Dualism
Dualism, in philosophy of mind,
is the view that the mental and the physical, e.g. the mind and the body, are
fundamentally different kinds of thing. Though Dualism has an ancient heritage,
its modern versions largely owe their existence to Rene Descartes (1596 – 1650) who argued that the mind was a
different substance from the body. As the Stanford Encyclopaedia of Philosophy
puts it: “Descartes was a substance Dualist. He believed that there
were two kinds of substance: matter, of which the essential property is that it
is spatially extended; and mind, of which the essential property is that it
thinks.”[1]
The view that human beings are
not simply physical beings, but that they have a non-physical aspect is known
as Dualism. Dualists take the view
that human beings are composite beings with two parts: a physical body and a
non-physical mind. Some might go so far as to say that the mind was none other
than the soul and they would contend that the soul can survive the death of the
body, thus proving that the mind and the body are separate things. Dualism is
the most widespread viewpoint concerning the mind, and it is enshrined within
all of the major religions, all of which think of the mind as being something
that leaves the body at the point of death, thereafter moving on to some form
afterlife such as heaven or reincarnation.
Meanwhile, there are people who
deny the existence of a non-physical mind and instead believe that human beings
are simply physical beings, and this is called Materialism. Materialists
take the view that the mind is something physical, being composed of material
just like the other entities in the world; they may say that the mind is simply
the brain, or that the mind is brain activity, and therefore when a person dies
their mind ceases to exist. For a Materialist a mental state is simply a brain
state, it is electrical and chemical activity in the brain, something which can
(or will in the future) be explained through science. Dualists argue that a
purely physical being could not have a mind, meaning that something like a robot
could never be conscious; meanwhile, from a Materialist perspective human
beings are simply complex robots of blood, flesh, and bone.
The mind and the soul
There are many Dualist
philosophers who would say that the mind and the soul are one and the same
entity simply being described with two different terms. For these philosophers
the mind is the soul, it is the very essence of a person and it can survive
death. The belief that we have souls is of course a major feature of religion
also, in Christianity it is the soul that separates man from animals, and in
Hinduism the soul is regarded as actually being a part of Brahman (God) that
rests within us. Meanwhile a Materialist would say that the mind and soul were
not the same thing, for whilst the mind exists and is one and the same with the
brain, the soul does not exist and is a fiction; Gilbert Ryle famously mocked the idea of a soul as being “the ghost
in the machine.”[2]Dualism and Monism
Dualism takes the view that there are two fundamental kinds of thing, those which are physical and made of matter and those which are non-physical, such as the mind or soul. Materialism, meanwhile, takes the view that there is only one fundamental kind of thing, physical material, and it therefore can be described as a form of Monism (from the Greek word ‘mono’ meaning ‘single’). Interestingly, however, there is another monistic path that we can take, and that is to deny the existence of physical matter altogether and argue that everything which exists is non-physical. This was essentially the view of George Berkeley (1685 – 1753) who argued that what fundamentally exists is the mind, and that the things we experience are not physical objects out in a material realm, but rather, are like dreams or ideas in the mind, hence the term Idealism is given to this theory. Though the perspective is interesting and noteworthy it will not be discussed in this article, which will operate under the assumption that a physical world (and a physical body) does indeed exist.
Additional Note: Realism Vs Idealism
Since our perceptions of the world are in our minds there is the possibility that everything we experience is in fact an illusion in our minds, essentially a dream. After all, some people have dreams that are so vivid they honestly believe themselves to be awake and having genuine experiences. Rene Descartes considered the possibility that everything he saw might be just a dream, although in the end he dismissed the idea. Meanwhile George Berkeley came to the conclusion that reality really was a dream in your mind, and that there was no external world. Those who believe a physical world exists outside of the mind are called Realists, whilst those who believe the world is imaginary are called Idealists.
What is the mind?
The first task at hand is to
define the mind, something which is not easy to do because there is a great
debate as to what we should include and what we should not. Taken in a broad
sense the human mind consists of several different elements, such as your
perceptions, ideas and imaginings, dreams, memories, emotions, desires, and
your thoughts, although this may not be an exhaustive list.
Firstly there are your perceptions of the world which are
generated thanks to the many senses such as sight, touch, hearing, taste, smell,
balance, thermoception (heat), nociception (pain), and so on; contrary to
popular belief, there are far more senses than five! These perceptions of the
world are ever changing as new information comes to your senses.
It is tempting to think that when you
see an object such as a tree you are seeing the tree itself, out there in the
world, however, philosophers such as John
Locke (1632 – 1704) and many
modern scientists attest to the view that actually what you are perceiving is a
mental representation, something in your mind. A good analogy is with a photo;
with a photo we do not see the object itself, but a representation of it. The
eyes are like cameras which pick up light that bounces off the surface of objects
in front of us; this information is then transmitted to your brain and then a
representation of the object appears in your mind. Essentially, then, what you
experience is not the world itself, but a representation of the world, like
virtual reality in your mind. Your perceptions of the world are in your mind,
much like a dream, which raises the question of whether the external world is
really there at all or if life is all just a dream.
Next there is the imagination, which allows us to picture
things in our minds, things which may not necessarily exist; using our
imagination we can take old ideas learned from experience and play around with
them to construct new ideas. We can use our imaginations to help us solve mathematical
problems, or think of how to rearrange a room, or even the best way to cheer a
friend up. We can imagine what the past was like or what the future might be
like, or make up stories to entertain people with.
Dreams may be described as amongst the denizens of the mind, they
are similar to perceptions and appear to be creations of the mind based on
memories, emotions, imagination, and so on. These vivid imaginings are generally
experienced during sleep.
Next there are memories, we can recall things that we
have seen in the past and see them again in our minds, even if in a less vivid
manner, we can picture what we have seen or remember what a song sounds like
and play it back in our minds. Arguably what we are doing here is using our
imagination to reconstruct the past, and often people remember inaccurately.
Another aspect of the mind is our
emotions and desires; we feel happy or sad, or fearful, or angry; we desire
things such as food or the company of others, or the latest mobile phone, or to
do well at school, or to help people, or to hurt them. Also, we are averse to some
things, desiring to avoid them, for instance we generally want to avoid pain. These
mental experiences seem to control how we act, and can highly influence how we
interpret what we perceive, for example, we might find a painting beautiful or
ugly depending on our mood.
The final aspect of our minds
that we should look at is something which many philosophers have viewed as
being its most important aspect of all: thought.
The term ‘thought’ can be used in a broad sense to include imagining things or
picturing them in your mind, but most notably it takes the form of the internal
monologue of language where we can put our thoughts and ideas in to words and
go through them as if you were explaining them to another person verbally. We
are able to reflect on all manners of issues, we can categorise and define
things, we can use logic, reflect on our own place within society and history,
and we can understand what others think about us and why. Moreover we are able
to justify our actions with reasons and principles rather than just act on our
moods, impulses, and inclinations.
Additional Note: The problem of Solipsism
According to Dualism
something like a robot could not have a mind, it may act like it is
thinking and perceiving the world, but such mental experiences are not
possible for it. The lights are on but no one is home, nothing is going on
‘upstairs’ so to speak. However, can we really be sure that others have
minds? They may act like they are
having thoughts, but is this so?
Could it not be that they have no thoughts, no feelings, no
perceptions, but are just mindless physical machines acting like they have
minds? Maybe you personally are the
only person with consciousness and are ‘on your own’ (solo). This is the problem of Solipsism: how can
you actually know if others have minds like your own? If you think it is
obvious others have minds, then ask this: how do you know that your PC
doesn’t have a mind? If a character
in a computer game acts angry, how can you be sure that he isn’t?
According to JS Mill the only way we can
conclude that others have minds is through analogy; we see that they have
the same physical components as ourselves, and that they act the same way,
so we guess that they must have a mind just like us (like effects have like
causes, and their actions are like our actions). However, this is still
just an educated guess, not a proof of their sentience and consciousness.
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Different philosophers have defined the mind in different ways, including and excluding different elements from the above list. Plato (424 – 348 BCE) suggests that perceptions, emotions and desires are parts of the irrational body, but that thinking and imagination are parts of the rational mind, something only found in human beings.[5] This seems to be the line we are taking in common language when we talk about people going out and participating in ‘mindless’ violence because it seems that they are not thinking properly and rationally about what they are doing and the effects it will have, they are just going with the irrational whims and desires, perhaps like animals. For Plato the mind is primarily the intellect, it seeks knowledge and its true home is with the Forms, which in Plato’s philosophy are non-physical eternal truths; the body is like a prison for the mind confining it to the flawed world of the senses and physical things:
Plato... likens the body to a prison in which the soul is
confined. While imprisoned, the mind is compelled to investigate the truth by
means of the body... While encumbered by the
body, the soul is forced to seek truth via the organs of perception, but this
results in an inability to comprehend that which is most real [i.e. the Forms].
Scott Calef, Internet
Encyclopedia of Philosophy [6]
Descartes
thinks of the mind as being a single indivisible entity, the ‘self’ or ‘I’
which endures and stays the same throughout one’s existence. Whilst the
hallmark of physical things is that they are extended in space (having a size
and shape and mass); Descartes claims this is not true of the mind which has no
size or shape or weight. Physical things
have parts and can be divided, but according to Descartes the mind is ‘simple’
(without parts) and indivisible, as Scott Calef puts it “Descartes calls the mind a thing that thinks and not an
extended thing. He defines the body as an extended thing and not a thing that
thinks.”[8]
Other philosophers, such as David Hume (1711 – 1776), take a much
broader view of the mind and would say that perceptions, ideas, memories, and
emotions were all equally parts of the mind. Hume rejected the notions of an
‘I’ or ‘self’ instead seeing the mind as simply a bundle of ever changing
thoughts with no ‘self’ at the centre of it.
Another thinker of import here is Sigmund
Freud (1856 – 1939) who argued that the mind was actually split in to three
distinct parts, again rejecting Descartes’ notion that it is a single
indivisible unity.
Two arguments for Materialism / against Dualism
In modern philosophy Materialism
is the generally accepted view, although it is not without its problems and
critics. I will begin this section with two of the most powerful arguments in
favour of Materialism because these will help to fully explain the Materialist
position and account for its current popularity. After this I will explain the
various arguments for Dualism before returning to some more arguments in favour
of Materialism. Arguments on both sides have both strengths and weaknesses and
these will be explored.
1) The interaction problem
There is an obvious connection
between the body and the mind: first light enters my eyes (physical), and then
I see an image of a glass of milk in my mind (mental). Next there is a desire
to drink the milk (mental), which is followed by my hand reaching out and
grasping the glass (physical). Next the milk enters my mouth (physical) and
then I experience the taste in my mind (mental). The fact is that physical
events result in mental events, and that mental events result in physical
events; stubbing your toe results in pain and feelings of annoyance, and
thinking of a great idea results in picking up a pen and writing. There is a
clear interaction between the mental and the physical, yet Dualism seems to
make it totally unclear how this interaction can happen.
It is a principle of science that
all physical events must have physical causes. If the mind is physical then
what we have is a case of physical processes causing other physical processes,
much in the same way as one domino falling causes another to fall by hitting
it, or the way one snooker ball impacting on another will transfer the motion.
In these cases the cause and the effect have something in common, a similar
nature which allows them to interact. But how precisely can a non-physical
entity such as the mind cause physical events? How is it that by exercising
willpower in the mind I am able to make my hand move and draw a picture? To
consider how odd this really is, pick an item you can see that is out of reach,
such as a book on a shelf. Now concentrate really hard and try to will it to
move with your mind. You’ll find that it is not possible to levitate the item
remotely, and many of us would instantly rule it out as impossible, it seems to
call for some kind of odd magical power. And yet, somehow we are accepting that
the non-physical mind can exercise exactly the same form of control over the
physical body, mysteriously making it move by willpower alone. This defies any
explanation.
Descartes believed that the
pineal gland in the brain was the mind’s method of interacting with the body;
the mind controls the pineal gland and then the pineal gland sends out signals
to control the body. Descartes chose the pineal gland because it is in the
centre of the brain and is a single entity seemingly without parts, like the
mind is meant to be. But there is still no explanation of how the mind causes
chemical activity in the pineal gland.
In short, it seems obvious that
the mind and the body interact, but it seems impossible that a physical thing
could affect a non-physical thing and vice versa, therefore Dualism should be
rejected as it makes interaction (which clearly happens) impossible, or at the least
it leaves interaction unexplained as we can have no idea how interaction functions.
If Dualism is true then interaction is a mystery. Therefore, arguably, we
should conclude that the mind and body have the same nature, they are both
physical, thereby allowing interaction to be explained.
Some Dualists have turned to the
power of God in order to explain this seeming interaction, for example arguing
that the body and the mind interact through God’s will; this is called Occasionalism. Alternatively there is
the view that physical events and mental events do not actually share a causal
link, but just so happen to occur at the same time, so that body and mind are
not connected but are side by side; this is called Parallelism. These possibilities will not be discussed here since
they rest on divine power, which cannot be proven or disproven.[9]
Perhaps the strongest argument for the mind having a physical nature is that we can make correlations between thought and brain activity as measured by MRI scans. When we think of different things different parts of our brain become active, for example the centres associated with language and problem solving are in the left side of the brain. Complexes such as psychopathy, schizophrenia, addiction, and depression can be related to specific brain abnormalities. Though neuroscience is not yet fully developed, brain scans can tell us a lot about a person, for example, moral centres in the brain have been discovered in the orbital cortex and amygdala which are related to impulsivity and emotions; those with little or no brain activity in these areas characteristically lack empathy, are selfish, and are often immoral, many even becoming serial killers.[10] Steven Pinker is a Materialist and he argues that modern neuroscience has ‘exorcised the ghost’ of Dualism:
When a surgeon
sends an electrical current into the brain, the person can have a vivid,
lifelike experience. When chemicals seep into the brain, they can alter the
person's perception, mood, personality and reasoning. When a patch of brain
tissue dies, a part of the mind can disappear: a neurological patient may lose
the ability to name tools, recognise faces, anticipate the outcome of his
behaviour, empathise with others, or keep in mind a region of space or of his
own body... Every emotion and thought
gives off physical signals, and the new technologies for detecting them are so
accurate that they can literally read a person's mind and tell a cognitive
neuroscientist whether the person is imagining a face or a place...
The first hint
came from Phineas Gage, the nineteenth century railroad worker familiar to
generations of psychology students. Gage was using a yard long spike to tamp
explosive powder into a hole in a rock when a spark ignited the powder and sent
the spike into his cheekbone, through his brain, and out the top of his skull.
Phineas survived with his perception, memory, language and motor functions
intact. But in the famous understatement of a co-worker, “Gage was no longer
Gage.” A piece of iron had literally turned him into a different person, from
courteous, responsible, and ambitious to rude, unreliable and shiftless. It did
this by impaling his ventromedial prefrontal cortex, the region of the brain
above the eyes now known to be involved in reasoning about other people.
Together with other areas of the prefrontal lobes and the limbic system (the
seat of the emotions), it anticipates the consequences of one's actions and
selects behaviours consonant with one's goals.
Steven Pinker, The Blank Slate [11]
It seems that our thoughts are
dependent on brain activity, that just as digestion is dependent upon the
stomach, so too is thought dependent on the brain. The simplest explanation is
that the mind is a physical entity, and that when the brain stops working the
mind also ceases to exist; why do we need to posit a non-physical entity to do
our thinking for us when the physical brain can do the job? Dualist philosophers are not unaware that
thoughts and feelings are often associated with brain activity, but they do
deny that thoughts and brain activity are the same thing, for example, excitement
or fear will be accompanied by adrenaline in the brain, but a Dualist would say
that adrenaline is not itself excitement, adrenaline is a physical chemical
whilst excitement is a feeling; you can put adrenaline in a test tube, but you
cannot do the same for excitement.
Arguments for Dualism / against Materialism
There are many arguments in
favour of Dualism, though none of them are without their problems and it is not
possible to include every argument here. Descartes provides two very strong arguments
to the effect that the mind has different properties from physical things, and
therefore it cannot be a physical entity.
1) The body can be doubted, but not the mind
Descartes wished to determine
which things could be known with certainty and which could be doubted, so he
set about trying to doubt everything that he could. He found that he could
doubt many of the findings of science because sometimes observations can be
mistaken, but that he could not doubt a
priori knowledge such as geometry and maths, for example that 2 + 2 = 4 or
that a triangle must have three sides. One thing he considered was the
possibility that everything he saw with his senses was an illusion or dream,
perhaps from some malignant demon playing tricks on his mind. This made it
possible that all of the things he had seen and experienced were in fact
fabrications; perhaps the other people he saw and the buildings he had visited
were just chimeras in a dream. But this then made it possible that even his
body was an illusion too. There was only one thing that he could not be made to
doubt, and that was that he had a mind and was thinking. Therefore, he
concluded that the body and mind were separate things which could exist
independently of one another:
I will suppose
then, that everything I see is spurious. I will believe that my memory tells me
lies, and that none of the things that it reports ever happened. I have no
senses. Body, shape, extension, movement and place are chimeras... Am I not so bound up with a body and with senses
that I cannot exist without them? ... No: if I convinced myself of something or
thought of anything at all then I certainly existed... I must finally conclude
that this proposition, I am, I exist,
is necessarily true whenever it is put forward by me or conceived in my mind.
But I do not yet have sufficient what this ‘I’ is that now necessarily
exists... Thinking? At last I have discovered it – thought; this
alone is inseparable from me. I am, I exist, that is certain. But for how long?
For as long as I am thinking. For it could be that were I totally to cease from
thinking, I should totally cease to exist.
Descartes, Meditations on First Philosophy, Meditation II [12]
This long argument is often
summed up with the simple quote “I think therefore I am.” The essence of a
human being is their thoughts, without these we cease to exist; the body can be
separated from thought because we can imagine the body not being there at all
and yet the thoughts continuing. Similarly, we can imagine taking away this
specific body (brain and all) and instead placing my thoughts and consciousness
in to another body. It just might be that I am an alien with a ball of slime
for a body and that I am just dreaming I have arms and legs etc. Since body and
mind are conceptually separable they must be different objects entirely,
capable of independent existence, thus Descartes concludes “I am really
distinct from my body, and can exist without it.”[13]
However, Descartes’ argument is
riddled with assumptions which render it ineffective. We know that sight is
dependent on the eyes such that if a person’s eyes were removed they would see
nothing. Similarly, removing the stomach would take away feelings of hunger,
and removing the ears would render a person deaf. Descartes concludes that he
is not the same thing as his perceptions etc. and is in some way distinct from
them. Here Descartes has a point. But then Descartes asks us to imagine the
removal of the whole body, including the brain, and he believes that thought
would still remain without it. But a Materialist would reject this and say that
without the brain there are no thoughts, so without the brain Descartes’ would
no longer exist. Indeed, neuroscientists have removed parts of the brain or
seen the effects of brain parts being damaged, and the result is that parts of
a person’s consciousness are changed or removed entirely, as Steven Pinker’s
comments above explained. Descartes says that he can imagine existing without
his body, but he comes from a position of doubt and therefore of ignorance;
Lois Lane can imagine Clark Kent dying and Superman continuing to exist, but
this is only because she is ignorant of the fact that they are actually one and
the same person, in reality if one is removed, so too is the other, and a Materialist
would say the same counts for the brain and mind.
2) The mind is not extended in space and is indivisible
Descartes argues that the mind
and the body must be different substances because they have entirely different
properties; this is why he is called a substance Dualist. To quote Scott Calef,
“substance
Dualists typically argue that the mind
and the body are composed of different substances and that the mind is a
thinking thing that lacks the usual attributes of physical objects: size,
shape, location, solidity, motion, adherence to the laws of physics, and so on.”[14] Descartes argues that whilst physical objects
have dimensions in space and weight the same does not hold of thoughts, for
example, an apple may be 15 cm in circumference and weigh 200 grams, but the
same cannot be said of your thoughts of an apple in your mind. As Calef puts it
“although it makes sense to speak of the left or right half of the brain, it
makes no sense to speak of half of a desire, several pieces of a headache, part
of joy, or two-thirds of a belief.”[15]
Descartes explains the difference himself thusly:
There is a great difference between the mind and the
body, inasmuch as the body is by its very nature always divisible, while the
mind is utterly indivisible. For when I consider the mind, or myself in so far
as I am merely a thinking thing, I am unable to distinguish any parts within
myself; I understand myself to be something quite single and complete.
Rene Descartes,
Meditations on First Philosophy,
Meditation VI [16]
We
can say that the brain activity related to my desire to eat pizza is 8 cm away
from the brain activity related to my thinking about driving my car, but does
it make any sense to say that my thoughts of pizza are 8 cm away from my
thoughts about my car? Surely not,
surely it seems like these thoughts have no particular spatial relationship to
each other whatsoever, they are neither close to each other or far away, they
are both just there in the mind; the mind is without shape or dimensions. If the mind and the brain are the same thing
then surely what we say about one must also be true of the other, for example,
Cicero and Tully are the same person, so if Cicero was 6 feet tall then the
same must be true of Tully, and if Tully was a Roman orator then the same must
by true of Cicero; this is called Leibniz’s Law (if x = y, then what is true
about x is also true about y). But we can see this does not hold with the brain
and mind; statements about the brain are not always true about the mind; the
brain and body can be described in terms of dimensions, weight, and so on, and
the brain can be divided, but this does not seem to be the case with the mind.
Or again, a thought can be true or false, but a brain state cannot be true or
false, it just is. The implication is that the mind and the brain cannot be the
same thing because what is said about one cannot always be said of the other.
Materialist objection: the mind is divisible
According to Descartes the mind must be different from
the body because: (i) unlike the body, thoughts or ‘the mind’ cannot be
measured in terms of dimensions such as height, width, volume or weight; (ii)
the mind cannot be divided. These properties are essential to physical
material, so if Descartes is right then the mind seems not to be physical.
However, it might be argued that the mind is divisible, for
example, John Locke pointed out that
the stream of consciousness is divided by sleep when we become unconscious; the
only link to our past is memory, and memories can be forgotten or in some cases
imagined. Sigmund Freud argued that the
mind actually had three parts, one which was conscious, the ‘ego’ (which is
equivalent to Descartes’ mind), the other two which are subconscious, the ‘id’
and ‘super-ego.’ The id is a riotous collection of our uncontrolled thoughts
and desires, many of which are suppressed because of being socially unacceptable,
for example, violent and selfish urges, stressful memories, and sexual urges.
Meanwhile, the super-ego is the thoughts that have been forced in to our head
by socialisation, it is the moral conscience that battles with and suppresses
the id and forces us to think of others. The ego is merely the desktop of the
mind, it is the tip of the iceberg, the edited highlights.
Many people disagree with Freud’s psychology, but it can
still be quite forcefully argued that the mind is divisible. The mind appears
to be composed of a variety of different elements: there are thoughts,
perceptions, emotions, memories, imaginings, and dreams, and each of these has
its variations, for example we perceive thousands of different things via the
senses in any moment, filtering through it subconsciously and picking out the
most important details to concentrate on, and these perceptions change
constantly, as do our thoughts and emotions. As David Hume puts it, the mind is
“nothing but a bundle or
collection of different perceptions which succeed each other with an
inconceivable rapidity, and are in a perpetual flux and movement.”[17]
Just
as the brain has many parts it seems we can argue that the mind also has many
parts, and thus it is divisible. This does not necessarily mean that the mind
must be physical, perhaps non-physical things have parts too, but it does mean
that Descartes’ argument loses some of its force. However, Dualists can still
maintain that thoughts and feelings do not have extension or weight, and that
this makes the properties of the mind different from those of physical things. In
short, perhaps the mind is divisible, but we still cannot attribute dimensions
and weight to its parts, so it still does not seem to be a physical thing.
However,
Descartes could still argue that the mind is indivisible, because his
philosophy does not necessarily say that perceptions and thoughts and feelings
are part of the mind itself, rather, Descartes seems to be arguing that the
mind is the ‘self’ or ‘I’ which experiences these things. On this
interpretation, the essence of a person is the ‘thinking substance’ which
observes perceptions, creates thoughts and feelings, and so on. The thoughts
and feelings may be various, and they may come and go and change, but the ‘self’
is not, the self is an indivisible thinking substance. Think about the
Cartesian Theatre analogy again, the self is not the perceptions on the screen
or the noise from the speakers (etc.), it is the man sitting watching these
things and reacting to them.
But
again this view can be challenged, in particular by David Hume who claimed that
there is no such thing as the self. It is not the case that we have a self and
then we have the perceptions; when we introspect we find that there is no self,
there is no viewer of perceptions or thinker of thoughts, all we ever find is
the perceptions themselves and the thoughts themselves. And if we took all the
individual perceptions and thoughts away we would not be left with a self or
‘I’ that simply had nothing to think about, there would simply be nothing:
If any impression gives rise to the idea of self, that
impression must continue invariably the same, through the whole course of our
lives; since self is supposed to exist after that manner. But there is no
impression constant and invariable. Pain and pleasure, grief and joy, passions
and sensations succeed each other, and never all exist at the same time... For my part, when I enter most intimately
into what I call myself, I always stumble on some particular perception or
other, of heat or cold, light or shade, love or hatred, pain or pleasure. I
never can catch myself at any time without a perception, and never can observe
anything but the perception. When my perceptions are removed for any time, as
by sound sleep; so long am I insensible of myself, and may truly be said not to
exist. And were all my perceptions removed by death, and could I neither think,
nor feel, nor see, nor love, nor hate after the dissolution of my body, I
should be entirely annihilated... I may
venture to affirm of the rest of mankind, that they are nothing but a bundle or
collection of different perceptions, which succeed each other with an
inconceivable rapidity, and are in a perpetual flux and movement.
Hume
states that there is no ‘I’ or ‘self’ which perceives things, there are only
the perceptions themselves. We do not ever catch sight of some ‘self’ or
‘thinking substance’ which generates thoughts and ideas, thoughts just appear.
When we subtract all the contents of the mind, such as specific thoughts,
perceptions, and feelings we are not left with a bare ‘self’ or some ‘thinking
substance’ but instead we are left with nothing, a void. This is what a
dreamless sleep is like, and this is what Hume supposes that death is like.
Hume concludes that there is no indivisible ‘I’ or ‘self’ at the centre of our
minds, the mind is just a collection or ‘bundle’ of changing thoughts and
perceptions; this is now known as the ‘bundle’ theory of mind.
Again,
if the mind is divisible it takes a lot of the strength out of Descartes’ Dualist
argument, but it still might be the case that this mind ‘bundle’ composed of
many elements is non-physical. Hume’s thesis actually bears a resemblance to
the Buddhist theory of mind, anatman (meaning ‘no self’). Buddhists deny that
there is a changeless soul, and instead see the mind as a changing set of
desires and thoughts; these thoughts are non-physical and can be reborn in to a
new body, but over a lifetime the whole composition of the mind changes so that
between childhood and adulthood, and even day to day, nothing remains quite the
same. None the less, for Buddhists the mind is still non-physical, it is just
changeable.
The
Cartesian notion of a single indivisible consciousness has also been challenged
by brain science. In certain cases of
epilepsy it is necessary to cut the corpus callosum, the part of the brain
which links the two hemispheres. Experiments on people with a ‘split brain’ by
scientists such as Michael Gazzaniga
have actively demonstrated that consciousness can be split so that one part of
a person is aware of things, whilst another part is not. The right side of each eye’s field of vision
is wired in to the left brain, and the left side of each eye’s field of vision
is wired in to the right brain. If we show a picture to the left field of vision
the right brain becomes aware of it, but the person is unable to name what he
sees because the brain’s language centres are in the left brain. Some of these
experiments show direct evidence that one part of you can be aware of things
that the other part is not, and thus that the self can be split, as Brain King
explains:
In the experiment each hemisphere of a
patient was exclusively presented a picture, one of a snow scene and one of a
chicken’s foot; the patient was also shown (to both hemispheres) four picture
cards. The right hemisphere saw the picture on the left (the snow scene),
and the left hemisphere saw the picture on the right (the chicken foot).
Both hemispheres could see all [four] of the cards. They were asked to select a
card that would fit the picture and the left hand pointed to the right
hemisphere’s choice (a shovel) and the right hand pointed to the left
hemisphere’s choice. The patient was then asked why his left hand had had
chosen the shovel; but the left hemisphere which deals in words, listens to
language and interprets it and talks, did not know why the right hand
hemisphere had chosen the shovel as it had not seen the snow scene. So the left
hemisphere made up a story and claimed that it selected the shovel to clean out
a chicken shed.
Brian King, Arguing About Philosophy
In
this example, the left brain did not know why the right brain had selected the
shovel, demonstrating that consciousness had been split, so it is as if we have
a left-self and a right-self. Not only that, but the left brain lies, it does
not just say “I don’t know”, which is the actual answer, it invents a reason.
This seems to indicate that when we act we often do so on some kind of impulse,
and that our reasons and justifications are invented after the event, which has
implications in terms of freewill, and might also suggest that our thought
processes aren’t really controlling us, they are often something fabricated by the
brain somehow; a worrying thought for one such as Descartes who believed
thought to be the very crux of the mind! It seems that we must conclude against
Descartes’ view that the self is indivisible, and the evidence given strongly
indicates that the mind is heavily dependent on the brain. However, it is not
impossible that the mind is non-physical, for example, epiphenomenalism (discussed below) takes the view that the mind is
non-physical, but that it is generated by brain activity and dies when the
brain stops working.
Arguments for Dualism continued…
The arguments so far prevented
seem to suggest that Materialism has the upper hand because it has the weight
of science on its side in the form of neuroscience and brain scans, and also
because both of Descartes’ arguments have flaws. However, there are many other arguments
for Dualism which may be granted some strength and are worthy of consideration.
3) If Materialism is correct then we are just biological robots
According to Materialism human
beings are essentially complex arrangements of atoms, and our brains are like
complex organic computers. But if this is the case then it follows that it
should be theoretically possible to create a robot or computer that is self-aware
just like a human being is, a computer which can see, hear, experience
emotions, think for itself and so on, just like we do. Many people do not see
how this is possible, and therefore reject the possibility that we are just
biological robots.
Consider a watermill; it is a
machine made from wood, stone, and metal. Water is poured on a wheel with cogs
which then turns, communicating its motion down a shaft. This shaft turns
further cogs which transmit the circular motion to a pair of stones which grind
up grain. The idea that a watermill made of such materials could feel and think
seems laughable, how could it ever feel the coldness of the water coming in, or
have knowledge of its purpose, or feel indigestion when grain gets stuck in its
millstones? Now think of a computer’s
microchips, surely these are little different from the watermill, they’re just
smaller. Electric pulses enter the microchip, these then set off a complex
system of switches which are either on or off (this is how binary code works, 0
= off, 1 = on), eventually resulting in various beads of light on the computer
screen being activated to generate images. The idea that the computer knows
what it is doing, for example that it understands Pythagoras’ theorem or sees
the image it has just found on Google, seems every bits as unbelievable as the
idea of a millstone feeling indigestion. It seems impossible to understand how
a physical thing made of atoms, such as a microchip could produce consciousness,
and seemingly the same applies to the human brain; an individual cell can’t be
conscious, so how is it that a grouping of cells suddenly produces perceptions
and emotions and thoughts and awareness?
As Jerry Fodor puts it
“Nobody has the slightest idea how anything material could be conscious. Nobody
even knows what it would be like to have the slightest idea about how anything
material could be conscious.”[19] It seems impossible that microchips could be
conscious, so conscious robots seems to be an impossibility, but similarly it also
seems impossible that the neurons which make up the brain could be conscious,
so how can the mind be physical?
To see the
problem, consider what brain activity is. Electrical activity in one neuron
causes that neuron to discharge a certain chemical – called a neurotransmitter
– which seeps out to another neuron across what is known as a synaptic gap, which
causes the second neuron to fire, and so on. That, ultimately, is what brain
activity is. But how can this sort of thing add up to the feeling you get when,
say, you stub your little toe, or fall in love, or see your favourite team win?
Brain activity, that is, just seems the wrong sort of thing to add up to
consciousness.
However
sophisticated, a machine is still just a machine, and a mere machine cannot
see, or taste, or feel pain or anger, or fall in love. It may perform all sorts
of actions, but there is nothing going on ‘inside.’
Chris Horner and Emrys Westacott, Thinking Through Philosophy [21]
On the other hand, Materialists say that robots could
potentially have minds, and that human beings are indeed robots, it is just
that we are extremely complex, as Pinker puts it “the brain has a staggering
complexity – a hundred billion neurons interconnected by a hundred trillion
synapses – which is fully commensurate with the staggering complexity of
thought and behaviour.”[22] It may well be true that mere atoms cannot
have thoughts or feelings, but when we arrange things differently their
properties and qualities change, as for example carbon can be arranged as
graphite (which is black and brittle) or as diamond (which is clear and
strong). Silicone cannot do mathematics, but if we arrange it in to computer
chips then it can. Perhaps consciousness is an emergent property which comes in
to being when materials are arranged in the correct way; perhaps it is simply
the case that our current computers and robots are not complex enough yet?
Mark Rowlands points out that traditional computers are
only good for one thing – crunching numbers and symbols to produce a specific
outcome. He uses the example of Deep Blue, a computer so ‘intelligent’ that it
was able to defeat the great Gary Kasparov at chess. The problem with these
computers, which Rowlands nicknames ‘nerds’, is that they are very good at only
one thing and awful at anything else, including tasks that we would view as
simple such as walking across a room and picking up a cup of tea. All they can
do is follow orders written by human programmers, and real life is so complex
that we would never be able to create complex enough algorithms for a robot
with such a linear computer as its ‘brain’ to deal with even the simplest
tasks. For a traditional computer such as a PC to work out how to move a
robotic body and balance it correctly in order to walk up a small flight of
steps requires millions of calculations.
On the other hand, the fact that
a machine might be able to act like a human being is not a certain proof that
it actually has a mind like a human being. For example, we might watch two
people on a park bench together and see that they are holding hands, laughing,
staring longingly in to each other’s eyes, and so on, and we might assume that
they are in love. What we are doing here is inferring an internal and hidden mental
feeling to the people based on their external observable actions. But what if
one of them (or both) is pretending, and no such feeling is really inside them?
We can take this further and ask, what
if there’s nothing going on in there at all? Solipsism is the philosophical idea that you personally are the only person
with a mind, whilst others are blank and mindless, seeming as if they have
feelings and thoughts, but actually not having them at all. The human body
completes all sorts of operations, such as making your heart beat or releasing
chemicals to control digestion, and yet you have no awareness of these things
happening at all, they happen blindly. Why could it not be that all of a
person’s actions are like this – robotic and without awareness? Perhaps
computers would be like this – able to move and react to the world, but without
any mental phenomena occurring at all. After all, we don’t suppose that a speed
camera sees the cars it takes
photographs of.
Alan Turing (1912 – 1954) proposed a test to see whether a computer
was intelligent or not: a person communicates via messages with an unknown
other; if the person cannot tell whether he is talking to a computer or not
then we can say that the computer is as intelligent as a human being. The basic
principle here is “if it walks like a duck and quacks like a duck, then it’s a
duck.” In other words, if it can converse as a human does then it must
consciously understand as a human does. However, John Searle rejected this, pointing out that that we cannot
guarantee that the computer actually has genuine intelligence and understanding
rather than just being a mindless machine for shifting symbols. Imagine that
someone who speaks only English is sat in a room. At one end of the room is a
letter hatch, through which questions are posted, but these questions are
written in Chinese. The man cannot speak Chinese and does not understand the
symbols, however, he has a very very large manual to look in which shows him
explains to him in English which symbols to draw in response to the symbols on
the paper posted in to him. He draws these symbols out and passes them back
through the hatch. Surely anyone outside of the room would believe that the man
inside the Chinese Room understood and could speak Chinese, but we can see this
is not so, he is merely mimicking understanding. Similarly, the fact that a
computer might be able to hold a conversation with a human does not prove it
has a conscious mind, a genuine artificial intelligence, because it might just
be mimicking understanding by following symbols rather than understanding
anything. Therefore, the Turing test cannot show us whether a computer or robot
actually has consciousness.
For a Dualist the very
possibility that a purely physical being like a robot or computer could be
self-conscious is impossible, as consciousness is only possible through having
a non-physical mind, which a computer or robot cannot have. However, for a
Materialist it must be possible, at least in principle, to create conscious
machines. However, the discussion above shows us that even if a robot were to
act like a human and converse with us, this would not prove that it was
actually conscious because the computer could be mimicking understanding.
Technically we have the same problem with other human beings, we have no
certain way of knowing whether they are conscious too (this is the problem of solipsism).
On the other hand, it might be argued that robots have to be conscious in order
to do the things that they already do, for example, how could a robot like
Asimo possibly identify, categorise, and interact with objects without actually
seeing them?
4) Dualism is required for freewill
According to Materialism each
human being is entirely composed of physical matter. Science tells us that all
physical matter is controlled by strict laws of cause and effect, for example,
snooker balls do not choose where they end up but simply go where they are
directed by forces of motion. If humans are simply physical beings then it
seems that we too will be determined by strict laws of cause and effect, for
example, that human actions are determined by electro-chemical brain activity. The implication is that there can be no
freewill: human beings are not capable of choosing between different possible
actions and different possible futures, but rather, a single specific outcome
is determined by chemicals in the brain. It follows, therefore, that Materialism
is incompatible with freewill. The only possible way that human beings could be
immune to the causal laws of physics, and so possess freewill, is for us to
have some part of us which is non-physical, and so free from physical determinism.
Whether freewill exists or not is
something we cannot hope to answer here, but it can be argued that this is a
weak argument for Dualism because it relies on circular reasoning: this is when
we use A to prove that B is true, but we have to use B to prove that A is true,
and so we argue in a circle; this proves neither A nor B, but leaves both as unproven
assumptions. In this case we would be
presuming that freewill exists in order to prove that the mind is non-physical,
but at the same time we need to presume that the mind is non-physical to prove
that freewill exists. Before we can use freewill as evidence for the existence
of a non-physical mind we must first possess strong evidence for the existence
of freewill itself.
Moreover, the argument depends on
a logical fallacy; it states that since physical things are governed by
deterministic laws, non-physical things must be free from deterministic laws.
This is faulty reasoning, it is like saying “girls are governed by human
nature, boys are not girls, therefore, boys are not governed by human nature.”
It makes sense to say that non-physical things are not controlled by physical
laws, but there is still the possibility that they are governed by some other
set of laws, so Dualism does not guarantee the possibility of freewill anyway.
5) Dualism is required for an afterlife
According to Materialism a person
is simply a complex collection of atoms, and when we die it is because we, as
machines, are irreparably damaged; consciousness stops when the brain stops
working and after death the body simply decays. It seems that Dualism is
required in order for there to be the possibility of life after death as this
is the only way the mind could survive the dissolution of the physical body. If
we can prove that there is an afterlife, then this will be strong evidence that
the mind is non-physical; although we like the idea of there being an
afterlife, we cannot simply presume the afterlife and soul are real, we need
evidence first, otherwise we are again arguing in a circle.
Evidence for the existence of an
afterlife does exist, but its strength is often questioned. Religious people
may offer their religious texts as evidence of an afterlife, for example the
Bible states “many of them that sleep in the dust of the earth shall awake,
some to everlasting life, and some to shame and everlasting contempt.” (Daniel
12:2). Mediums claim that they are able to commune with the spirits of the dead
during séances and deliver messages to the living from their lost loved ones,
and there are numerous claimed sightings of ghosts. Some people claim to have
memories of their past lives, which appears to indicate reincarnation, and
there are several examples of children who have reported stories of previous
lives, and have even been able to demonstrate knowledge and skills beyond the
ken of ordinary children. For example there is the case of James Leininger who,
from a young age, was able to speak of his memories of being a World War II
fighter pilot; not only did he accurately describe some of the actions of a
pilot called James Houston Jr., but he
was also aware of technical information about second world war planes.
His parents claim he had no way of knowing these details, and therefore that
his memories must be genuine rather than made up. Lastly there are numerous
reports of people having Near Death Experiences (NDEs), in which they
experienced travelling down a tunnel of light, or even meeting religious
figures or dead relatives, before being rescued from the clutches of death. The
extent to which these pieces of evidence can be called reliable or compelling
is questioned by many philosophers, who take a sceptical approach to such
claims. For example, many scientists believe that NDEs do not demonstrate the
existence of any genuine afterlife, but instead show that the human brain is
susceptible to hallucinations when starved of oxygen, as is often the case when
close to death. Similar doubts can be raised about the other forms of evidence
given, which makes the argument from an afterlife dubious as strong evidence
for the existence of a non-physical mind or soul.
6) Materialism cannot account for Qualia
According to Materialism we are
biological robots, and this implies that we ought to be able to actually make
robots with consciousness like our own. Imagine that I were to create a robot,
and that the robot had pressure sensors on its metal skin. One day the metal on
its skin gets damaged in some way. The robot’s CPU analyses the data from the
pressure sensors and registers a change which indicates damage. The robot
travels to a local repair centre and has the damaged metal skin repaired. In a
sense what the robot has done is not too much different from what happens to
injured human beings, we have nerves which detect damage, then once we detect
the damage we might go to a hospital to get the problem sorted out, for example
having wound stitched up. According to a school of Materialism called Functionalism the robot has exhibited
that it has a mind because it has performed the same functions that a mind
does, e.g. registering the circumstances and taking the appropriate actions.
But surely something is missing from this account of what has happened to the
robot: surely the robot has not actually experienced any pain? Surely the robot will
have acted totally mindlessly without any awareness or feelings?
Qualia is the name we give to a
raw feeling, such as the taste of wine, the sight of the colour yellow, and the
feeling of pain. It seems clear that atoms do not have such experiences, for
example a table does not feel pain when it gets chopped in half with a saw. It
seems impossible that a mere physical machine like a robot could ever
experience qualia, and therefore this indicates that the mind must be
non-physical in order to have qualia experiences. The chemical constituents of
food and its effects on nutrition are purely physical qualities, but the actual
taste of the food is something mental which does not seem to be reducible to
physical properties such as chemical formulas. Though I may know all the facts
about sugar, such as where it is produced and how, and its chemical formula
(e.g. glucose is C6H12O2), none of these facts
capture the sensation of its sweetness when eaten.
The idea of qualia derives from
the work of Frank Jackson and his
‘what Mary didn’t know’ thought experiment. Suppose that Mary has spent her
entire life studying the scientific qualities of the colour red, for example,
she knows all about its frequency on the electromagnetic spectrum, and about
how the eyes and brain process visual information, and even about its cultural
connotations as being the colour of love, or indeed of war and bloodshed.
However, Mary has lived in an entirely black and white environment all of her
life, wearing monochromatic tinted glasses which effectively make her colour
blind. Surely if she were to take the glasses off and step out of her lab and
look at some sun ripened tomatoes or a Chinese flag, she would suddenly learn
something new: what red actually looks like – something which seemingly cannot
be reduced to physical qualities alone.[24] The conclusion from Jackson is that qualia
cannot be explained in purely physical terms and indicates something
non-physical in the makeup of the mind.
There is a famous thought experiment called ‘The Ship of Theseus.’ Theseus is the captain of a ship and he is sailing across the seas. Thanks to a variety of accidents, battles, and the general battering of the elements, various parts of the ship get damaged and have to be replaced. First a mast breaks, so the mast and sails must be replaced. Then a fire destroys the deck and this has to be replaced. Then a storm rips away the rudder and another repair must be made. Over ten years every last rope, sail, timber, and nail of the boat is replaced with new copies, so that none of the original is left. Furthermore, all of the crew have died off or left and been replaced, including the captain, who is now Theseus’ son, Theseus Junior. How is it possible to say that it is the same boat?[25]
There is a good case to say that
it is not the same boat at all, but is a totally new boat, a clone of the old
boat perhaps. After all, if I were to give a broom three new heads and two new
handles over a number of years we would say it was no longer the same broom,
and that the original was long gone, it is not the same object, it is not the
same collection of material. But here is the problem: according to Materialism
each person is nothing but a collection of atoms, but these change over a
person’s lifetime. Old cells die and are replaced by new ones; even your bones
are renewed over a period of time. After about 10 years nothing of the original
‘you’ actually remains; the human body is much like the boat. So how then can
you be the same person? Surely common
sense tells you that you are now the same person as you were when you were six,
but science tells us that the entire body of your six year old self is gone. So
seemingly, under Materialism you are not the same person as that six year old
‘you’, but instead you are like a clone of him, a copy with many modifications
(e.g. you are now bigger). Imagine, for example, that every year a part of your
body was removed and replaced by a synthetic robotic replica; surely there
would come a point when we would have to say that you were dead and all that
remained was a robot standing in your shoes?
Dualism purports to give us an
answer to this riddle: even though the whole physical body has changed, you are
the same person because you have the same mind or soul, this being something
which does not change but stays the same throughout life. If you are the same
person as you were 10, 20 or even 60 years ago, then this does seem to require
something that has stayed the same for all that time and has not changed, and
the soul seems a good candidate for this. In some religions there is a belief
in reincarnation, which means that your soul has come from the body of another
person, someone who has died. According to this belief you are the same person
as them, even though you have a different body from them, indeed you are the
same person even though you may have a different genetic code, personality,
race, class, gender, and no memories of that other life.
One suggestion to solve the
problem comes from John Locke, who states that you are the same person so long
as you remember being your younger self, but this can be countered with
examples of amnesia, or indeed false memories. Another suggestion is that you
are the same person so long as you have a continuous mental life (including
memories), a conception of yourself as being the same person as you used to be.
Julian Baggini asks us to imagine being
beamed to Mars using a ‘teletransporter’ device.[26]
The device scans your body structure, destroys the original, transmits the
blueprints to the destination, and reconstructs you from new materials on Mars.
You would feel like the same person, and remember being the person who just
left Earth, indeed, you would simply feel like you had just fallen asleep in
one place and awoken in another. Surely you would be the same person as the one
who stepped in to the device on Earth if you felt like you were and could
remember being them? But on the other
hand, Baggini considers, wouldn’t it actually be the case that you had just
been killed and a clone of you created elsewhere? Don’t we need the body in order to survive? And
yet how can that be true if the body slowly changes?
Derek Parfait discusses the issue of personal identity in depth in
his article Reasons and Persons, and
provides us with the following interesting thought experiment. Suppose that you
could cut a person in half down the middle (let’s call him Derek), and then use
some special machine to regenerate the missing halves, ending up with two
copies of Derek, each of which had one half of the original. It might be
tempting to ask which one is the ‘real’ Derek, but surely each one has an equal
claim in that matter. It might be tempting to say that both of them are Derek,
or that neither of them is Derek; to a large extent it depends how you
personally look at it, so it seems more a matter of opinion than truth. One
suggestion is that we should look on them both as ‘continuations’ of Derek:
Derek(1) is gone and has been replaced by Derek(2A) and Derek(2B). After all,
this is the case with institutions like sports clubs: old members leave and new
members come, and the buildings change, but it remains the same club over time
because we can see it has a continuing history, with the current organisation
having ‘grown out of’ the old institution. Perhaps this is the case with human
beings too, over time the old self is eradicated and it is replaced by a new
version that is a continuation of the old version rather than being the
identical same thing.
The question of personal identity
is perplexing because there are so many different options to take for how to
solve the problem, so the issue cannot be solved in this short space. Materialism
causes a problem for personal identity, because the body changes dramatically
over time, so the Dualist notion of a soul that stays the same is appealing.
But perhaps we need to accept that there is no enduring personal identity? Just
because a possibility is unappealing it does not mean that it is false.
However, Materialists are able to provide alternative explanations for personal
identity which do not require reference to an enduring and unchanging
non-physical mind or soul.
Arguments against Dualism, and for Materialism
Materialism is the position of
most philosophers in today’s world, however, there are various different Materialist
positions such as Behaviourism and Functionalism. To simplify the debate
this article will largely stick to the view that the mind is the brain, or
alternatively that the mind is brain activity.
3) The soul / mind is described in purely negative terms
Generally speaking, we come to
understand something by describing its qualities in positive terms, for example
we may describe a dog by saying that it is a mammal, that dogs
characteristically have four legs, hair, snouts with a good sense of smell, and
so on. On occasion it may be necessary to use negative terms, for example
saying that a blind man cannot see, but positive comments are generally most
helpful. However, with the Dualist’s mind or soul we do not find positive
descriptions at all, we are simply told that it is not physical, not extended
in space, that it is not controlled by the laws of physics, that it is not
mortal and so on; at no point are we given any positive indications of what the
mind or soul actually is. Though we are told that it is the entity which thinks
and feels we are told nothing about how it carries out these processes. We are
denied any frame of reference which might help us understand its nature. Mark
Rowlands explains this criticism thusly:
The mind has no
size or shape; has no mass, hence no weight; has no colour, smell, etc.; is not
made up of recognised physical particles such as atoms and molecules; does not
obey the laws of nature (such as, for example, the law of energy conservation).
One thing jumps
out here of course. This is a purely negative
attempt to explain what the mind is. But this is not to tell us anything about
what the mind is, it is simply to
tell us what the mind is not. It is
like trying to explain what a dog is by listing everything that a dog is not: not a rock, not a cat, not a cloud,
not a split-level ranch house, etc. Even if you were patient (and immortal)
enough to list everything in the universe that a dog is not, you still wouldn’t
have gone any way to explaining what a dog is to someone who did not know. And
so it is not clear that when the dualist tells us that the mind is a
non-physical thing he has said anything meaningful at all. It is not clear,
that is, that the dualist has any idea what he is talking about.
Mark Rowlands, The Philosopher at The End of The Universe [27]
The mind or soul is simply a
mystery, a ‘je ne sais quoi’ which we are denied any explanation or knowledge
of. Effectively then, by referring to a non-physical mind in order to solve
problems such as how qualia is possible we are not actually giving a genuine
solution, but rather, we are wrapping one mystery for another and pretending
that we have an answer. If this
criticism is correct then it could potentially show that the very word ‘soul’
is practically meaningless because essentially no one actually has a clue what
they are talking about when they use the word. Then again, the same can be said
for various physical concepts; we can explain what atoms are in terms of their
sub-atomic particles, such as electrons and protons, and we can explain these
in terms of being composed of quarks. What are quarks? They are like condensed
particles of energy? What is energy? Can it actually be defined? Many would
argue it cannot be, it is an abstract idea that we do not fully comprehend, much
like ‘the soul.’
4) The mind is a category mistake
According to Gilbert Ryle (1900 –
1976) the idea of a soul is a category mistake, a mistake that has arisen from
confusions in language. We use language to group things and categorise them as
being similar and different, however, it is often the case that we make
mistakes in doing so. In order to give an indication of what he means by a
‘category mistake’ Ryle uses the example of a university:
A foreigner
visiting Oxford or Cambridge for the first time is shown a number of colleges,
libraries, playing fields, museums, scientific departments and administrative
offices. He then asks ‘But where is the university?’ ... His mistake lay in the
innocent assumption that it was correct to speak of Christ Church, the Bodleian
Library, the Ashmolean Museum and the
University, to speak, that is, as if ‘the University’ stood for an extra member
of the same class of which these other units are members. He was mistakenly
allocating the University to the same category as that to which the other
institutions belong.
Gilbert Ryle, The Concept of Mind [28]
To explain, the foreign tourist
has made the mistake of thinking that ‘the University’ refers to a specific
building which he has not seen yet, whereas in fact ‘the University’ is a term
which refers to the collection of all the other buildings – the libraries,
laboratories, dormitories and so forth. He thinks it correct to speak of the
colleges, libraries, museums and the
University, whereas instead he should realise that the colleges, libraries and
museums are the University.
It is tempting to look at your
body and say “I can see my legs, and my arms, and my head, and my torso,
but where is the me that owns these
things?” Because of this we conclude that the ‘me’ or ‘self’ that owns these
things is another object separate from them, only one we can’t physically see.
Here the same mistake has been made as with the university, thinking that there
are the various body parts and then in addition there is the ‘person’ that owns
those body parts. Meanwhile, Ryle argues that this is a category mistake – it
is not a case of my arms, legs, head, torso and
me, but rather, my arms, legs, head and torso are me – ‘me’ is just the word we use for the collection of all
these parts. In short it is not a case
of ‘my body and me’ (two things) but
rather, ‘my body is me’ (one thing).
Thanks to this mistaken way of speaking about ourselves we have managed to
double count ourselves thinking that there is the body and then there is a
separate self, instead of realising that the body is the self – there is only one thing not two.
5) The idea of a soul is a product of history, when people lacked
science
If you have ever seen a dead
body, particularly one belonging to someone you knew, you probably found it an extremely
odd experience, one that was hard to comprehend. Every part of the person seems to be there,
they still have their heart and lungs and other organs and they weigh the same
amount; physically what you see is precisely the same as what was there when
the person was alive, and yet, something seems to be gone and missing... To look upon a corpse it very much seems that
something is absent, the personality has gone, and it is all too easy to
imagine that some animating force has somehow left the body leaving it motionless.
Because of this eerie experience it is easy to think of the mind or the soul as
being something that is non-physical and leaves the body at death.
Now, suppose that I were to send
an MP3 player back in time to ancient Rome or some similar place. People would probably
look at the machine and think that it had some kind of soul with in it that was
making it sing, indeed, they might even suppose it to be possessed by a demon.
Eventually the batteries would stop working, and surely these ancient people
would conclude that the device had ‘died’ and that its soul had moved on to
another place. Just as with the dead body it would look the same after it
stopped playing music as it had done before, no physical part would be missing,
so the assumption would be that something non-physical had left the device,
leaving it inactive and dead. But of course we know that this is not the case,
the device has no soul, it is simply broken and has stopped working.
The examples of the dead body and
the ‘dead’ MP3 player seem to be exactly parallel. Materialist could argue,
therefore, that human beings are just machines which unfortunately are liable
to break, and that the idea of a soul has come from misunderstanding what
happens at the point of death – wrongly assuming that some kind of animating
force has left the body, just as would happen with the MP3 player. If we can give a naturalistic suggestion of
how the idea of a soul could have mistakenly emerged then it seems to suggest
that the idea is indeed a mistake.
6) Where does the mind or ‘soul’ come from if it is not physical?
When a human being is created it
starts out simply as a single egg and a single sperm, things which we would not
accredit with minds, consciousness, or souls; it seems clear that sperm and eggs
are purely physical objects because they are merely single celled
organisms. When the egg is fertilised by
the sperm we again simply have a single celled organism, and yet somehow this
grows in to an adult who does have a conscious mind or soul. It can therefore be asked how this soul comes
to be: does the soul somehow grow too?
Is the soul implanted within the growing foetus by God (this view is
called ensoulment), and if so, where was this soul before it was placed inside
its physical host; did God create it afresh or does he have them stored up for
future use? Horner and Westacott help to
explain the various difficulties:
Dualists are
going to have to answer some pretty awkward questions in order to make their
theory work. When in the development of a human embryo does a mind become
attached to the body? How does this happen? Where does the mind come from? Does
it ever happen that the mind fails to attach itself? At what point in evolution
did minds first appear? How, and why, did this come about? Obviously the list
of difficult questions could be extended.
Horner and Westacott, Thinking Through Philosophy [29]
Another question that can be
asked is this: if we are machines of flesh and blood and we can somehow have
souls, then why could a machine of metal and wires (a robot) not also have a
soul within itself, and therefore genuinely have a mind just as a human being
does? Also, if amoebas do not have minds, but humans do, then does something
in-between like a mouse have a half mind or soul? These questions are
perplexing for Dualists, especially those of a non-religious variety who cannot
rely on God to plant souls within people. One solution would be to say that the
brain somehow generates the soul, so that as the brain develops the soul naturally
emerges, but if this is so then it would seem that the soul is dependent on the
brain and should stop or die when the brain stops working.
Has Dualism been defeated?
It may seem that Dualism has been
defeated and that the idea of a non-physical soul must be rejected; the
arguments for Dualism have floundered in various ways, and those for Materialism
seem largely to fit in with our modern scientific paradigm. However, Dualism
still flourishes in some philosophical circles, particularly in light of the
seeming inability of Materialists to explain how atoms can become conscious or
experience qualia. For this reason there are philosophers who support a
modified version of Dualism called epiphenomenalism.Both the Dualist position and the Materialist position have their strengths, but also their weaknesses. Materialism seems to be true because of the correlation between brain activity and our thoughts, but at the same time, arguably it is not clear how mere physical material can allow for qualia and consciousness, it might seem that a non-physical mind is needed for this. Meanwhile, Dualism seems unsatisfactory because of the interaction problem, which is also a threat to the laws of science, according to which physical events must have physical causes. Epiphenomenalism is an attempt at a compromise between the two positions, although in many ways it seems counter intuitive because it states that “mental states or events are caused by physical states or events in the brain but do not themselves cause anything.”[30] In other words, that your thoughts, desires, feelings, and even perceptions do not control or influence what your body actually does.
According to Epiphenomenalism the
body acts like an automaton, with brain processes governing bodily actions
unconsciously, meanwhile, the mind is non-physical and is generated by the
processes of the brain like a side effect. The mind does not control or influence
the actions of the body, it is merely a spectator. We may feel a desire for an
apple and then reach out to pick one up, or we may feel fear and then run away
from some kind of danger, but according to epiphenomenonalism these feelings do
not cause the actions, they just accompany them. Finally, when the brain dies
the mind dies too because there is no brain activity to generate the mind.
Consider the following diagram:
Figure A:
Physical stimulus, e.g. light into the eyes.
Which leads to:
Perception of an apple and desire to eat it.
and
Electrical and chemical activity in the brain.
Figure B:
Physical stimulus, e.g. light into the eyes.
Which leads to:
Electrical and chemical activity in the brain.
Which leads to:
Perception of an apple and desire to eat it.
and
Action of picking the apple up and eating it.
Figue A shows our ordinary conception of the
relationship between body and mind: first physical stimulus enters the body,
such as light going in to the eyes; next we have electrical and chemical activity
in the brain, but also we have mental phenomena such as perceptions of an apple,
which may be coupled with desires, such as the desire to eat the apple. Here is
where the mind-body problem truly comes from, because we seem to have two
things going on and it is not easy to see how they can be related, or how they
could both just be the one same thing. Finally these perceptions and brain activity will lead to an action such as
picking the apple up and eating it.
With epiphenomenalism, show in Figure B, we have a different series of events:
physical stimulus enters the eyes and sets off activity in the brain, and this
alone by itself can cause actions such as picking up the apple and eating it –
all of which could technically be done unconsciously and mechanically,
according to an epiphenomenalist. The primary effect of brain activity is action,
but as a secondary effect or side effect, it just so happens that we human
beings are conscious – that we are aware of what is happening, that we see and
feel and think. But we must not make the mistake of thinking that these mental
experiences are actually having any influence on our actions; feeling a desire
to eat an apple does not make your reach out and pick it up and eat it, this is
just an unnecessary accompaniment to the brain activity that causes the action.
A famous proponent of
Epiphenomenalism was Thomas Henry Huxley
(1825 – 1895), and it was he who first used the steam train analogy. Huxley
pointed to the example of a French soldier who had suffered severe brain damage
in the Franco-Prussian war as evidence that complex bodily movements could be
performed without consciousness, therefore suggesting that mental activity was
not necessary for physical actions, all that was needed was brain activity:
If the man happens to be in a place to which he is
accustomed, he walks about as usual; [...] He eats, drinks, smokes, walks
about, dresses and undresses himself, rises and goes to bed at the accustomed
hours. Nevertheless, pins may be run into his body, or strong electric shocks
sent through it, without causing the least indication of pain; no odorous
substance, pleasant or unpleasant, makes the least impression; he eats and
drinks with avidity whatever is offered, and takes asafœtida, or vinegar, or
quinine, as readily as water; no noise affects him; and light influences him
only under certain conditions.
TH Huxley, On The Hypothesis That Animals Are Automata,
and Its History [31]
The evidence suggests, although
it does not completely prove, that the injured soldier was unconscious whilst
performing these actions and therefore that his actions were controlled by the
brain alone without the presence of a mental life. A mental life, therefore, is
merely a bonus rather than an essential part of our lives. On the other hand,
perhaps we might respond that the man’s consciousness was merely limited or
restricted rather than totally absent, for example, perhaps he was able to see
his environment and therefore he could dress and smoke, and so on, but the part
of his brain relating to pain was damaged so that he did not react to it simply
because he did not feel it, much as a deaf person will not react to sounds in
the environment around him. However, there are various things our bodies can do
without mental awareness, such as digestion, keeping the heart beating, and
homeostasis, so it might be asked why action needs conscious thought,
especially if we are just repeating patterns of behaviour encoded in our DNA or
learned from experience.
Further evidence seems to come
from the experiments of Benjamin Libet. Test subjects were asked to press a
button when they felt the urge to do so; they should not plan when to press the
button or hesitate, but press it as soon as they felt the urge to act. There
was on average 0.2 seconds between the test subjects feeling the volition to
act and then subsequently pressing the button. At the same time Libet scanned
and monitored their brain activity, and it was shown that there was a surge in
brain activity in the motor cortex an average of 0.5 seconds before the button
was pressed. This seems to show that there is a 0.3 second gap between the
brain making the decision to push the button and the person becoming
consciously aware of it. This would suggest that it is not our conscious mind
which is making decisions, but instead they are made unconsciously without us
realising it. Not only does this have implications in terms of freewill and
determinism, it seems to show that the conscious mind is indeed an after effect
of non-conscious brain activity. It seems that our brain concocts the feeling
of having a will that chooses our actions, as Daniel Wenger puts it:
The unique human convenience of conscious thoughts that
preview our actions gives us the privilege of feeling we wilfully cause what we
do. In fact, unconscious and inscrutable mechanisms create both conscious
thought about action and the action, and also produce the sense of will we
experience by perceiving the thought as cause of the action.
Daniel Wegner, The Illusion of Conscious Will [32]
Meanwhile, many scientists and
philosophers believe that the conclusions from Libet’s tests should not be
drawn yet as there are many possibilities and many more experiments to be
undertaken. Regardless of the ambiguity of this evidence, Epiphenomenalism
seems to be the only option to take so long as we wish to maintain Dualism
within a scientific age which sees everything as governed by mechanistic
physical laws, as Sven Walter explains:
Epiphenomenalism can be regarded as the inevitable result
of the attempt to combine a scientific naturalism with respect to the body with
a dualism with respect to the mind. Human beings are exhaustively governed by
physical laws so that no non-physical causes must be invoked to explain their behaviour,
but since they are also subjects of non-physical minds, these minds must be
causally irrelevant. Whenever our trust in the causal authority of the physical
is overwhelmed by our first-person experience of ourselves as creatures with an
essentially non-physical mind, epiphenomenalism is waiting in the wings.
Sven Walter, Epiphenomenalism [33]
Problems with Epiphenomenalism
There are very few philosophers
who agree with Epiphenomenalism, not least because it is decidedly counter
intuitive. According to Alec Hyslop Epiphenomenalism is unacceptable because it
means that our conscious self – the mind – is merely ‘piggybacking’ on a body
which it has no control of, which means that we lose all sense of ourselves.
The conscious part of us, the part which seems most important, is in fact an
irrelevant addition which makes no difference to the actions of the body that
carries it around: “Epiphenomenalism would be the
ruin of the self and that self’s life... Our supposed self is illusory, and we
are deluded... We lose ourselves when consciousness ceases to be effective in
what we chose.”[34]
However, the fact that something is
counter intuitive or unpalatable does not mean it is not true.
Another
argument is that we experience mental causation, for example, we have a chain
of thoughts in our minds, such as the different thoughts you might have whilst
trying to come up with a story to write. You draft and redraft it in your mind
until you get it right and put pen to paper. Surely it seems that only after we
have pictured a possible storyline in
our minds that might we decide to accept or reject it and so write it down or
modify it? Hence our mental life seems
to be necessary to decision making and thinking processes, they seem not to be
able to be done by the unconscious brain alone. But this again does not prove
that Epiphenomenalism is false because according to the Epiphenomenalist the
brain is indeed capable of thinking processes by itself, all our mind
experiences is a view of what is happening.
Another
argument against Epiphenomenalism comes from the evolutionary perspective; all
animals seem to be conscious to one extent or another, but if having a
conscious mind is unnecessary for performing actions and they can be performed
blindly and without consciousness, then we can surely ask why evolution
happened to produce creatures that have minds, after all, what practical use
would they have? One possible response
would be that sometimes two traits are interlinked, for example, a polar bear
can only have a warm fur coat by also happening to have a heavy coat which
slows it down, so perhaps similarly it just so happens that the brain set up we
need to survive just so happens to produce consciousness, so its existence is
just coincidental. The extent to which this is a satisfactory answer is
disputed.
Epiphenomenalism,
then, is a coherent theory in the logical sense that it does not contradict
itself or any other known facts, this means that it might well be true. The
central problem in discussing Epiphenomenalism is that the world would
seemingly look exactly the same if it were true as it would if it were false,
so there is no way of telling whether it is true or not. Many simply reject it
because they feel that it is an unnecessary theory and that it is far simpler
to just stick with Materialism, after all, Epiphenomenalism offers no real
answers to the problem of how consciousness is generated by the brain, it
merely states that it is indeed generated by the brain, and that it is
non-physical.
[1] Howard
Robinson, Dualism, in The Stanford
Encyclopaedia of Philosophy, http://plato.stanford.edu/entries/Dualism/ (accessed 13/09/11).
[2] Gilbert Ryle,
The Concept of Mind, ch.1.
[3] cf. JK
Rowling, Harry Potter and The Half-Blood
Prince.
[4] cf. The
Simpsons, Bart Sells His Soul, series
7, episode 4.
[5] cf. Plato, Phaedo,
which discusses Plato’s views on the immortality of the soul.
[6] Scott Calef, Dualism and Mind, in The Internet
Encyclopaedia of Philosophy, http://www.iep.utm.edu/Dualism/ (accessed 13/09/11)
[7] Rene
Descartes, Meditations on First
Philosophy, Second Meditation,
translated and edited by John Cottingham, p.19, Cambridge University Press
(1996)
[8] Scott Calef, Dualism and Mind, in The Internet
Encyclopaedia of Philosophy
[9] cf. Scott Calef, Dualism and Mind and Howard Robinson, Dualism for information on occasionalism and parallelism.
[10] Horizon, Are You Good or Evil?, BBC 2, broadcast
Wednesday 7th September 2011.
[11] Steven Pinker,
The Blank Slate, Penguin Books
(2003).
[12] Rene
Descartes, Meditations on First
Philosophy, Second Meditation,
pp.16 – 18.
[13] Rene
Descartes, Meditations on First
Philosophy, Sixth Meditation,
p.54.
[14] Scott Calef, Dualism and Mind, in The Internet
Encyclopaedia of Philosophy.
[15] Scott Calef, Dualism and Mind, in The Internet
Encyclopaedia of Philosophy.
[16] Rene
Descartes, Meditations on First
Philosophy, Sixth Meditation,
p.59.
[17] David Hume, A Treatise of Human Nature, book 1, part
4, section 6, Of Personal Identity: http://ebooks.adelaide.edu.au/h/hume/david/h92t/B1.4.6.html (accessed 20/09/11).
[18] David Hume, A Treatise of Human Nature, book 1, part
4, section 6, Of Personal Identity
[19] Jerry Fodor, The Big Idea: Can There Be A Science of The
Mind?, in The Times Literary Supplement, July 3rd 1992.
[20] Mark Rowlands,
The Philosopher at The End of The
Universe, Ch.3, Terminator I & II
and the Mind-Body Problem, p.59.
[21] Chris Horner
and Emrys Westacott, Thinking Through
Philosophy, p.63.
[22] Steven Pinker,
The Blank Slate, Penguin Books
(2003).
[23] Mark Rowlands,
The Philosopher at The End of The
Universe, Ch.3, Terminator I & II
and the Mind-Body Problem, p.81.
[24] cf. Frank
Jackson, Epiphenomenal Qualia, in
Philosophical Quarterly 32 (1982), pp. 127 – 136.
[25] cf. Julian
Baggini, The Pig That Wants To Be Eaten
and 99 Other Thought Experiments, No. 11, The Ship Theseus, pp. 31-33.
[26] cf. Julian
Baggini, The Pig That Wants To Be Eaten, No.
2, Beam Me Up..., pp. 4-6.
[27] Mark Rowlands,
The Philosopher at The End of The
Universe, Ch.3, Terminator I & II
and the Mind-Body Problem, pp. 67-68.
[28] Gilbert Ryle, The Concept of Mind, pp. 17-18, Penguin
Books, (c) 2000.
[29] Horner and
Westacott, Thinking Through Philosophy,
p.64.
[30] Sven Walter, Epiphenomenalism, in The Internet
Encyclopedia of Philosophy, http://www.iep.utm.edu/epipheno/ (accessed 10/11/11).
[31] TH Huxley, On The
Hypothesis That Animals Are Automata, and Its History, quoted in Sven Walter, Epiphenomenalism.
[32] Daniel Wenger,
The Illusion of Conscious Will,
quoted in Sven Walter, Epiphenomenalism.
[33] Sven Walter, Epiphenomenalism.
[34] Alec Hyslop, Methodological Epiphenomenalism, quoted
in Sven Walter, Epiphenomenalism.
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