There is the simple observation that one has no conscious experience during dreamless sleep. (A panpsychist could respond that maybe one merely lacks memory of one's sleeping experience, but that would be epicyclic).
That's just ordinary compatibilism -- as I said, "it’s not libertarian free will." All the work is being done by using a definition of free will that doesn't require indeterministic "elbow room", so none of it is being done by all the physics and metaphysics. If it is valid, it would be just as valid under naturalistic monism, supernaturalistic determinism, etc.
And compatibilism isn't universally accepted as the solution to free will because the quale of freedom is libertarian -- one feels that one could have done otherwise. (At least , mine is like that).
An additional non physical layer of consciousness might buy you qualia, but delivers no guarantee that they will be accurate... a quale of libertarian free will is necessarily illusory under determinism.
An additional non physical layer of consciousness might have bought you downwards causation and libertarian free will.
But you are not legitimising it as a subjective impression that correctly represents reality... only as an illusion: you can feel free in a deterministic world, but you can't be free in one.
Under physicalist epiphenomenalism (which is the standard approach to the mind-matter relation), the mind is super-impressed on reality, perfectly synchronized, and parallel to it.
Under dualist epiphenomenalism, that might be true. Physicalism has it either that consciousness is non existent rather than causally idle (eliminitavism), or identical to physical brain states (and therefore sharing their causal powers).
Understanding why some physical systems make an emergent consciousness appear (the so called “hard problem of consciousness”) or finding a procedure that quantify the intensity of consciousness emerging from a physical system (the so called “pretty hard” problem of consciousness) is impossible:
You could have given a reason why.
It's a warning if the history consists of various groups having extreme confidence about solving all the problems in ways that subsequent groups don't accept.
You are conflating subjective as in "by subjects" with subjective as in "for subjects". A subject can have preferences for objectivity, universality, impartiallity, etc.
The other problem is that MWI is up against various subjective and non-realist interpretations, so it's not it's not the case that you can build an ontological model of every interpretation.
Huh? The whole point of the Born rule is to get a set of ordinary probabilities, which you can then test frequentistically, over a run of experiments. Quantum mechanical measure-- amplitude-- isn't ordinary probability, but that's the thing you put into the Born rule, not the thing you get out of it. And it has it's own role, which is explaining how much contribution to a coherent superposition each component state makes.
ETA
There is a further problem interpreting the probabilities of fully decohered branches. (Calling then Everett branches is very misleading -- a clear theory of decoherence is precisely what's lacking in Everett's work)
Whether you are supposed to care about them ethically is very unclear, since it is not clear how utilitarian style ethics would apply, even if you could make sense of the probabilities. But you are not supposed to care about them for the purposes of doing science, since they can no longer make any difference to your branch. MWI works like a collapse theory in practice.
always thought that in naive MWI what matters is not whether something happens in absolute sense, but what Born measure is concentrated on branches that contain good things instead of bad things.
It's tempting to ethically discount low measure decoherent branches in some way, because that most closely approximates conventional single world utilitarianism -- that is something "naive MWI" might mean. However, one should not jump to the conclusion that something is true just because it is convenient. And of course, MWI is a scientific theory so it doesn't comes with built in ethics.
The alternative view starts with the question of whether a person low measure world still count as a full.person? If they should not, is that because they are a near-zombie, with a faint consciousness that weighs little in a hedonic utilitarian calculus? If they are not such zombies, why would they not count as a full person -- the standard utilitarian argument that people in far-off lands are still moral patients seems to apply. Of course, MWI doesn't directly answer the question about consciousness.
(For example, if I toss a quantum fair coin n times, there will be 2^n branches with all possible outcomes.)
If "naive MWI" means the idea that any elementary interaction produces decoherent branching, then it is wrong for the reasons I explain here. Since there are some coherent superpositions, and not just decoherent branches, there are cases where the Born rule gives you ordinary probabilities, as any undergraduate physics student knows.
(What is the meaning of the probability measure over the branches if all branches coexist?)
It's not the existence, it's the lack of interaction/interference.
By "equally" I meant:
"in the same ways (and to the same degree)".
If you actually believe in florid many worlds, you would end up pretty insuoucient, since everything possible happens, and nothing can be avoided.
"it" isn't a single theory.
The argument that Everettian MW is favoured by Solomonoff induction, is flawed.
If the program running the SWE outputs information about all worlds on a single output tape, they are going to have to be concatenated or interleaved somehow. Which means that to make use of the information, you gave to identify the subset of bits relating to your world. That's extra complexity which isn't accounted for because it's being done by hand, as it were..