No ghost in the machine

Science has come far in recent centuries, and in many cases popular perception of reality has kept pace.  For example, most people today know that most disease is caused by bad diet or microorganisms and not by evil spirits or magic spells, and actually behave in accordance with that knowledge, or try to.  Yet in other areas, notably those where cherished illusions are involved, the grip of pre-scientific thinking has proven harder to shake.

One such case is the belief that humans (and perhaps other animals as well) contain some kind of "soul" or "spirit", an entity distinct from the physical body and brain, which inhabits the body and brain somewhat like a ghost inhabiting a haunted house.  Even many atheists who would scoff at a religious term like "soul" visualize consciousness the same way -- that "you" are an entity distinct from your body, sitting inside your body and controlling it the way a driver sits inside a car and controls it.  It's not obvious to me how or why this concept got started, but it is deeply entrenched in human thinking in many cultures.

The study of the mind is a difficult field and our knowledge is still far from complete, but we know enough to be fairly confident that this Cartesian "ghost in the machine" concept, like the pre-Galilean flat-Earth-and-crystal-spheres model of the cosmos, is simply not an accurate picture of reality.  Your consciousness or self or "soul", or whatever you want to call it, is not an entity which inhabits your brain, it's a set of operations which your brain is continuously performing.  When the part of the brain which performs a given type of operation is injured or destroyed, the victim often loses the corresponding aspect of his or her mental ability -- memory, or the ability to feel a particular emotion, or whatever.  The deterioration of the brain which often accompanies aging has the same effect, robbing the victim of various faculties and sometimes even causing changes in personality.  Your "self" is not a distinct entity separable from your physical brain, any more than your heartbeat is a distinct entity from your heart, or your digestive process is a separate entity from your digestive tract.

The "ghost in the machine" delusion brings other concepts with it in consequence.  One is the belief that the consciousness can leave the body and take up residence in another one, or lead a free-floating existence independent of matter, just as the driver of a car could get out and drive a different car or walk around on his own.  Many religious and superstitious ideas are rooted in this belief, such as reincarnation or demonic possession (if the self is a supernatural "spirit" separable from the body, it's easy enough to imagine some other, alien "spirit" barging in and seizing control), or the Christian idea that the "soul" continues to exist after death and goes to Heaven or Hell, continuing to be conscious and have experiences despite the loss of the brain and sense organs which actually do those things.  In modern terms, it's similar to believing that if your heart were destroyed, your heartbeat could somehow continue on as a disembodied "thing" despite the disappearance of the organ which was doing it (a process or action, not a "thing").  If you set a wheel spinning and then destroy it, nobody believes that the rotation of the wheel is a separate "thing" which can somehow still exist independently after the wheel itself no longer exists.  Yet the idea that the "soul" can survive the death of the brain is more or less equivalent to this.

HG Wells wrote a story in which an elderly man tried to extend his life by transferring his consciousness into the body of a young man, rather like a demon possessing a person in medieval superstition.  Modern anti-aging research, fortunately, has not wasted any effort on trying to realize such a strategy.

(Note that this is a separate issue from the existence of free will, which I discussed here.  I consider it to be self-evident that our free will and consciousness are real.  While we don't yet know how free will works, it seems obvious that it is simply another process performed by the brain; there is no reason to think anything supernatural is involved.)

Another such consequential error is the concept of being "born in the wrong body", which has actually been gaining ground recently, leading to further misunderstandings and problems.  Yet another is the ancient belief that some kind of "higher" consciousness or "spirituality" can be attained by renouncing the pleasures of the physical body, perceived as an impure or lowly vessel which degrades or holds back the reified "soul" trapped within it.

But there is no such trapped or indwelling "soul".  There is no ghost in the machine.  There is only the machine, performing a great variety of actions, even if some of those actions are too complex and subtle for us to understand yet.