WHAT GOOD IS CONSCIOUSNESS?
Fred Dretske
If consciousness is good for something, conscious
things must differ in some causally
relevant
way from unconscious things. If they
do not,
then, as Davies and Humphrey (1993:
4-5) conclude, too bad for consciousness:
"psychological theory need not
be concerned
with this topic."
Davies and
Humphrey
are applying a respectable metaphysical
idea--the
idea, namely, that if X's having C
does make
a difference to what X does, if X's
causal
powers are in no way altered by its
possession
of C, then nothing X does can be explained
by its being C. A science dedicated
to explaining
the behavior of X need not, therefore,
concern
itself with C. That is why being an
uncle
is of no concern to the psychology
(let alone
the physics) of uncles. I am an uncle,
yes,
but my being so does not (causally
speaking[1])
enable me to do anything I would not
otherwise
be able to do. The fact that I am an
uncle
(to be distinguished, of course, from
my
believing I am an uncle) does not explain
anything I do. From the point of view
of
understanding human behavior, then,
the fact
that some humans are uncles is epiphenomenal.
If consciousness is like that--if it
is like
being an uncle--then, for the same
reason,
psychological theory need not be concerned
with it. It has no purpose, no function.
No good comes from being conscious.
Is this really
a worry?
Should it be a worry? The journals
and books,
I know, are full of concern these days
about
the role of consciousness.[2] Much
of this
concern is generated by startling results
in neuropsychology (more of this later).
But is there a real problem here? Can
there
be a serious question about the advantages,
the benefits, the good, of being conscious?
I don't think so. It seems to me that
the
flurry of interest in the biological
function
of consciousness betrays a confusion
about
several quite elementary distinctions.
Once
the distinctions are in place--and
there
is nothing especially arcane or tricky
about
them--the advantages (and, therefore,
the
good) of consciousness is obvious.
1. The First Distinction:
Conscious Beings vs. Conscious States.
Stones
are not conscious, but we are.[3] And
so
are many animals. We are not only conscious
(full stop), we are conscious of things--of
objects (the bug in my soup), events
(the
commotion in the hall), properties
(the color
of his tie), and facts (that he is
following
me). Following Rosenthal (1990), I
call all
these creature consciousness. In this
sense
the word is applied to beings who can
lose
and regain consciousness and be conscious
of things and that things are so.
Creature consciousness is to be distinguished
from what Rosenthal calls state consciousness--the
sense in which certain mental states,
processes,
events and activities
(in or of conscious beings) are said
to be
either conscious. or unconscious. When
we
describe desires, fears, and experiences
as being conscious or unconscious we
attribute
or deny consciousness, not to a being,
but
to some state, condition or process
in that
being. States (processes, etc.), unlike
the
creatures in whom they occur, are not
conscious
of anything or that anything is so
although
we can be conscious of them and their
occurrence
in a creature may make that creature
conscious
of something.
That is the distinction. How does it
help
with our question? I'll say how in
a moment,
but before I do, I need to make a few
things
explicit about my use of relevant terms.
Not everyone (I've discovered) talks
the
way I do when they talk about consciousness.
So let me say how I talk. My language
is,
I think, entirely standard (I use no
technical
terms), but just in case my readers
talk
funny, I want them to know how ordinary
folk
talk about these matters.
For purposes of
this
discussion and in accordance with most
dictionaries
I regard "conscious" and
"aware"
as synonyms. Being conscious of a thing
(or
fact) is being aware of it. Alan White
(1964)
describes interesting differences between
the ordinary use of "aware"
and
"conscious". He also describes
the different liaisons they have to
noticing,
attending, and realizing. Though my
use of
these expressions as synonymous for
present
purposes blurs some of these ordinary
distinctions,
I think nothing essential to this topic
is
lost by ignoring the nuances.
I assume, furthermore, that seeing,
hearing,
smelling, tasting and feeling are specific
forms--sensory forms--of consciousness.
Consciousness
is the genus; seeing, hearing, and
smelling
are species (the traditional five sense
modalities
are not, of course, the only species
of consciousness).
Seeing is visual awareness. Hearing
is auditory
awareness. Smelling burning toast is
becoming
aware--in an olfactory way--of burning
toast.
One might also see the burning toast.
And
feel it. These are other modalities
of awareness,
other ways of being conscious of the
toast.[4]
You may not pay much attention to what
you
see, smell, or hear, but if you see,
smell
or hear it, you are conscious of it.
This is important.
I
say that if you see (hear, etc.) it,
you
are conscious of it. The "it"
refers
to what you are aware of (the burning
toast),
not that you are aware of it. There
are two
ways one might, while being aware of
burning
toast, fail to be aware that one is
aware
of it. First, one might know one is
aware
of something, but not know what it
is. "What
is that I smell," is the remark
of a
person who might well be aware of (i.
e.,
smell) burning toast without being
aware
that he is aware of burning toast.
Second,
even if one knows what it is one is
aware
of--knows that it is burning toast--one
might
not understand what it means to be
aware
of it, might not, therefore, be aware
that
one is aware of it. A small child or
an animal--creatures
who lack the concept of awareness--can
be
conscious of (i. e., smell) burning
toast
without ever being aware that they
are aware
of something. Even if they happen to
know
that what they are aware of is burning
toast,
they do not know--are not, therefore,
aware--that
they are aware of it.
The language here
is
a bit tricky, so let me give another
example.
One can be aware of (hear) a french
horn
without being aware that that is what
it
is. One might think it is a trombone
or (deeply
absorbed in one's work) not be paying
much
attention at all (but later remember
hearing
it). If asked whether you hear a french
horn,
you might well think and say (falsely)
that
you are not. Not being aware that you
are
aware of a french horn does not mean
you
are not aware of a french horn. Hearing
a
french horn is being conscious of a
french
horn. It is not--not necessarily anyway--to
be aware that it is a french horn or
aware
that you are aware of it (or, indeed,
anything).
Mice who hear--and thereby become auditorily
aware of--french horns never become
aware
that they are aware of anything--much
less
of french horns.[5]
So, once again,
when
I say that if you see, hear, or smell
something
you must be conscious of it , the "it"
refers to what you are aware of (burning
toast, a french horn), not what it
is you
are aware of or that you are aware
of it
. To be conscious of an F is not the
same
as being conscious that it is an F
and certainly
not the same as being conscious that
one
is conscious of an F. Animals (not
to mention
human infants) are presumably aware
of a
great many things (they see, smell,
and feel
the things around them). Nonetheless,
without
the concept of awareness, and without
concepts
for most of the things they are aware
of,
they are not aware of what they are
aware
of nor that they are aware of it. What
they
are conscious of is burning toast.
They are
not aware that it is burning toast
nor that
they are aware of it.
So much for terminological
preliminaries. I have not yet said
anything
that is controversial. Still, with
only these
meagre resources, we are in a position
to
usefully divide our original question
into
two more manageable parts. Questions
about
the good of consciousness, about its
purpose
or function, can either be questions
about
creature consciousness or about state
consciousness.
I will, for the rest of this section,
take
them to be questions about creature
consciousness.
I return to state consciousness in
the next
section.
If, then, we take
our
question about the purpose of consciousness
as a question about creature consciousness,
about the benefits that consciousness
affords
the animals who are conscious, the
answer
would appear to be obvious. If animals
could
not see, hear, smell and taste the
objects
in their environment--if they were
not (in
these ways) conscious--how could they
find
food and mates, avoid predators, build
nests,
spin webs, get around obstacles, and,
in
general, do the thousand things that
have
to be done in order to survive and
reproduce?
Let an animal--a
gazelle,
say--who is aware of prowling lions--where
they are and what they are doing--compete
with one who is not and the outcome
is predictable.
The one who is conscious will win hands
down.
Reproductive prospects, needless to
say,
are greatly enhanced by being able
to see
and smell predators. That , surely,
is an
evolutionary answer to questions about
the
benefits of creature consciousness.[6]
Take
away perception--as you do, when you
remove
consciousness--and you are left with
a vegetable.
You are left with an eatee, not an
eater.
That is why the eaters of the world
(most
of them anyway) are conscious.
This answer is
so easy
I expect to be told that I'm not really
answering
the question everyone is asking. I
will surely
be told that questions about the function
of consciousness are not questions
about
why we--conscious beings--are conscious.
It is not a question about the biological
advantage of being able to see, hear,
smell,
and feel (thus, being conscious of)
the things
around us. It is, rather, a question
about
state consciousness, a question about
why
there are conscious states, processes,
and
activities in conscious creatures.
Why, for
instance, do conscious beings have
conscious
experiences and thoughts?
2. The Second Distinction:
Objects vs. Acts of Awareness. If our
question
is a question about the benefits of
state
consciousness, then, of course, we
have preliminary
work to do before we start answering
it.
We have to get clear about what a conscious
state (process, activity) is. What,
for instance,
makes an experience, a thought, a desire,
conscious? We all have a pretty good
grip
on what a conscious animal is. It is
one
that is--via some perceptual modality--aware
of things going on around (or in) it.
There
are, no doubt, modes of awareness,
ways of
being conscious, which we do not know
about
and will never ourselves experience.
We do
not, perhaps, understand bat phenomenology
or what it is like for dogfish to electrically
sense their prey. But we do understand
the
familiar modalities--seeing, hearing,
tasting
and so on-- and these, surely, qualify
as
ways of being conscious. So I understand,
at a rough and ready level, what someone
is talking about when they talk about
a creature's
being conscious in one of these ways.
But
what does it mean to speak, not of
an animal
being conscious in one of these ways,
but
of some state, process, or activity
in the
animal as being conscious? States,
remember,
aren't conscious of anything. They
are just
conscious (or unconscious) full stop.
So
what kind of property is this? And
what makes
a state conscious? Until we understand
this,
we won't be in a position to even speculate
about what the function of a conscious
state
is.
There are, as far as
I can see, only two options for making sense
out of state consciousness. Either a state
is made conscious by its being an object
or by its being an act of creature consciousness.
A state of creature S is an object of creature
consciousness by S being conscious of it.
A state of creature S is an act of creature
consciousness, on the other hand, not by
S being aware of it, but by S being made
aware (so to speak) with it--by its occurrence
in S making (i. e., constituting) S's awareness
and, therefore, if there is an object that
stands in the appropriate relation to this
awareness, S's awareness of some object.
When state-consciousness is identified with
a creature's acts of awareness, the creature
need not be aware of these states for them
to be conscious. What makes them conscious
is not S's awareness of them, but their role
in making S conscious--typically (in the
case of sense perception), of some (external)
object.
Consider the second possibility
first. On this option, a conscious state
(e. g., an experience) is one that makes
an animal conscious. When a gazelle sees
a lion, its visual experience of the lion
qualifies as a conscious experience, a conscious
state, because it makes the gazelle visually
conscious of the lion. Without this experience,
the gazelle would not be visually aware of
anything--much less a lion.
There are, to be
sure,
states of (processes and activities
in) the
gazelle which are not themselves conscious
but which are necessary to make the
animal
(visually) aware of the lion. Without
eyes
and the assorted events occurring therein,
the animal would not see anything--would
not, therefore, be visually conscious
of
lions or any other external object.
This
is true enough, but it is irrelevant
to the
act conception of state-consciousness.
According
to the act conception of state-consciousness,
a conscious visual state is one without
which
the creature would not be visually
conscious
of anything--not just external objects.
The
eyes may be necessary for the gazelle
to
be conscious of (i. e., to see) the
lion,
but they are not necessary for the
animal
to be conscious, to have the sort of
visual
experiences that, when things are working
right, are normally caused by lions
and are,
therefore, experiences of lions. A
conscious
visual state is one that is essential
not
just to a creature's visual awareness
of
this or that kind of thing (e. g.,
external
objects), but to its visual awareness
of
anything--including the sorts of "things"
(properties) one is aware of in hallucinations
and dreams. That is why, on an act
account
of state consciousness, the processes
in
early vision, those occurring in the
retina
and optic nerve, are not conscious.
They
may be necessary to a creature's visual
awareness
of external objects, but they are not
essential
to visual awareness. Even without them,
the
creature can still dream about or hallucinate
the things it can no longer see. The
same
acts of awareness can still occur.
They just
don't have the same (according to some,
they
don't have any) objects
If we agree about
this--agree,
that is, that conscious states are
states
that constitute creature consciousness
(typically,
of things), then the function, the
good,
of state consciousness is evident.
It is
to make creatures conscious, and if
(see
above) there is no problem about why
animals
are conscious, then, on the act conception
of what a conscious state is, there
is no
problem about why states are conscious.
Their
function is to make creatures conscious.
Without state consciousness, there
is no
creature consciousness. If there is
a biological
advantage in gazelles being aware of
prowling
lions, then there is a purpose in gazelles
having conscious experiences. The experiences
are necessary to make the gazelle conscious
of the lions.
I do not expect
many
people to be impressed with this result.
I expect to be told that the states,
activities,
and processes occurring in an animal
are
conscious not (as I have suggested)
if the
animal is conscious with them, but,
rather,
if the animal (in whom they occur)
is conscious
of them. A conscious state is conscious
in
virtue of being an object, not an act,
of
creature awareness. A state becomes
conscious,
according to this orthodox line of
thinking,
when it becomes the object of some
higher-order
thought or experience. Conscious states
are
not states that make the creatures
in whom
they occur conscious; it is the other
way
around: creatures make the states that
occur
in them conscious by becoming conscious
of
them.
Since the only
way states
can become an object of consciousness
is
if there are higher order acts which
have
them as their objects, this account
of state
consciousness has come to be called
a HO
(for Higher Order ) theory of consciousness.
It has several distinct forms, but
all versions
agree that an animal's experience (of
lions,
say) remains unconscious (or, perhaps,
non-conscious)
until the animal becomes aware of it.
A higher
order awareness of one's lion-experience
can take the form of a thought
(a HOT theory)--in which case one is
aware
that (i. e., one thinks that) one is
experiencing
a lion--or the form of an experience
(a HOE
theory)--in which case one is aware
of the
lion-experience in something like the
way
one is aware of the lion: one experiences
one's lion-experience (thus becoming
aware
of one's lion-experience) in the way
one
is aware of (experiences) the lion.
I have elsewhere
(Dretske
1993, 1995) criticized HO theories
of consciousness,
and I will not repeat myself here.
I am more
concerned with what HO theories have
to say--if,
indeed, they have anything to say--about
the good of consciousness. If conscious
states
are states we are, in some way, conscious
of, why have conscious states? What
do conscious
states do that unconscious states don't
do?
According to HO theory, we (i. e.,
creatures)
could be conscious of (i. e., see,
hear,
and smell) most of the objects and
events
we are now conscious of (and this includes
whatever bodily conditions we are proprioceptively
aware of) without ever occupying a
conscious
state. To be in a conscious state is
to be
conscious of the state, and since the
gazelle,
for example, can be conscious of a
lion without
being conscious of the internal states
that
make it conscious of the lion, it can
be
conscious of the lion--i. e., see,
smell,
feel and hear the lion--while occupying
no
conscious states at all. This being
so, what
is the purpose, the biological point,
of
conscious states? It is awareness of
the
lion that is useful, not awareness
of one's
lion experiences. It is the lions,
not the
lion-experiences, that are dangerous.
On an object conception
of state-consciousness, it is difficult
to
imagine how conscious states could
have a
function. To suppose that conscious
states
have a function would be like supposing
that
conscious ball bearings--i. e., ball
bearings
we are conscious of--have a function.
If
a conscious ball bearing is a ball
bearing
we are conscious of, then conscious
ball
bearings have exactly the same causal
powers
as do the unconscious ones. The causal
powers
of a ball bearing (as opposed to the
causal
powers of the observer of the ball
bearing)
are in no way altered by being observed
or
thought about. The same is true of
mental
states like thoughts and experiences.
If
what makes an experience or a thought
conscious
is the fact that S (the person in whom
it
occurs) is, somehow, aware of it, then
it
is clear that the causal powers of
the thought
or experience (as opposed to the causal
powers
of the thinker or experiencer) are
unaffected
by its being conscious. Mental states
and
processes would be no less effective
in doing
their job--whatever, exactly, we take
that
job to be--if they were all unconscious.
According to HO theories of consciousness,
then, asking about the function of
conscious
states in mental affairs would be like
asking
about the function of conscious ball
bearings
in mechanical affairs.
David Rosenthal
(a practising
HOT theorist) has pointed out to me
in correspondence
that though experiences do not acquire
causal
powers by being conscious, there may
nonetheless
be a purpose served by their being
conscious.
The purpose might be served, not by
the beneficial
effects of a conscious experience (conscious
and unconscious experiences have exactly
the same effects acccording to HO theories),
but by the effects of the higher-order
thoughts
that makes the experience conscious.
Although
the conscious experiences don't do
anything
the unconscious experiences don't do,
the
creatures in which conscious experiences
occur are different as a result of
having
the higher order thoughts that make
their
(lower order) experiences conscious.
The
animal having conscious experiences
is therefore
in a position to do things that animals
having
unconscious experiences are not. They
can,
for instance, run from the lion they
(consciously)
experience--something they might not
do by
having an unconscious experience of
the lion.
They can do this because they are (let
us
say) aware that they are aware of a
lion--aware
that they are having a lion experience.[7]
Animals in which the experience of
the lion
is unconscious, animals in which there
is
no higher-order awareness that they
are aware
of a lion, will not do this (at least
not
deliberately) This, then, is an advantage
of conscious experience; perhaps--who
knows?--it
is the function of conscious experiences.
I concede the point.
But I concede it about ball bearings
too.
I cannot imagine conscious ball bearings
having a function--simply because conscious
ball bearings don't do anything non-conscious
ball bearings don't do--but I can imagine
their being some purpose served by
our being
aware of ball bearings. If we are aware
of
them, we can, for instance, point at
them,
refer to them, talk about them. Perhaps,
then, we can replace defective ones,
something
we wouldn't do if we were not aware
of them,
and this sounds like a useful thing
to do.
But this is something we can do by
being
aware of them, not something they can
do
by our being aware of them. If a conscious
experience was an experience we were
aware
of, then there would be no difference
between
conscious and unconscious experiences--anymore
than there would be a difference between
conscious and unconscious ball bearings.
There would simply be a difference
in the
creatures in whom such experiences
occurred,
a difference in what they were aware
of.
The fact that some
people
who have cancer are aware of having
it while
others who have it are not aware of
having
it does not mean there are two types
of cancer--conscious
and unconscious cancers. For exactly
the
same reason, the fact that some people
(you
and me, for instance) are conscious
of having
visual and auditory experiences of
lions
while others (parrots and gazelles,
for example)
are not, does not mean that there are
two
sorts of visual and auditory experiences--conscious
and unconscious. It just means that
we are
different from parrots and gazelles.
We know
things about ourselves that they don't,
and
it is sometimes useful to know these
things.
It does not show that what we know
about--our
conscious experiences--are any different
from theirs. We both have experiences--conscious
experiences--only we are aware of having
them, they are not. Both experiences--those
of the gazelle and those of a human--are
conscious because, I submit, they make
the
creature in which they occur aware
of things--whatever
objects and conditions are perceived
(lions,
for instance). Being aware that you
are having
such experiences is as relevant--which
is
to say, totally irrelevant--to the
nature
of the experiences one has as it is
to the
nature of observed ball bearings.[8]
3. The Third Distinction:
Object vs. Fact Awareness. Once again,
I
expect to hear that this is all too
quick.
Even if one should grant that conscious
states
are to be identified with acts, not
objects,
of creature awareness, the question
is not
what the evolutionary advantage of
perceptual
belief is, but what the advantage of
perceptual
(i. e., phenomenal) experience is.
What is
the point of having conscious experiences
of lions (lion-qualia) as well as conscious
beliefs about lions? Why are we aware
of
objects (lions) as well as various
facts
about them (that they are lions, that
they
are headed this way)? After all, in
the business
of avoiding predators and finding mates,
what is important is not experiencing
(e.
g., seeing, hearing) objects, but knowing
certain facts about these objects.
What is
important is not seeing a hungry lion
but
knowing (seeing) that it is a lion,
hungry,
or whatever (with all that this entails
about
the appropriate response on the part
of lion-edible
objects). Being aware of (i. e., seeing)
hungry lions and being aware of them,
simply,
as tawny objects or as large shaggy
cats
(something a two-year old child might
do)
isn't much use to someone on the lion's
dinner
menu. It isn't the objects you are
aware
of, the objects you see--and, therefore,
the qualia you experience--that is
important
in the struggle for survival, it is
the facts
you are aware of, what you know about
what
you see. Being aware of (seeing) poisonous
mushrooms (these objects) is no help
to an
animal who is not aware of the fact
that
they are poisonous. It is the representation
of the fact that another animal is
a receptive
mate, not simply the perception of
a receptive
mate, that is important in the game
of reproduction.
As we all know from long experience,
it is
no trick at all to see sexually willing
(or,
as the case may be, unwilling) members
of
the opposite sex. The trick is to see
which
is which--to know that the willing
are willing
and the others are not. That is the
skill--and
it is a cognitive skill, a skill involving
knowledge of facts--that gives one
a competitive
edge in sexual affairs. Good eyesight,
a
discriminating ear, and a sensitive
nose
(and the qualia associated with these
sense
modalities) are of no help in the struggle
for survival if such experiences always
(or
often) yield false beliefs about the
objects
perceived. It is the conclusions, the
beliefs,
the knowledge, that is important, not
the
qualia-laden experiences that normally
give
rise to such knowledge. So why do we
have
phenomenal experience of objects as
well
as beliefs about them? Or, to put the
same
question differently: Why are we conscious
of the objects we have knowledge about?
Still another way of
putting this question is to ask why we aren't
all, in each sense modality, the equivalent
of blindsighters who appear able to get information
about nearby objects without experiencing
(seeing) the objects.[9] In one way of describing
this baffling phenomenon, blindsighters seem
able to "see" the facts (at least
they receive information about what the facts
are--that there is, say, an X (not an O)
on the right---without being able to see
the objects (the X's) on the right. No qualia.
No phenomenal experience. If, therefore,
a person can receive the information needed
to determine appropriate action without experience,
why don't we?[10] Of what use is phenomenal
experience in the game of cognition if the
job can be done without it?
These are respectable
questions. They deserve answers--scientific,
not philosophical, answers. But the answers--at
least in a preliminary way--would appear
to be available. There are a great many important
facts that we cannot be made aware of unless
we are, via phenomenal experience, made aware
of objects these facts are facts about. There
are also striking behavioral deficits--e.
g., an inability to initiate intentional
action with respect to those parts of the
world one does not experience (Marcel
1988a). Humphrey (1970, 1972, 1974),
worked
for many years with a single monkey,
Helen,
whose capacity for normal vision was
destroyed
by surgical removal of her entire visual
cortex. Although Helen originally gave
up
even looking at things, she regained
certain
visual capacities.
She improved so greatly over the next
few
years that eventually she could move
deftly
through a room full of obstacles and
pick
up tiny currants from the floor. She
could
even reach out and catch a passing
fly. Her
3-D spatial vision and her ability
to discriminate
between objects that differed in size
or
brightness became almost perfect.
(Humphrey 1992: 88). Nonetheless, after
six
years she remained unable to identify
even
those things most familiar to her (e.
g.,
a carrot). She did not recover the
ability
to recognize shapes or colors. As Humphrey
described Helen in 1977 (Humphrey 1992:
89),
She never regained what we--you and
I--would
call the sensations of sight. I am
not suggesting
that Helen did not eventually discover
that
she could after all use her eyes to
obtain
information about the environment.
She was
a clever monkey and I have little doubt
that
, as her training progressed, it began
to
dawn on her that she was indeed picking
up
'visual' information from somewhere--and
that her eyes had something to do with
it.
But I do want to suggest that, even
if she
did come to realize that she could
use her
eyes to obtain visual information,
she no
longer knew how that information came
to
her: if there was a currant before
her eyes
she would find that she knew its position
but, lacking visual sensation, she
no longer
saw it as being there. . . . The information
she obtained through her eyes was 'pure
perceptual
knowledge' for which she was aware
of no
substantiating evidence in the form
of visual
sensation . . . If we follow Humphrey
and
suppose that Helen, though still able
to
see where objects were (conceptually
represent
them as there), was unable to see them
there,
had no
(visual) experience of them, we have
a suggestion
(at least) of what the function of
phenomenal
experience is: we experience (i. e.,
see,
hear, and smell) them to help in our
identification
and recognition of them. Remove visual
sensations
of X and S might still be able to tell
where
X is, but S will not be able to tell
what
X is. Helen couldn't. That is--or may
be--a
reasonable empirical conjecture for
the purpose
of experience--for why animals (including
humans) are, via perceptual experience,
made
aware of objects. It seems to be the
only
way--or at least a way--of being made
aware
of pertinent facts about them.
Despite the attention generated by
dissociation
phenomena, it remains clear that people
afflicted
with these syndromes are always "deeply
disabled" (Weiskrantz 1991:
8). Unlike Helen, human patients never
recover
their vision to anything like the same
degree
that the monkey did. Though they do
much
better than they "should"
be able
to do, they are still not very good
Humphrey
(1992: 89). Blindsight subjects cannot
avoid
bumping into lamp-posts, even if they
can
guess their presence or absence in
a forced-choice
situation. Furthermore,
All these subjects lack the ability
to think
about or to image the objects that
they can
respond to in another mode, or to inter-relate
them in space and in time; and this
deficiency
can be crippling (Weiskrantz, 1991:
8). This
being so, there seems to be no real
empirical
problem about the function (or at least
a
function) of phenomenal experience.
The function
of experience, the reason animals are
conscious
of objects and their properties, is
to enable
them to do all those things that those
who
do not have it cannot do. This is a
great
deal indeed. If we assume (as it seems
clear
from these studies we have a right
to assume)
that there are many things people with
experience
can do that people without experience
cannot
do, then that is a perfectly good answer
to questions about what the function
of experience
is. That is why we, and a great many
other
animals, are conscious of things and,
thus,
why, on an act conception of state
consciousness,
we have conscious experiences. Maybe
something
else besides experience would enable
us to
do the same things, but this would
not show
that experience didn't have a function.
All
it would show is that there was more
than
one way to skin a cat--more than one
way
to get the job done. It would not show
that
the mechanism that did the job wasn't
good
for something.
REFERENCES
Davies, M. and G. W. Humphreys (1993).
Introduction.
In Davies and Humphreys (1993), eds.
Consciousness.
Oxford; Blackwell, 1-39.
Dretske, F. (1993). Conscious experience.
Mind, vol 102.406, 1-21.
Dretske, F. (1995). Naturalizing the
Mind.
Cambridge, Ma.; MIT Press, A Bradford
Book.
Humphrey, N. (1970). What the frog's
eye
tells the monkey's brain. Brain, Beh.
Evol,
3: 324-37.
Humphrey, N. (1972). Seeing and nothingness.
New Scientist 53: 682-4.
Humphrey, N. (1974). Vision in a monkey
without
striate cortex: a case study. Perception
3: 241-55.
Humphrey, N. (1992). A History of the
Mind:
Evolution and the Birth of Consciousness.
New York: Simon and Schuster.
Milner, A. D. (1992). Disorders of
perceptual
awareness-- commentary. In Milner &
Rugg
(1992), 139-158.
Milner, A. D. & M. D. Rugg, eds.
(1992).
The Neuropsychology of Consciousness.
London:
Academic Press.
Rosenthal, D. (1990). A theory of consciousness.
Report No. 40, Research Group on Mind
and
Brain, ZiF, University of Bielefeld.
Rosenthal, D. (1991). The independence
of
consciousness and sensory quality.
In Villanueva
1991, 15-36.
Rey, G. (1988). A question about consciousness,
in H. Otto and J. Tuedio, eds., Perspectives
on Mind. Dordrecht: Reidel.
van Gulick, R. (1985). Conscious wants
and
self awareness. The Behavioral and
Brain
Sciences, 8.4, 555-556.
van Gulick, R. (1989). What difference
does
consciousness make? Philosophical Topics,
17: 211-30.
Velmans, M. (1991). Is human information
processing conscious? Behavioral and
Brain
Sciences 14.4,651-668.
Villanueva, E., ed. (1991). Consciousness.
Atascadero, CA; Ridgeview Publishing
Co.
Walker, S. (1983). Animal Thought.
London:
Routledge and Kegan Paul.
White, A. R. (1964). Attention. Oxford:
Basil
Blackwell
Weiskrantz, L., ed. (1986). Blindsight:
A
Case Study and Implications. Oxford:
Oxford
University Press.
Weiskrantz, L. (1991). Introduction:
Dissociated
Issues. In Milner and Rugg (1991):
1-10.
FOOTNOTES
1. There is a sense in which it enables
me
to do things I would not otherwise
be able
to do--e. g., bequeath my books to
my nephews
and nieces--but this, clearly, is a
constitutive,
not a causal, sense of "enable."
Spelling out this difference in a precise
way is difficult. I will not try to
do it.
I'm not sure I can. I hope the intuitive
distinction will be enough for my purposes.
2. For recent expressions of interest,
see
Velmans 1991, Rey 1988, and Van Gulick
1989.
3. I here ignore dispositional senses
of
the relevant terms--the sense in which
we
say of someone or something that it
is a
conscious being even if, at the time
we describe
it this way, it is not (in any occurrent
sense) conscious. So, for example,
in the
dispositional sense, I am a conscious
being
even during dreamless sleep.
4. I here ignore disputes about whether,
in some strict sense, we are really
aware
of objects or only (in smell) odors
emanating
from them or (in hearing) voices or
noises
they make. I shall always take the
perceptual
object--what it is we see, hear, or
smell
(if there is such an object)--to be
some
external physical object or condition.
I
will not be concerned with just what
object
or condition this is.
5. In saying this I assume two things,
both
of which strike me as reasonably obvious:
(1) to be aware that you are aware
of a french
horn requires some understanding of
what
awareness is (not to mention an understanding
of what a french horn is); and (2)
mice (even
if we give them some understanding
of french
horns) do not understand what awareness
is
(they do not have this concept).
6. This is not to say that consciousness
is always advantageous. As Georges
Rey reminds
me, some tasks--playing the piano,
pronouncing
language, and playing sports--are best
performed
when the agent is largely unaware of
the
performatory details. Nonetheless,
even when
one is unconscious of the means, consciousness
of the end (e. g., the basket into
which
one is trying to put the ball, the
net into
which one is trying to hit the puck,
the
teammate to whom one is trying to throw
the
ball) is essential. You don't have
to be
aware of just how you manage to backhand
the shot to do it skillfully, but,
if you
are going to be successful in backhanding
the puck into the net, you have to
be aware
of where the net is.
7. I assume here that, according to
HOT theories,
the higher order thought one has about
a
lion experience that makes that experience
conscious is that it is a lion experience
(an experience of a lion). This needn't
be
so (Rosenthal 1991denies that it is
so),
but if it isn't so, it is even harder
to
see what the good of conscious experiences
might be. What good would be a thought
about
a lion experience that it was . . .
what?
. . . a (generic) experience?
8. I'm skipping over a difficulty that
I
should at least acknowledge here. There
are
a variety of mental states--urges,
desires,
intentions, purposes, etc.--which we
speak
of as conscious (and unconscious) whose
consciousness
cannot be analyzed in terms of their
being
acts (instead of objects ) of awareness
since,
unlike the sensory states associated
with
perceptual awareness (seeing, hearing,
and
smelling), they are not, or do not
seem to
be, states of awareness. If these states
are conscious, they seem to be made
so by
being objects, not acts of consciousness
(see, e. g., Van Gulick 1985). I don't
here
have the space to discuss this alleged
difference
with the care it deserves. I nonetheless
acknowledge its relevance to my present
thesis
by restricting my claims about state-consciousness
to experiences--more particularly,
perceptual
experiences. Whatever it is that makes
a
desire for an apple, or an intention
to eat
one, conscious, experiences of apples
are
made conscious not by the creature
in whom
they occur being conscious of them,
but by
making the creature in whom they occur
conscious
(of apples).
9. For more on blindsight see Weiskrantz
1986 and Milner & Rugg 1992. I
here assume
that a subject's (professed) absence
of visual
experience is tantamount to a claim
that
they cannot see objects, that they
have no
visual experience. The question that
blindsight
raises is why one has to see objects
(or
anything else, for that matter) in
order
to see facts pertaining to those objects--what
(who, where, etc.) they are. If blindsighters
can see where an object is, the fact
that
it is there (where they point), without
seeing
it (the object at which they point),
what
purpose is served by seeing it?
10. There are a good many reflexive
"sensings"
(Walker 1983: 240) that involve no
awareness
of the stimulus that is controlling
behavior--e.
g., accommodation of the lens of the
eye
to objects at different distances,
reactions
of the digestive system to internal
forms
of stimulation, direction of gaze toward
peripherally seen objects. Milner
(1992:143) suggests that these "perceptions"
are probably accomplished by the same
midbrain
visuomotor systems as mediate prey
catching
in frogs and orienting reactions in
rats
and monkeys. What is puzzling about
blindsight
is not that we get information we are
not
aware of (these reflexive sensings
are all
instances of that), but that in the
case
of blindsight one appears able to use
this
information in the control and guidance
of
deliberate, intentional, action (when
put
in certain forced choice situations)--the
sort of action which normally requires
awareness.
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