I didn't just mean political power or power over people. Consider the "power" to fly to another country or to talk with someone on the other side of the world. Science and technology produce a lot of powers like that. The advance of knowledge to the point that you could rejuvenate a person or revive someone from cryonics implies an enormous leap in that sort of power.
Total relinquishment doesn't work because it requires absolutely everyone else to be persuaded of your view. If just one country opts out and keeps doing R&D, then relinquishment fails. But a society where advanced technology does already exist has some chance of controlling where and how it gets reinvented. Such a society could become overtly hierarchical and have no notion of equal rights.
But even a society with deep egalitarian values would need to find a way to assimilate these powers, rather than just renounce them, to remain in control of its own destiny. Otherwise it risks waking up one day to find that a different set of values are in charge, or just that someone played with matches and burned down the house.
One irony of technological power is that it offers ways for egalitarian values to survive, even in deeply destabilizing circumstances. A theme of the modern world is the fear of homemade WMDs. As knowledge of chemistry, biology, nanotechnology, robotics... advances, it becomes increasingly easy for an isolated lab to cook up a doomsday device. One response to that would be to just strip 99% of humanity of the power and the right to make a technology lab. The posthuman technocrats live in orbit and monitor the Earth to see that no-one's in a cave reinventing rocketry, and everyone else goes back to hunting and gathering. Luddism and transhumanism reach a compromise.
Hopefully you can see that a luddite world with a small transhuman elite is more stable than a purely luddite world. The hunter-gatherers can't do much about it if someone restarts the industrial revolution. This is why total reliquishment is impractical.
But what about transhuman egalitarianism? Is that workable? If anyone can make a doomsday lab, won't it all come crashing down? This is why there's a "neuro" in "neuro-technocracy". Advanced technology's doomsday problem is mostly due to malice (I want to destroy) or carelessness (I'm playing with matches). Malice and carelessness are psychological states. So are benevolence and competent caution. Human society already has a long inventory of ways, old and new, in which it tries to instil benevolence and competence in its members, in which it watches for sociopathy and mental breakdown, and tries to deal with such problems when they arise.
In a society with truly profound neuroscientific knowledge, all of that will be amplified too. It should be possible to make yourself smarter or more moral by something akin to increasing the density of neural connections in the relevant parts of your brain. I don't mean that neural connectedness is seriously the answer to everything, it's just a concrete example for the purposes of discussion. The idea is that there are properties of your brain which have an impact on the traits that determine whether you can or can't be trusted with the keys to advanced technology.
For a culture that has absorbed advanced technology, neuroscience and neurotechnology can become one of the ways that it protects and propagates itself, alongside more traditional methods like education and socialization. This is yet another futurist frontier where there's an explosion of possibilities which we hardly have the concepts to discuss. We still need to work through the cartoon examples, like spacepeople and cavepeople, in order to get a feel for how it could function, before we try to be more realistic.
So let's go back to the scenario where we have high technology in orbit and a new stone age on Earth. I set that up as an example of a nonegalitarian but stable scenario. Now let's modify the details a bit. What if stoners and spacers have a shared culture and it's a matter of choice where you reside and how you live? All a stoner has to do is go to the local communication monolith and say, I want to join the spacers. As a member of solar-system civilization, they will have access to all those technologies that are forbidden on Earth. So a condition of solar citizenship might be, a regular and ongoing neuropsychological examination and tune-up, to ensure that bad or stupid impulses aren't developing. Down on Earth they can be a little more lax, but solar society is full of dangerously powerful technologies, and so it's part of the social contract that everyone stays morally and intellectually calibrated, to a degree that is superhuman by present-day standards. And when someone migrates from the stone age to the space age, it's a condition of entry that they adopt space-age standards of character and behavior, and the personal practices which protect those standards.
That's the cartoon version of benevolent space-age neurotechnocracy. :-)
If you don't believe in an afterlife, then it seems you currently have two choices: cryonics or permanent death. Now, I don't believe that cryonics is pseudoscience, but it's still pretty poor odds (Robin Hanson uses an estimate of 5% here). Unfortunately, the alternative offers a chance of zero. I see five main concerns with current cryonic technology:
So I wonder if we can do better.
I recall reading of juvenile forms of amphibians in desert environments that could survive for decades of drought in a dormant form, reviving when water returned. One specimen had sat on a shelf in a research office for over a century (in Arizona, if I recall correctly) and was successfully revived. Note: no particular efforts were made to maintain this specimen: the dry local climate was sufficient. It was suggested at the time that this could make an alternative method of preserving organs. Now the advantages of this approach (which I refer to flippantly as "dryonics") is:
There is one big disadvantage of this approach, of course: no one knows how to do it (it's not entirely clear how the juvenile amphibians do it) or even if it would be possible in larger, more complex organisms. And, so far as I know, no one is working on it. But it would seem to offer a much better prospect than our current options, so I would suggest it worth investigating.
I am not a biologist, and I'm not sure where one would start developing such a technology. I frankly admit that I am sharing this in the hope that someone who does have an idea will run with it. If anyone knows of any work on these lines, or has an idea how to proceed, please send a comment or email. Or even if you have another alternative. Because right now, I don't consider our prospects good.
[Note: I am going on memory in this post; I really wish I could provide references, but there does not seem much activity along these lines that I can find. I'm not even sure what to call it: mummification? Probably too scary. Dehydration? Anyway feel free to add suggestions or link references.]