But your mention of "truth values" here may be driving us into a diversion from the main issue.
I gave up on the main issue, and so described my understanding of the reasons that justify giving up.
Because I maintain that simple "ought" sentences do not have truth values. Only "is" sentences can be analyzed as true or false in Tarskian semantics.
Yes, and this is the core of our disagreement. Since your position is that something is meaningless, and mine is that there is a sense behind that, this is a failure of communication and not a true disagreement, as I didn't manage to communicate to you the sense I see. At this point, I can only refer you to "metaethics sequence", which I know is not very helpful.
One last attempt, using an intuition/analogy dump not carefully explained.
Where do the objective conclusions about "is" statements come from? Roughly, you encounter new evidence, including logical evidence, and then you look back and decide that your previous understanding could be improved upon. This is the cognitive origin of anything normative: you have a sense of improvement, and expectation of potential improvement. Looking at the same situation from the past, you know that there is a future process that can suggest improvements, you just haven't experienced this process yet. And so you can reason about the truth without having it immediately available.
If you understand the way previous paragraph explains the truth of "is" questions, you can apply exactly the same explanation to "ought" questions. You can decide in the moment what you prefer, what you choose, which action you perform. But in the future, when you learn more, experience more, you can look back and see that you should've chosen differently, that your decision could've been improved. This anticipation of possible improvement generates semantics of preference over the decisions that is not logically transparent. You don't know what you ought to choose, but you know that here is a sense in which some action is preferable to some other action, and you don't know which is which.
I gave up on the main issue, and so described my understanding of the reasons that justify giving up.
Sorry. I missed that subtext. Giving up may well be the best course.
your position is that something is meaningless, and mine is that there is a sense behind that, this is a failure of communication.
But my position is not that something (specifically an 'ought' statement) is meaningless. I only maintain that the meaning is not attained by assigning "truth value conditions".
One last attempt ...
Your attempt was a step in the right dir...
Ben Goertzel:
Robin Hanson:
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.