You're confusing epistemological solipsism with metaphysical solipsism. If metaphysical solipsism is true, you are the only mind that exists, while the epistemic version is about doubting that you can ascertain the truth of whether or not other minds exist. Hence, if metaphysical solipsism is true then I'm not sure postulating possible worlds where there are other minds or p-zombies really helps, because then isn't it by definition necessarily the case? Or at best, you could slide to the epistemological version, which means the question of whether or not possible metaphysical truths are necessarily true becomes a non sequitur.
Regardless, I guess I could parse metaphysical truths into 2 camps: necessary metaphysical truths (NMTs) and unnecessary metaphysical truths (UMTs). The former refers to possibly necessary metaphysical truths that, if coherent, have to be true, while the latter refers to metaphysical truths that only happen to be true, but didn't have to be. Thus, my argument would seem to hold, since metaphysical naturalism is self-evidently a NMT (as is God), which would rule out God if you accept modal ontological arguments as valid operating methods.
But really, the above is all problematic. From what I understand, Immanuel Kant essentially destroyed metaphysics - or certainly dealt it a near KO - so even trying to make metaphysical arguments like Plantinga's MOA (and my own) are non-starters without an amazing metaphysical grounding and defense, which no one has really managed to do. That's why - from what I think I understand and from what I've heard - contemporary philosophy has abandoned metaphysics.
Regardless, I guess I could parse metaphysical truths into 2 camps: necessary metaphysical truths (NMTs) and unnecessary metaphysical truths (UMTs). The former refers to possibly necessary metaphysical truths that, if coherent, have to be true, while the latter refers to metaphysical truths that only happen to be true, but didn't have to be. Thus, my argument would seem to hold, since metaphysical naturalism is self-evidently a NMT (as is God), which would rule out God if you accept modal ontological arguments as valid operating methods.
But really, the above is all problematic. From what I understand, Immanuel Kant essentially destroyed metaphysics - or certainly dealt it a near KO - so even trying to make metaphysical arguments like Plantinga's MOA (and my own) are non-starters without an amazing metaphysical grounding and defense, which no one has really managed to do. That's why - from what I think I understand and from what I've heard - contemporary philosophy has abandoned metaphysics.
