From
a Flaw in the Knowledge Argument to a Physicalist Account of Qualia
1
Introduction
In this
paper, I examine Frank Jackson's famous 'grey Mary' thought experiment, first
presented in "Epiphenomenal Qualia" (Jackson 1982) in support of his
Knowledge argument against physicalism. I argue that it cannot be claimed as
the basis for rejecting physicalism. First, because it is flawed, being so
formulated as to predetermine the outcome of the thought experiment in favour
of a refutation of physicalism. Second, because, once this is recognised, it
becomes clear that there is a perspective on the qualia-physical relationship
that will permit physicalism to survive the thought experiment. This
perspective, it is suggested, has potential as a good candidate theory for a
physicalist account of qualia. The arguments are presented from Section 3
onwards; Section 2 covers the Knowledge argument itself and positions taken for
and against it in the literature.
2
Jackson's Knowledge Argument
2.1
The Argument
This is
how Jackson first set out his Knowledge argument against physicalism in terms
of what is sometimes called the 'grey Mary' thought experiment:
Mary is a brilliant scientist who is, for whatever reason, forced
to investigate the world from a black and white room via a black and white
television monitor. She specializes in the neurophysiology of vision and
acquires, let us suppose, all the physical information there is to obtain about
what goes on when we see ripe tomatoes, or the sky, and use terms like 'red',
'blue', and so on...
....What will happen when Mary is released from her black and
white room or is given a color television monitor? Will she learn anything or
not? It seems just obvious that she will learn something about the world and
our visual experience of it. But then it is inescapable that her previous
knowledge was incomplete. But she had all the physical information. Ergo there
is more to have than that, and Physicalism is false.
(Jackson,
1982)
On the
face of it, the case is a persuasive one. The conclusion follows<1> if it
is true both:
(1) That Mary (before her release)
knows everything physical there is to know about other people. [Premise A]
(2) That Mary (before her release)
does not know everything there is to know about other people (because she
learns something about them on her release). [Premise B]
(Jackson
1986)
If
physicalism is true the argument runs, then physical facts are the only facts -
but if Mary learns all of the physical facts about colour vision in her black
and white room and still learns something new on leaving it, she has acquired a
fact that is not a physical fact and physicalism cannot be true.
Whether
the conclusion is correct is, of course, another matter, and it is true to say
that there is a fair degree of dispute on the point.
2.2
Challenging Premise B
Jackson's
argument is usually regarded as presenting a challenge to physicalism that
cannot easily be ignored or discounted<2>, but there is much debate over
his conclusion. A steady stream of responses for and against it has appeared in
the literature since its initial airing in 1982, and the activity shows no sign
of ceasing<3>. In the present
paper, I shall argue against his conclusion on the grounds that premise A is
false. However, since much of the literature to date reflects a continuing
debate on challenges to premise B, it is worth considering this first, if only
to show that the efficacy of such challenges is still in dispute after many
years of discussion
The
major positions taken against premise B are these:
2.2.1
Physicalism stands because, contrary to our intuition, Mary learns nothing new
on leaving the room
This is
a position most often associated with Dennett, (1991), but a similar point is
put by Churchland (1985). On Dennett's account, there is no challenge to
physicalism. Mary learns nothing new on leaving the room because she is already
capable, before leaving it, of identifying the colours she is about to
experience by making inferences from observations of the physical states they
induce. But is being able to identify a colour by this means the same as
knowing what it is like? Others - including Robinson (1993) and Alter (1998) -
argue (with some justice) that it is not, and that, therefore, Mary does learn
something new and the challenge to physicalism stands.
2.2.2
Physicalism stands because what Mary learns is not a fact, but something else
such as know-how or ability.
This
position is primarily associated with Nemirov (1980<4>, 1990) and Lewis
(1988), but others have supported them or put similar positions<5>. On
this account, physicalism is not refuted because Mary does not acquire a new
fact on leaving the room, only an ability to imagine, recognise and identify
colours like red or green. She is like someone who knows all the facts about
bikes and how they work but has never ridden one and learns something new (a
new ability or new 'know-how') when she does.
Numerous
objections to the ability hypothesis have been raised in the literature (see,
for example, Alter 1998, 2001, Chalmers 1996, Conee 1994, Deutsch 1998, Gertler
1999, Loar 1990 and Lycan 1995, 1996), but the primary difficulty seems to be
that, as Chalmers points out, it seems likely that Mary acquires more than just
an ability when she experiences red for the first time, she also seems to
acquire knowledge of what red as experienced is like: 'For all she knew before,
the experience of red things might have been like this, or it might have been
like that, or it might have been like nothing at all. But now she knows it is
like this'. Lycan makes essentially the same point, arguing amongst other
things that:
·
Knowing
what it is like to have an experience is arguably to know that it is like such
and such to have that experience - so it is knowing a fact, rather than having
an ability.
·
Since
one can try to describe an experience such as the taste of pineapple to
someone, even if we would probably fail, it would appear that knowing what it
is like means having some fact to impart.
2.2.3
Physicalism stands because what Mary learns is not a new fact only an old fact
in a new guise.
Another
much favoured position taken by a range of writers (Horgan 1984, Churchland
1985, Loar 1990, Lycan 1995, Papineau 1993, Tye 1986 are examples, others are
referenced in Nida-Rümelin 2002 and Chalmers 1996) is the so-called old
fact/new guise argument. This is the view that physicalism is not refuted
because what Mary comes to know on leaving the black and white room is not a
new fact, just a fact she already new in a new guise. On this account, she is
like a person who knows that Mark Twain wrote Tom Sawyer then learns that
Samuel Clemens wrote Tome Sawyer, the argument being that physicalism is not
refuted because what appears to be a new fact is just an old fact in a new
guise.
The
following counter-arguments show the difficulty with this position:
(1) Someone who knows that Mark
Twain wrote Tom Sawyer then learns that Samuel Clemens wrote Tom Sawyer still
learns something new - that Mark Twain and Samuel Clemens are the same person.
On this argument, even if experienced red is only brain event X in a new guise, Mary still learns something new
when she experiences red - that there is more to be known about seeing red than
is known when it is known about in terms of brain event X. Thus it is still the
case that she has learned something new.
(2) Second, as Alter 1998 argues,
the old fact/new guise argument seems to suggest that the new phenomenal guise
(experienced red as opposed to its neurological correlates, for example) is
incidental to knowing the fact in question. In the case of qualities such as
experienced red, however, knowing the 'phenomenal guise' - the actual
experience - appears central to the fact
itself. We cannot know experienced red - the fact itself - without knowing the
'phenomenal guise', and since this cannot be known in a black and white room,
it cannot be an old fact, it must be a new one. The threat to physicalism
stands. An analogy (provided by Alter) would be the suggestion that one could
know that the boxer called Ali had once been called Clay without first having
acquired the label 'Clay'.
A
variation associated with Bigelow and Pargetter (1990) likens Mary to a
forgetful historian who has all the objective facts but can still learn that
today is July 4th, American Independence day - she has all of the objective
facts about colour vision but can still learn that this (experienced red) is
red. What is acquired in both cases, it is said, is indexical knowledge and
this does not refute physicalism. Again, however, there is a counter argument
(Chalmers 1996). No matter how much Mary knew about her indexical relationship
to the physical world, she still would not know what red is like.
2.3
Concluding Points; Jackson on Premise B
I will
not labour the point on challenges to premise B. The question of their efficacy
(or otherwise) has no direct bearing on the arguments presented below. The
position developed is that the Knowledge argument fails to refute physicalism
because of a problem with premise A, and there is an implication in this that
challenges to premise B are unnecessary, but no position is taken, one way or
the other, on the question of whether or not such challenges can succeed, and
the case made does not depend in any way on the outcome of such challenges. The
summary presented above is significant here only insofar as it shows that there
is a continuing dispute as to the efficacy of such challenges after many years
of discussion - and insofar as this suggests that an approach which takes the
focus away from premise B may be worth examining.
One
final point is worth making on this front. Jackson himself has latterly
suggested (Jackson 1998) that premise B is false. However, as Vinueza n.d.
notes, Jackson does not really present a case, only indicates his feeling that
there must be one. In any case, if I understand him correctly, he is
approaching the problem from the following perspective:
·
Physicalism
must be true;
·
The
Knowledge argument is valid, so physicalism must be false unless our intuition
is false;
·
Therefore,
the puzzle is to explain why we are mistaken in our intuition.
If this
is so, he may well be willing to concede that the solution to the conundrum of
the Knowledge argument proposed in the present paper offers a better
alternative, despite the fact that it entails an assumption that Mary does
acquire new knowledge. Certainly, his own suggestion as to why our intuition
might be mistaken does not convince. This is that Mary's knowledge is not new,
but could be arrived at by following a long and complex chain of inference. Our
intuition that it is new is an illusion created by the fact that it is acquired
in a much more immediate 'all at once' fashion.
3
Challenging Premise A: The Flaw in the Knowledge Argument
3.1
The Flaw in the Knowledge Argument
I
believe that Jackson is correct in suspecting that there is a problem with the
Knowledge argument, but that the problem lies, not with premise B, but with
premise A. The position I take shares common ground, in varying degrees, with
positions taken by writers such as:
·
Flanagan
1992, who exposes essentially the same problem with premise A identified in the
present paper, albeit in a different fashion, and also reaches a similar
conclusion as regards Mary's new knowledge - that it can be physical and a way
of knowing the physical world without being fully expressible in the language
of even a completed science.
·
Conee
1994, who argues that Mary's new knowledge is only acquaintance knowledge, not
prepositional knowledge, and that there is no case for believing that acquiring such knowledge represents a challenge to
physicalism - that acquaintance knowledge may just be knowledge of something
physical that Mary already has prepositional knowledge of and that does not
encompass any new (prepositional) fact.
·
Deutsch
1998, who argues that the Knowledge argument does refute physicalism if we
adopt what he calls the language of science conception of physical facts but
not if we adopt an ontological conception of the physical facts, and that the
first of these is harmless and only tells us that the language of science
cannot handle subjective physical facts.
·
Sommers
2002, who argues (albeit on different grounds than I do) that we assume too
much when we accept premise A.
Echoes
of all of the above views are to be found in what follows, although the the
argument is, I think, a new one. In essence, it is that the Knowledge argument
as usually formulated is flawed - that, through premise A, it is so constructed
as to predetermine the outcome of the thought experiment in favour of a
refutation of physicalism.
Briefly
put, the position is this.
If we know that it is 'just obvious' that there is knowledge that cannot be
acquired inside a black and white room, then the simple act of asserting that
all physical knowledge can be acquired inside it presupposes, both that the
knowledge that cannot be acquired inside the room is non-physical, and that
physicalism is false.
If we
know there is more knowledge than can be acquired inside a black and white room
when constructing our thought experiment, then, by formulating the Knowledge
argument so as to assert that all physical knowledge can be acquired inside the
room, we effectively define the knowledge that cannot be acquired inside it as
non-physical, thereby predetermining the outcome of the thought experiment in
favour of a refutation of physicalism (since, if non-physical knowledge exists,
physicalism must be false). The appearance of inference is a sham, albeit an
unwitting one. If we know that there is knowledge that cannot be acquired
inside the room and assert that the knowledge that can be acquired inside it is
all of the physical knowledge that exists, then, by implication, we assert that
non-physical knowledge exists and presuppose that physicalism is false. More,
by taking the set of all knowledge and stating that only a portion of it is all
physical knowledge, we assert that the set of all knowledge is subdivided into
physical and non-physical knowledge - that physicalism is false.
An
illustration may help drive home the point. Imagine a Mary with colour vision
in a room full of children's bricks. She collects 99 red bricks and concludes
that the statement all bricks in the room are red is true. Then a child
tells her he put another brick in a cupboard. He cannot recall its colour and
the cupboard is now locked. Mary wants to know if her conclusion still holds.
She might argue, as a Knowledge argument supporter might, that since she
already has all the red bricks in the room, the remaining brick must be a
non-red brick and that the statement all bricks in the room are red is
false. If she does, however, she rather obviously skews the argument in favour
of a refutation of the statement. To assert that the bricks she has are all the
red bricks knowing there is another brick in the cupboard she has not seen, is
to define the remaining brick as non-red, ensuring that the statement will be
refuted. More, it is to assert that the complete set of bricks is divided into
red and non-red bricks and so assume directly that the statement is false.
3.2
All True Statements Versus Physical Knowledge
Of
course, the implication in Jackson's argument is that we actually know that
Mary can acquire a complete knowledge of the physical in her black and white
room - else, as Jackson 1982 points out, the Open University would need colour
television to conduct its business. If this is true, we presuppose nothing and
the argument holds. But how can it be true? Certainly, there is a good case for
holding that Mary in her black and white room can acquire a knowledge of all
true statements about the physical, of their significance, and of still and
moving pictures of their real world referents (in black and white). We can
safely assume, I think:
·
That
the physicalists outside Mary's room, who do not suffer the limitations that
Mary does, can, given sufficient time, ingenuity, and instrumentation, acquire
such knowledge of the physical;
·
That
they can then express this in a set of books and videos illustrated in colour;
·
That
they can then convert these to black and white but work to ensure that in every
case where distinguishing between colours is vital to an understanding of a
true statement about the physical, such a distinction is made clear in black
and white (and shades of grey) and can be made by someone in a black and white
room.
Suppose
then that Mary in her black and white room has access to these books and
videos, and also to remotely controlled instruments that allow her to repeat
key experiments in black and white (and unlimited time). Suppose further that
she also has access to interactive instruction from the scientists themselves
who do have access to colour information, do understand its relevance to the
set of statements, and do understand the limitations placed on Mary and
actively strive to overcome them. In these circumstances, there are, I submit,
no grounds for holding that she cannot acquire knowledge of all true statements
about the physical inside her black and white room. As long as she can
distinguish between colours, albeit in black and white, she can learn to
understand the contents of the books and videos and also make and understand
the observations that support true statements and refute false statements. This
being so, there is, I submit, no reason to suppose that she cannot acquire
knowledge of all true statements about the physical, of their significance, and
of still and moving pictures of their real world referents inside her black and
white room<6>. This is sufficient to meet the needs of the Open
University in a world before colour TV. It is sufficient to ensure that Mary
can pass any exam that might be set on the nature of the physical world. It is
even sufficient to ensure that, on leaving her black and white room, she need
acquire no new operational knowledge of the physical world despite the
limitation she was previously subject to. But is it sufficient to allow us to
conclude that she has acquired all physical knowledge inside her black and
white room?
The
answer, of course, is that it is not. As long as we know that it is 'just
obvious' that Mary will learn something new on leaving her room, we cannot
safely assume that she has acquired all of the physical knowledge when inside
it - any more than our Mary with the bricks can assume that she has all the red
bricks in the room when she knows there is another brick of unknown colour in a
locked cupboard.
3.3
A Continuing Threat to Physicalism from the Grey Mary Thought Experiment
As it
stands, the Knowledge argument is flawed and the problem lies with premise A,
the assertion that all physical knowledge can be acquired inside Mary's black
and white room. The assumption that this is true leads inevitably to the
conclusion that Mary's new knowledge is non-physical and that physicalism is
false. This conclusion is problematical on two counts:
(1) Given that there is knowledge
that can only be acquired outside the black and white room, the assumption that
all physical knowledge can be acquired inside it:
·
Effectively
defines the knowledge that can only be acquired outside the room as
non-physical, thereby predetermining the outcome of the thought experiment in
favour of a refutation of physicalism
·
Subdivides
the set of all knowledge into some that is physical and some that is not,
thereby assuming in a more direct way that physicalism is false
(2) We can only know for certain
that premise A is true by examining Mary's new knowledge and determining
directly whether or not it is or, rather (since this is a thought experiment), can
be physical knowledge. However, the assumption that premise A is true stops
us making this examination by forcing the conclusion that Mary's new knowledge must
be non-physical.
Once
this flaw is recognised, the apparent threat to physicalism from the Knowledge
argument as stated is negated. It is no longer possible to hold that Mary has
acquired all physical knowledge in her black and white room and that,
therefore, the knowledge she acquires on leaving it is necessarily non-physical
knowledge that must refute physicalism. Notice, however, that this does not
necessarily negate the threat to physicalism posed by Mary's acquisition of new
knowledge on leaving her black and white room - by the thought experiment
itself. It is still possible that Mary's new knowledge will refute physicalism.
In fact, in this new scenario, it becomes clear that there are additional
possibilities to consider in this regard. Mary's new knowledge will refute
physicalism if it is non-physical knowledge, or is itself 'made of' something
non-physical, or both. What is different in this new situation is that the
question is left open. It is no longer necessarily the case that Mary's
new knowledge must refute physicalism because it can be nothing but
non-physical knowledge. Instead, the question of whether or not physicalism is
refuted by the grey Mary thought experiment is decided (as it must be) through
an examination of the new knowledge itself. If it can be shown that it is
possible, in the situation described in
the thought experiment, for Mary's new knowledge to be valid knowledge of the
physical that is itself 'made of' something physical, the thought experiment
cannot be successfully used as a basis for refuting physicalism. If it can be
shown that this is not possible, it can continue to be so used (although not on
the basis of Jackson's Knowledge argument).
4
How Physicalism Can Survive the Grey Mary Thought Experiment
In
fact, as will now be shown, there is only one set of circumstances in which it
is possible for Mary's new knowledge to be physical itself and valid knowledge
of the physical given the situation described in the thought experiment - a
particular physicalist account of qualia must be true. Specifically,
physicalism can survive the thought experiment if and only if it is true of
Mary's new knowledge and - by extension - any quale<7>:
(1) That it is really nothing but,
or entirely reducible to, some physical event within the organism experiencing
it - a physical event experienced as a quale by an inside observer of that
human organism, and as an aspect of the flesh, blood and brains view of the
organism<8> by an outside observer.
Suppose that, in the first instance, what Mary learns on leaving
the black and white room is what experienced yellow is like - that her new
knowledge is a yellow quale. Clearly, the new knowledge is a new event in Mary
- one that has not occurred before. If this event is not a physical event, it
must be a non-physical event and physicalism is refuted. But there is no
physical event in humans generally (as opposed to herself individually) that
Mary does not already have an outside observer's knowledge of - so if this new
event in herself is something physical, it can only be a different perspective
on a physical event she already has an outside observer's knowledge of in
humans generally. More, it must be true that it is really nothing over and
above the physical event in question. If it is not, then it can only be
something over and above everything physical in the organism - which is to say
something non-physical that will refute physicalism.
(2) That both the inside observer's
private experience of it (as a quale) and the outside observer's experience of
it (as some aspect of the flesh, blood and brains view of the organism) are
limited perspectives on this physical event that 'just is' the quale - that
each is the reality as known as distinct from the reality as such.
Suppose that an outside observer experiences the physical event
that 'just is' the yellow quale as an electro-chemical reaction occurring
between pinky-white fibres in the brain - something very different from the
yellow quale experienced by the inside observer, Mary. Call the reaction in the
brain a firing b-fibre. If physicalism is to survive the thought experiment, it
must be the case (see under point 4(1) above) that the yellow quale is really
nothing over and above the firing b-fibre. But how can this be true when the
firing b-fibre is so different from the yellow quale - and other qualia such as
a dull ache or a loud noise - that it is hard to imagine how the two could
possibly be one? There is, I submit, only one possibility. If the two are, in
fact, a single reality, it can only be true that each is the reality as known
(from a particular limited viewpoint) as distinct from the reality as such. If
a yellow quale is really something that has the characteristics we associate
with aspects of the flesh, blood and brains view of the human organism, and
vice versa, then what we get when we experience a yellow quale or a firing
b-fibre must be a limited perspective on a reality rather than the reality in
its own right.
This is probably easier to accept of a quale than it is of the
firing b-fibre, which we tend to think of as being, in some sense, more real.
In this latter case, however, there is additional supporting evidence. Although
I have focused for the sake of simplicity on the idea that Mary's new knowledge
is only knowledge of the colour yellow, in reality she would, on leaving her
black and white room, begin to experience everything - including the outside
observer's flesh, blood and brains view of other humans - in colour. Clearly,
therefore, this view is itself a private perspective in the experience of an
outside observer and hence, must be something other than the reality of the
other human that the outside observer is observing.
Moreover, it should, in any case, be self-evident that the outside
observer's physical view is the reality as known as distinct from the reality
as such. In this instance, the observer is clearly physically distinct from the
reality observed and can only have access to it via his own senses and thoughts
which, since he is an outside observer, can only, by definition, be something
other than the reality itself - the reality as known as distinct from the
reality as such.
Further support for this conclusion comes from a consideration of
Leibniz's Law and Kripke's problem for proposed identities.
Leibniz's law
Leibniz's law is concerned with the conditions under which things
can be regarded as identical. It states that if x is y, then any property of x
is a property of y. This is a not a problem for a view that holds that what we
get when we experience a quale is the reality as known as distinct from the
reality as such, but it is otherwise. To claim that something like a yellow
quale is identical with something in the brain like a firing b-fibre is to
claim that any property of the one is a property of the other. However, if the
quale we know 'just is' the reality of the quale, and the same is true of the
firing b-fibre, then, on the face of it, each has quite different (and, indeed,
incompatible) properties:
·
The
b-fibre appears solid, fleshy, material, and probably pinky-white, the quale
appears yellow and anything but solid, fleshy, and material.
·
The
b-fibre is publicly observable, the quale is the opposite - a private event
known only to the person experiencing it.
·
The
b-fibre has a definite, locatable, position in space, the quale cannot be so
located.
Again, the question is how can two such unalike things be
identical?
The answer to this, of course, is provided by the position
defended here. In this perspective, what we get when we experience the quale on
the one hand and the firing b-fibre on the other is (in each case) the reality
as known as distinct from the reality as such. This means that it is entirely
consistent with both Leibniz's law and common sense that the two are simply one
thing known in two different ways:
·
It is
not a problem that the yellowness of the quale is not a property of what McGinn
(1989) called the 'soggy grey matter' of the brain and its b-fibres and vice
versa, because both can be said to be characteristics of this single underlying
reality that is the real basis of the identity.
·
The
fact that public observability is not a property of the quale, and private
observability is not a property of the firing b-fibres, and that anything
public is, by definition, not private, and vice versa, is not a problem. There
is no difficulty because it can be said to be characteristic of the single
underlying reality, both that it can be known publicly, and that it can be
known privately.
·
The
fact that every aspect of what the outside observer knows as soggy grey matter
has a precise location in physical space and that a quale is impossible to
locate in physical space is not a problem. Again, locatability in public space
and knowability in terms of private experiences that cannot be so located are
both characteristic of the underlying reality in which the identity resides. The
reality known by an inside observer as a private experience can be said to be
located in public space when known and observed publicly by outside observers.
It is simply that, when it is known privately, it is known in a way which makes
location in space impossible.
Kripke's Problem for Proposed Identities.
Distinguishing between the reality as known as distinct from the
reality as such in this way is also the only way in which an identity position
can deal with Kripke's problem for proposed identities. Kripke (1980) notes
that Leibniz's Law demands that if A is B then A is necessarily B. There are no
circumstances in which this is not true - it is true in all possible worlds.
There are examples in the world of identities where this may appear to be false
- where it appears we can conceive of possible circumstances in which the
identity does not hold. However, if there is true identity, these must arise
from a misconception of some kind, and it will be possible to discover and
specify the basis of the misconception.
An example is the identity between H2O and water. We can imagine a
possible world in which water is not H2O but XYZ - but this, to quote Chalmers
(1996) is illusory. In fact, we are imagining something that has the properties
of water, but that is not actually water. The identity is not threatened
because what we have imagined is not an instance of water not being H2O but
only of something like water not being H2O.
Now consider that it is possible to conceive of circumstances in
which a quale, such as an experience of pain, can exist without being
accompanied by a firing b-fibre, and vice versa - the idea of disembodied pain
seems to us to be plausible, as does the idea of a zombie who has the firing
b-fibres, but no feelings of pain or anything else. These are examples of a
possible world in which a claimed identity between the quale and a firing
b-fibre appears not to hold. By Kripke's argument, unless it can be shown that
they are based on misconceptions, they threaten the claimed identity.
This is a potential problem for a claim that any given quale is
identical with some aspect of the flesh, blood and brains view of the human
organism. The kind of argument detailed above for H2O and XYZ does not work for
pain and firing b-fibres. Pain 'just is' pain, and firing b-fibres 'just are'
firing b-fibres. We cannot plausibly argue for the existence of something that
feels like pain but is not or something that appears to be a firing b-fibre but
is not. If the examples of zombies without feelings and disembodied pain are to
be shown to be misconceptions, it must be on some other basis.
As will be evident, however, the problem disappears if we accept
the perspective outlined in this section (4(2)). From this position, what we
know as pain and what we know as the corresponding b-fibre are different
perspectives on one underlying reality. Zombies and disembodied pain appear
reasonable to us, but this is based on a misconception. They appear reasonable
because they are usually only observed in isolation from each other - one of
the perspectives is accessible only to an inside observer of the human
organism, the other is accessible only to an outside observer, and (except in
very unusual circumstances) the two are unlikely to ever be accessible to one
observer simultaneously. Despite this, they are, in this view, one reality.
Zombies and disembodied pain seem reasonable possibilities but they are not -
pain is always accompanied by the corresponding firing b-fibre and vice versa.
We can observe the one occurring without the other if our perspective is
limited. However, in reality, they do not exist separately - they are different
views of one underlying reality.
If, however, we do not distinguish between what we know as pain
and an underlying reality, and what we know as b-fibres and an underlying
reality, this explanation is not available. This means that it cannot be the
case that a quale is really nothing but some aspect of the flesh, blood and
brains perspective on the human organism and, hence, that physicalism cannot
survive the grey Mary thought experiment.
(3) That the knowledge content of
the inside observer's perspective on the physical event that 'just is' the
quale:
·
Cannot
be expressed verbally without loss
Clearly, if the knowledge content of Mary's new knowledge can be
expressed verbally without loss, then it can be expressed as a statement. But
Mary has already acquired all true physical statements in her black and white
room. If she learns something new that can be expressed as a statement, the
knowledge must be non-physical and physicalism is refuted. Only if the
knowledge content of her yellow quale is experiential knowledge that cannot be
expressed verbally without loss - an entirely reasonable circumstance given
what we know about qualia - can physicalism survive her acquisition of new
knowledge.
·
Is
irreducible to the knowledge content of the set of true physical statements
that comprise a complete propositional knowledge of the event
Equally clearly, if Mary's new knowledge cannot be expressed
verbally without loss, as must be the case if physicalism is to survive, it is
obviously irreducible to the set of true physical statements that comprise a
complete propositional knowledge of the event (and must be so if physicalism is
to survive).
·
Is
nevertheless additional physical knowledge that is in some sense valid.
Finally, either Mary's new knowledge is non-physical knowledge and
physicalism fails, or it is physical knowledge and physicalism stands. If it is
truly physical knowledge, and is irreducible to the set of true physical
statements, then it is clearly physical knowledge that is additional to this
set of true statements. If it cannot be expressed verbally without loss, then
it cannot be held to be true (or false) in the normal sense, but if it is (as
it must be in the scenario described in the thought experiment) truly physical
knowledge then, it must, in some sense, be valid physical knowledge -
specifically, knowledge that is a true reflection of what the occurrence of the
physical event in question is like for an inside observer of the human
organism.
(4) That the set of true physical
statements that comprise a complete verbally expressible knowledge of the
(physical) event that 'just is' the quale is sufficiently comprehensive in
terms of knowledge content:
·
To
permit the re-creation of the event, including its experiential aspect
If physicalism is true, a quale 'just is' the physical event known
to an outside observer as something like a firing b-fibre. The outside
observer's experience of the event as a firing b-fibre is the reality as known
as distinct from the reality as such, but it is the reality as such that is
studied by scientists<9>, and it is this study that gives rise to our
propositional knowledge of the event. Normally, if we have acquired a complete
propositional knowledge of a physical reality then, practical difficulties
aside, it is safe to say that we have sufficient knowledge to recreate the
event, together with all of its characteristics, and there is no reason to
suppose that the same would not be true of the physical event that 'just is' a
quale. If the quale 'just is' a particular firing b-fibre, then making that
b-fibre fire will give rise, in the organism itself, to the experience
associated with the quale - and, practical difficulties aside, we should have
no difficulty in making the b-fibre fire if we have a complete propositional
knowledge of it. If it turns out that we do, then there must be some doubt as
to whether the quale 'just is' the firing b-fibre (or whatever physical event
we like to substitute for it) - and, hence, some doubt as to whether
physicalism holds.
·
To
account for it having, both this experiential characteristic and, indeed, any
experiential characteristic at all
We should also, in these circumstances, be able to account both,
for the physical event that 'just is' the quale having this particular
experiential characteristic, and for it having any experiential characteristic
at all. Once it is recognised that the yellow experience is as much a
characteristic of the physical event that underlies the firing b-fibre as its
pinky-white colour or fleshy feel, it becomes evident that we can account for
it having both this particular experiential characteristic, and for it having
any experiential characteristic at all. We should be able to do this in the
same way that we do it for all other observed characteristics of things in the
physical world - by specifying what physical things have the characteristics,
how they differ from other physical things that do not, and how those
differences account for the differences in observed characteristics. If
physicalism is true, then some physical things 'just are' qualia - they exhibit
experiential characteristics and they do so because they differ in discoverable
ways from physical things that are not qualia. Equally, different physical
things that exhibit these characteristics differ in the kinds of experiential
characteristics they display - and they do so because they differ in
discoverable ways from each other. Again, if this is not true there must be
some doubt as to whether the quale 'just is' some physical event and, hence,
whether physicalism is true.
(5) That a comprehensive physical
knowledge of the quale must nevertheless include the irreducible knowledge
content of the experiential aspect itself if it is to be considered complete
It is, of course, possible to express our explanation of
experiential qualities in wholly verbal terms, and this will normally be enough
for most human purposes – most of us know what is meant by phrases like 'yellow
experience' and 'sweet taste'. However, if experiential knowledge is valid
knowledge of the physical that cannot be expressed verbally without loss and is
additional to the set of all true physical statements (as - see 4(3) it must be
if physicalism is true), then a purely verbal account of qualia cannot, of
itself, be considered complete. If it is to be regarded as comprehensive, our
physical knowledge of the quale must be explicitely recognised as including the
non-verbal ‘what its like’ experience associated with the quale and, more, must
actually encompass, not just a verbal reference to that non-verbal experience,
but the actual non-verbal experience itself. An alien race with entirely
different sensory systems might in time come to understand our verbal account
of experience and experiential differences, but they would never have a
complete knowledge of the physical events that 'just are' qualia, because they
would lack knowledge of what it is like to experience them.
The
above analysis does not show that physicalism is true, nor even that the grey
Mary thought experiment fails to refute it. What it shows is that the question
of whether or not the grey Mary thought experiment refutes physicalism can only
be resolved by further examination of the perspective on the qualia-physical
relationship drawn out as a result of the analysis. If the perspective is false
- if the position set out under 4 (1) to 4(5) above is not an accurate
description of the actual nature of qualia - the thought experiment will refute
physicalism, there being no other position that will permit it to survive the
thought experiment. If the perspective is true - if it is an accurate
description of the actual nature of qualia - the thought experiment will fail
to refute physicalism, a significant outcome in circumstances where qualia are
probably the only question mark remaining against the physicalist viewpoint.
5
The Hard Problem of Consciousness
Another
significant point in favour of the position outlined is this. The perspective
described in 4(4) and 4(5) above permits us to give an account of experience in
terms of what Chalmers (1995) calls the physical as we presently understand it,
to do so without losing the unique experiential aspect of qualia, and - since
the experiential is included as knowledge that cannot be expressed as a
statement and cannot be true or false in the normal sense, but only as valid,
non-propositional, knowledge of the physical - to do so without in any way undermining
our view of the physical as we presently understand it.
The key
to this is the recognition that a quale and some aspect of the flesh, blood and
brains view of the human organism can be one physical reality provided we
recognise that what we get when we perceive this reality from either of these
perspectives is the reality as known as distinct from the reality as such.
Without this distinction then, as is clear from 4(2) above, we are left with a
position where qualia are (or appear to be) irreducible to the physical as we
presently understand it and cannot be dealt with in terms of it. If we give a
complete account of the human organism in terms of the physical as we presently
understand it without making this distinction, it fails to deal with experience
on two counts. On the one hand, since experience is irreducible to the physical
in this perspective, we cannot reasonably hold that the physical account deals
with experience. On the other, a purely physical account (in this perspective)
leaves experience itself out of the account. If we then wish to deal with
experience in terms of a physical viewpoint, we are led inevitably to a
position akin to that expounded by Chalmers (1995) where experience itself must
be taken as a fundamental property of the world alongside mass, charge, and
space-time (we must, in effect, 'add' experience to our view of what we regard
as physical).
The
position outlined above does not require this and is therefore a better
solution to what Chalmers calls the hard problem of consciousness (although, in
this account, it is just another of the 'easy' problems of consciousness). Some
physical things 'just are' qualia - they exhibit experiential characteristics
and they do so because they differ in discoverable ways from physical things
that are not qualia. Equally, different physical things that exhibit these
characteristics differ in the kinds of experiential characteristics they
display - and they do so because they differ in discoverable ways from each
other. A complete verbally expressible account of the physical events and their
inter-relationships will account, both for the experience itself, and the
differences between types of experience. Of itself, such an account will also
'miss out' experience. However, in this perspective it is an easy matter to
include it as additional knowledge that cannot be expressed verbally, is
neither true nor false but valid physical knowledge nonetheless, and that
simply makes our knowledge of experience comprehensive by encompassing what it
is like in our total physical account. It is not necessary, as it is in
Chalmers' perspective, to regard it as an additional fundamental feature of the
world alongside mass, charge, and space-time.
6
Conclusion: A Candidate Theory for a Physicalist Account of Qualia
Whether
or not the perspective outlined is an accurate description of the true nature
of qualia is a matter for further discussion and debate. I submit, however,
that it does have a potential as a candidate theory for a physicalist account of
qualia:
(1)
Dealing with Jackson's Thought Experiment
It is
not simply one position that will permit physicalism to survive the grey Mary
thought experiment, it is the only position that will permit it to do so -
physicalism fails if any of the requirements described above are not met. This,
in itself, makes it of interest as a candidate theory for a physicalist account
of qualia. Not only does the position outlined negate the force of a thought
experiment that many regard as a serious challenge to physicalism, it is the
only position that can do so - the challenge against physicalism succeeds if
the position is not an accurate description of the actual situation.
(2)
Dealing with Leibniz's Law.
It
shows how the idea that qualia can be identical with some aspect of the
physical as we presently understand it can be consistent with Leibniz's
law.
(3)
Dealing with Kripke's Problem for Proposed Identities.
It
shows how an identity position can deal with Kripke's Problem for Proposed
Identities.
(4) Dealing
with Chalmers' Hard Problem.
It
offers a solution to Chalmers' hard problem without the need to take experience
itself as a fundamental property of the world alongside mass, charge, and
space-time (Chalmers 1995).
(5) A
Plausible Account.
It is a
plausible account of the qualia-physical relationship - it is quite possible
and reasonable to imagine that it may be true.
These
various points are not conclusive. The position outlined may have flaws not
drawn out here, or may, in the event, turn out to be a view that can be shown
empirically to be incorrect. I submit, however, that the position does have
clear points in its favour and is worthy of further consideration as a
reasonable candidate theory for a physicalist account of qualia (or, at least, the
basis for one<10>).
Notes
<1>.
As Thomas 1998 notes, there appears to be a general acceptance in the
literature that the argument itself is sound, a point I will not dispute since
it is not necessary to my case
<2>.
See, for example, Graham and Horgan 2000 - self-confessed physicalists who
argue that the strength of its challenge to physicalism cannot be ignored
<3>.
For further information on this literature see Nida-Rümelin 2002
<4>.
Its first statement predates the Knowledge argument as such, and was a response
to Nagel's 'What is it Like to be a Bat?' (Nagel, 1994). This is an influential
paper to which Jackson (1982) acknowledges a debt, but is not considered
further in the present paper.
<5>.
See, e.g. Churchland (1985), who goes further and argues the new knowledge need
not be an ability to refute Jackson's argument so long as it is a different
type of knowledge of exactly the same thing, and Mellor 1993.
<6>.
Thomas 1998 has argued that Jackson's argument fails because it is incoherent -
that Mary could not acquire a complete knowledge of the physical inside the
black and white room because it is impossible to do so without access to colour
information. This may or may not be true, but even if it is true, it need not
affect Mary in the circumstances described. On the one hand, Mary is only
claimed to have acquired knowledge of true statements, not experiential colour
knowledge. On the other, she does have indirect knowledge of colour - because
the scientists have this knowledge and make every effort to pass it on to her
where it is relevant to her acquisition of true statements.
<7>.
In the thought experiment described here, Mary's new knowledge comprises only
all colour qualia - a blue quale, a green quale, a red quale, and so on.
However, as Jackson himself notes in his initial paper on the Knowledge
argument (Jackson , 1982), "... the same style of Knowledge argument could
be developed for taste, hearing, the bodily sensations...". In short,
Mary's new knowledge in this example can be taken as representative of any
quale.
<8>.
I avoid calling this perspective physical deliberately here. If physicalism is
true, both perspectives are 'physical views' of the organism.
<9>.
When we conduct scientific experiments and record the results, we make our
observations via our senses or our senses as extended by instrumentation –
through ‘the reality as known’. However, it is the reality itself that we put
in the experimental circumstances, and it is the reality itself that reacts to
those circumstances and that provides the data for our observations and the
basis for our propositional knowledge.
<10>.
Note that the repeated references to firing b-fibres in the account are
illustrative only. There is no suggestion that a firing b-fibre (whatever that
may be) is the type of physical event that a quale is identical with, only that
it is possible to derive a position in which it is possible for a quale to be
identical with some (as yet undiscovered) physical event.
References
Alter,
T. (1998). A Limited Defense of the Knowledge Argument. Philosophical
Studies, 90, pp. 35-56.
Alter,
T. (2001). Know-how, Ability, and the Ability Hypothesis. Theoria 67,
229-239.
Bigelow
J. and Pargetter R (1990). Acquaintance with Qualia. Theoria 56, 129-147
Chalmers,
D. J. (1995). Facing up to the problem of consciousness. Journal of
Consciousness Studies, 2(3), 200-219
Chalmers,
D. J. (1996). The Conscious Mind. New York and Oxford: Oxford University
Press.
Churchland,
P.M. (1985). Reduction, Qualia, and the Direct Introspection of Brain states. Journal
of Philosophy, 82, 8-28.
Conee,
E. (1994). Phenomenal Knowledge. Australasian Journal of Philosophy, 72,
136-150
Dennett,
D. (1991). Consciousness Explained. Harmondsworth: Penguin Books.
Deutsch,
M. (1998). Subjective Physical Facts. Retrieved May 11, 2001 from http://www.neologic.net/rd/chalmers/mdeutsch.html
Flanagan,
O. (1992). Consciousness Reconsidered. Cambridge: MIT Press.
Gertler,
B. (1999). A Defense of the Knowledge Argument. Philosophical Studies,
93, 317-36.
Graham,
G. and Horgan, T. (2000). Mary, Mary, Quite Contrary. Philosophical Studies,
99, 59-87.
Horgan,
T. (1984). Jackson on Physical Information and Qualia. Philosophical Quarterly,
34, 147-52.
Jackson,
F. (1982). Epiphenomenal Qualia. Philosophical Quarterly, 32, 127-36.
Jackson,
F. (1986). What Mary Didn't Know. The Journal of Philosophy, 83, 291-95.
Jackson,
F. (1998). 'Postscript on Qualia'. from Mind, Method, and Conditionals:
Selected Essays. Jackson, F. ed.
London
and NewYork: Routledge, 76-79.
Kripke,
S (1980). Naming and Necessity. Cambridge, MA: Harvard University Press.
Lewis,
D. (1988). 'What Experience Teaches'. from Mind and Cognition: A Reader.
Lycan, W. G. ed., Cambridge, MIT: Blackwell, 499-519.
Loar,
B. (1990). ‘Phenomenal States’. from Philosophical Perspectives IV: Action
Theory and Philosophy of Mind. Tomberlin, J. ed. Atascadero: Ridgeview,
81-108.
Lycan,
W. (1995). 'A Limited Defense of Phenomenal Information'. From Conscious
Experience. Metzinger, T. ed., Tucson: University of Arizona Press, 243-258
Lycan,
W. (1996). Consciousness and Experience. Cambridge, MA: The MIT Press,
91-108.
McGinn,
C. (1989). Can We Solve the Mind-Body Problem, Mind, Vol 98, no. 891,
349-366.
Mellor,
D. (1993). Nothing Like Experience. Proceedings of the Aristotelian Society.
93,1-16.
Nagel,
T. (1974). What is it Like to be a Bat? The Philosophical Review. 83
(4), 435-450.
Nemirov,
L. (1980). Review of Mortal Questions by Thomas Nagel. Philosophical Review
89, 473-477.
Nemirov,
L. (1990). 'Physicalism and the Cognitive Role of Acquaintance'. From Mind
and Cognition: A Reader. Lycan, W. G. ed. Cambridge, MIT: Blackwell,
490-499.
Nida-Rümelin,
M. (2002). 'Qualia: The Knowledge Argument'. From The Stanford Encyclopedia
of Philosophy. Retrieved November 15, 2002 from http://plato.stanford.edu/entries/qualia-knowledge/
Papineau,
D. (1993). Physicalism, Consciousness and the Antipathetic Fallacy. Australasian
Journal of Philosophy. 71: 169-183.
Robinson,
H. (1993). Dennett on the Knowledge Argument. Analysis. 53.3, 174-77.
Sommers,
T. (2002). Of Zombies, Color Scientists, and Floating Iron Bars. Psyche.
8(22), November 2002, Retrieved November 7, 2002 from http://psyche.cs.monash.edu.au/v8/psyche-8-22-sommers.html
Thomas,
N. J.T. (1998). Mary Doesn't Know Science: On Misconceiving a Science of
Consciousness. Paper given at the annual meeting of the Pacific Division of
the American Philosophical Association, March 26, 1998. Retrieved March 12,
2001 from http://web.calstatela.edu/faculty/nthomas/marytxt.htm
Tye, M.
(1986). The Subjective Qualities of Experience, Mind, 95, pp. 1-17.
Tye, M.
(1999). Phenomenal Consciousness: The Explanatory Gap as a Cognitive Illusion, Mind,
108, pp. 705-725.
Vinueza,
A. (No date). 'The Knowledge Argument'.
From Dictionary of Philosophy of Mind Eliasmith, C. Ed. Retrieved March
9, 2004 from http://www.artsci.wustl.edu/~philos/MindDict/knowledgeargument.html