Subjects covered in the fnal test – consciousness
Descartes theory on the relatonshii between conscious mind and body
Rene Descartes came up with a theory called Cartesian dualism, which is the best-known version of
dualism. He wanted to base his philosophy only on frm foundatons that were beyond doubt. He
concluded that a certain kind of the thinking self (I think, therefore I am) was not material, like the
physical body that moves about mechanically and takes up space. In his view, the world consists of
two kinds of stuff the extended stuf of which physical bodies are made and the unextended,
thinking stuf of which minds are made.
Descartes’ theory is a form of substance dualism, which can be contrasted with property dualism or
dual aspect theory. According to property dualism, the same thing can be described using mental
terms or physical terms, but one descripton cannot be reduced to the other. This theory avoids the
need for two diferent substances but leaves open many questons about the relatonship between
the physical and mental propertes, and therefore comes in many diferent versions.
The insuperable problem for substance dualism is how the mind interacts with the body when the
two are made of diferent substances. For the whole theory to work the interacton has to be in both
directons. Thoughts and feelings must be able to inluence the physical stuf. Descartes supported
that the two interacted through the pineal gland in the centre of the brain, but proposing a place
where it happens doesn’t solve the mystery.
Your mind sends electric signals and your body has hydronic processes. The languages between the
mind and body would be diferent, but they would communicate through tny things in your mind
that translates one thing to the other and vice versa.
Materialist aiiroaches to consciousness
Amongst the monist theories, some claim that the mental world is fundamental and others that the
physical world is. You can either think that for example pencils don’t actually exist (being a mentalist)
or that there is only mater (being a materialist). Materialism includes identty theory, which makes
mental states identcal with physical states, and functonalism, which equates mental states identcal
with functonal states.
Some people fnd materialism unatractve as an theory of consciousness, because it seems to take
away the very phenomenon, subjectve experience. The powerful feeling we have that our conscious
decisions cause our actons is reduced to purely physical causes. There is also difculty of
understanding how thoughts and feelings and mental images can really be mater when they seem to
be so diferent. Materialism makes it hard to fnd any way of talking about consciousness that does
justce the way it feels. They avoid problems by ignoring/denying the queston of how mind and brain
are related.
In materialism, only mater exists. Regarding identty, the brain is the mind. Regarding functonalism,
brain states are mental states.
Qualia
In philosophy, private qualites are known as qualia.
The term qualia is used to emphasize quality; to get away from talking about psychical proportons or
descriptons and to experience itself. A quale is what something is like. Conscious experience consists
of qualia, and the problem of consciousness can be rephrased in terms of how qualia are related to
the physical world, or how objectie brains produce subjectie qualia. The substance dualist believes
that qualia are part of a separate mental world from physical objects. The epiphenomenalist believes
,that qualia exist but have no causal propertes. The idealist believes that everything is ultmately
qualia. The eliminatve materialist denies that qualia exist, and so on.
Dennet says qualia don’t exist. He doesn’t deny the reality of conscious experience, or of the things
we say and the judgements we make about our own experiences, but only of the special, inefable,
private, subjectve ‘raw feels’, or ‘the way things seem to us’, called qualia.
Dennet provides many ‘intuiton pumps’ to undermine this very natural way of thinking. It may be,
as said by philosophers, that it is difcult to deny the existence of qualia, but we should try because
‘contrary to what seems obvious at frst blush, there simply are no qualia at all’.
Qualia do not have physical propertes that can be measured. We can, however, do thought
experiments (experiments done in the head).
Mary, the color scientst
Imagine Mary, who knows everything about colours, but has only seen black and white. One day she
gets to see colours, and she feels what colours are like the frst tme. Or does she already know what
they are like?
As said by Chalmers, no amount of knowledge about, or reasoning from, the physical facts could have
prepared Mary for the raw feel of what it is like to see a blue sky or green grass. In other words the
physical facts about the world are not all there is to know, and therefore materialism has to be false.
There have been lots of other conclusions to this thought experiment. You can also deny that Mary
will be surprised. With an alternatve ending to the story, Mary gets a blue banana from the
experimenters. She would than tell them that that is not possible, because she knows eierything
about colour vision and she already knows exactly what impressions yellow and blue objects would
make on her nervous system, and exactly what thoughts this would induce in her. In this case, she
knows all the physical facts.
If you believe that Mary will be surprised when she comes out, then you believe that consciousness,
subjectve experience, or qualia, are something additonal to knowledge of the physical world. If you
think she will not be surprised then you believe that knowing all the physical facts tells you
everything there is to know – including what it is like to experience something.
Philosoihers’ zombie
Imagine someone exactly like you, with the only diference that this creature is not conscious. There
is nothing it is like to be this creature. There is no view from within. No consciousness. No qualia. This
is the philosopher’s zombie.
In zombie world, the whole populaton consists of zombies, who talk as well. They might be able to
talk about sleep and dreaming because they have learned to use the words appropriately, but they
would not have the experiences of dreaming as we do. This is the same for terms like think, believe
and imagine.
For zombie philosophers, the problem of other minds, or the way we agonise about qualia and
consciousness, would make no sense. This way, their philosophy would end diferently from ours.
Even though they are individually indistnguishable from conscious creatures, they would stll show
the mark of zombiehood at the level of culture. At this level, consciousness is not inessental – it
makes a diference.
Since zombies are defned as being indistnguishable from conscious humans they must be truly
indistnguishable. If their philosophy, or the terms they invented, were diferent, then they would be
distnguishable from us and hence not count as zombies. If you really follow the rules, there is
nothing lef of the diference between a conscious human and a zombie.
Now imagine a more complex zombie, who also monitors its own actvites, including even its own
internal actvites’, a zimbo. A zimbo is a zombie that, as a result of self-monitoring, has internal (but
,unconscious) higher-order informatonal states that are about its other, lower-order informatonal
states. The zimbo would (unconsciously) believe that it was in various mental states – precisely the
mental states it is in positon to report about should we ask questons. It would think that it was
conscious, even though it isn’t. This is how Dennet came to the conclusion that we’re all zombies. He
meant that we are complex self-monitoring zombies – zimboes – that can talk and think about
mental images, dreams, and feelings.
Milner & Goodale on the relatonshii between conscious ierceiton and acton
There is a dissociaton between fast motor reactons and conscious percepton. An explanaton for
this is that the two are based on entrely diferent systems in the brain.
Milner and Goodale (1995) suggest a functonal dissociaton between two vision systems and map
this onto the two neural streams in the visual system; the ventral and dorsal streams. These have
been ofen described as being concerned with object vision and spatal vision respectvely; the ‘what’
and ‘where’ of vision. Instead of this theory, Milner and Goodale argue for a distncton based on two
fundamentally diferent tasks that the brain has to carry outf fast visuomotor control and the (less
urgent) visual percepton. They call these the iision-for-acton and iision-for-percepton systems.
Global Worksiace Theory of Baars
The GWT was frst explicated by Bernard Baas (1988) and subsequently used as a framework for
future research and for computatonal modelling. Baars proposed that the cognitve system is built
on a global workspace or blackboard architecture, analogous to a stage in the theatre of the mind.
Unconscious processors compete for access to the bright spotlight of atenton that shines on the
stage, from where informaton is broadcast globally to the unconscious audience. It is this global
broadcast that consttutes consciousness.
According to Baars, consciousness is a supremely functonal biological adapton. It is a kind of
gateway; a facility for accessing, discriminatng and exchanging informaton and for exercising global
coordinaton and control. He lists nine functons for consciousness and describes it as ‘essental in
integratng percepton, thought, and acton, in adaptng to novel circumstances, and in providing
informaton to a self-system’. He rejects the idea that consciousness has no causal role in the nervous
system.
On this theory, actons that are performed consciously are shaped by conscious feedback while
unconscious experiences are not. The GWT claims that any ‘piece of informaton’ is conscious if it is
broadcast widely to many areas of the unconscious brain. Conscious actons are those that achieve
access to the global workspace and are broadcast to a large audience.
GWT describes how integraton and global control of actons may be achieved in a complex brain, but
not why global availability is equivalent to subjectve experience. It is not clear whether
consciousness is supposed to be the cause or the result of access to the GW.
The conceit of a “Cartesian Theatre”
David Hume (1711-1776) came up with the idea to describe the mind as a theatre.
If you can think about what it feels like to be you right now, you may be conjuring up what Dennet
(1991) calls the Cartesian Theatre. This means we seem to imagine that there is some place inside
‘my’ mind or brain where ‘I’ am. This place has something like a mental screen or stage on which
images are presented for viewing by my mind’s eye. In this special place everything that we’re
conscious of at a given moment is present together and consciousness happens. The ideas, images
and feelings that are in this place are in consciousness and all the rest are unconscious. The show in
the Cartesian Theatre is the stream of consciousness and the audience is me.
Dennet entrely rejects Cartesian dualism. He argues that many of who say to be materialists
, implicitly stll believe in something like a central place or tme where consciousness happens and
someone to whom it happens. He calls this belief Cartesian materialism (CM) and defnes it as ‘the
view that there is a crucial fnish line or boundary somewhere in the brain, marking a place where the
order or arrival equals the order of ‘presentaton’ in experience because what happens there is what
you are conscious of’.
You believe In the CT if you believe in some kind of metaphorical space or place or stage within which
conscious experiences happen and into which the ‘contents of consciousness’ come and go. You are
a Cartesian Materialist if you also believe that consciousness is not separate from the brain and so
there must be some brain basis for this theatre of mind where ‘it all comes together’ and
consciousness happens.
Dennett’s multile-drafs theory
Dennet aims to get rid of powerful intuitons.
Dennet proposes his multple drafs theory. eerceptons, emotons, thoughts and all kinds of mental
actvity are accomplished in the brain by parallel, multtrack processes that interpret and elaborate
sensory inputs, and are all under contnuous revision. eerceptons and thoughts are constantly
revised and altered, and at any point in tme there are multple drafs of narratve fragments at
various stages of editng in various places in the brain.
When you ask yourself which ones are conscious, you are imagining a Cartesian Theatre in which
some drafs are re-presented for the audience to see. Dennet calls this the ‘myth of double
transducton’, where you show something again for the beneft of consciousness. On the multple
drafs theory discriminatons only have to be made once. There is no ‘self’ who has some of the
experiences and no ‘central meaner’ who understands them. There are only multple drafs being
edited all at once.
According to Dennet, you don’t have the actual experience of something happening. Contents arise,
get revised, afect behaviour and leave traces in memory, which then get overlaid by other traces and
so on. This process produces various narratves which are single versions of a porton of the stream
of consciousness, but we shouldn’t make the mistake of supposing that there are facts about which
contents were conscious and which were not at the tme. You won’t know what you actually
experienced when something happened.
Concerning the audience, Dennet argues that when a porton of the world comes to compose a
skein of narratves, that porton of the world is the observer. The observer is a ‘Center of Narratve
Gravity’. As contents are fxed by probing the stream at various points, as we make judgements and
as we speak about what we are doing of what we have experienced, so the benign illusion is created
of there being an author.
According to this theory, there are no fxed facts about the stream of consciousness independent of
partcular probes, so it depends on the way the parallel stream was probed. When someone asks you
what happens during a moment, you probably recall the most recent thing that happened and say
you’re conscious of that moment.
The multple drafs theory is a radical way of completely replacing the idea of a theatre and its
audience. It deals with subjectvity by throwing out a lot of the assumptons that we make about it.
Dennet says it’s wrong to conclude you’re at any point conscious of what you are experiencing at
that moment. Dennet doesn’t explain consciousness, but he explains it away. According to him,
experience can be electrochemical happenings in a brain.
Dennet’s theory is difcult to understand, because to understand his theory you throw away a lot of
your usual habits of thought concerning your own consciousness. Dennet denies there is an answer
of the queston ‘Am I conscious now?’
