Modal Argument: The Mind is Not the Brain

[Rational AKD]

I'm still not fully read up on modal logic, so please forgive me if I make a silly statement... but isn't this begging the question?

it would only be begging the question if I said P1 is supported by the conclusion. but P1 is supported by the reasons in objection 3, that we can coherently conceive a mind separate from the body. which means, in a modal sense, there is at least one possible world where the mind exists without the body. there is no possible world where the brain exists without the brain. therefore, the conclusion follows that they are not the same.

But then without even knowing if the mind exists as a separate entity, it seems like this argument is valid only because of semantics i.e. the mind is *really* the brain, but because of the different label and the question-begging of such a thing even existing, it seems like we have the "mind" possibly being separate to the brain.

it's not just semantics. the fact that we can coherently conceive of mind existing without body means there are possible worlds where they exist separate. that is something impossible for the brain. therefore they are not the same.

1) The brain needs chemical energy to function
2) The mind is not the brain
3) Therefore, the mind does not need chemical energy to function
4) The mind commands our physical body to move
5) Our physical bodies require chemical energy to move
6) Therefore, energy is being *created* whenever the mind commands the body to move
C) Energy can be created by the mind

premise 6 doesn't follow from premise 5 because the mind can be connected to the brain without chemical energy being shared between the two. the only necessity for premise 5 is chemical energy being sent from brain to body.