There are ceveral medical proofs of people living with a hole in their brains, sometimes people even missing a large part of their brain. The people however would have to learn to write again, or speak again, or would suddenly have a change of personality.

In theory, 50% of the brain could easialy compensate for the missing 50%. If you would devide a living brain in half and keep it medically alive, maybe even letting 2 people live with it (not really ethically, but it's just a theory. btw they once switched the head of 2 monkeys so I bet they can).

What part of the 2 still living, still thinking brains would be the Soul? Would there be 2 souls? Where would the souls go in 'heaven'? Would the person come back together?

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Bisides that a 'soul' could not 'travel' to heaven. Unless there would be a paralel dimension and really, there is No way that's true. Becouse then there would have to be an afterlife-dimension for every religion. Christianity has no advantage in plausibility at all compairing to any other religion.

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