One's mind and one's brain are not identical

He is absolutely correct in that my argument deals with metaphysical possibility and possible world semantics. Clarifications There are different types of possibilities and impossibilities, and there are many times when people confuse them. If something is physically impossible, that means that the proposition violates the laws of physics, or the way we know nature to work. If something is metaphysically impossible, that means that it is internally and/ or externally contradictory, or violates metaphysical principles in some fashion. However, something physically impossible can still be metaphysically possible. For example, going faster than the speed of light may be physically impossible, but it is metaphysically possible. Gravity producing cubed planets instead of spherical planets is physically impossible, but metaphysically possible. Therefore, any arguments about how mental states X existing without brain states X is physically impossible does not effect its metaphysical possibility. The ArgumentP1: If the mind is identical to the brain, then whatever is true for the mind is true for the brainP2: There is something that is true for the mind, that is not true for the brainC: Therefore, the mind is not identical to the brain Defense of P1This is based on the logical law of the Indiscernibility of Identicals[1]. The law states that if A is identical to B, then whatever is true for A is also true for B. For example, if "George Bush" and "the 41st president of the United States" are identical (which they are), then if it was possible for George Bush not to go to Iraq, then it was possible for the 41st president of the United States not to go to Iraq. If George Bush got punched in the face yesterday, then it is necessary that the 41st president of the United States got punched in the face yesterday. If it is impossible for George Bush to turn into an angel, then it is impossible for the 41st president of the United States to turn into an angel. I think you get the point. .. If A and B are truly the same, then whatever is true for one should be true for the other. Therefore, if I can show that there is something true about your mental states that is not true about your brain states; it follows necessarily that your mental states and brain states are not the same. Defense of P2Lets take your mental states X and brain states X. Imagine you woke up tomorrow in a beetles body, in this case you would have your mental states X, but not your brain states X (you are in a completely different body, with a different brain in this scenario). Even if this is physically impossible, it is not logically contradictory, there doesn't seem to be anything external which contradicts this possibility, and it is a perfectly conceivable scenario. Thus, it is reasonable to conclude that it is metaphysically possible for your mental states X to exist without brain states X. It is not possible for brain states X to exist without brain states X however (that is contradictory). Thus, there is something that is true for your mental states X, but not your brain states X:P: Exists in some possible world without brain states XSince P is true for your mental states X, but not your brain states X; your mental states and brain states cannot be identical. ConclusionIf the mind is identical to the brain, then whatever is true for the mind is true for the brain. It is true for the mind that it can conceivably exist without the brain, but it is not true for the brain that it can conceivably exist without the brain. Since there is something true for the mind that is not true for the brain; they are not the same. Sources[1] . http://www.oberlin.edu...