Thanks for your comments!
In the second paragraph you quote, I was not trying to make a strong statement about scientific theories being equivalent to Ramsey sentences, though I see how that is a natural interpretation of it. I meant to support my previous paragraph about the lack of a strong distinction between conceptual implications and definitions, and contingent/nomological laws. For each "fundamental law of physics", there can be one axiomatization of physical theory where it is a contingent relation between fundamental entities, and another one where it is a definition or conceptual relation. It is central for Chalmers' viewpoint that the relation between consciousness and functional states is irreducibly contingent, but this kind of law would be unlike any other one in physics.
This isn't an assumption. It's an inference from the empirical character of introspection. That is, it has a defeasible (quasi-)perceptual basis. Many eliminativists want it to be the case that dualists are question-begging when they treat introspective evidence as evidence, but introspective evidence is evidence. Chalmers does not take it as axiomatic, prior to examining the way his stream of consciousness actually looks, that there is a special class of phenomenal concepts.
I think you are mixing two things here: whether introspective evidence is evidence, which I agree to (e.g., when I "feel like I am seeing something green", I very likely am in the state of "seeing something green"); and whether that "stuff" that when we introspect we describe with phenomenal concepts must necessarily be described with those concepts (instead of with more sophisticated and less intuitive concepts, for which the zombie/Mary's Room/etc arguments would fail).
Yeah, Chalmers would agree that adding phenomenal consciousness would be a very profound break with the sort of theory physics currently endorses, and not just because it appears anthromorphizing.
whether that "stuff" that when we introspect we describe with phenomenal concepts must necessarily be described with those concepts (instead of with more sophisticated and less intuitive concepts, for which the zombie/Mary's Room/etc arguments would fail).
I haven't yet seen a concept that my phenomenal states appear to fall under, that blocks Mary's Room or Zombie World. Not even a schematic, partly-fleshed-out concept. (And this is itself very surprising, given physicalism.)
Let's say Bob's terminal value is to travel back in time and ride a dinosaur.
It is instrumentally rational for Bob to study physics so he can learn how to build a time machine. As he learns more physics, Bob realizes that his terminal value is not only utterly impossible but meaningless. By definition, someone in Bob's past riding a dinosaur is not a future evolution of the present Bob.
There are a number of ways to create the subjective experience of having gone into the past and ridden a dinosaur. But to Bob, it's not the same because he wanted both the subjective experience and the knowledge that it corresponded to objective fact. Without the latter, he might as well have just watched a movie or played a video game.
So if we took the original, innocent-of-physics Bob and somehow calculated his coherent extrapolated volition, we would end up with a Bob who has given up on time travel. The original Bob would not want to be this Bob.
But, how do we know that _anything_ we value won't similarly dissolve under sufficiently thorough deconstruction? Let's suppose for a minute that all "human values" are dangling units; that everything we want is as possible and makes as much sense as wanting to hear the sound of blue or taste the flavor of a prime number. What is the rational course of action in such a situation?
PS: If your response resembles "keep attempting to XXX anyway", please explain what privileges XXX over any number of other alternatives other than your current preference. Are you using some kind of pre-commitment strategy to a subset of your current goals? Do you now wish you had used the same strategy to precommit to goals you had when you were a toddler?