Saying “in many worlds you make all possible decisions” is technically true, but it is important to add that some actions happen with large probabilities, and some of them happen with microscopic probabilities. That doesn’t undermine decision theory; you can still use it to do the right thing with 99.9999% probability.
(Unless you believe in a version of “many worlds” that says that everything happens with the same measure, which is not what physicists believe. If that was true, then quantum computers would be useless for any purpose other than generating perfectly random numbers.)
(And if your objection is that you can’t make “decisions” when the atoms in your brain are following the laws of physics, then 1. this is unrelated to quantum or classical physics, and 2. yes you can, this is exactly how evolution designed us by selecting for configurations of atoms that were more likely than random to do the right thing.)
That doesn’t undermine decision theory; you can still use it to do the right thing with 99.9999% probability.
If it’s possible to use decision theory in a deterministic universe, then MWI doesnt make things worse except by removing refraining. However, the role of decision theory in a deterministic universe is pretty unclear, since you can’t freely decide to use it to make a better decision than the one you would have made anyway.
(And if your objection is that you can’t make “decisions” when the atoms in your brain are following the laws of physics, then 1. this is unrelated to quantum or classical physics,
If it’s possible to use decision theory in a deterministic universe, then MWI doesnt make things worse except by removing refraining. However, the role of decision theory in a deterministic universe is pretty unclear, since you can’t freely decide to use it to make a better decision than the one you would have made anyway.
Saying “in many worlds you make all possible decisions” is technically true, but it is important to add that some actions happen with large probabilities, and some of them happen with microscopic probabilities. That doesn’t undermine decision theory; you can still use it to do the right thing with 99.9999% probability.
(Unless you believe in a version of “many worlds” that says that everything happens with the same measure, which is not what physicists believe. If that was true, then quantum computers would be useless for any purpose other than generating perfectly random numbers.)
(And if your objection is that you can’t make “decisions” when the atoms in your brain are following the laws of physics, then 1. this is unrelated to quantum or classical physics, and 2. yes you can, this is exactly how evolution designed us by selecting for configurations of atoms that were more likely than random to do the right thing.)
If it’s possible to use decision theory in a deterministic universe, then MWI doesnt make things worse except by removing refraining. However, the role of decision theory in a deterministic universe is pretty unclear, since you can’t freely decide to use it to make a better decision than the one you would have made anyway.
Deterministic physics excludes free choice. Physics doesn’t.
MWI is deterministic over the multiverse, not per-universe.
Yes, and it still precludes free choice, like single universe determinism, as well as precluding refraining