The Problem of Personal Identity for the Hope of an Afterlife

It’s easy enough to understand why we all have a natural, evolutionary aversion to death, and how this might translate into an almost instinctual desire for an afterlife of some kind. The question of whether there might be some way to live on after our physical deaths seems so important that, however remote we might consider the possibility, most of us probably still feel at least a wishful hope that it could be true. But is this hope actually even coherent? Does it really make sense to be so deeply concerned about the idea of a possible future afterlife that we can even meaningfully wish it to be true on a conscious, rational level? When considered in light of the problem of personal identity, this begins to seem rather doubtful.

The problem of personal identity is the question of what makes you the same person at different points in time. It’s a difficult philosophical challenge to articulate exactly why an infant who grows up to be an adult should still be considered the same person even though virtually all the physical material that comprised the infant’s body has been swapped out by natural processes, as individual cells continually die off and get replaced. But when we try to extend the reasoning even to life beyond death, what was merely difficult begins to look more like complete absurdity.

Suppose for the sake of argument that the essence of personal identity is a non-physical soul that survives death, as most people who believe in an afterlife probably assume for religious reasons. In this case, after the current body is destroyed, God (if such a being exists) could simply associate the soul with a new body, perhaps inhabiting an entirely different universe. The new body would then be, or perhaps more accurately house, the exact same person that the old one did. Voila: life after death! So what is the problem, believers in this view might ask?

The problem is that it is very difficult to see what this proposed non-physical essence of personal identity called the soul actually does for us that could possibly be relevant to the issue. Before modern science it was commonly assumed that the soul was the seat of our personality and the repository of our memories. But this is almost impossible to believe now that we have abundant evidence (though admittedly still not nearly as much understanding as we’d like) that our memories and personality traits are encoded physically in our brains, and can be altered by injuries to our brains, for example. This doesn’t logically preclude the idea that there might be a non-physical soul in addition to the physical brain, of course. But the point is, even if there is such a thing, why should it be the soul instead of the brain that is relevant to our personal identity, given that it is the physical brain that apparently stores all our memories and personality traits?

To put this in a slightly different, perhaps more illustrative way, if the soul serves no identifiable function other than to be the carrier of personal identity, then how does it make sense to care so deeply about this personal identity that the soul supposedly carries? A traditional Hindu might worry that his soul (or what he would call “atman”) will be reincarnated as a chicken, just as a traditional Christian might hope that her soul will be given a new body after death. But those not so steeped in these respective religions would probably ask how it makes sense to see either the chicken or the new body as being the same “person” as the original in any tangible sense that could possibly be worth caring about, since it does not share the original person’s brain, which appears to be the organ that makes us who we are in every functional way. The mere assertion that it is the same person because it has the same soul doesn’t mean much if the soul doesn’t do anything. So in order for the hope of an afterlife to make much sense on this theory of a non-physical soul that survives death, it seems we’d have to speculate that the soul redundantly duplicates the memories and other functions of the brain, in addition to being the carrier of personal identity. But this idea of the brain and soul serving redundant functions seems fairly absurd, since it renders the brain totally unnecessary. Why should the brain bother storing memories if the soul already accomplishes that purpose?

Alternatively, suppose that the essence of personal identity is not a non-physical soul, but simply the continuation of our unique combination of personality traits and memories, as stored in our brains. In this case, the afterlife could consist in God (if there is such a being) re-creating the exact physical configuration of our brains, or perhaps more generally just uploading the relevant parts of our brain’s “software,” including our personality traits and memories, into a new kind of brain. If the physical configuration is exactly the same, this would be like Captain Kirk going into the transporter room, being totally dissassembled at the molecular or even subatomic level, and then reconstructed shortly afterward out of a totally different set of subatomic particles in a totally different location. This seems like a more defensible theory of the afterlife on scientific grounds, but is there really any more reason to care whether or not we will be re-created in this way in a new universe after we die than there was to care about the continuation of our proposed non-physical souls, whether in a new human body or in a chicken? I suggest there is not.

Perhaps the easiest way to see this is to consider the various postulates many philosophers and scientists have ventured about how there may well be an infinite number of physical universes. If this is true, then an almost inconceivably tiny fraction of these alternate universes would by sheer chance include exact replicas of you and me, right down to our same personality traits and memories. And although tiny, this fraction would still amount to many universes, of course. (Infinitely many, in fact—that’s how infinity works.) I don’t have any idea how likely or unlikely any of these hypotheses are to be true, but the relevant point to make here is, neither do I particularly care. And I doubt that many others care very deeply about whether or not there are exact duplicates of their physical selves inhabiting alternate universes, either. So why should I care about whether a new instance of me might possibly be created in another universe we call the afterlife, any more than I care about whether there might be other instances of me in other universes unconnected to this one? Bluntly put, even on this theory of personal identity that says an exact duplicate of me is not just my doppelgänger but actually counts as a legitimate instance of the true “me,” I still can’t find any reason to be deeply concerned in any practical way about other instances of myself besides the one that inhabits this particular universe during this particular lifetime. (And I probably wouldn’t even care very much about that one if it could be easily duplicated in the same world using a transporter-like device, but that is a different issue.)

In conclusion, while our gut instinct may be to think that we should care as much about our possible existence in an afterlife as we do about our existence in this life, it is really quite difficult to defend this feeling on consistently rational grounds, no matter which theory of personal identity we accept. One could argue that there may be another theory of personal identity I have not discussed here that makes the feeling more plausible, of course. Maybe neither the existence of a non-physical soul nor the continuation of the brain’s configuration or “software” is in itself the essence of personal identity, but the combination of both of them somehow is, for example. I acknowledge it is logically possible that some such theory might provide an adequate justification for being deeply concerned about the possibility of an afterlife, in some way that I just fail to grasp. But when I try to think the issue through, I find myself believing it is far more likely that our instinct is simply misleading us, and my own urge to care about the possibility of an afterlife is significantly dissipated. I simply think of death instead as a tragedy we all struggle to accept and yet will face in the end, after sensibly trying to prolong our lives as much as possible. And while I could be wrong (and part of me can’t help hoping that I am, no matter how absurd it seems), I don’t think the admittedly natural hope or wish for an afterlife in which someone somehow legitimately counts as being “me” for some unknown reason is a rationally meaningful way of responding to this inevitability.

This page copyright © 2017 Edward A. Morris.  Created March 31, 2017.  Last updated March 31, 2017.

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