My point was that you're thinking that you know enough to decide that for everyone. You're also bringing in a concept of need (need for what?) when I think the relevant question is whether people want to live longer.

To my mind, the selfishness was that you thought you could reasonably make that sort of decision for the whole human race.

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. :-)

Maybe you're right about that, although you're stretching it a bit with the infant mortality argument.

Really? It was the chief method of population-control once upon a time, much like death by aging is now. They seem pretty analogous in most ways.

People were "selfish" back then to not want their infant babies die. People are the same sort of selfish now to not want to see their parents die.

Lack of death in both cases causes the same sorts of problems, but people adjust to problems. Fertility declined after infant mortality dropped -- fertility per year will also be declined in people have their youthful years extended indefinitely.

Maybe you do think the latter but I think if immortality was discovered tomorrow it would be concentrated in the hands of a rich elite who judge their lives to be more important than the rest of ours. After a while it would be sold to those wealthy enough to afford it.

Do you understand that you just made two contradictory arguments -- before you said there will be overpopulation, because it will be given to all. Now you say it will be given only to some (so there's no problem of overpopulation), but these few will create an elite.

Those are two opposite problems -- which one do you believe will be the actual case?

These people would control the world through the generations and decide their own world order.

How does that follow? In what way does medical immortality give these people greater powers of control than any current or medieval non-immortal dictator or monarchical dynasty?

Two points:

1) I'm doubtful that the distinction between lifesaving procedures and immortality will end up being a clear distinction. I'm optimistic that humanity will eventually have the capability to do things like replace lost limbs with new limbs. Once we have that level of capacity, most of the modern causes of death go away - if you survive to reach the hospital, you're likely to be able to leave basically good as new.

2) Given our current levels of technology, Western-level standards of living for everyone are not sustainable. Nor do there appear to be imminent technological advances that would make that sustainable. But radical life-extension technology (of whatever form) is also nowhere near imminent. Why do you think that the kind of technology advances you dislike are closer to achievement than carrying-capacity advances?

Some of your comments suggest that you would oppose carrying capacity increases (like colonizing other planets) even if they were within humanities capacity because these technological capacities would be bad for humanity. Assuming you are correct that these technological revolutions would fundamentally change human society, why are these hypothetical changes worse than the changes caused by developments like selective breeding of livestock, practical steam engines, cell phones, the Internet, or agriculture itself?