Tuesday, April 28, 2015

Do Humans Have a Soul?

In my previous 3 posts, I’ve provided evidence that religiosity and spiritual experiences are not based on supernatural forces, and free will is merely an illusion. Given this information, is there still room for an immaterial soul? Based on the best available evidence regarding brain functioning, there is no reason to believe anything akin to the human soul exists.

The Mind and Body

The Catechism of the Catholic Church defines the soul as the “subject of human consciousness and freedom; soul and body together form one unique human nature.”[1] In other words, theists believe the mind is controlled by the soul, which is separate from the body (brain). Studies have shown the belief in this mind/body distinction is present in infants and young children, suggesting it is innate.[2] However, just because we naturally feel that our thoughts and personalities exist outside of our bodies does not mean this view is accurate.

http://www.viewzone.com/whoyou.top.jpgBrain Damage

If our minds, consciousness, and ultimately the essence of our true selves are based on supernatural forces outside of our physical bodies, then no amount of brain damage should alter a person’s character. However, this is far from the truth. In fact, families and friends of individuals with traumatic brain injuries often use the word “stranger” to describe them.[3][4] Those who experience damage to their frontal or temporal lobes, amygdala, and/or hippocampus often experience agitation, volatile emotions, memory impairment, verbal and physical aggression, and impaired impulse control.[5] In one of the most famous cases of brain damage, railroad foreman Phineas Gage had an iron rod driven through his skull damaging his frontal lobe.[6] His physician noted that “He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint of advice when it conflicts with his desires, at times pertinaciously obstinent, yet capricious and vacillating, devising many plans of future operation, which are no sooner arranged than they are abandoned in turn for others appearing more feasible. In this regard, his mind was radically changed, so decidedly that his friends and acquaintances said he was ‘no longer Gage’.”[7]

Alzheimer's Disease

Anyone who has ever known someone with dementia can understand the effects a brain disorder can have on a person’s character. On top of memory issues, Alzhemier’s disease (a form of dementia) can lead to moodiness, paranoia, compulsivity, decreased agreeableness, and decreased conscientiousness.[8][9] My grandmother had the disease for many years, and there is one event that always sticks in my mind as evidence that she was fundamentally changed. While she was always a very kind and loving person, she was never one for physical affection. In fact, I cannot think of any time in which she offered someone a hug or a kiss. However, when I visited her in her assisted living facility at a time in which her Alzhemer’s left her confused but not incapacitated, she greeted me with a kiss on the cheek. While this gesture may seem insignificant to most, it came as quite a shock to me since it was so out of character.

http://static.someecards.com/someecards/usercards/MjAxMy00MzliNTZmODM1NGZjMmJj.pngThe Seat of Consciousness

As one Christian blogger put it, “consciousness seems to point to an immaterial self that observes the physical world.”[10] However, Neuroscientist Antonio Damasio would beg to differ. He believes he has isolated the mechanisms behind this seemingly mystical phenomenon, and has broken it down into 3 levels of “self”:[11]

  • Protoself: “[It] corresponds to a gathering of information regarding the state of the body. It is constructed in the brain stem and it generates feelings that signify our existence. The protoself is the necessary foundation of the overall self, and in its absence one cannot be conscious”
  • Core Self: “It is constructed in a dialogue between the brain stem and a few parts of the cerebral cortex. It yields a sense of the ‘here and now’, devoid of historical perspective. It gives us a consciousness of the moment.”
  • Autobiographical Self: “[It] creates the more or less coherent picture of our history, a narrative with a lived past and an anticipated future. The narrative is culled from real events, from imaginary events, and from past interpretations and re-interpretations of events. Identity emerges from the autobiographical self.”

Given that the cerebral cortex is responsible for much of our advanced cognitive functioning, it makes sense that it would be involved in consciousness.[12] However, the brain stem is much less of an obvious player in the phenomenon, since it is merely a primitive structure tied to automatic life supporting functions.[13] In his TED video entitled “The Quest to Understand Consciousness” Antonio explained that damage to the upper portion of the brain stem leads to coma and a complete loss of consciousness, or as he put it “you lose the grounding of the self and you no longer have access to the feeling of your experience.”[14] On the other hand, when the lower portion of the brain stem is damaged, paralysis and not a loss of consciousness is the result.[15] Thus, our “self” is ultimately tied to this particular region in our brain stem.


As the same Christian blogger I referred to earlier stated “Although a neuroscientist may have more knowledge of my brain states than me, he can never achieve a greater knowledge of my mental life than me, for only I have access to this.”[16] For the time being, the blogger is quite correct. However, scientists have started to develop technology that may lead to the ability to read people’s thoughts. For example, researchers at Cornell University used fMRI scans to discern which of four imaginary people their subjects were thinking about.[17] In another study at UC Berkeley, scientists were able to reconstruct movie clips that subjects had viewed using an fMRI scanner and a software program that pulled 18 million seconds of random YouTube videos.[18]


Given that our personalities and even our sense of self can be irreversibly altered by damaging parts of the brain, and since scientists have already begun developing mind-reading technologies, there seems no reason to believe that our minds exist outside of our bodies. Thus, if the human soul is synonymous with our minds and the core of our selves, its existence is highly improbable.


Great video “Antonio Demassio: The quest to understand consciousness”

Fascinating paper regarding our innate dualistic beliefs

Good article about dealing with a family member that has severe brain damage

Another article about family members with brain damage

1 comment:

  1. >If our minds, consciousness, and ultimately the essence of our true selves are based on supernatural forces outside of our physical bodies, then no amount of brain damage should alter a person’s character.

    The problem is that according to St Thomas, the immaterial part of the soul is only the intellect. Your imagination, visual replay, and so on are entirely material. But the intellect cannot function without the material senses, and so the immaterial intellect, by itself, is not the person but is only an incomplete part of that person.