Unfortunately even “possible me” zombies may be used against physicalism. The argument for that I read in Kant’s “The critique of pure reason”.
Imagine two full universes, one real and one possible, and ask a question what is the difference between them. There will be no material differences between them—energy, atoms and observers will be the same. Any difference between them will be something unobservable. For Kant it is not a problem, as its just shows absurdity of asking such questions, and I sure that in our time he would use idea of p-zombies just to demonstrate principal limits of our knowledges about metaphysics. Kant mention this very short, even shorter than I explain this here. He just said that there is no difference between the thing which is possible in all aspects and real thing.
So we need to add some kind of “vital energy” to possible world to make it actual, or to accept timeless mathematical universe model, where any possible world is actual. As LW and EY seems to accept last version, in it any possible observer must have experiences, and no possible p-zombies exist (lets call them PP-zombies). The price for it is that I can’t choose between two futures, without summoning mystical idea of “measure of existence”, which is the probability that I will find myself one of my future copies with one type of experience.
For example, if I have two possible futures, one normal, and one where golden meteor hit my garden, and I am modal realist, I should think about them as both real. As it results in absurd expectation, I should add that some of them are more real than others, based on their “measure of existence”. Any attempts to define measure of existence result in unexpected complexity, as we need to consider numbers of different and equal copies in different worlds, quantum theory, cosmology, infinities, anthropics, non-normal predictions and ethical paradoxes. This is what I meant when said that modal realism comes with price.
In short, trying to kill one monster, p-zombies, we create another monster in form of “measure of existence”.
Your counterargument is based on idea that any possible thing is only a thing which exist in my imagination. It contradicts timeless mathematical universe reality hypothesis. I think that there could be many other definitions of possibility—uncertainty, future, quantum Shroedinger cat, separated possible universes.
Before, you were comparing a(n apparently) possible universe in which you do one thing, with an actual universe in which you do something else. These are not universes with no material differences.
But now you want me to imagine two otherwise identical worlds, one actual and one merely possible. This seems doubtfully coherent to me in two different ways. First, I am not at all sure it actually makes sense to distinguish between an imagined imaginary world and am imagined actual world: both, in fact, are merely imagined. Second and worse, if some possible world is identical to the actual world term I say it is in fact the actual world.
How you get from there to needing to choose between “vital energy” and modal realism, I don’t understand; it seems to me that if any theory is in need of such “vital energy” (which I’m not at all sure if the case) then it’s modal realism. And the thing you say is the “price” of modal realism seems to me obviously innocuous. Indeed, the most obvious way to try to implement something like modal realism is Everett quantum mechanics—which comes automatically with exactly the kind of measure you’re talking about.
Saying that your imagined possible-you who goes home by a different route is a figment of your imagination doesn’t contradict the mathematical universe hypothesis; it just means declining to identify the constructs of your imagination with portions of the (hypothetical) mathematical universe. When you say “of course I could have gone home the other way” on the basis that it just seems obvious, you are not identifying a portion of the Tegmark universe, you’re just indulging in imagination. (For the avoidance of doubt, there’s nothing wrong with that.)
I’m not sure that the counterfactual mugging thought experiment exactly shows that you have to do anything in particular, but by all means take into account possible or ways you could behave—but doing so really doesn’t have the exotic metaphysical commitments you seem to be claiming it has.
Unfortunately even “possible me” zombies may be used against physicalism. The argument for that I read in Kant’s “The critique of pure reason”.
Imagine two full universes, one real and one possible, and ask a question what is the difference between them. There will be no material differences between them—energy, atoms and observers will be the same. Any difference between them will be something unobservable. For Kant it is not a problem, as its just shows absurdity of asking such questions, and I sure that in our time he would use idea of p-zombies just to demonstrate principal limits of our knowledges about metaphysics. Kant mention this very short, even shorter than I explain this here. He just said that there is no difference between the thing which is possible in all aspects and real thing.
So we need to add some kind of “vital energy” to possible world to make it actual, or to accept timeless mathematical universe model, where any possible world is actual. As LW and EY seems to accept last version, in it any possible observer must have experiences, and no possible p-zombies exist (lets call them PP-zombies). The price for it is that I can’t choose between two futures, without summoning mystical idea of “measure of existence”, which is the probability that I will find myself one of my future copies with one type of experience.
For example, if I have two possible futures, one normal, and one where golden meteor hit my garden, and I am modal realist, I should think about them as both real. As it results in absurd expectation, I should add that some of them are more real than others, based on their “measure of existence”. Any attempts to define measure of existence result in unexpected complexity, as we need to consider numbers of different and equal copies in different worlds, quantum theory, cosmology, infinities, anthropics, non-normal predictions and ethical paradoxes. This is what I meant when said that modal realism comes with price.
In short, trying to kill one monster, p-zombies, we create another monster in form of “measure of existence”.
Your counterargument is based on idea that any possible thing is only a thing which exist in my imagination. It contradicts timeless mathematical universe reality hypothesis. I think that there could be many other definitions of possibility—uncertainty, future, quantum Shroedinger cat, separated possible universes.
Counterfactual mugging thought experiment shows that I must take into account behavior of possible me (and it could be much more complex than in the experiment) https://wiki.lesswrong.com/wiki/Counterfactual_mugging
Before, you were comparing a(n apparently) possible universe in which you do one thing, with an actual universe in which you do something else. These are not universes with no material differences.
But now you want me to imagine two otherwise identical worlds, one actual and one merely possible. This seems doubtfully coherent to me in two different ways. First, I am not at all sure it actually makes sense to distinguish between an imagined imaginary world and am imagined actual world: both, in fact, are merely imagined. Second and worse, if some possible world is identical to the actual world term I say it is in fact the actual world.
How you get from there to needing to choose between “vital energy” and modal realism, I don’t understand; it seems to me that if any theory is in need of such “vital energy” (which I’m not at all sure if the case) then it’s modal realism. And the thing you say is the “price” of modal realism seems to me obviously innocuous. Indeed, the most obvious way to try to implement something like modal realism is Everett quantum mechanics—which comes automatically with exactly the kind of measure you’re talking about.
Saying that your imagined possible-you who goes home by a different route is a figment of your imagination doesn’t contradict the mathematical universe hypothesis; it just means declining to identify the constructs of your imagination with portions of the (hypothetical) mathematical universe. When you say “of course I could have gone home the other way” on the basis that it just seems obvious, you are not identifying a portion of the Tegmark universe, you’re just indulging in imagination. (For the avoidance of doubt, there’s nothing wrong with that.)
I’m not sure that the counterfactual mugging thought experiment exactly shows that you have to do anything in particular, but by all means take into account possible or ways you could behave—but doing so really doesn’t have the exotic metaphysical commitments you seem to be claiming it has.