknowledged it doesn't really change anything.