In The God Delusion, Richard Dawkins quotes a writer who claims that hardly any of the atoms that made up our brains when we were children are still in situ. I can’t track down a source to tell us exactly how quickly all these atoms get replaced, but the idea is highly plausible. The brain is a dynamic chemical system and we also know that when you consume a mildly radioactive substance, scientists can measure how it is spread around the body and slowly disappears again. The upshot of this is that, whatever we are, we are not simply a particular set of atoms. All carbon atoms are identical and it doesn’t matter which ones go into making us.
You might interpret this to mean that if you built an exact copy of yourself, the copy would be conscious and identical to you. Philosophers have been scratching their heads about this for years. Many materialists believe that the copy would be a conscious being in its own right. Christians instinctively shy away from this idea because it throws up the question of whether or not the copy has a soul. Other philosophers suggest that although the copy would act and look like us, it would not actually be conscious. All the lights would be on, but there’d be no one at home. The technical term for one of these unconscious beings is a ‘zombie’. Several sizable woods have been chopped down to provide the paper generated by this debate. More likely, in my opinion, the exact copy of you would be a dead body. Unless you could also get all the atoms in it to move in exactly the same way that they do in you, the result would just be an inert lump. In other words, a corpse.
However, my reading on studies of the brain has led me to draw the conclusion that having a body is essential to having a soul. Without a body, we cannot exist. There is no question that you can detach the soul from the body and expect it to float around like a ghost. The idea that the soul is the ‘real’ person that has temporarily decided to live in a material body comes from Plato. It was part of the package of Greek thinking that the Christian fathers adopted during the first few centuries of our era. The Cathars took body/soul dualism it even further with their doctrines of metempsychosis
You won’t find souls floating around anywhere in the Bible (except perhaps the highly dubious witch of Endor). Indeed, St Paul and the example of Jesus’s resurrection are quite explicit that to be alive, you need a body. Christians believe that we will be resurrected bodily (or they should believe this) and not that we will be disembodied ghosts after death. Plato’s idea made some sort of sense to the Cathars because they believed in re-incarnation. Orthodox Christians reject this and so they have no business imagining that the soul is separable from a body.
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