In the Carrier-Wanchick debate, Carrier gives an argument for naturalism from the fact that minds are embodied in brains. As part of the setup, he writes:

If BT [Biblical theism] is true, then (a) a brainless mind is possible, (b) God could have imbued humans with one, (c) no mind exists that was not deliberately created or allowed by God, and (d) in choosing what to do or allow, God would have obeyed the same moral code that a majority of Christians obey.

Following this, he argues that, if Biblical theism is true, it would be more likely that we have minds without brains and would be a better state of affairs if we had minds without brains. Since we see the opposite, this is evidence for naturalism and against theism.

Wanchick responds by saying that

AMBD quickly derails itself too, as Carrier claims that God could’ve created us with immaterial “brainless minds” (BMs). This entails that human minds are disembodied in some possible world (PW); consequently, human minds are possibly disembodied in every PW. But if anything can possibly exist disembodied, it is not a material substance, since material substances can’t exist without matter. Therefore, human minds are immaterial substances. But since CN [Carrier naturalism] requires that consciousness arises only from a “complex physical system,” CN is false and theism is bolstered.

Wanchick is making a mistake about the structure and nature of Carrier’s argument. Carrier is arguing that if CN is true, then “consciousness arises only from a ‘complex physical system,'” while Wanchick is interpreting the argument to mean that “consciousness arises only from a ‘complex physical system'” is a necessary truth independent of CN. Likewise, Carrier is not arguing for the logical impossibility of disembodied minds, yet Wanchick takes Carrier’s argument to be self-refuting because Carrier says that, if BT is true, there could be disembodied minds.

The mere logical possibility of minds based in “spiritual substance” rather than matter doesn’t entail that minds are necessarily not material, contrary to Wanchick’s statement that “if anything can possibly exist disembodied, it is not a material substance, since material substances can’t exist without matter.” A building can be made out of a variety of different materials; the fact that it could have been built from wood doesn’t mean that it is therefore not built from bricks. The building is more than the raw materials–it is also dependent upon the particular arrangement of the materials–but this kind of supervenience is not problematic for a physicalist and doesn’t require a supernatural theory of buildings.

Note that Carrier spoke of “brainless minds,” not “disembodied minds.” He doesn’t argue that this distinction makes a difference, but I would argue that the functionality of a mind has to be imbued into some kind of substance (which need not necessarily be a biological brain), and that BT has no account or theory of any kind to offer about what “spiritual substance” is or how minds could be instantiated in it. I’m inclined to the view that talk of “spiritual substance” is nonsense and that the notion of a disembodied mind is, in fact, incoherent, and thus that if BT entails such a thing, that the proper inference is a modus tollens–that BT is therefore false.

For this reason, I don’t particularly care for Carrier’s argument, and would prefer Wanchick’s restatement in terms of Perfect Minds rather than Brainless Minds (or disembodied minds). Wanchick states that God does follow the Golden Rule and would want his creations to have perfect minds, and that “God would do this [create all children with perfect minds].” He then goes on to say that, under the rules of the debate, Carrier cannot use this alternative argument, but he doesn’t say how he would respond to it–it is quite clear that human beings do not have perfect minds, so Wanchick must have some additional explanation for imperfection. I presume he would offer an argument in terms of original sin.