Modal Argument: The Mind is Not the Brain

[Ben Davis]

Purpose: many atheists claim the afterlife is impossible since the mind and the brain are the same. my aim is specifically against those claims, showing they are in fact not the same and establishing the independent function of the mind from the brain is possible.

No one who knows what they're talking about, irrespective of their beliefs, claims that the mind & the brain are the same thing. The claim that results from the best evidence, currently available, is that the mind is an emergent property of certain neurological functions of the brain. Consequently, you are trying to address a straw-man.

Argument:
P1: it is possible (meaning conceivably possible) for the mind to act independently of the brain.

Yes, it's conceivable. That doesn't mean it's realistic. I mean, I once dreamed I was a hedge. What's your point?

P2: it is impossible for the brain to act independently of the brain.

True, a tautology.

C1: there is an aspect of the mind that is different from the brain (P1, P2).

Yes. That's one of the reasons we have different words for them.

P3: if two things are the same (meaning same identity), they must have exactly the same aspects and properties. if there is a single aspect that is different, then the two are not the same.

Indeed. The law of Identity.

C2: the mind and the brain are not the same (C1, P3).

Yes. As I said earlier, as far as I'm aware, no-one worth listening to claims that they are.

Conclusion: the mind and the brain are not the same thing, therefore it is possible for the mind to function independent of the brain.

No. You cannot reach that conclusion from your position because you have made no statements regarding the definitions of the functions of mind & brain, only the semantic definitions.

Objections:
1. this doesn't prove the mind can function independent of the brain-- correct. it only proves it's possible, which is all this argument aspires to establish.

All you establish is that it's possible for the labels 'brain' & 'mind' to have 2 different definitions.

2. but what happens to the brain can affect what happens to the mind, so that proves they are the same-- that may be true, but that only establishes a connection not an equivalence. the brain can affect the mind without being the same as the mind.

Once again, no-one seriously claims that means they're 'the same', all it means is that there's a relationship, likely a complicity between mind & brain.

3. P1 is false therefore both conclusions are also false-- in that premise I was speaking of conceivable possibility. it would be easier to understand that with some basic knowledge of modal logic. what it means though, is we can conceive of such a thing happening without creating a logical incoherence. it can be shown that it is not incoherent by the numerous stories/movies of people who have their minds switched, or transferred, or astral project. we can conceive of such things without thinking it incoherent, therefore it is conceivably possible.

Aha, the point of P1. Concept= reality? Nope.

So, what you've failed to plug in to your argument are:

1. all the necessary terms
2. rigorous definitions of those terms
3. evidence to support the use of those terms in context

It's no wonder your conclusion is erroneous.