I doubt human value is particularly fragile. Human value has evolved and morphed over time and will continue to do so. It already takes multiple different forms. It will likely evolve in future in coordination with AGI and other technology. I think it's fairly robust.
Like Ben, I think it is ok (if not ideal) if our descendants' values deviate from ours, as ours have from our ancestors. The risks of attempting a world government anytime soon to prevent this outcome seem worse overall.
We all know the problem with deathism: a strong belief that death is almost impossible to avoid, clashing with undesirability of the outcome, leads people to rationalize either the illusory nature of death (afterlife memes), or desirability of death (deathism proper). But of course the claims are separate, and shouldn't influence each other.
Change in values of the future agents, however sudden of gradual, means that the Future (the whole freackin' Future!) won't be optimized according to our values, won't be anywhere as good as it could've been otherwise. It's easier to see a sudden change as morally relevant, and easier to rationalize gradual development as morally "business as usual", but if we look at the end result, the risks of value drift are the same. And it is difficult to make it so that the future is optimized: to stop uncontrolled "evolution" of value (value drift) or recover more of astronomical waste.
Regardless of difficulty of the challenge, it's NOT OK to lose the Future. The loss might prove impossible to avert, but still it's not OK, the value judgment cares not for feasibility of its desire. Let's not succumb to the deathist pattern and lose the battle before it's done. Have the courage and rationality to admit that the loss is real, even if it's too great for mere human emotions to express.
Yes. So, for "our values", read "our extrapolated volition".
It's not clear to me how much you and Nesov actually disagree about "changing" values, vs. you meaning by "change" the sort of reflective refinement that CEV is supposed to incorporate, while Nesov uses it to mean non-reflectively-guided (random, evolutionary, or whatever) change.
I do not mean "reflective refinement" if that refinement is expected to take place during a FOOM that happens within the next century or two. I expect values to change after the first superhuman AI comes into existence. They will inevitably change by some small epsilon each time a new physical human is born or an uploaded human is cloned. I want them to change. The "values of mankind" are something like the musical tastes of mankind or the genome of mankind. It is a collage of divergent things, and the set of participants in that collage continues to change.
VN and I are in real disagreement, as far as I can tell.