Originally written November, 2008
Consciousness
stands alone today as a topic that often leaves even the most sophisticated
thinkers tongue-tied and confused. And, as with all of the earlier mysteries,
there are many who insist -- and hope -- that there will never be a
demystification of consciousness. –Daniel Dennett
It is no surprise that many
theists are not fans of evolutionary theory, and it is not hard to understand
why. If the scientific view of earth's history is correct, the entire basis of
Christianity, and reason that Jesus had to die on the cross (sin), is rendered
as nothing more than mythology.
However, many theists are
able to square the circle of biology with Christian theology. Many point out
(and I would agree) that evolution does not disprove the existence of God. In
my mind, it just disproves the traditional monotheistic religions.
As someone who is
interested in cognitive science, philosophy of the mind and consciousness, I
have always found it odd that such topics are met with resistance from theists.
I have never understood why this was. What is so scary about the brain?
Upon reflection of this
issue, I recently came to realize what the threat of cognitive science was to
theology. God is defined as an immaterial mind. Christianity teaches that each
person has an immaterial mind -- a soul that will survive death. That is, our
mind, our awareness, and our consciousness survive after our bodies have
perished.
The threat from cognitive
science is this: If the mind and consciousness are found to just be products of
a physical brain, that means that not only does our mind/consciousness not
survive bodily death, but that God (an immaterial mind) does not exist either.
If everything mental requires something physical, an immaterial God (who is a
mind) cannot exist.
In this blog post, I will
attempt to show you that theism has no hope of surviving modern cognitive
science. I will not be attempting to explain consciousness in general. But I
will argue that what we already know about the brain
does not leave any room for the immaterial or the supernatural. There is no
soul which can survive our bodily death, and the idea of God being an
immaterial, disembodied mind is completely impossible.
Split-Brain Patients
Many people suffer from
epilepsy. A select few of these people suffer from seizures that are so severe,
that the only thing that will relieve them is to have the neural pathway that
connects the left and right hemisphere, the corpus callosum, cut. When this
pathway is severed, electricity from each hemisphere can no longer be passed
back and forth, and the seizures stop. However, the pathway is also the only
way to get information from one hemisphere to the other. Because of this, there
are very strange effects that occur as a result.
For example, if you were to
whisper into the left ear of one of these people, and say "my favorite
fruit is an apple" and then whisper into the right ear, asking "what
is my favorite fruit?" the person will have no idea! But if you return to
the left ear and quietly ask "what is my favorite fruit?" the person
will answer "apple."
Now this comes as no
surprise, since information cannot be passed between the two hemispheres.
However, it also turns out that both hemispheres do not always agree with each
other. If you ask one side "do you prefer chocolate or vanilla?" one
side may say chocolate, and the other might say vanilla. One side might prefer
blondes, the other brunettes. And interestingly enough, in one case, one side
believed in God, and the other did not!
The point is that when you
cut the brain in half, you then have someone who has two spheres of
consciousness—two minds, separate from each other. So if someone has two
spheres of consciousness as a result of their brain being cut in half, we have
to ask: is this something we would expect to see if the mind was a result of
the physical brain, or if the mind was immaterial? Obviously, this only makes
sense in light of the fact that the brain is not controlled by an immaterial
mind. If it were, then there is no reason for there to be two spheres of
consciousness, or two minds, when the brain is cut in half. Physically changing
the brain should have no effect on something immaterial.
This, in my opinion, is the
nail in the coffin for theism. Looking at this evidence, there is no doubt that
the mind is completely a product of the physical brain. But to drive the point
home, let's go through some more examples, and then counter the one (and only)
argument theists have against this.
Brain Damage
There is a certain part of
the brain that control your ability to recognize faces. If this part is damaged,
your ability to recognize faces no longer exists. This disorder is called
prosopagnosia. Recognizing faces is definitely part of our consciousness, and
losing that ability undoubtedly renders one aspect of our consciousness
inoperative.
So are we to believe that
when part of the brain is damaged, we can't recognize faces, but if the brain
is completely destroyed, we float through a bright tunnel, and are able to
recognize grandma?
If you have damage to the
language part of the brain, often times you will suffer from what is called
aphasia. People who have suffered such brain damage have all sorts of strange
problems regarding speech and language. In some cases, people are unable to
comprehend language. In others, they are unable to name certain objects, other
times they can no longer read, sometimes they cannot write. In some cases, when
trying to speak, instead of saying "the dog needs to go out, so I will
take him for a walk" they might say "You know that smoodle pinkered
and that I want to get him round and take care of him like you want
before." These people have no idea that they are engaging in such a thing,
and become frustrated when no one can understand what they are trying to say.
Language is an enormous
part of our conscious experience. It is how we communicate, and it is how we
think. People who have not been exposed to language have very limited abilities
in regards to abstract thinking. So language is a hugely important aspect to
our consciousness, and suffering from aphasias wipes that aspect of ourselves
out.
Another part of the brain
controls your body image. I don't mean how you feel about yourself, but the
model of your body that your brain uses to figure out where your body stops,
and everything else begins. If this area is damaged, the person feels
disconnected from their body (stimulation on parts of the brain can also induce
out of body experiences). People have suffered damage to this part of the
brain, which then causes very strange results to occur. One patient went as far
to state that his own leg was actually a severed leg that someone had put in
his bed, and was not his own! Your body image, the ability to recognize that
your hand is your own hand, and control it, is obviously part of your conscious
experience-- part of your mental world. And if damage to that part of the brain
occurs, part of your consciousness is destroyed.
Other parts of the brain,
if damaged, render you unable to process things on the left (or right) field of
vision. This is simply called hemispatial neglect. With neglect, not only do you not see
anything to the left side of the field of vision, but you become completely
unaware that it even exists. People have this problem won't eat food on the
left side of the plate, won't shave the left side of their face, are unable to
turn left, etc. The entire left (or right) side of the universe is no longer
exists for them.
Of course, your ability to
recognize and comprehend the world (not just the left or right side), is part
of your conscious experience-- part of your mental world. And if damage to that
part of the brain occurs, part of your conscious awareness is gone forever.
Most people know that there
are specific parts of the brain that store certain types of memories (visual,
auditory, etc). Likewise, there is an area in the back of the brain, the visual
cortex, which processes all of the information that is received through the
eyes.
In one case, a man had
damage to both the visual cortex, as well as the part of the brain that stored
his visual memories. So not only did he lose his vision, he lost his visual
memories—memory of anything he had ever seen. So he went blind, and had no
idea! As a result, he no longer understood what was meant by "light"
or "color". He couldn't comprehend it, since, as far as he was
concerned, he had never had any experience vision in the first place.
Your perception of the
world is made up mostly from your experience with it (your memories). All of
these past memories help create the conscious experience that you currently
have. But if such memories, as well as the ability to see are taken away, you
lose a very large part of your conscious experience in the world.
There are many other
examples of this sort, but with these few, a pattern has started to emerge. The
people that have suffered such brain damage have lost part of their
consciousness. But why? If we have a soul or immaterial mind that is
responsible for these things, like consciousness and memories, then there
should be no problem. But if consciousness is a result of the brain, then isn't
this exactly what we would expect? Absolutely!
Anesthesia
Now, if we were to
anesthetize you with halothane (a form of general anesthesia), you wouldn't be
able to move. You wouldn't even be able to wiggle a finger. Why not? If your
brain is responsible for moving your limbs, this makes sense. But if your
immaterial mind is responsible, then why is your arm unable to be moved? Why is
your immaterial soul/mind being affected by something physical--anesthesia?
If immaterial minds are all
that are needed for consciousness, and immaterial minds able to affect physical
objects (like brains), then what is the point of a brain to begin with? Our
brains are big, heavy, and biologically expensive. They are delicate, take a
lot of energy to run properly, and are easily damaged. If it weren't for modern
medical science, many women would die giving birth to babies with enormous
heads.
If the brain was only
around to run things like the heart and lungs, that would be a good argument
for the existence of an immaterial mind. If there was no evidence that our
brains stored memory, or ran all the programs necessary for us to perceive and
understand the world around us, theism might have a chance. But modern brain
imaging techniques have tied literally every thought and emotion to neural
activity. Literally everything your mind does has a neural correlate.
Counter Argument
The only argument that
exists in response to this type of argument follows as such: The brain is like
a television, whereas the mind/soul is the signal. Sure, you can fiddle with
the knobs on the TV, which will change the color, brightness, etc. But that
doesn't change the signal that the TV receives. And if you unplug the TV, that
doesn't mean that the signal still isn't out there.
Likewise, the brain can be
fiddled with, changing our perception of the world. You can even turn off the
brain, but that doesn't mean that the mind/soul does not continue to exist. While this argument is
clever, it fails on multiple counts.
First of all, it completely
ignores the first line of evidence I presented. Sure, tweaking with TV knobs
will change the picture, but will cutting the TV in half create two separate
signals? Not a chance. So already, that example takes care of the attempted
counter argument.
Secondly, it doesn't
explain what the purpose of a giant brain would be. If the immaterial mind can
somehow control the physical brain, which then controls the body, why not skip
the middle man and leave the brain out of it?
Thirdly, it presumes that
an immaterial entity has causal power in the material world. This has been a
problem for theists for centuries. And to this day, there is absolutely no
explanation on how such an event could possibly occur.
There are many other
objections to this counter argument, and many other examples of consciousness
being eclipsed by damage to certain areas of the brain. But I think it is safe
to say, that while consciousness on a whole may still be a mystery, it is no
mystery that it is purely a result of our brains. When we die, our brains
decompose, and all of our memories and experiences, everything that made us who
we are, die as well.
And since immaterial minds
cannot exist independent of a physical brain, it is safe to say that the
immaterial mind in the heavens, God, cannot exist either.
- God is a conscious, immaterial
mind.
- Conscious, immaterial minds exist
independently of physical brains.
- A change in a physical brain will
change the conscious mind.
- Therefore, conscious minds are not
immaterial or independent of physical brains, and an immaterial mind (such
as a soul or God) cannot exist.
To wrap things up, here are
a few quotes by some of the very top neuroscientists and philosophers of the
mind around...
It never ceases to amaze me
that all the richness of our mental life, all our feelings, our emotions, our
thoughts, our ambitions, our love life, our religious sentiments, and even what
each of us regards as our own intimate, private self, is simply the activity of
these little specks of jelly in our head, our brain. There is nothing else. –V.S.
Ramacahndran
All mental processes, even
the most complex psychological processes, derive from operations of the brain. –Eric
Kandel
Modern neuroscience has shown that there is no
user. "The soul" is, in fact, the information-processing activity of
the brain. New imaging techniques have tied every thought and emotion to neural
activity. And any change to the brain—from strokes, drugs, electricity or
surgery—will literally change your mind. –Steven Pinker
There's a scientific consensus that hard-core
dualism, which says that people can think without using their brain or that
memories will survive the death of your body, is just flat mistaken. Your
mental life is a product of your brain. –Paul Bloom
There is something approaching a consensus among
philosophers and cognitive scientists: no immaterial mind/soul makes any sense
at all. –Daniel Dennett
No dualist has ever been able to give an account
of how a brain can affect a mind, or how a mind can affect a brain. Dualism,
for most philosophers today, is not a real option. –John Searle
All conscious states are caused by brain
processes. There aren’t any exceptions. Every single conscious state is caused
by brain processes. –John Searle
