The Soul--A Rational Belief?

Because this blog attracts readers of varying philosophical experience, I have chosen to summarize some of the philosophical concepts involved in the discussion of the mind rather than assume the reader's knowledge of them. More versed readers will forgive the often hasty generalizations of complex ideas (especially the many ideas regarding the philosophy of the mind).

Most Christians (and many other theists) believe in a dualistic human nature--i.e. that humans are both physical and spiritual beings. In this view, there is a brain and a spiritual consciousness. It is thought that the spiritual consciousness determines a person's identity, personality, and behavior. Many theists believe this spiritual consciousness can live on after the brain and physical body of a human is destroyed. They are committed to the idea that the brain and a spiritual consciousness are independent, yet somehow linked.

In this post, I will argue against the plausibility of a spiritual human consciousness separate from the human brain. I will argue that the brain alone is responsible for a person's identity, personality, and behavior. After constructing a few informal philosophical arguments that rely on what I will refer to as "brain-dependence"(hereafter, BD) and conclude that the existence of a spiritual consciousness separate from the brain is implausible, I will describe and give examples for BD.

From the evidence listed below, it seems indisputable that the human brain is, at least, partially responsible for a person's identity, personality, and behavior (traits traditionally ascribed to a spiritual human consciousness). If a theist agrees that the brain can affect a person's identity, personality, and behavior, they must either concede that the brain can exercise control over a person's supposed spiritual consciousness or they must believe that the spiritual consciousness can exercise control over a person but that the brain cannot affect it in any way. Both are problematic for theists who believe in a spiritual consciousness.

If the brain is clearly and demonstrably responsible for some aspects of a person's identity, personality, and behavior, it does not seem unreasonable to assume that the brain is responsible for all aspects of a person's identity, personality, and behavior. In fact, it seems as if the notion of a spiritual consciousness is completely superfluous. If human identity, personality, and behavior can be determined by the brain it seems that this is the most natural explanation of human (non-spiritual consciousness). Any further additions would seem to violate Ockham's razor--the principle that one should not multiply explanations when a simple one answers the question (e.g. If I saw a George Washington standing over a freshly-cut cherry tree with an axe, it would be illogical for me to argue that aliens flew down and knocked the tree over with their laser blaster. The simplest explanation is that GW chopped the tree down. In the same way, if the brain can be responsible for a person's identity, personality, and behavior, there is no reason to posit some kind of spiritual consciousness).

If, instead, a theist asserts the transcendence of the spiritual consciousness so that it cannot be affected by the brain, many questions follow. The brain, for instance, limits learning. If a spiritual consciousness is not limited by the brain, then everything that consciousness experiences, it must retain. Every spiritual consciousness is a little Einstein, smarter even. Not only would every spiritual consciousness retain every memory and piece of information it was ever exposed to, it would also be free from the reasoning limitations of the brain. It would take all of the available information and put them together perfectly.

But if this is the aspect of a person's self that lives on, can one really argue that she will survive her death? The spiritual consciousness is not at all like the consciousness that a person is aware of after the brain has limited it. It is smarter, more well-reasoned, has more memories, and doesn't even share the same body as the one a person has been aware of. The person emerging from death wouldn't be anything like who they were in life. That person would have truly died and a new entity (an unlimited spiritual consciousness) would live on.

BD states that there is an inextricable link between the human brain and human consciousness. It has been shown that altering part of the brain alters certain states of consciousness and that the destruction of parts of the brain destroys certain states of consciousness. Furthermore, it has been empirically verified that every thought corresponds to an occurrence in the brain. Steven Pinker, a psycholinguist, says, "We know that every form of mental activity -- every emotion, every thought, every percept -- gives off electrical, magnetic, or metabolic signals that can be recorded with increasing precision by Positron Emission Tomography, functional Magnetic Resonance Imaging, Magnetoencephalography, and other techniques." Adam Marczyk writes, "there is no aspect of the mind that does not correspond to any area of the brain."

There are many examples of how human consciousness is affected by brain injury (I am indebted to Adam Marczyk's article "A Ghost in the Machine" for most of the specific examples). I may have gone a little overboard with the actual cases (I thought they were interesting), so if you want to read a couple

Anterograde amnesia is the inability to form new memories (if you are familiar with the movie, Momento, the main character has this disorder). Conifer writes, "Dr. Kenneth Heilman tells us of a patient named Flora Pape whose left and right fornices [the area of the brain responsible for memory] both had to be excised to save her from a life-threatening brain tumor. Mrs. Pape had lived in east Kentucky all of her life, until she and her husband both moved to Jacksonville, Florida, two years before her surgery. At the time of her surgery, she had two sons in their 20s, both of whom still lived in Kentucky." Heilman recounts what took place after leaving the hospital:

When she was discharged from the hospital, her husband drove her from Gainesville to their home in Jacksonville. After leaving Gainesville, her husband noticed that she was looking out the window and saying, "Oh, my!" He asked what was troubling her and she said, "What happened to the mountains?"
He asked, "What mountains?"
She replied, "You know, the mountains."
He said, "There are no mountains here."
She replied, "No mountains in Kentucky. We must be in the western part of the state. What are we doing here?"
Mr. Pape had been told by [the doctor] that the surgery might make her memory worse, but he was still surprised. "Dear, we are not in Kentucky. We are in Florida."
She asked, "Why are we in Florida?"
He told her that they had moved to Jacksonville about 2 years earlier. She said, "Moved to Jacksonville? Why?" He told her that the company had asked him to transfer. She asked, "Where are we going now?"
"Back to Jacksonville from Gainesville. You had some surgery on your brain. It was a tumor. The doctors think they got it all out. You are having some memory problems, but the surgeons hope it will improve with time."
Then she asked, "Who is watching the boys?"
"No one," he replied. "They are grown and live in Kentucky."
"What do you mean, grown? They are still teenagers."
"No, they are not. They are in their twenties. They are coming down this weekend to see you."
She stopped asking questions for a few minutes and looked out of the car window. Then she turned to her husband and asked, "Where are all the mountains?"

Now, is this wife really the same person she was before the surgery? What does it mean to be you? Are you not a product of your memories? Are you the same person now that you were two years ago?

This also introduces other problems for religious theists. What if this wife had been an atheist two years before the surgery, but had then become a theist (let's say, a Christian theist). After the surgery, however, she only remembers her reasons for not believing in a god. She, now, espouses the strong atheism she held prior to the surgery. Is she or is she not a Christian?

The point is that if there is a spiritual consciousness that exists outside of the brain, why does damage to the brain change a person's identity? A person is a collection of their thoughts and memories (e.g. If I were asked to describe myself, I would talk about what I've experienced, what I think, what I do for a living, etc. All of these descriptions would change if I lost two years of my life like Mrs. Pape).

Some religious theists argue that, perhaps, the soul/consciousness works through the brain and, if the brain is damaged, has trouble expressing its true self. A disorder known as callosal disconnection raises some interesting questions about this theory.

The right and left hemispheres of the brain can be naturally (by a stroke) or surgically disconnected (this is done for patients with severe epilepsy to help with seizures). The hemispheres of the brain lose the ability to communicate with one another. These two hemispheres can gain a consciousness exclusive of one another. An interesting example is of a patient was asked what his ideal profession was. Verbally (a function of the left hemisphere), the man said draftsman. When asked to spell it out using blocks with his left hand (which is controlled by the right hemisphere), the man spelled "automobile race." It seems that, in the same person, there were two consciousnesses--one wanted to be a draftsman, the other a racer.
A more interesting (and, more frightening example) can be seen in alien hand syndrome. One recorded case is about a woman who came to her doctor because, every now and then, her left hand would try to strangle her to death. The doctor checked her for psychiatric disorders, but found no evidence of any. He theorized that if she had experienced a natural callosal disconnection in her brain, her right hemisphere might have suicidal tendencies and might be trying to act out on them (the right hemisphere cannot communicate verbally, and it has been shown that the left hemisphere is responsible for controlling most erratic behaviors). After she died of unrelated causes, the autopsy showed that she had, in fact, experienced a callosal disconnection. Subsequent cases have substantiated alien hand syndrome. (In another case, a man's left hand attacked his wife and he had to use his right hand to stop it.)

How can two consciousnesses (or "souls" for many theists) be explained within the same person? Is there a devil in one hemisphere and an angel in the other? Does the spiritual consciousness of one hemisphere go to heaven and the other to hell (assuming religious traditions believing in reward and punishment)?

Capgras syndrome has the unusual effect of causing a person to suddenly insist that a loved-one is an imposter. When a person meets someone else, they "start a file" on that person. The limbic system of the brain recognizes familiar faces and accesses emotional centers connected with those faces. If the face is that of a loved-one, the limbic system accesses positive emotional centers. If that limbic system is damaged, however, a person will recognize the familiar face, but will not have the same emotional connection with that face. They cannot believe that it is the same person. The brain starts another file for this person who looks like a loved-one but does not have a positive emotion associated with them.

Why can't this person's soul recognize his "soul-mate"? Why doesn't the spiritual consciousness hold on to this?

Phineas Gage had his ventromedial prefrontal cortex blown out in a dynamiting accident. Before the accident, he was a kind-hearted, reasonable, well-liked man. After the accident, though, he became mean-spirited and ill-tempered. The part of his brain that was damaged is the part that is believed to control normal decision-making and social skills.

Anecdotally, my brother-in-law knows a person that demonstrates signs of this syndrome. He knew a Christian man who was a very loving husband and father. After an automobile accident in which he sustained a head injury, he became both verbally and physically abusive to his wife and young children. The doctors and his family blamed the behavior on his head trauma. The injury, however, completely altered his personality. He was a different person after the injury.

Both cases raise difficult questions about the responsibility of any soul in so-called "sinful action." If Gage's spiritual consciousness existed outside of his mind, is that spiritual consciousness morally responsible for his post-trauma behavior? Is the Christian man now in sin because of his actions and his failure to live up to his wedding vows? He promised to love his wife until death, but now he hates her and denies that she is who she is. Further, if sin can be blamed on the brain and not the spiritual consciousness, can it be argued that all sin occurs because of the brain and the spiritual consciousness (if it existed) cannot be held responsible for any action?

Frontotemporal dementia in the right hemisphere of the brain has been shown to affect "food and dress choice, political ideology, social behavior, sexual preference, and [even] religion." Now, if a person is ultimately judged for the religion they choose, what are the ramifications if someone walks away from her religion because of a deterioration of her brain? Isn't this supposed to be a decision made by a person's consciousness/soul? Will they be judged because of a condition of their brain?

A Jesuit priest had a stroke that damaged the right hemisphere of his brain. After the accident, he lost the ability to have intense emotions. He joked when his parents told him that his sister had leukemia and he lost all of his passion for his ministry. His parents complained to the doctor, "That's not the way our son acted before he became sick . . . He now sounds like a robot."

Where is the priests "true self"? What happened to his spiritual consciousness?

"Mary" was a student at an Ivy-league school. During her first two years, she did extremely well. She was a devout Baptist who did not drink or sleep around. During her third year, however, Mary became belligerent to other people, started drinking heavily, and became very sexually active. She could not explain why her behavior had changed so dramatically. An MRI revealed that Mary had a tumor in the frontal lobes of her brain (the area of the brain that controls impulses). Almost immediately after the removal of the tumor, Mary's behavior changed back to what it was before.

Another man was a teacher who suddenly became obsessed with sex with minors. He was convicted on molestation charges. He said that he couldn't understand why he couldn't resist his impulses. An MRI revealed that he, too, had a tumor in the frontal lobes of his brain. After the removal, the man claimed that he no longer had the desire for aberrant sex acts. A few years later, though, the man started having headaches and began buying pornography again. He went to the doctor and an MRI revealed that the tumor had begun growing back.

A hard-working Baptist minister who had refused pay from his church (choosing, rather, to support himself so that the church could direct funds elsewhere) began showing up late for appointments, then skipping them altogether, then doing nothing but sitting in front of the TV even choosing to urinate on himself rather than go to the bathroom. An MRI showed that there was a tumor pressing on his frontal lobes. After the removal of the tumors, he began faithfully working again and living an active life.

If the spiritual consciousness exists, why does a tumor affect a person's identity so much? Who that person is is affected by his or her brain?

In summary, I argued that theists who believe in the existence of a spiritual consciousness face the difficult challenge of making room for it. If they believe agree that the brain can affect identity, personality, and behavior, then, it seems that the brain is the most natural and easiest explanation of all identity, personality and behavior. Adding the concept of a spiritual consciousness violates the principle of Ockham's razor. If, instead, the theist believes that a spiritual consciousness can affect the brain, but cannot be affected by the brain, then the spiritual consciousness would be much different than the consciousness of which the person is aware, and if the spiritual consciousness lived on, it would not be the same person. I, then, attempted to prove BD through case studies that demonstrate that the brain can affect identity, personality, and behavior.

After posting this in my former blog, I got this comment:

I think there are a few areas lacking in your post. First, you don’t address the problem of qualia . . . the fact that I thought that a painting is beautiful cannot be reduced to any physical fact about my brain and central nervous system (also another problem with qualia).

I responded (in part):

For those who have not done much study in the philosophy of the mind, qualia are the subjective experiences of things, the difference between "knowing about" something and "knowing" something. The classical example is of a fictional woman who had never experienced color (only black and white). She studies all about color and knows how they affect the brain, but until she actually sees a color, she does not really "know" it. This sujective knowledge (compared to objective knowledge) is a qualia.

Dualists often argue that this indicates that there is something non-physical in our consciousness, something that is beyond the brain. Two additional medical cases (also from ) may be relevent to this "problem":

Pain asymbolia occurs through brain damage and causes patients to lose all subjective responses (but not physical perceptions) of phenomena. The patient will know the difference between hot and cold, but will no longer have any subjective response to it. After having nerves in the brain surgically severed because of chronic, intense pain, one patient commented, "The pain is the same, but I feel much better now." The patient's subjective experience of pain was altered physically by a procedure on the brain.

Synesthesia is a condition that mixes the subjective experiences people have of things. One woman can actually taste different musical tones. Not only does she hear them, she also tastes them. She can distinguish between tones by taste.

Both of these examples show that there is a physical basis for qualia. Adding a spiritual consciousness is, again, multiplying necessities.

. . . [On beauty]

I have a friend who had a neurological condition that changed her tastes. Things that she enjoyed eating before, tasted terrible to her after. It certainly seems that the fact that she thought something tasted good could "be reduced to any physical fact about [her] brain and central nervous system."

I also think this is covered in my discussion of Capgras syndrome. This is the condition that causes people not to have the same emotional responses to familiar faces.

In Steven Pinker's How the Mind Works he discusses how art "tickles" parts of the brain so that the person enjoys them. Also, beauty can rely heavily on the senses (e.g. a person can have a poor olafactory response to say, wine, and not be able to distinguish between certain tastes that someone with a greater sense).

First posted 3/20/06