Brain Damage and the Soul

While going through videos on YouTube the other day, I came across an argument for atheism that I had not seen before.  A man claimed that he used to be a Christian before a devastating experience made him an atheist.  He said that he had had an operation to remove a brain tumor and that this operation had resulted in a change of personality.  While he had previously been punctual and reliable, after the operation he had become lazy and unpredictable.  While he had previously enjoyed fish and certain kinds of music, after the operation he couldn’t stand fish and his taste in music changed.  His experience led him to believe that Christianity was not true and he lost his faith.  If brain damage could cause his personality and behaviour to change, he reasoned, then personality and behaviour are determined by brain chemistry and there is no soul that can be responsible for our deeds.  If there is no soul and if we cannot be responsible for our deeds, then the Bible is not true and there is no God.

As I thought about this man’s experience, I soon realized that I had, in fact, come across this argument many times before.  It is another variant on the human free will is an illusion argument which I have considered in a number of previous posts.  Of course, this argument has the additional twist of behavioural change caused by brain damage which made it new to my experience.  Let’s consider this new form of the argument.

The first question to ask is if we need to take this argument seriously.  Is the man telling the truth?  Can brain damage really change behaviour?  Or are the scientific studies that indicate that brain damage can change behaviour fraudulent?  While some Christians might argue that this man was being untruthful about his experience, I don’t believe in using this kind of argument.  I would rather answer, “I don’t know the answer to this question, but I do have reasons for the hope that is within me.” and assume the truthfulness of the person telling me the story than accuse the scientists and victims of lying.  I might die never having a satisfactory answer to this question, but this is preferable to making accusations against someone without knowledge.  Satan is called the “accuser of the brethren” and I do not feel comfortable joining him in this kind of activity.  Fortunately for us, modern science gives us powerful hints as to what might be going on here and we have a much more satisfactory answer than “I don’t know.”

While some of the thinking that I am going to present below goes back years, most of it comes from an absolutely astonishing video on YouTube which I watched recently and highly recommend.  While the author of the video doesn’t address this question directly, a satisfying answer can be derived in a straightforward manner from the material in the video.  Allow me to present a possible answer based on this material.

Let us imagine a person who has had damage to the nervous system such that he no longer has any feelings from his legs.  Modern technology allows him to walk and stand normally, but he does not feel anything from his extremities.  Now let us further imagine that he meets some old acquaintances that don’t know about his accident or his unfortunate condition.  One of them says to the other, “Bob has really changed.  He was standing on my foot the whole time we were talking.  He knew it hurt and just looked at me as though nothing was wrong.  What a jerk he has become!”

In this thought experiment, we see that Bob has had what other people consider a change in personality which we know was not really a change.  Had he known that he was standing on this other persons foot, he would immediately have apologized just like he had done before.  His accident, however, left him unable to tell that he was standing on someone else’s foot and so his behaviour under those circumstances has changed in an understandable way.

Now instead of the damage that Bob experienced being done to the nerves in his legs, let us say that it was done to the empathetic centre of Bob’s brain.  Bob no longer knows that standing on your foot causes pain or that you might be irritated by that.  To Bob, standing on your foot seems as harmless as putting his hand on your shoulder or taking a drink from his glass of water while you are talking.  Has a personality change occurred?  Or has damage to the information processing centres of the brain changed a person’s actions because it changed their ability to perceive certain components of reality?

As strange as it may seem, research into brain function demonstrates that this kind of damage is possible.  There are centres of the human brain which process and understand body language, humour and all of the stimuli that we experience on a daily basis.  The brain is like a computer running a number of different applications that give human beings a variety of different capabilities.  If the hardware is damaged, then the human ability to perceive reality can be impaired in astonishing ways.

As an example of some of the strange effects of brain damage, consider damage to the centres of the brain responsible for detecting motion.  When I read about this research it was tremendously surprising.  Evidently, when a person with such damage is shown the video of a moving dog, they think that it is a series of dogs that disappear and appear instead of a single dog that is moving.  When I thought about this experiment, it was inconceivable to me that a person could see two identical dogs a few feet apart in rapid succession and not perceive that as motion.  The fact of motion seems logically deducible to me and logic seems essential to my personality and self.  How to understand the results of such experiments?

A similar problem shows up in the military.  Let’s say you have 5 radar stations 100 miles apart and each has 5 blips.  Is this 25 different aircraft?  Or is it 5 aircraft seen from 5 different radar stations?  This correlation problem requires an enormous amount of information processing.  If the correlation software in the brain is damaged the process of identifying the relationship between the sequential data from different visual processing centres in the brain is no longer automatic.  A person with such damage may be able to deduce motion logically, but that information is not available for other mental processes.  They would not, for example, be able to throw a ball to a moving dog.  In just this way, a person with brain damage might be able to tell you that showing up late for work would make a person a bad employee but not be able to use this information to motivate himself to get up in the morning.  How does this help us to answer the question asked by the atheist above?

Let us say that a mind and a will exist in relationship with the capacities provided by a brain.  The mind chooses to be a responsible employee and uses the knowledge and capacities of the brain to reach this desired goal.  As long as the brain has the capacity to determine the kind of behaviour that would displease employers and family members, the whole person is able to be responsible and punctual.  Once the brain loses the capacity to process basic social interactions, the person is no longer whole and this lack of wholeness can incapacitate that person with regard to virtues that require social information processing.

From this point of view, there are essentially two ways to have certain negative personality traits.  The first way is to be capable of exhibiting the positive personality trait and choosing not to, the second way is to be incapable of exhibiting the positive personality trait because of some defect in the biological hardware.  As modern research suggests, it is possible for a person who chooses to exercise various brain capacities to improve those capacities and be more capable of a given virtue.  Given our understanding of brain plasticity it should be possible, for example, to make yourself more empathetic by exercising your empathy and developing these mental skills just as you can develop math or language skills.  It is also possible to lose the capacity for certain virtues by not exercising the relevant brain capacities. That this loss of brain capacity can be caused by physical damage to the brain as well as by choosing to let these brain capacities atrophy through lack of use should not be surprising.  In this way, the fact that brain damage can impair our ability to exercise certain virtues is not a problem for Christian belief.


It is interesting to note that the explanation above makes sense of the atheists own words where his own position does not.  When he rejected Christianity because of his observed personality change, he was essentially saying, “I wanted to be a punctual and responsible person, but after the brain damage I was unable to do that at all.  Because I was so deeply disappointed by my own personality change, I became disillusioned with the idea that God exists and became an atheist.”  If his view was correct, he shouldn’t have cared about the personality change that he perceived.  The view presented above, on the other hand, is completely consistent with a desire to exhibit certain virtues but an inability to do so.  Regardless, his Christian “faith” seems to have been predicated on his own ability to do things that are “good” and a belief that your acceptability before God is based on your performance of good actions is not a genuine Christian belief.

About Robert V

Former atheist currently living in Toronto.
This entry was posted in Atheist Arguments, Free Will and tagged , , , . Bookmark the permalink.

2 Responses to Brain Damage and the Soul

  1. Well, that was a boat load of assumptions. Too many to be able to draw any conclusions from.

    • Mal,

      Good to hear from you again and thank you for the comment.

      I am not quite sure I know what you mean by assumptions. The kind of brain damage that I am talking about is well known. There are empathetic centres whose damage results in behavioural change: I explain this in terms of the Christian worldview by suggesting that this person would choose to be sensitive if his brain provided him that capability. Unfortunately, since the capacity to understand other people’s feelings or reactions is diminished or destroyed by such brain damage this is no longer possible. I am not certain that this requires any speculation, it is just my best attempt to reconcile some difficult data with the Christian worldview.

      I modified the **DISCUSSION** section at the end to provide an example of the kind of thing I am talking about.

      Merry Christmas


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