Afternoon. You have the lot, architecture,
layout, design, all the features you want with the house, and the funds to pay
as long as you sell your present home. The papers are signed and money
deposited where needed. Now it is up to the City of Westerville to okay the
blueprints which will be created, hopefully, this week. Sometime in November
you will have a meeting with your construction manager/foreman a few days
before they break ground and building begins. The proper papers were electronically
signed last night and you drove up and gave your second deposit to M/I this
morning. After saying hello to Kim and leaving a full box and several bubbled
paintings and prints for storage you had lunch at Max and Erma's then headed
home. - Amorella
1624 hours. So far everything is working better than planned. I take it
this is a good sign. It is going to be rather pleasant taking a break from all
the determined physical aspects of the plan and contents and the paper
work that goes with it. I love the way M/I plans and ratios the fuller aspects
of their community of homes. The ratios of house sizes and accompanying lots,
the community spacing for a natural protected area and small ponds -- the
dimensions are good. Our area has smaller homes and the lots are smaller but
nothing appears crunched or army barracks-like in the process. The area appears
to me as small village of about seventy homes dropping from the top of a hill
of once pasture down to a natural ravine area below. The street from the
entrance drops to the bottom of a hill of larger homes with medium lots to
continue up the hill to its north where it connects with an east-west road at
the top where we and others are located then drops down half way from the top
and returns to the main entrance road that drops to the right then back up the
hill with the larger homes where it connects with the main entrance of
Sanctuary on the Lakes at the north-south Africa Road. Aesthetically, looking
down from the entrance the smaller homes appear as a small village set in an
early time, a village of homes without a main street of the usual village shops.
I like it. The ratios of the larger homes on top of the entrance side of the
hill are connected to a well-constructed golf course. But as the smaller homes
are well built to compliment the larger home settings, there is a sense of
smaller but worthy of the connection. It is a very good design to give an area
to mostly older, retired people who have given up their larger homes because
they don't need them anymore. Retired people many of whom still like to be
closely connected to the country and golfing than the urban small town areas
less the four or five miles away. We don't play golf but we don't mind those
who do. We will enjoy the several thickly wooded parklands within a mile or two
at Alum Creek Reservoir. And, we are less than five miles from Uptown
Westerville and 'our' Alma Mater, Otterbein. I am getting more excited with the
prospects each month. The area of Franklin and Delaware Counties was a good place
to grow up and get an education in and it seems to me to be a good place for a
natural exit. That's my hope. (1658)
You surprise yourself with these thoughts. You've
a Neo-classic mind stuck with a sensory system leaning to the Romantic. Post. -
Amorella
1702 hours. You are a likeable twist to my way of viewing the world. I
am glad we are friends, my spiritual Amorella.
You
had ice water plus a bowl of black beans three well sliced turkey dogs mixed
with a dollop of ketchup for supper. Carol had a turkey sandwich on flat bread.
You watched NBC News, "Madam Secretary" and the first of the season's
"NCIS.LA". And, you have two questions about my recent comment on who
I am. - Amorella
2141 hours. First, you always emphasis "the" before Amorella,
why? Second, you are a spirit "beside" my own. My first thought is
that you are as a doppelgänger, I realize this is incorrect by definition but
it appears in this recent context that we are equal since we are
"beside" each other. This is not acceptable because seven and some
years of blog evidence shows you are above or beyond my sense of
heartansoulanmind. Besides, you are not a 'trinity' built spiritual format are
you? I am confused. You have always shown a consistency of being from my
perspective of a one-dimensional conscious-like form. (2152)
I, "the" Amorella, am a unique
spiritual being; being within your own heartansoulanmind as well as without. I
do not define one dimensional because from your perspective I am
non-dimensional. I am not a form. I am a nonphysical consciousness.
2212
hours. The definition below is better than the definition of consciousness I
have used previously from Wikipedia
** **
Consciousness
Explaining the nature of consciousness is one of the most
important and perplexing areas of philosophy, but the concept is notoriously
ambiguous. The abstract noun “consciousness” is not frequently used by itself
in the contemporary literature, but is originally derived from the Latin con(with) and scire (to
know). Perhaps the most commonly used contemporary notion of a conscious mental
state is captured by Thomas Nagel’s famous “what it is like” sense (Nagel
1974). When I am in a conscious mental state, there is something it is like for
me to be in that state from the subjective or first-person point of view. But
how are we to understand this? For instance, how is the conscious mental state
related to the body? Can consciousness be explained in terms of brain activity?
What makes a mental state be a conscious mental state? The problem of
consciousness is arguably the most central issue in current philosophy of mind
and is also importantly related to major traditional topics in metaphysics,
such as the possibility of immortality and the belief in free will. This
article focuses on Western theories and conceptions of consciousness,
especially as found in contemporary analytic philosophy of mind.
The two broad, traditional and competing theories of mind
are dualism and
materialism (or physicalism). While there are many versions of each, the former
generally holds that the conscious mind or a conscious mental state is
non-physical in some sense, whereas the latter holds that, to put it crudely,
the mind is the brain, or is caused by neural activity. It is against this
general backdrop that many answers to the above questions are formulated and
developed. There are also many familiar objections to both materialism and
dualism. For example, it is often said that materialism cannot truly explain
just how or why some brain states are conscious, and that there is an important
“explanatory gap” between mind and matter. On the other hand, dualism faces the
problem of explaining how a non-physical substance or mental state can causally
interact with the physical body.
Some philosophers attempt to explain consciousness directly in
neurophysiological or physical terms, while others offer cognitive theories of
consciousness whereby conscious mental states are reduced to some kind of
representational relation between mental states and the world. There are a
number of such representational theories of consciousness currently on the
market, including higher-order theories which hold that what makes a mental
state conscious is that the subject is aware of it in some sense. The
relationship between consciousness and science is also central in much current
theorizing on this topic: How does the brain “bind together” various sensory
inputs to produce a unified subjective experience? What are the neural
correlates of consciousness? What can be learned from abnormal psychology which
might help us to understand normal consciousness? To what extent are animal
minds different from human minds? Could an appropriately programmed machine be
conscious?
The concept of consciousness is notoriously ambiguous. It is important
first to make several distinctions and to define related terms. The abstract
noun “consciousness” is not often used in the contemporary literature, though
it should be noted that it is originally derived from the Latin con(with) and scire (to know).
Thus, “consciousness” has etymological ties to one’s ability to know and
perceive, and should not be confused with conscience, which has the much more
specific moral connotation of knowing when one has done or is doing something
wrong. Through consciousness, one can have knowledge of the external world or
one’s own mental states. The primary contemporary interest lies more in the use
of the expressions “x is conscious” or “x is conscious of y.” Under the former
category, perhaps most important is the distinction between state and creature
consciousness (Rosenthal 1993a). We sometimes speak of an individual mental
state, such as a pain or perception, as conscious. On the other hand, we also
often speak of organisms or creatures as conscious, such as when we say “human
beings are conscious” or “dogs are conscious.” Creature consciousness is also
simply meant to refer to the fact that an organism is awake, as opposed to
sleeping or in a coma. However, some kind of state consciousness is often
implied by creature consciousness, that is, the organism is having conscious
mental states. Due to the lack of a direct object in the expression “x is
conscious,” this is usually referred to as intransitive consciousness, in
contrast to transitive consciousness where the locution “x is conscious of y”
is used (Rosenthal 1993a, 1997). Most contemporary theories of consciousness
are aimed at explaining state consciousness; that is, explaining what makes a
mental state a conscious mental state.
It might seem that “conscious” is synonymous with, say,
“awareness” or “experience” or “attention.” However, it is crucial to recognize
that this is not generally accepted today. For example, though perhaps somewhat
atypical, one might hold that there are even unconscious experiences, depending
of course on how the term “experience” is defined (Carruthers 2000). More
common is the belief that we can be aware of external objects in some
unconscious sense, for example, during cases of subliminal perception. The
expression “conscious awareness” does not therefore seem to be redundant.
Finally, it is not clear that consciousness ought to be restricted to
attention. It seems plausible to suppose that one is conscious (in some sense)
of objects in one’s peripheral visual field even though one is only attending
to some narrow (focal) set of objects within that visual field.
Perhaps the most fundamental and commonly used notion of
“conscious” is captured by Thomas Nagel’s famous “what it is like” sense (Nagel
1974). When I am in a conscious mental state, there is “something it is like”
for me to be in that state from the subjective or first-person point of view.
When I am, for example, smelling a rose or having a conscious visual
experience, there is something it “seems” or “feels” like from my perspective.
An organism, such as a bat, is conscious if it is able to experience the outer
world through its (echo-locatory) senses. There is also something it is like to
be a conscious creature whereas there is nothing it is like to be, for example,
a table or tree. This is primarily the sense of “conscious state” that will be
used throughout this entry. There are still, though, a cluster of expressions
and terms related to Nagel’s sense, and some authors simply stipulate the way
that they use such terms. For example, philosophers sometimes refer to
conscious states as phenomenal or qualitative states. More technically,
philosophers often view such states as having qualitative properties called “qualia” (prounced
like "kwal' ee uh"; the singular is quale). There is significant
disagreement over the nature, and even the existence, of qualia, but they are
perhaps most frequently understood as the felt properties or qualities of
conscious states.
Ned Block (1995) makes an often cited distinction between
phenomenal consciousness (or “phenomenality”) and access consciousness. The
former is very much in line with the Nagelian notion described above. However,
Block also defines the quite different notion of access consciousness in terms
of a mental state’s relationship with other mental states; for example, a
mental state’s “availability for use in reasoning and rationality guiding
speech and action” (Block 1995: 227). This would, for example, count a visual
perception as (access) conscious not because it has the “what it’s likeness” of
phenomenal states, but rather because it carries visual information which is
generally available for use by the organism, regardless of whether or not it
has any qualitative properties. Access consciousness is therefore more of a
functional notion; that is, concerned with what such states do. Although this
concept of consciousness is certainly very important in cognitive science and
philosophy of mind generally, not everyone agrees that access consciousness
deserves to be called “consciousnesses” in any important sense. Block himself
argues that neither sense of consciousness implies the other, while others urge
that there is a more intimate connection between the two.
Finally, it is helpful to distinguish between consciousness and
self-consciousness, which plausibly involves some kind of awareness or
consciousness of one’s own mental states (instead of something out in the
world). Self-consciousness arguably comes in degrees of sophistication ranging
from minimal bodily self-awareness to the ability to reason and reflect on
one’s own mental states, such as one’s beliefs and desires. Some important
historical figures have even held that consciousness entails some form of
self-consciousness (Kant 1781/1965, Sartre 1956), a view shared by some
contemporary philosophers (Gennaro 1996a, Kriegel 2004).
Interest in the nature of conscious experience has no doubt been
around for as long as there have been reflective humans. It would be impossible
here to survey the entire history, but a few highlights are in order. In the
history of Western philosophy, which is the focus of this entry, important
writings on human nature and the soul and mind go back to ancient philosophers,
such as Plato.
More sophisticated work on the nature of consciousness and perception can be
found in the work of Plato’s most famous student Aristotle (see
Caston 2002), and then throughout the later Medieval period. It is, however,
with the work of René Descartes (1596-1650) and his
successors in the early modern period of philosophy that consciousness and the
relationship between the mind and body took center stage. As we shall see,
Descartes argued that the mind is a non-physical substance distinct from the
body. He also did not believe in the existence of unconscious mental states, a
view certainly not widely held today. Descartes defined “thinking” very broadly
to include virtually every kind of mental state and urged that consciousness is
essential to thought. Our mental states are, according to Descartes, infallibly
transparent to introspection. John Locke(1689/1975) held a
similar position regarding the connection between mentality and consciousness,
but was far less committed on the exact metaphysical nature of the mind.
Perhaps the most important philosopher of the period explicitly to
endorse the existence of unconscious mental states was G.W. Leibniz (1686/1991, 1720/1925). Although Leibniz also believed
in the immaterial nature of mental substances (which he called “monads”), he
recognized the existence of what he called “petit perceptions,” which are
basically unconscious perceptions. He also importantly distinguished between
perception and apperception, roughly the difference between outer-directed
consciousness and self-consciousness (see Gennaro 1999 for some discussion).
The most important detailed theory of mind in the early modern period was
developed by Immanuel Kant. His main work Critique of Pure Reason (1781/1965) is as equally
dense as it is important, and cannot easily be summarized in this context.
Although he owes a great debt to his immediate predecessors, Kant is arguably
the most important philosopher since Plato and Aristotle and is highly relevant
today. Kant basically thought that an adequate account of phenomenal
consciousness involved far more than any of his predecessors had considered.
There are important mental structures which are “presupposed” in conscious
experience, and Kant presented an elaborate theory as to what those structures
are, which, in turn, had other important implications. He, like Leibniz, also
saw the need to postulate the existence of unconscious mental states and
mechanisms in order to provide an adequate theory of mind (Kitcher 1990 and
Brook 1994 are two excellent books on Kant’s theory of mind.).
Over the past one hundred years or so, however, research on
consciousness has taken off in many important directions. In psychology, with
the notable exception of the virtual banishment of consciousness by behaviorist
psychologists (e.g., Skinner 1953), there were also those deeply interested in
consciousness and various introspective (or “first-person”) methods of
investigating the mind. The writings of such figures as Wilhelm Wundt (1897),
William James (1890) and Alfred Titchener (1901) are good examples of this
approach. Franz Brentano (1874/1973) also had a profound effect on some
contemporary theories of consciousness. Similar introspectionist approaches
were used by those in the so-called “phenomenological” tradition in philosophy,
such as in the writings of Edmund Husserl (1913/1931, 1929/1960) and Martin Heidegger (1927/1962). The work of Sigmund Freud was
very important, at minimum, in bringing about the near universal acceptance of
the existence of unconscious mental states and processes.
It must, however, be kept in mind that none of the above had very
much scientific knowledge about the detailed workings of the brain. The
relatively recent development of neurophysiology is, in part, also responsible
for the unprecedented interdisciplinary research interest in consciousness,
particularly since the 1980s. There are now several important journals
devoted entirely to the study of consciousness: Consciousness
and Cognition, Journal of Consciousness
Studies, and Psyche. There
are also major annual conferences sponsored by world-wide professional
organizations, such as the Association for the Scientific Study of
Consciousness, and an entire book series called “Advances in Consciousness
Research” published by John Benjamins. (For a small sample of
introductory texts and important anthologies, see Kim 1996, Gennaro 1996b,
Block et. al. 1997, Seager 1999, Chalmers 2002, Baars et. al. 2003, Blackmore
2004, Campbell 2005, Velmans and Schneider 2007, Zelazo et al. 2007, Revonsuo
2010.)
Metaphysics is the branch of philosophy concerned with the
ultimate nature of reality. There are two broad traditional and competing
metaphysical views concerning the nature of the mind and conscious mental
states: dualism and
materialism. While there are many versions of each, the former generally holds
that the conscious mind or a conscious mental state is non-physical in some
sense. On the other hand, materialists hold that the mind is the brain, or, more
accurately, that conscious mental activity is identical with neural activity.
It is important to recognize that by non-physical, dualists do not merely mean
“not visible to the naked eye.” Many physical things fit this description, such
as the atoms which make up the air in a typical room. For something to be
non-physical, it must literally be outside the realm of physics; that is, not
in space at all and undetectable in principle by the instruments of physics. It
is equally important to recognize that the category “physical” is broader than
the category “material.” Materialists are called such because there is the
tendency to view the brain, a material thing, as the most likely physical
candidate to identify with the mind. However, something might be physical but
not material in this sense, such as an electromagnetic or energy field. One
might therefore instead be a “physicalist” in some broader sense and still not
a dualist. Thus, to say that the mind is non-physical is to say something much
stronger than that it is non-material. Dualists, then, tend to believe that
conscious mental states or minds are radically different from anything in the
physical world at all.
There are a number of reasons why some version of dualism has been
held throughout the centuries. For one thing, especially from the introspective
or first-person perspective, our conscious mental states just do not seem like
physical things or processes. That is, when we reflect on our conscious perceptions,
pains, and desires, they do not seem to be physical in any sense. Consciousness
seems to be a unique aspect of the world not to be understood in any physical
way. Although materialists will urge that this completely ignores the more
scientific third-person perspective on the nature of consciousness and mind,
this idea continues to have force for many today. Indeed, it is arguably the
crucial underlying intuition behind historically significant “conceivability
arguments” against materialism and for dualism. Such arguments typically reason
from the premise that one can conceive of one’s conscious states existing
without one’s body or, conversely, that one can imagine one’s own physical
duplicate without consciousness at all (see section 3b.iv). The metaphysical
conclusion ultimately drawn is that consciousness cannot be identical with
anything physical, partly because there is no essential conceptual connection
between the mental and the physical. Arguments such as these go back to
Descartes and continue to be used today in various ways (Kripke 1972, Chalmers
1996), but it is highly controversial as to whether they succeed in showing
that materialism is false. Materialists have replied in various ways to such
arguments and the relevant literature has grown dramatically in recent years.
Historically, there is also the clear link between dualism and a
belief in immortality, and hence a more theistic perspective than one tends to
find among materialists. Indeed, belief in dualism is often explicitly theologically
motivated. If the conscious mind is not physical, it seems more plausible to
believe in the possibility of life after bodily death. On the other hand, if
conscious mental activity is identical with brain activity, then it would seem
that when all brain activity ceases, so do all conscious experiences and thus
no immortality. After all, what do many people believe continues after bodily
death? Presumably, one’s own conscious thoughts, memories, experiences,
beliefs, and so on. There is perhaps a similar historical connection to a
belief in free will, which is of course a major topic in its own right. For our
purposes, it suffices to say that, on some definitions of what it is to act
freely, such ability seems almost “supernatural” in the sense that one’s
conscious decisions can alter the otherwise deterministic sequence of events in
nature. To put it another way: If we are entirely physical beings as the
materialist holds, then mustn’t all of the brain activity and behavior in
question be determined by the laws of nature? Although materialism may not
logically rule out immortality or free will, materialists will likely often
reply that such traditional, perhaps even outdated or pre-scientific beliefs
simply ought to be rejected to the extent that they conflict with materialism.
After all, if the weight of the evidence points toward materialism and away
from dualism, then so much the worse for those related views.
One might wonder “even if the mind is physical, what about the
soul?” Maybe it’s the soul, not the mind, which is non-physical as one might be
told in many religious traditions. While it is true that the term “soul” (or
“spirit”) is often used instead of “mind” in such religious contexts, the
problem is that it is unclear just how the soul is supposed to differ from the
mind. The terms are often even used interchangeably in many historical texts
and by many philosophers because it is unclear what else the soul could be
other than “the mental substance.” It is difficult to describe the soul in any
way that doesn’t make it sound like what we mean by the mind. After all, that’s
what many believe goes on after bodily death; namely, conscious mental
activity. Granted that the term “soul” carries a more theological connotation,
but it doesn’t follow that the words “soul” and “mind” refer to entirely
different things. Somewhat related to the issue of immortality, the existence
of near death experiences is also used as some evidence for dualism and
immortality. Such patients experience a peaceful moving toward a light through
a tunnel like structure, or are able to see doctors working on their bodies
while hovering over them in an emergency room (sometimes akin to what is called
an “out of body experience”). In response, materialists will point out that such
experiences can be artificially induced in various experimental situations, and
that starving the brain of oxygen is known to cause hallucinations.
Various paranormal and psychic phenomena, such as clairvoyance,
faith healing, and mind-reading, are sometimes also cited as evidence for
dualism. However, materialists (and even many dualists) will first likely wish
to be skeptical of the alleged phenomena themselves for numerous reasons. There
are many modern day charlatans who should make us seriously question whether
there really are such phenomena or mental abilities in the first place. Second,
it is not quite clear just how dualism follows from such phenomena even if they
are genuine. A materialist, or physicalist at least, might insist that though
such phenomena are puzzling and perhaps currently difficult to explain in
physical terms, they are nonetheless ultimately physical in nature; for
example, having to do with very unusual transfers of energy in the physical
world. The dualist advantage is perhaps not as obvious as one might think, and
we need not jump to supernatural conclusions so quickly.
Interactionist Dualism or simply “interactionism” is the most
common form of “substance dualism” and its name derives from the widely
accepted fact that mental states and bodily states causally interact with each
other. For example, my desire to drink something cold causes my body to move to
the refrigerator and get something to drink and, conversely, kicking me in the
shin will cause me to feel a pain and get angry. Due to Descartes’ influence,
it is also sometimes referred to as “Cartesian dualism.” Knowing nothing about
just where such causal interaction could take place, Descartes speculated that
it was through the pineal gland, a now almost humorous conjecture. But a modern
day interactionist would certainly wish to treat various areas of the brain as
the location of such interactions.
Three serious objections are briefly worth noting here. The first
is simply the issue of just how does or could such radically different
substances causally interact. How something non-physical causally interacts
with something physical, such as the brain? No such explanation is forthcoming
or is perhaps even possible, according to materialists. Moreover, if causation
involves a transfer of energy from cause to effect, then how is that possible
if the mind is really non-physical? Gilbert Ryle (1949) mockingly calls the
Cartesian view about the nature of mind, a belief in the “ghost in the machine.”
Secondly, assuming that some such energy transfer makes any sense at all, it is
also then often alleged that interactionism is inconsistent with the
scientifically well-established Conservation of Energy principle, which says
that the total amount of energy in the universe, or any controlled part of it,
remains constant. So any loss of energy in the cause must be passed along as a
corresponding gain of energy in the effect, as in standard billiard ball
examples. But if interactionism is true, then when mental events cause physical
events, energy would literally come into the physical word. On the other hand,
when bodily events cause mental events, energy would literally go out of the
physical world. At the least, there is a very peculiar and unique notion of
energy involved, unless one wished, even more radically, to deny the
conservation principle itself. Third, some materialists might also use the
well-known fact that brain damage (even to very specific areas of the brain)
causes mental defects as a serious objection to interactionism (and thus as
support for materialism). This has of course been known for many centuries, but
the level of detailed knowledge has increased dramatically in recent years. Now
a dualist might reply that such phenomena do not absolutely refute her
metaphysical position since it could be replied that damage to the brain simply
causes corresponding damage to the mind. However, this raises a host of other
questions: Why not opt for the simpler explanation, i.e., that brain damage causes
mental damage because mental processes simply are brain processes? If the
non-physical mind is damaged when brain damage occurs, how does that leave
one’s mind according to the dualist’s conception of an afterlife? Will the
severe amnesic at the end of life on Earth retain such a deficit in the
afterlife? If proper mental functioning still depends on proper brain
functioning, then is dualism really in no better position to offer hope for
immortality?
It should be noted that there is also another less popular form of
substance dualism called parallelism, which denies the causal interaction
between the non-physical mental and physical bodily realms. It seems fair to
say that it encounters even more serious objections than interactionism.
While a detailed survey of all varieties of dualism is beyond the
scope of this entry, it is at least important to note here that the main and
most popular form of dualism today is called property dualism. Substance
dualism has largely fallen out of favor at least in most philosophical circles,
though there are important exceptions (e.g., Swinburne 1986, Foster 1996) and
it often continues to be tied to various theological positions. Property
dualism, on the other hand, is a more modest version of dualism and it holds
that there are mental properties (that is, characteristics or aspects of
things) that are neither identical with nor reducible to physical properties.
There are actually several different kinds of property dualism, but what they have
in common is the idea that conscious properties, such as the color qualia involved
in a conscious experience of a visual perception, cannot be explained in purely
physical terms and, thus, are not themselves to be identified with any brain
state or process.
Two other views worth mentioning are epiphenomenalism and
panpsychism. The latter is the somewhat eccentric view that all things in
physical reality, even down to micro-particles, have some mental properties.
All substances have a mental aspect, though it is not always clear exactly how
to characterize or test such a claim. Epiphenomenalism holds that mental events
are caused by brain events but those mental events are mere “epiphenomena”
which do not, in turn, cause anything physical at all, despite appearances to
the contrary (for a recent defense, see Robinson 2004).
Finally, although not a form of dualism, idealism holds that there
are only immaterial mental substances, a view more common in the Eastern tradition.
The most prominent Western proponent of idealism was 18th century empiricist
George Berkeley. The idealist agrees with the substance dualist, however, that
minds are non-physical, but then denies the existence of mind-independent
physical substances altogether. Such a view faces a number of serious
objections, and it also requires a belief in the existence of God.
Some form of materialism is probably much more widely held today
than in centuries past. No doubt part of the reason for this has to do with the
explosion in scientific knowledge about the workings of the brain and its
intimate connection with consciousness, including the close connection between
brain damage and various states of consciousness. Brain death is now the main
criterion for when someone dies. Stimulation to specific areas of the brain
results in modality specific conscious experiences. Indeed, materialism often
seems to be a working assumption in neurophysiology. Imagine saying to a
neuroscientist “you are not really studying the conscious mind itself” when she
is examining the workings of the brain during an fMRI. The idea is that science
is showing us that conscious mental states, such as visual perceptions, are
simply identical with certain neuro-chemical brain processes; much like the
science of chemistry taught us that water just is H2O.
There are also theoretical factors on the side of materialism,
such as adherence to the so-called “principle of simplicity” which says that if
two theories can equally explain a given phenomenon, then we should accept the
one which posits fewer objects or forces. In this case, even if dualism could
equally explain consciousness (which would of course be disputed by
materialists), materialism is clearly the simpler theory in so far as it does
not posit any objects or processes over and above physical ones. Materialists
will wonder why there is a need to believe in the existence of such mysterious
non-physical entities. Moreover, in the aftermath of the Darwinian revolution,
it would seem that materialism is on even stronger ground provided that one
accepts basic evolutionary theory and the notion that most animals are
conscious. Given the similarities between the more primitive parts of the human
brain and the brains of other animals, it seems most natural to conclude that,
through evolution, increasing layers of brain areas correspond to increased
mental abilities. For example, having a well-developed prefrontal cortex allows
humans to reason and plan in ways not available to dogs and cats. It also seems
fairly uncontroversial to hold that we should be materialists about the minds
of animals. If so, then it would be odd indeed to hold that non-physical
conscious states suddenly appear on the scene with humans.
There are still, however, a number of much discussed and important
objections to materialism, most of which question the notion that materialism
can adequately explain conscious experience.
Joseph Levine (1983) coined the expression “the explanatory gap”
to express a difficulty for any materialistic attempt to explain consciousness.
Although not concerned to reject the metaphysics of materialism, Levine gives
eloquent expression to the idea that there is a key gap in our ability to
explain the connection between phenomenal properties and brain properties (see
also Levine 1993, 2001). The basic problem is that it is, at least at present,
very difficult for us to understand the relationship between brain properties
and phenomenal properties in any explanatory satisfying way, especially given
the fact that it seems possible for one to be present without the other. There
is an odd kind of arbitrariness involved: Why or how does some particular brain
process produce that particular taste or visual sensation? It is difficult to
see any real explanatory connection between specific conscious states and brain
states in a way that explains just how or why the former are identical with the
latter. There is therefore an explanatory gap between the physical and mental.
Levine argues that this difficulty in explaining consciousness is unique; that
is, we do not have similar worries about other scientific identities, such as
that “water is H2O” or that “heat is mean molecular kinetic energy.” There is
“an important sense in which we can’t really understand how [materialism] could
be true.” (2001: 68)
David Chalmers (1995) has articulated a similar worry by using the
catchy phrase "the hard problem of consciousness," which basically
refers to the difficulty of explaining just how physical processes in the brain
give rise to subjective conscious experiences. The “really hard problem is the
problem of experience…How can we explain why there is something it is like to
entertain a mental image, or to experience an emotion?” (1995: 201) Others have
made similar points, as Chalmers acknowledges, but reference to the phrase “the
hard problem” has now become commonplace in the literature. Unlike Levine,
however, Chalmers is much more inclined to draw anti-materialist metaphysical
conclusions from these and other considerations. Chalmers usefully
distinguishes the hard problem of consciousness from what he calls the
(relatively) “easy problems” of consciousness, such as the ability to
discriminate and categorize stimuli, the ability of a cognitive system to
access its own internal states, and the difference between wakefulness and
sleep. The easy problems generally have more to do with the functions of
consciousness, but Chalmers urges that solving them does not touch the hard
problem of phenomenal consciousness. Most philosophers, according to Chalmers,
are really only addressing the easy problems, perhaps merely with something
like Block’s “access consciousness” in mind. Their theories ignore phenomenal
consciousness.
There are many responses by materialists to the above charges, but
it is worth emphasizing that Levine, at least, does not reject the metaphysics
of materialism. Instead, he sees the “explanatory gap [as] primarily an
epistemological problem” (2001: 10). That is, it is primarily a problem having
to do with knowledge or understanding. This concession is still important at
least to the extent that one is concerned with the larger related metaphysical
issues discussed in section 3a, such as the possibility of immortality.
Perhaps most important for the materialist, however, is
recognition of the fact that different concepts can pick out the same property
or object in the world (Loar 1990, 1997). Out in the world there is only the
one “stuff,” which we can conceptualize either as “water” or as “H2O.” The
traditional distinction, made most notably by Gottlob Frege in
the late 19th century, between “meaning” (or “sense”) and “reference” is also
relevant here. Two or more concepts, which can have different meanings, can
refer to the same property or object, much like “Venus” and “The Morning Star.”
Materialists, then, explain that it is essential to distinguish between mental
properties and our concepts of those properties. By analogy, there are
so-called “phenomenal concepts” which uses a phenomenal or “first-person”
property to refer to some conscious mental state, such as a sensation of red
(Alter and Walter 2007). In contrast, we can also use various concepts couched
in physical or neurophysiological terms to refer to that same mental state from
the third-person point of view. There is thus but one conscious mental state
which can be conceptualized in two different ways: either by employing
first-person experiential phenomenal concepts or by employing third-person
neurophysiological concepts. It may then just be a “brute fact” about the world
that there are such identities and the appearance of arbitrariness between
brain properties and mental properties is just that – an apparent problem
leading many to wonder about the alleged explanatory gap. Qualia would then
still be identical to physical properties. Moreover, this response provides a
diagnosis for why there even seems to be such a gap; namely, that we use very
different concepts to pick out the same property. Science will be able, in
principle, to close the gap and solve the hard problem of consciousness in an
analogous way that we now have a very good understanding for why “water is H2O”
or “heat is mean molecular kinetic energy” that was lacking centuries ago.
Maybe the hard problem isn’t so hard after all – it will just take some more
time. After all, the science of chemistry didn’t develop overnight and we are
relatively early in the history of neurophysiology and our understanding of
phenomenal consciousness. (See Shear 1997 for many more specific responses to
the hard problem, but also for Chalmers’ counter-replies.)
There is a pair of very widely discussed, and arguably related,
objections to materialism which come from the seminal writings of Thomas Nagel
(1974) and Frank Jackson (1982, 1986). These arguments, especially Jackson’s,
have come to be known as examples of the "knowledge argument" against materialism, due to their clear
emphasis on the epistemological (that is, knowledge related) limitations of
materialism. Like Levine, Nagel does not reject the metaphysics of materialism.
Jackson had originally intended for his argument to yield a dualistic
conclusion, but he no longer holds that view. The general pattern of each
argument is to assume that all the physical facts are known about some
conscious mind or conscious experience. Yet, the argument goes, not all is
known about the mind or experience. It is then inferred that the missing
knowledge is non-physical in some sense, which is surely an anti-materialist
conclusion in some sense.
Nagel imagines a future where we know everything physical there is
to know about some other conscious creature’s mind, such as a bat. However, it
seems clear that we would still not know something crucial; namely, “what it is
like to be a bat.” It will not do to imagine what it is like for us to be a
bat. We would still not know what it is like to be a bat from the bat’s
subjective or first-person point of view. The idea, then, is that if we accept
the hypothesis that we know all of the physical facts about bat minds, and yet
some knowledge about bat minds is left out, then materialism is inherently
flawed when it comes to explaining consciousness. Even in an ideal future in
which everything physical is known by us, something would still be left out.
Jackson’s somewhat similar, but no less influential, argument begins by asking
us to imagine a future where a person, Mary, is kept in a black and white room
from birth during which time she becomes a brilliant neuroscientist and an
expert on color perception. Mary never sees red for example, but she learns all
of the physical facts and everything neurophysiologically about human color
vision. Eventually she is released from the room and sees red for the first
time. Jackson argues that it is clear that Mary comes to learn something new;
namely, to use Nagel’s famous phrase, what it is like to experience red. This
is a new piece of knowledge and hence she must have come to know some
non-physical fact (since, by hypothesis, she already knew all of the physical
facts). Thus, not all knowledge about the conscious mind is physical knowledge.
The influence and the quantity of work that these ideas have
generated cannot be exaggerated. Numerous materialist responses to Nagel’s
argument have been presented (such as Van Gulick 1985), and there is now a very
useful anthology devoted entirely to Jackson’s knowledge argument (Ludlow et.
al. 2004). Some materialists have wondered if we should concede up front that
Mary wouldn’t be able to imagine the color red even before leaving the room, so
that maybe she wouldn’t even be surprised upon seeing red for the first time.
Various suspicions about the nature and effectiveness of such thought
experiments also usually accompany this response. More commonly, however,
materialists reply by arguing that Mary does not learn a new fact when seeing
red for the first time, but rather learns the same fact in a different way.
Recalling the distinction made in section 3b.i between concepts and objects or
properties, the materialist will urge that there is only the one physical fact
about color vision, but there are two ways to come to know it: either by
employing neurophysiological concepts or by actually undergoing the relevant
experience and so by employing phenomenal concepts. We might say that Mary,
upon leaving the black and white room, becomes acquainted with the same neural
property as before, but only now from the first-person point of view. The
property itself isn’t new; only the perspective, or what philosophers sometimes
call the “mode of presentation,” is different. In short, coming to learn or
know something new does not entail learning some new fact about the world.
Analogies are again given in other less controversial areas, for example, one
can come to know about some historical fact or event by reading a (reliable)
third-person historical account or by having observed that event oneself. But
there is still only the one objective fact under two different descriptions.
Finally, it is crucial to remember that, according to most, the metaphysics of
materialism remains unaffected. Drawing a metaphysical conclusion from such
purely epistemological premises is always a questionable practice. Nagel’s
argument doesn’t show that bat mental states are not identical with bat brain
states. Indeed, a materialist might even expect the conclusion that Nagel
draws; after all, given that our brains are so different from bat brains, it
almost seems natural for there to be certain aspects of bat experience that we
could never fully comprehend. Only the bat actually undergoes the relevant
brain processes. Similarly, Jackson’s argument doesn’t show that Mary’s color
experience is distinct from her brain processes.
Despite the plethora of materialist responses, vigorous debate
continues as there are those who still think that something profound must
always be missing from any materialist attempt to explain consciousness;
namely, that understanding subjective phenomenal consciousness is an inherently
first-person activity which cannot be captured by any objective third-person
scientific means, no matter how much scientific knowledge is accumulated. Some
knowledge about consciousness is essentially limited to first-person knowledge.
Such a sense, no doubt, continues to fuel the related anti-materialist
intuitions raised in the previous section. Perhaps consciousness is simply a
fundamental or irreducible part of nature in some sense (Chalmers 1996). (For
more see Van Gulick 1993.)
Finally, some go so far as to argue that we are simply not capable
of solving the problem of consciousness (McGinn 1989, 1991, 1995). In short,
“mysterians” believe that the hard problem can never be solved because of human
cognitive limitations; the explanatory gap can never be filled. Once again,
however, McGinn does not reject the metaphysics of materialism, but rather
argues that we are “cognitively closed” with respect to this problem much like
a rat or dog is cognitively incapable of solving, or even understanding,
calculus problems. More specifically, McGinn claims that we are cognitively
closed as to how the brain produces conscious awareness. McGinn concedes that
some brain property produces conscious experience, but we cannot understand how
this is so or even know what that brain property is. Our concept forming
mechanisms simply will not allow us to grasp the physical and causal basis of
consciousness. We are not conceptually suited to be able to do so.
McGinn does not entirely rest his argument on past failed attempts
at explaining consciousness in materialist terms; instead, he presents another
argument for his admittedly pessimistic conclusion. McGinn observes that we do
not have a mental faculty that can access both consciousness and the brain. We
access consciousness through introspection or the first-person perspective, but
our access to the brain is through the use of outer spatial senses (e.g.,
vision) or a more third-person perspective. Thus we have no way to access both
the brain and consciousness together, and therefore any explanatory link
between them is forever beyond our reach.
Materialist responses are numerous. First, one might wonder why we
can’t combine the two perspectives within certain experimental contexts. Both
first-person and third-person scientific data about the brain and consciousness
can be acquired and used to solve the hard problem. Even if a single person
cannot grasp consciousness from both perspectives at the same time, why can’t a
plausible physicalist theory emerge from such a combined approach? Presumably,
McGinn would say that we are not capable of putting such a theory together in
any appropriate way. Second, despite McGinn’s protests to the contrary, many
will view the problem of explaining consciousness as a merely temporary limit
of our theorizing, and not something which is unsolvable in principle (Dennett
1991). Third, it may be that McGinn expects too much; namely, grasping some
causal link between the brain and consciousness. After all, if conscious mental
states are simply identical to brain states, then there may simply be a “brute
fact” that really does not need any further explaining. Indeed, this is
sometimes also said in response to the explanatory gap and the hard problem, as
we saw earlier. It may even be that some form of dualism is presupposed in
McGinn’s argument, to the extent that brain states are said to “cause” or “give
rise to” consciousness, instead of using the language of identity. Fourth,
McGinn’s analogy to lower animals and mathematics is not quite accurate. Rats,
for example, have no concept whatsoever of calculus. It is not as if they can
grasp it to some extent but just haven’t figured out the answer to some
particular problem within mathematics. Rats are just completely oblivious to
calculus problems. On the other hand, we humans obviously do have some grasp on
consciousness and on the workings of the brain -- just see the references at
the end of this entry! It is not clear, then, why we should accept the
extremely pessimistic and universally negative conclusion that we can never
discover the answer to the problem of consciousness, or, more specifically, why
we could never understand the link between consciousness and the brain.
Unlike many of the above objections to materialism, the appeal to
the possibility of zombies is often taken as both a problem for materialism and
as a more positive argument for some form of dualism, such as property dualism.
The philosophical notion of a “zombie” basically refers to conceivable
creatures which are physically indistinguishable from us but lack consciousness
entirely (Chalmers 1996). It certainly seems logically possible for there to be
such creatures: “the conceivability of zombies seems…obvious to me…While this
possibility is probably empirically impossible, it certainly seems that a
coherent situation is described; I can discern no contradiction in the
description” (Chalmers 1996: 96). Philosophers often contrast what is logically
possible (in the sense of “that which is not self-contradictory”) from what is
empirically possible given the actual laws of nature. Thus, it is logically
possible for me to jump fifty feet in the air, but not empirically possible.
Philosophers often use the notion of “possible worlds,” i.e., different ways
that the world might have been, in describing such non-actual situations or
possibilities. The objection, then, typically proceeds from such a possibility
to the conclusion that materialism is false because materialism would seem to
rule out that possibility. It has been fairly widely accepted (since Kripke
1972) that all identity statements are necessarily true (that is, true in all
possible worlds), and the same should therefore go for mind-brain identity
claims. Since the possibility of zombies shows that it doesn’t, then we should
conclude that materialism is false. (See Identity Theory.)
It is impossible to do justice to all of the subtleties here. The
literature in response to zombie, and related “conceivability,” arguments is
enormous (see, for example, Hill 1997, Hill and McLaughlin 1999, Papineau 1998,
2002, Balog 1999, Block and Stalnaker 1999, Loar 1999, Yablo 1999, Perry 2001,
Botterell 2001, Kirk 2005). A few lines of reply are as follows: First, it is
sometimes objected that the conceivability of something does not really entail
its possibility. Perhaps we can also conceive of water not being H2O, since
there seems to be no logical contradiction in doing so, but, according to
received wisdom from Kripke, that is really impossible. Perhaps, then, some
things just seem possible but really aren’t. Much of the debate centers on
various alleged similarities or dissimilarities between the mind-brain and
water-H2O cases (or other such scientific identities). Indeed, the entire issue
of the exact relationship between “conceivability” and “possibility” is the
subject of an important recently published anthology (Gendler and Hawthorne
2002). Second, even if zombies are conceivable in the sense of logically
possible, how can we draw a substantial metaphysical conclusion about the
actual world? There is often suspicion on the part of materialists about what,
if anything, such philosophers’ “thought experiments” can teach us about the
nature of our minds. It seems that one could take virtually any philosophical
or scientific theory about almost anything, conceive that it is possibly false,
and then conclude that it is actually false. Something, perhaps, is generally
wrong with this way of reasoning. Third, as we saw earlier (3b.i), there may be
a very good reason why such zombie scenarios seem possible; namely, that we do
not (at least, not yet) see what the necessary connection is between neural
events and conscious mental events. On the one side, we are dealing with
scientific third-person concepts and, on the other, we are employing phenomenal
concepts. We are, perhaps, simply currently not in a position to understand
completely such a necessary connection.
Debate and discussion on all four objections remains very active.
Despite the apparent simplicity of materialism, say, in terms of
the identity between mental states and neural states, the fact is that there
are many different forms of materialism. While a detailed survey of all varieties
is beyond the scope of this entry, it is at least important to acknowledge the
commonly drawn distinction between two kinds of “identity theory”: token-token
and type-type materialism. Type-type identity theory is the stronger thesis and
says that mental properties, such as “having a desire to drink some water” or
“being in pain,” are literally identical with a brain property of some kind.
Such identities were originally meant to be understood as on a par with, for
example, the scientific identity between “being water” and “being composed of
H2O” (Place 1956, Smart 1959). However, this view historically came under
serious assault due to the fact that it seems to rule out the so-called
“multiple realizability” of conscious mental states. The idea is simply that it
seems perfectly possible for there to be other conscious beings (e.g., aliens,
radically different animals) who can have those same mental states but who also
are radically different from us physiologically (Fodor 1974). It seems that commitment
to type-type identity theory led to the undesirable result that only organisms
with brains like ours can have conscious states. Somewhat more technically,
most materialists wish to leave room for the possibility that mental properties
can be “instantiated” in different kinds of organisms. (But for more recent
defenses of type-type identity theory see Hill and McLaughlin 1999, Papineau
1994, 1995, 1998, Polger 2004.) As a consequence, a more modest “token-token”
identity theory has become preferable to many materialists. This view simply
holds that each particular conscious mental event in some organism is identical
with some particular brain process or event in that organism. This seems to
preserve much of what the materialist wants but yet allows for the multiple
realizability of conscious states, because both the human and the alien can
still have a conscious desire for something to drink while each mental event is
identical with a (different) physical state in each organism.
Taking the notion of multiple realizability very seriously has
also led many to embrace functionalism, which is the view that conscious mental
states should really only be identified with the functional role they play
within an organism. For example, conscious pains are defined more in terms of
input and output, such as causing bodily damage and avoidance behavior, as well
as in terms of their relationship to other mental states. It is normally viewed
as a form of materialism since virtually all functionalists also believe, like the
token-token theorist, that something physical ultimately realizes that
functional state in the organism, but functionalism does not, by itself, entail
that materialism is true. Critics of functionalism, however, have long argued
that such purely functional accounts cannot adequately explain the essential
“feel” of conscious states, or that it seems possible to have two functionally
equivalent creatures, one of whom lacks qualia entirely (Block 1980a, 1980b,
Chalmers 1996; see also Shoemaker 1975, 1981).
Some materialists even deny the very existence of mind and mental
states altogether, at least in the sense that the very concept of consciousness
is muddled (Wilkes 1984, 1988) or that the mentalistic notions found in folk
psychology, such as desires and beliefs, will eventually be eliminated and
replaced by physicalistic terms as neurophysiology matures into the future
(Churchland 1983). This is meant as analogous to past similar eliminations
based on deeper scientific understanding, for example, we no longer need to
speak of “ether” or “phlogiston.” Other eliminativists, more modestly, argue
that there is no such thing as qualia when they are defined in certain
problematic ways (Dennett 1988).
Finally, it should also be noted that not all materialists believe
that conscious mentality can be explained in terms of the physical, at least in
the sense that the former cannot be “reduced” to the latter. Materialism is
true as an ontological or metaphysical doctrine, but facts about the mind
cannot be deduced from facts about the physical world (Boyd 1980, Van Gulick
1992). In some ways, this might be viewed as a relatively harmless variation on
materialist themes, but others object to the very coherence of this form of
materialism (Kim 1987, 1998). Indeed, the line between such “non-reductive
materialism” and property dualism is not always so easy to draw; partly because
the entire notion of “reduction” is ambiguous and a very complex topic in its
own right. On a related front, some materialists are happy enough to talk about
a somewhat weaker “supervenience” relation between mind and matter. Although
“supervenience” is a highly technical notion with many variations, the idea is
basically one of dependence (instead of
identity); for example, that the mental depends on the physical in the sense
that any mental change must be accompanied by some physical change (see Kim
1993).
Most specific theories of consciousness tend to be reductionist in
some sense. The classic notion at work is that consciousness or individual
conscious mental states can be explained in terms of something else or in some
other terms. This section will focus on several prominent contemporary
reductionist theories. We should, however, distinguish between those who
attempt such a reduction directly in physicalistic, such as neurophysiological,
terms and those who do so in mentalistic terms, such as by using unconscious
mental states or other cognitive notions.
The more direct reductionist approach can be seen in various, more
specific, neural theories of consciousness. Perhaps best known is the theory
offered by Francis Crick and Christof Koch 1990 (see also Crick 1994, Koch
2004). The basic idea is that mental states become conscious when large numbers
of neurons fire in synchrony and all have oscillations within the 35-75 hertz
range (that is, 35-75 cycles per second). However, many philosophers and
scientists have put forth other candidates for what, specifically, to identify
in the brain with consciousness. This vast enterprise has come to be known as
the search for the “neural correlates of consciousness” or NCCs (see section 5b
below for more). The overall idea is to show how one or more specific kinds of
neuro-chemical activity can underlie and explain conscious mental activity
(Metzinger 2000). Of course, mere “correlation” is not enough for a fully
adequate neural theory and explaining just what counts as a NCC turns out to be
more difficult than one might think (Chalmers 2000). Even Crick and Koch have
acknowledged that they, at best, provide a necessary condition for
consciousness, and that such firing patters are not automatically sufficient
for having conscious experience.
Many current theories attempt to reduce consciousness in
mentalistic terms. One broadly popular approach along these lines is to reduce
consciousness to “mental representations” of some kind. The notion of a
“representation” is of course very general and can be applied to photographs,
signs, and various natural objects, such as the rings inside a tree. Much of
what goes on in the brain, however, might also be understood in a
representational way; for example, as mental events representing outer objects
partly because they are caused by such objects in, say, cases of veridical
visual perception. More specifically, philosophers will often call such
representational mental states “intentional states” which have representational
content; that is, mental states which are “about something” or “directed at
something” as when one has a thought about the house or a perception of the
tree. Although intentional states are sometimes contrasted with phenomenal
states, such as pains and color experiences, it is clear that many conscious
states have both phenomenal and intentional properties, such as visual
perceptions. It should be noted that the relation between intentionalilty and
consciousness is itself a major ongoing area of dispute with some arguing that
genuine intentionality actually presupposes consciousness in some way (Searle
1992, Siewart 1998, Horgan and Tienson 2002) while most representationalists
insist that intentionality is prior to consciousness (Gennaro 2012, chapter
two).
The general view that we can explain conscious mental states in
terms of representational or intentional states is called
“representationalism.” Although not automatically reductionist in spirit, most
versions of representationalism do indeed attempt such a reduction. Most
representationalists, then, believe that there is room for a kind of
“second-step” reduction to be filled in later by neuroscience. The other
related motivation for representational theories of consciousness is that many
believe that an account of representation or intentionality can more easily be
given in naturalistic terms, such as causal theories whereby mental states are
understood as representing outer objects in virtue of some reliable causal
connection. The idea, then, is that if consciousness can be explained in
representational terms and representation can be understood in purely physical
terms, then there is the promise of a reductionist and naturalistic theory of
consciousness. Most generally, however, we can say that a representationalist
will typically hold that the phenomenal properties of experience (that is, the
“qualia” or “what it is like of experience” or “phenomenal character”) can be
explained in terms of the experiences’ representational properties.
Alternatively, conscious mental states have no mental properties other than
their representational properties. Two conscious states with all the same
representational properties will not differ phenomenally. For example, when I
look at the blue sky, what it is like for me to have a conscious experience of
the sky is simply identical with my experience’s representation of the blue
sky.
A First-order representational (FOR) theory of consciousness is a
theory that attempts to explain conscious experience primarily in terms of
world-directed (or first-order) intentional states. Probably the two most cited
FOR theories of consciousness are those of Fred Dretske (1995) and Michael Tye
(1995, 2000), though there are many others as well (e.g., Harman 1990, Kirk
1994, Byrne 2001, Thau 2002, Droege 2003). Tye’s theory is more fully worked
out and so will be the focus of this section. Like other FOR theorists, Tye
holds that the representational content of my conscious experience (that is,
what my experience is about or directed at) is identical with the phenomenal
properties of experience. Aside from reductionistic motivations, Tye and other
FOR representationalists often use the somewhat technical notion of the
“transparency of experience” as support for their view (Harman 1990). This is
an argument based on the phenomenological first-person observation, which goes
back to Moore (1903), that when one turns one’s attention away from, say, the
blue sky and onto one’s experience itself, one is still only aware of the
blueness of the sky. The experience itself is not blue; rather, one “sees right
through” one’s experience to its representational properties, and there is
nothing else to one’s experience over and above such properties.
Whatever the merits and exact nature of the argument from
transparency (see Kind 2003), it is clear, of course, that not all mental
representations are conscious, so the key question eventually becomes: What
exactly distinguishes conscious from unconscious mental states (or
representations)? What makes a mental state a conscious mental state? Here Tye
defends what he calls “PANIC theory.” The acronym “PANIC” stands for poised,
abstract, non-conceptual, intentional content. Without probing into every
aspect of PANIC theory, Tye holds that at least some of the representational
content in question is non-conceptual (N), which is to say that the subject can
lack the concept for the properties represented by the experience in question,
such as an experience of a certain shade of red that one has never seen before.
Actually, the exact nature or even existence of non-conceptual content of
experience is itself a highly debated and difficult issue in philosophy of mind
(Gunther 2003). Gennaro (2012), for example, defends conceptualism
and connects it in various ways to the higher-order thought theory of
consciousness (see section 4b.ii). Conscious states clearly must also have
“intentional content” (IC) for any representationalist. Tye also asserts that
such content is “abstract” (A) and not necessarily about particular concrete
objects. This condition is needed to handle cases of hallucinations, where
there are no concrete objects at all or cases where different objects look
phenomenally alike. Perhaps most important for mental states to be conscious,
however, is that such content must be “poised” (P), which is an importantly
functional notion. The “key idea is that experiences and feelings...stand ready
and available to make a direct impact on beliefs and/or desires. For
example…feeling hungry… has an immediate cognitive effect, namely, the desire
to eat….States with nonconceptual content that are not so poised lack
phenomenal character [because]…they arise too early, as it were, in the
information processing” (Tye 2000: 62).
One objection to Tye’s theory is that it does not really address
the hard problem of phenomenal consciousness (see section 3b.i). This is partly
because what really seems to be doing most of the work on Tye’s PANIC account
is the very functional sounding “poised” notion, which is perhaps closer to
Block’s access consciousness (see section 1) and is therefore not necessarily
able to explain phenomenal consciousness (see Kriegel 2002). In short, it is
difficult to see just how Tye’s PANIC account might not equally apply to
unconscious representations and thus how it really explains phenomenal
consciousness.
Other standard objections to Tye’s theory as well as to other FOR
accounts include the concern that it does not cover all kinds of conscious
states. Some conscious states seem not to be “about” anything, such as pains,
anxiety, or after-images, and so would be non-representational conscious
states. If so, then conscious experience cannot generally be explained in terms
of representational properties (Block 1996). Tye responds that pains, itches,
and the like do represent, in the sense that they represent parts of the body.
And after-images, hallucinations, and the like either misrepresent (which is
still a kind of representation) or the conscious subject still takes them to
have representational properties from the first-person point of view. Indeed,
Tye (2000) admirably goes to great lengths and argues convincingly in response
to a whole host of alleged counter-examples to representationalism.
Historically among them are various hypothetical cases of inverted qualia (see
Shoemaker 1982), the mere possibility of which is sometimes taken as
devastating to representationalism. These are cases where behaviorally
indistinguishable individuals have inverted color perceptions of objects, such
as person A visually experiences a lemon the way that person B experience a
ripe tomato with respect to their color, and so on for all yellow and red
objects. Isn’t it possible that there are two individuals whose color
experiences are inverted with respect to the objects of perception? (For more on
the importance of color in philosophy, see Hardin 1986.)
A somewhat different twist on the inverted spectrum is famously
put forth in Block’s (1990) Inverted Earth case. On Inverted Earth every object
has the complementary color to the one it has here, but we are asked to imagine
that a person is equipped with color-inverting lenses and then sent to Inverted
Earth completely ignorant of those facts. Since the color inversions cancel
out, the phenomenal experiences remain the same, yet there certainly seem to be
different representational properties of objects involved. The strategy on the
part of critics, in short, is to think of counter-examples (either actual or
hypothetical) whereby there is a difference between the phenomenal properties
in experience and the relevant representational properties in the world. Such
objections can, perhaps, be answered by Tye and others in various ways, but
significant debate continues (Macpherson 2005). Intuitions also dramatically
differ as to the very plausibility and value of such thought experiments. (For
more, see Seager 1999, chapters 6 and 7. See also Chalmers 2004 for an
excellent discussion of the dizzying array of possible representationalist
positions.)
As we have seen, one question that should be answered by any
theory of consciousness is: What makes a mental state a conscious mental state?
There is a long tradition that has attempted to understand consciousness in
terms of some kind of higher-order awareness. For example, John Locke
(1689/1975) once said that “consciousness is the perception of what passes in a
man’s own mind.” This intuition has been revived by a number of philosophers
(Rosenthal, 1986, 1993b, 1997, 2000, 2004, 2005; Gennaro 1996a, 2012;
Armstrong, 1968, 1981; Lycan, 1996, 2001). In general, the idea is that what
makes a mental state conscious is that it is the object of some kind of
higher-order representation (HOR). A mental state M becomes conscious when
there is a HOR of M. A HOR is a “meta-psychological” state, i.e., a mental
state directed at another mental state. So, for example, my desire to write a
good encyclopedia entry becomes conscious when I am (non-inferentially) “aware”
of the desire. Intuitively, it seems that conscious states, as opposed to unconscious
ones, are mental states that I am “aware of” in some sense. This is sometimes
referred to as the Transitivity Principle. Any theory which attempts to explain
consciousness in terms of higher-order states is known as a higher-order (HO)
theory of consciousness. It is best initially to use the more neutral term
“representation” because there are a number of different kinds of higher-order
theory, depending upon how one characterizes the HOR in question. HO theories,
thus, attempt to explain consciousness in mentalistic terms, that is, by
reference to such notions as “thoughts” and “awareness.” Conscious mental
states arise when two unconscious mental states are related in a certain
specific way; namely, that one of them (the HOR) is directed at the other (M).
HO theorists are united in the belief that their approach can better explain
consciousness than any purely FOR theory, which has significant difficulty in
explaining the difference between unconscious and conscious mental states.
There are various kinds of HO theory with the most common division
between higher-order thought (HOT) theories and higher-order perception (HOP)
theories. HOT theorists, such as David M. Rosenthal, think it is better to understand
the HOR as a thought of some kind. HOTs are treated as cognitive states
involving some kind of conceptual component. HOP theorists urge that the HOR is
a perceptual or experiential state of some kind (Lycan 1996) which does not
require the kind of conceptual content invoked by HOT theorists. Partly due to
Kant (1781/1965), HOP theory is sometimes referred to as “inner sense theory”
as a way of emphasizing its sensory or perceptual aspect. Although HOT and HOP
theorists agree on the need for a HOR theory of consciousness, they do
sometimes argue for the superiority of their respective positions (such as in
Rosenthal 2004, Lycan 2004, and Gennaro 2012). Some philosophers, however, have
argued that the difference between these theories is perhaps not as important
or as clear as some think it is (Güzeldere 1995, Gennaro 1996a, Van Gulick
2000).
A common initial objection to HOR theories is that they are
circular and lead to an infinite regress. It might seem that the HOT theory
results in circularity by defining consciousness in terms of HOTs. It also
might seem that an infinite regress results because a conscious mental state
must be accompanied by a HOT, which, in turn, must be accompanied by another
HOT ad infinitum. However, the standard reply is that when
a conscious mental state is a first-order world-directed state the higher-order
thought (HOT) is not itself conscious; otherwise, circularity and an infinite
regress would follow. When the HOT is itself conscious, there is a yet
higher-order (or third-order) thought directed at the second-order state. In
this case, we have introspection which involves a conscious HOT directed at an
inner mental state. When one introspects, one's attention is directed back into
one's mind. For example, what makes my desire to write a good entry a conscious
first-order desire is that there is a (non-conscious) HOT directed at the
desire. In this case, my conscious focus is directed at the entry and my
computer screen, so I am not consciously aware of having the HOT from the
first-person point of view. When I introspect that desire, however, I then have
a conscious HOT (accompanied by a yet higher, third-order, HOT) directed at the
desire itself (see Rosenthal 1986).
Peter Carruthers (2000) has proposed another possibility within HO
theory; namely, that it is better for various reasons to think of the HOTs as
dispositional states instead of the standard view that the HOTs are actual,
though he also understands his “dispositional HOT theory” to be a form of HOP
theory (Carruthers 2004). The basic idea is that the conscious status of an
experience is due to its availability to higher-order thought. So “conscious
experience occurs when perceptual contents are fed into a special short-term
buffer memory store, whose function is to make those contents available to
cause HOTs about themselves.” (Carruthers 2000: 228). Some first-order
perceptual contents are available to a higher-order “theory of mind mechanism,”
which transforms those representational contents into conscious contents. Thus,
no actual HOT occurs. Instead, according to Carruthers, some perceptual states
acquire a dual intentional content; for example, a conscious experience of red
not only has a first-order content of “red,” but also has the higher-order
content “seems red” or “experience of red.” Carruthers also makes interesting
use of so-called “consumer semantics” in order to fill out his theory of
phenomenal consciousness. The content of a mental state depends, in part, on
the powers of the organisms which “consume” that state, e.g., the kinds of
inferences which the organism can make when it is in that state. Daniel Dennett
(1991) is sometimes credited with an earlier version of a dispositional account
(see Carruthers 2000, chapter ten). Carruthers’ dispositional theory is often
criticized by those who, among other things, do not see how the mere
disposition toward a mental state can render it conscious (Rosenthal 2004; see
also Gennaro 2004, 2012; for more, see Consciousness, Higher Order Theories of.
It is worth briefly noting a few typical objections to HO theories
(many of which can be found in Byrne 1997): First, and perhaps most common, is
that various animals (and even infants) are not likely to have to the conceptual
sophistication required for HOTs, and so that would render animal (and infant)
consciousness very unlikely (Dretske 1995, Seager 2004). Are cats and dogs
capable of having complex higher-order thoughts such as “I am in mental state
M”? Although most who bring forth this objection are not HO theorists, Peter
Carruthers (1989) is one HO theorist who actually embraces the conclusion that
(most) animals do not have phenomenal consciousness. Gennaro (1993, 1996) has
replied to Carruthers on this point; for example, it is argued that the HOTs
need not be as sophisticated as it might initially appear and there is ample
comparative neurophysiological evidence supporting the conclusion that animals
have conscious mental states. Most HO theorists do not wish to accept the
absence of animal or infant consciousness as a consequence of holding the
theory. The debate continues, however, in Carruthers (2000, 2005, 2008) and
Gennaro (2004, 2009, 2012, chapters seven and eight).
A second objection has been referred to as the “problem of the
rock” (Stubenberg 1998) and the “generality problem” (Van Gulick 2000, 2004),
but it is originally due to Alvin Goldman (Goldman 1993). When I have a thought
about a rock, it is certainly not true that the rock becomes conscious. So why
should I suppose that a mental state becomes conscious when I think about it?
This is puzzling to many and the objection forces HO theorists to explain just
how adding the HO state changes an unconscious state into a conscious. There
have been, however, a number of responses to this kind of objection (Rosenthal
1997, Lycan, 1996, Van Gulick 2000, 2004, Gennaro 2005, 2012, chapter four). A
common theme is that there is a principled difference in the objects of the HO
states in question. Rocks and the like are not mental states in the first
place, and so HO theorists are first and foremost trying to explain how a
mental state becomes conscious. The objects of the HO states
must be “in the head.”
Third, the above leads somewhat naturally to an objection related
to Chalmers’ hard problem (section 3b.i). It might be asked just how exactly
any HO theory really explains the subjective or phenomenal aspect of conscious
experience. How or why does a mental state come to have a first-person
qualitative “what it is like” aspect by virtue of the presence of a HOR
directed at it? It is probably fair to say that HO theorists have been slow to
address this problem, though a number of overlapping responses have emerged
(see also Gennaro 2005, 2012, chapter four, for more extensive treatment).
Some argue that this objection misconstrues the main and more modest purpose of
(at least, their) HO theories. The claim is that HO theories are theories of
consciousness only in the sense that they are attempting to explain what differentiates
conscious from unconscious states, i.e., in terms of a higher-order awareness
of some kind. A full account of “qualitative properties” or “sensory qualities”
(which can themselves be non-conscious) can be found elsewhere in their work,
but is independent of their theory of consciousness (Rosenthal 1991, Lycan
1996, 2001). Thus, a full explanation of phenomenal consciousness does require
more than a HO theory, but that is no objection to HO theories as such. Another
response is that proponents of the hard problem unjustly raise the bar as to
what would count as a viable explanation of consciousness so that any such
reductivist attempt would inevitably fall short (Carruthers 2000, Gennaro
2012). Part of the problem, then, is a lack of clarity about what would even
count as an explanation of consciousness (Van Gulick 1995; see also section
3b). Once this is clarified, however, the hard problem can indeed be
solved. Moreover, anyone familiar with the literature knows that there are
significant terminological difficulties in the use of various crucial terms
which sometimes inhibits genuine progress (but see Byrne 2004 for some helpful
clarification).
A fourth important objection to HO approaches is the question of
how such theories can explain cases where the HO state might misrepresent the
lower-order (LO) mental state (Byrne 1997, Neander 1998, Levine 2001, Block
2011). After all, if we have a representational relation between two states, it
seems possible for misrepresentation or malfunction to occur. If it does, then
what explanation can be offered by the HO theorist? If my LO state registers a
red percept and my HO state registers a thought about something green due, say,
to some neural misfiring, then what happens? It seems that problems loom for
any answer given by a HO theorist and the cause of the problem has to do with
the very nature of the HO theorist’s belief that there is a representational
relation between the LO and HO states. For example, if the HO theorist takes
the option that the resulting conscious experience is reddish, then it seems
that the HO state plays no role in determining the qualitative character of the
experience. On the other hand, if the resulting experience is greenish, then
the LO state seems irrelevant. Rosenthal and Weisberg hold that the HO
state determines the qualitative properties even in cases when there is no LO
state at all (Rosenthal 2005, 2011, Weisberg 2008, 2011a, 2011b). Gennaro
(2012) argues that no conscious experience results in such cases and wonders,
for example, how a sole (unconscious) HOT can result in a conscious state at
all. He argues that there must be a match, complete or partial, between
the LO and HO state in order for a conscious state to exist in the first place.
This important objection forces HO theorists to be clearer about just how to
view the relationship between the LO and HO states. Debate is ongoing and
significant both on varieties of HO theory and in terms of the above objections
(see Gennaro 2004a). There is also interdisciplinary interest in how various HO
theories might be realized in the brain (Gennaro 2012, chapter nine).
A related and increasingly popular version of representational
theory holds that the meta-psychological state in question should be understood
as intrinsic to (or part of) an overall complex conscious state. This stands in
contrast to the standard view that the HO state is extrinsic to (that is,
entirely distinct from) its target mental state. The assumption, made by Rosenthal
for example, about the extrinsic nature of the meta-thought has increasingly
come under attack, and thus various hybrid representational theories can be
found in the literature. One motivation for this movement is growing
dissatisfaction with standard HO theory’s ability to handle some of the
objections addressed in the previous section. Another reason is renewed
interest in a view somewhat closer to the one held by Franz Brentano
(1874/1973) and various other followers, normally associated with the phenomenological
tradition (Husserl 1913/1931,
1929/1960; Sartre 1956; see also Smith 1986, 2004). To varying degrees, these
views have in common the idea that conscious mental states, in some sense,
represent themselves, which then still involves having a thought about a mental
state, just not a distinct or separate state. Thus, when one has a conscious
desire for a cold glass of water, one is also aware that one is in that very
state. The conscious desire both represents the glass of water and itself. It
is this “self-representing” which makes the state conscious.
These theories can go by various names, which sometimes seem in
conflict, and have added significantly in recent years to the acronyms which
abound in the literature. For example, Gennaro (1996a, 2002, 2004, 2006, 2012)
has argued that, when one has a first-order conscious state, the HOT is better
viewed as intrinsic to the target state, so that we have a complex conscious
state with parts. Gennaro calls this the “wide intrinsicality view” (WIV) and
he also argues that Jean-Paul Sartre’s theory of consciousness can be
understood in this way (Gennaro 2002). Gennaro holds that conscious mental
states should be understood (as Kant might have today) as global brain states
which are combinations of passively received perceptual input and presupposed
higher-order conceptual activity directed at that input. Higher-order concepts
in the meta-psychological thoughts are presupposed in having first-order
conscious states. Robert Van Gulick (2000, 2004, 2006) has also explored the
alternative that the HO state is part of an overall global conscious state. He
calls such states “HOGS” (Higher-Order Global States) whereby a lower-order
unconscious state is “recruited” into a larger state, which becomes conscious
partly due to the implicit self-awareness that one is in the lower-order state.
Both Gennaro and Van Gulick have suggested that conscious states can be understood
materialistically as global states of the brain, and it would be better to
treat the first-order state as part of the larger complex brain state. This
general approach is also forcefully advocated by Uriah Kriegel (Kriegel
2003a, 2003b, 2005, 2006, 2009) and is even the subject of an entire anthology
debating its merits (Kriegel and Williford 2006). Kriegel has used several
different names for his “neo-Brentanian theory,” such as the SOMT (Same-Order
Monitoring Theory) and, more recently, the “self-representational theory of
consciousness.” To be sure, the notion of a mental state representing itself or
a mental state with one part representing another part is in need of further
development and is perhaps somewhat mysterious. Nonetheless, there is agreement
among these authors that conscious mental states are, in some important sense,
reflexive or self-directed. And, once again, there is keen interest in
developing this model in a way that coheres with the latest neurophysiological
research on consciousness. A point of emphasis is on the concept of global
meta-representation within a complex brain state, and attempts are underway to
identify just how such an account can be realized in the brain.
It is worth mentioning that this idea was also briefly explored by
Thomas Metzinger who focused on the fact that consciousness “is something that
unifies or synthesizes experience” (Metzinger 1995: 454). Metzinger calls this
the process of “higher-order binding” and thus uses the acronym HOB. Others who
hold some form of the self-representational view include Kobes (1995), Caston
(2002), Williford (2006), Brook and Raymont (2006), and even Carruthers’ (2000)
theory can be viewed in this light since he contends that conscious states have
two representational contents. Thomas Natsoulas also has a series of papers
defending a similar view, beginning with Natsoulas 1996. Some authors (such as
Gennaro 2012) view this hybrid position to be a modified version of HOT theory;
indeed, Rosenthal (2004) has called it “intrinsic higher-order theory.” Van
Gulick also clearly wishes to preserve the HO is his HOGS. Others, such as
Kriegel, are not inclined to call their views “higher-order” at all and call
it, for example, the “same-order monitoring” or “self-representational” theory
of consciousness. To some extent, this is a terminological dispute, but,
despite important similarities, there are also key subtle differences between
these hybrid alternatives. Like HO theorists, however, those who advocate this
general approach all take very seriously the notion that a conscious mental
state M is a state that subject S is (non-inferentially) aware that S is in. By
contrast, one is obviously not aware of one’s unconscious mental states. Thus,
there are various attempts to make sense of and elaborate upon this key
intuition in a way that is, as it were, “in-between” standard FO and HO theory.
(See also Lurz 2003 and 2004 for yet another interesting hybrid account.)
Aside from the explicitly representational approaches discussed
above, there are also related attempts to explain consciousness in other
cognitive terms. The two most prominent such theories are worth describing
here:
Daniel Dennett (1991, 2005) has put forth what he calls the
Multiple Drafts Model (MDM) of consciousness. Although similar in some ways to
representationalism, Dennett is most concerned that materialists avoid falling
prey to what he calls the “myth of the Cartesian theater,” the notion that
there is some privileged place in the brain where everything comes together to
produce conscious experience. Instead, the MDM holds that all kinds of mental
activity occur in the brain by parallel processes of interpretation, all of
which are under frequent revision. The MDM rejects the idea of some “self” as
an inner observer; rather, the self is the product or construction of a
narrative which emerges over time. Dennett is also well known for rejecting the
very assumption that there is a clear line to be drawn between conscious and
unconscious mental states in terms of the problematic notion of “qualia.” He
influentially rejects strong emphasis on any phenomenological or first-person
approach to investigating consciousness, advocating instead what he calls
“heterophenomenology” according to which we should follow a more neutral path
“leading from objective physical science and its insistence on the third person
point of view, to a method of phenomenological description that can (in
principle) do justice to the most private and ineffable subjective experiences.”
(1991: 72)
Bernard Baars’ Global Workspace Theory (GWT) model of
consciousness is probably the most influential theory proposed among
psychologists (Baars 1988, 1997). The basic idea and metaphor is that we should
think of the entire cognitive system as built on a “blackboard architecture”
which is a kind of global workspace. According to GWT, unconscious processes
and mental states compete for the spotlight of attention, from which
information is “broadcast globally” throughout the system. Consciousness
consists in such global broadcasting and is therefore also, according to Baars,
an important functional and biological adaptation. We might say that
consciousness is thus created by a kind of global access to select bits of
information in the brain and nervous system. Despite Baars’ frequent use of
“theater” and “spotlight” metaphors, he argues that his view does not entail
the presence of the material Cartesian theater that Dennett is so concerned to
avoid. It is, in any case, an empirical matter just how the brain performs the
functions he describes, such as detecting mechanisms of attention.
Objections to these cognitive theories include the charge that
they do not really address the hard problem of consciousness (as described in
section 3b.i), but only the “easy” problems. Dennett is also often accused of
explaining away consciousness rather than really explaining it. It is also
interesting to think about Baars’ GWT in light of the Block’s distinction
between access and phenomenal consciousness (see section 1). Does Baars’ theory
only address access consciousness instead of the more difficult to explain
phenomenal consciousness? (Two other psychological cognitive theories worth
noting are the ones proposed by George Mandler 1975 and Tim Shallice 1988.)
Finally, there are those who look deep beneath the neural level to
the field of quantum mechanics, basically the study of sub-atomic particles, to
find the key to unlocking the mysteries of consciousness. The bizarre world of
quantum physics is quite different from the deterministic world of classical
physics, and a major area of research in its own right. Such authors place the
locus of consciousness at a very fundamental physical level. This somewhat
radical, though exciting, option is explored most notably by physicist Roger
Penrose (1989, 1994) and anesthesiologist Stuart Hameroff (1998). The basic
idea is that consciousness arises through quantum effects which occur in
subcellular neural structures known as microtubules, which are structural
proteins in cell walls. There are also other quantum approaches which aim to
explain the coherence of consciousness (Marshall and Zohar 1990) or use the
“holistic” nature of quantum mechanics to explain consciousness (Silberstein
1998, 2001). It is difficult to assess these somewhat exotic approaches at
present. Given the puzzling and often very counterintuitive nature of quantum
physics, it is unclear whether such approaches will prove genuinely
scientifically valuable methods in explaining consciousness. One concern is
simply that these authors are trying to explain one puzzling phenomenon
(consciousness) in terms of another mysterious natural phenomenon (quantum
effects). Thus, the thinking seems to go, perhaps the two are essentially related
somehow and other physicalistic accounts are looking in the wrong place, such
as at the neuro-chemical level. Although many attempts to explain consciousness
often rely of conjecture or speculation, quantum approaches may indeed lead the
field along these lines. Of course, this doesn’t mean that some such theory
isn’t correct. One exciting aspect of this approach is the resulting
interdisciplinary interest it has generated among physicists and other
scientists in the problem of consciousness.
Over the past two decades there has been an explosion of
interdisciplinary work in the science of consciousness. Some of the credit must
go to the ground breaking 1986 book by Patricia Churchland entitled Neurophilosophy. In this section, three of the most
important such areas are addressed.
Conscious experience seems to be “unified” in an important sense;
this crucial feature of consciousness played an important role in the philosophy
of Kant who argued that unified conscious experience must be the product of the
(presupposed) synthesizing work of the mind. Getting clear about exactly what
is meant by the “unity of consciousness” and explaining how the brain achieves
such unity has become a central topic in the study of consciousness. There are
many different senses of “unity” (see Tye 2003; Bayne and Chalmers 2003,
Dainton 2000, 2008, Bayne 2010), but perhaps most common is the notion that,
from the first-person point of view, we experience the world in an integrated
way and as a single phenomenal field of experience. (For an important anthology
on the subject, see Cleeremans 2003.) However, when one looks at how the brain
processes information, one only sees discrete regions of the cortex processing
separate aspects of perceptual objects. Even different aspects of the same
object, such as its color and shape, are processed in different parts of the
brain. Given that there is no “Cartesian theater” in the brain where all this
information comes together, the problem arises as to just how the resulting
conscious experience is unified. What mechanisms allow us to experience the
world in such a unified way? What happens when this unity breaks down, as in
various pathological cases? The “problem of integrating the information
processed by different regions of the brain is known as the binding problem”
(Cleeremans 2003: 1). Thus, the so-called “binding problem” is inextricably
linked to explaining the unity of consciousness. As was seen earlier with
neural theories (section 4a) and as will be seen below on the neural correlates
of consciousness (5b), some attempts to solve the binding problem have to do
with trying to isolate the precise brain mechanisms responsible for
consciousness. For example, Crick and Koch’s (1990) idea that synchronous
neural firings are (at least) necessary for consciousness can also be viewed as
an attempt to explain how disparate neural networks bind together separate
pieces of information to produce unified subjective conscious experience.
Perhaps the binding problem and the hard problem of consciousness (section
3b.i) are very closely connected. If the binding problem can be solved, then we
arguably have identified the elusive neural correlate of consciousness and have,
therefore, perhaps even solved the hard problem. In addition, perhaps the
explanatory gap between third-person scientific knowledge and first-person
unified conscious experience can also be bridged. Thus, this exciting area of
inquiry is central to some of the deepest questions in the philosophical and
scientific exploration of consciousness.
As was seen earlier in discussing neural theories of consciousness
(section 4a), the search for the so-called “neural correlates of consciousness”
(NCCs) is a major preoccupation of philosophers and scientists alike (Metzinger
2000). Narrowing down the precise brain property responsible for consciousness
is a different and far more difficult enterprise than merely holding a generic
belief in some form of materialism. One leading candidate is offered by Francis
Crick and Christof Koch 1990 (see also Crick 1994, Koch 2004). The basic idea
is that mental states become conscious when large numbers of neurons all fire in
synchrony with one another (oscillations within the 35-75 hertz range or 35-75
cycles per second). Currently, one method used is simply to study some aspect
of neural functioning with sophisticated detecting equipments (such as MRIs and
PET scans) and then correlate it with first-person reports of conscious
experience. Another method is to study the difference in brain activity between
those under anesthesia and those not under any such influence. A detailed
survey would be impossible to give here, but a number of other candidates for
the NCC have emerged over the past two decades, including reentrant cortical
feedback loops in the neural circuitry throughout the brain (Edelman 1989,
Edelman and Tononi 2000), NMDA-mediated transient neural assemblies (Flohr 1995),
and emotive somatosensory haemostatic processes in the frontal lobe (Damasio
1999). To elaborate briefly on Flohr’s theory, the idea is that anesthetics
destroy conscious mental activity because they interfere with the functioning
of NMDA synapses between neurons, which are those that are dependent on
N-methyl-D-aspartate receptors. These and other NCCs are explored at length in
Metzinger (2000). Ongoing scientific investigation is significant and an
important aspect of current scientific research in the field.
One problem with some of the above candidates is determining
exactly how they are related to consciousness. For example, although a case can
be made that some of them are necessary for conscious mentality, it is unclear
that they are sufficient. That is, some of the above seem to occur
unconsciously as well. And pinning down a narrow enough necessary condition is
not as easy as it might seem. Another general worry is with the very use of the
term “correlate.” As any philosopher, scientist, and even undergraduate student
should know, saying that “A is correlated with B” is rather weak (though it is
an important first step), especially if one wishes to establish the stronger
identity claim between consciousness and neural activity. Even if such a correlation
can be established, we cannot automatically conclude that there is an identity
relation. Perhaps A causes B or B causes A, and that’s why we find the
correlation. Even most dualists can accept such interpretations. Maybe there is
some other neural process C which causes both A and B. “Correlation” is not
even the same as “cause,” let alone enough to establish “identity.” Finally,
some NCCs are not even necessarily put forth as candidates for all conscious
states, but rather for certain specific kinds of consciousness (e.g., visual).
Philosophers have long been intrigued by disorders of the mind and
consciousness. Part of the interest is presumably that if we can understand how
consciousness goes wrong, then that can help us to theorize about the normal
functioning mind. Going back at least as far as John Locke (1689/1975), there
has been some discussion about the philosophical implications of multiple
personality disorder (MPD) which is now called “dissociative identity disorder”
(DID). Questions abound: Could there be two centers of consciousness in one
body? What makes a person the same person over time? What makes a person a
person at any given time? These questions are closely linked to the traditional
philosophical problem of personal identity, which is also importantly related
to some aspects of consciousness research. Much the same can be said for memory
disorders, such as various forms of amnesia (see Gennaro 1996a, chapter 9).
Does consciousness require some kind of autobiographical memory or
psychological continuity? On a related front, there is significant interest in
experimental results from patients who have undergone a commisurotomy, which is
usually performed to relieve symptoms of severe epilepsy when all else fails.
During this procedure, the nerve fibers connecting the two brain hemispheres
are cut, resulting in so-called “split-brain” patients (Bayne 2010).
Philosophical interest is so high that there is now a book series
called Philosophical Psychopathology published by MIT
Press. Another rich source of information comes from the provocative and
accessible writings of neurologists on a whole host of psychopathologies, most
notably Oliver Sacks (starting with his 1987 book) and, more recently, V. S. Ramachandran
(2004; see also Ramachandran and Blakeslee 1998). Another launching point came
from the discovery of the phenomenon known as “blindsight” (Weiskrantz 1986),
which is very frequently discussed in the philosophical literature regarding
its implications for consciousness. Blindsight patients are blind in a well
defined part of the visual field (due to cortical damage), but yet, when
forced, can guess, with a higher than expected degree of accuracy, the location
or orientation of an object in the blind field.
There is also philosophical interest in many other disorders, such
as phantom limb pain (where one feels pain in a missing or amputated limb),
various agnosias (such as visual agnosia where one is not capable of visually
recognizing everyday objects), and anosognosia (which is denial of illness,
such as when one claims that a paralyzed limb is still functioning, or when one
denies that one is blind). These phenomena raise a number of important
philosophical questions and have forced philosophers to rethink some very basic
assumptions about the nature of mind and consciousness. Much has also recently
been learned about autism and various forms of schizophrenia. A common view is
that these disorders involve some kind of deficit in self-consciousness or in
one’s ability to use certain self-concepts. (For a nice review article, see
Graham 2002.) Synesthesia is also a fascinating abnormal phenomenon, although
not really a “pathological” condition as such (Cytowic 2003). Those with
synesthesia literally have taste sensations when seeing certain shapes or have
color sensations when hearing certain sounds. It is thus an often bizarre
mixing of incoming sensory input via different modalities.
One of the exciting results of this relatively new sub-field is the
important interdisciplinary interest that it has generated among philosophers,
psychologists, and scientists (such as in Graham 2010, Hirstein 2005, and
Radden 2004).
Two final areas of interest involve animal and machine
consciousness. In the former case it is clear that we have come a long way from
the Cartesian view that animals are mere “automata” and that they do not even
have conscious experience (perhaps partly because they do not have immortal
souls). In addition to the obviously significant behavioral similarities
between humans and many animals, much more is known today about other
physiological similarities, such as brain and DNA structures. To be sure, there
are important differences as well and there are, no doubt, some genuinely
difficult “grey areas” where one might have legitimate doubts about some animal
or organism consciousness, such as small rodents, some birds and fish, and
especially various insects. Nonetheless, it seems fair to say that most philosophers
today readily accept the fact that a significant portion of the animal kingdom
is capable of having conscious mental states, though there are still notable
exceptions to that rule (Carruthers 2000, 2005). Of course, this is not to say
that various animals can have all of the same kinds of sophisticated conscious
states enjoyed by human beings, such as reflecting on philosophical and
mathematical problems, enjoying artworks, thinking about the vast universe or
the distant past, and so on. However, it still seems reasonable to believe that
animals can have at least some conscious states from rudimentary pains to
various perceptual states and perhaps even to some level of self-consciousness.
A number of key areas are under continuing investigation. For example, to what
extent can animals recognize themselves, such as in a mirror, in order to
demonstrate some level of self-awareness? To what extent can animals deceive or
empathize with other animals, either of which would indicate awareness of the
minds of others? These and other important questions are at the center of much
current theorizing about animal cognition. (See Keenan et. al. 2003 and Beckoff
et. al. 2002.) In some ways, the problem of knowing about animal minds is an
interesting sub-area of the traditional epistemological “problem of other
minds”: How do we even know that other humans have conscious minds? What
justifies such a belief?
The possibility of machine (or robot) consciousness has intrigued
philosophers and non-philosophers alike for decades. Could a machine really
think or be conscious? Could a robot really subjectively experience the
smelling of a rose or the feeling of pain? One important early launching point
was a well-known paper by the mathematician Alan Turing (1950) which proposed
what has come to be known as the “Turing test” for machine intelligence and
thought (and perhaps consciousness as well). The basic idea is that if a
machine could fool an interrogator (who could not see the machine) into
thinking that it was human, then we should say it thinks or, at least, has
intelligence. However, Turing was probably overly optimistic about whether
anything even today can pass the Turing Test, as most programs are specialized
and have very narrow uses. One cannot ask the machine about virtually anything,
as Turing had envisioned. Moreover, even if a machine or robot could pass the
Turing Test, many remain very skeptical as to whether or not this demonstrates
genuine machine thinking, let alone consciousness. For one thing, many philosophers
would not take such purely behavioral (e.g., linguistic) evidence to support
the conclusion that machines are capable of having phenomenal first person
experiences. Merely using words like “red” doesn’t ensure that there is the
corresponding sensation of red or real grasp of the meaning of “red.” Turing
himself considered numerous objections and offered his own replies, many of
which are still debated today.
Another much discussed argument is John Searle’s (1980)
famous Chinese
Room Argument, which has spawned an enormous amount of literature
since its original publication (see also Searle 1984; Preston and Bishop 2002).
Searle is concerned to reject what he calls “strong AI” which is the view that
suitably programmed computers literally have a mind, that is, they really
understand language and actually have other mental capacities similar to
humans. This is contrasted with “weak AI” which is the view that computers are
merely useful tools for studying the mind. The gist of Searle’s argument is
that he imagines himself running a program for using Chinese and then shows
that he does not understand Chinese; therefore, strong AI is false; that is,
running the program does not result in any real understanding (or thought or
consciousness, by implication). Searle supports his argument against strong AI
by utilizing a thought experiment whereby he is in a room and follows English
instructions for manipulating Chinese symbols in order to produce appropriate
answers to questions in Chinese. Searle argues that, despite the appearance of
understanding Chinese (say, from outside the room), he does not understand
Chinese at all. He does not thereby know Chinese, but is merely manipulating
symbols on the basis of syntax alone. Since this is what computers do, no
computer, merely by following a program, genuinely understands anything. Searle
replies to numerous possible criticisms in his original paper (which also comes
with extensive peer commentary), but suffice it to say that not everyone is
satisfied with his responses. For example, it might be argued that the entire
room or “system” understands Chinese if we are forced to use Searle’s analogy
and thought experiment. Each part of the room doesn’t understand Chinese (including
Searle himself) but the entire system does, which includes the instructions and
so on. Searle’s larger argument, however, is that one cannot get semantics
(meaning) from syntax (formal symbol manipulation).
Despite heavy criticism of the argument, two central issues are
raised by Searle which continue to be of deep interest. First, how and when
does one distinguish mere “simulation” of some mental activity from genuine
“duplication”? Searle’s view is that computers are, at best, merely simulating
understanding and thought, not really duplicating it. Much like we might say
that a computerized hurricane simulation does not duplicate a real hurricane,
Searle insists the same goes for any alleged computer “mental” activity. We do
after all distinguish between real diamonds or leather and mere simulations
which are just not the real thing. Second, and perhaps even more important,
when considering just why computers really can’t think or be conscious, Searle
interestingly reverts back to a biologically based argument. In essence, he
says that computers or robots are just not made of the right stuff with the
right kind of “causal powers” to produce genuine thought or consciousness.
After all, even a materialist does not have to allow that any kind of physical stuff
can produce consciousness any more than any type of physical substance can,
say, conduct electricity. Of course, this raises a whole host of other
questions which go to the heart of the metaphysics of consciousness. To what
extent must an organism or system be physiologically like us in order to be
conscious? Why is having a certain biological or chemical make up necessary for
consciousness? Why exactly couldn’t an appropriately built robot be capable of
having conscious mental states? How could we even know either way? However one
answers these questions, it seems that building a truly conscious Commander
Data is, at best, still just science fiction.
In any case, the growing areas of cognitive science and artificial
intelligence are major fields within philosophy of mind and can importantly
bear on philosophical questions of consciousness. Much of current research
focuses on how to program a computer to model the workings of the human brain,
such as with so-called “neural (or connectionist) networks.”
Selected and edited from the Internet Encyclopedia of Philosophy: http://www
dot iep dot utm dot edu/consciou/ (A
Peer-Reviewed Academic Resource)
** **
The
above definition is good stuff from your perspective and worth a re-read in the
morning. Post. - Amorella
2231
hours. I have to 'make' a consciousness that has only itself as a form, a
system of sorts that I can at most, overview mentally. A one dimensional being
would be so obviously simple (in my mind) and the problem with the human mind
is that it appears by definition to be amazingly complex. The concept of the
heartansoulanmind as a unity, a trinity, represents the human spirit (in my
thinking). Yet, following my reasoning for/of simplification, it has to be less
than the separate parts that make it up. Indeed, this is good stuff to consider
and think on. Fun stuff. Cool. Neat. Simple. Wow, inside out.
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