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De-modalizing anti-physicalism:
the priority of the knowledge argument
(DRAFT OF 14 SEPTEMBER, 2004)
Howard M. Robinson
robinson@ceu.hu
István A. Aranyosi
fphari01@phd.ceu.hu
Philosophy, Central European University
1. The modal understanding
By a modal understanding of anti-physicalism we mean an argumentative startegy of the sort
that appeals to epistemic and metaphysical modal notions, like conceivability and possibility.
The general recipe for formulating a modal argument against physicalism is along the following
lines. You start with epistemic modals, and assert that it is conceivable, that is, not ruled out a
priori that there be a world where everything from our world is duplicated as regards matters
physical, but there is somehting different from our world as regards the mental phenomena.
Then you appeal to a principle that would link epistemic modality and metaphysical modality,
and deduce that it is possible that there be such a situation. Finally, you deduce a truth about the
actual world, namely that mentality is contingently related to the physical phenomena.
The fact that this sort of argument has become the most popular and discussed nowadays
is related to the fact that physicalism has recently received a standard and widely accepted
definition, which is formulated in such modal terms. The definition is part of the approach to
physicalism put forth by Frank Jackson (1992, 1994, 1998) and David Chalmers (1996). Jackson
defines physicalism by way of minimal physical duplication of worlds. Physicalism is true at a
world iff a minimal physical duplicate of that world is a duplicate simpliciter of it. By minimal
physical duplicate we should mean a world which duplicates everything physical and nothing
more. For instance, if the original world which is to be tested for the truth of physicalism
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contains some strange stuff, like ghosts, then the existence of such things will not affect the truth
of physicalism, given the Jacksonian definition. Of course, we are interested in the actual truth
of physicalism, and therefore we should apply the definition to our world. Chalmers appeals to
the notion of logical supervenience. Physicalism is then the doctrine according to which any
truth at the actual world logically supervenes on the totality of actual physical truths. To
logically supervene means to be a priori entailed, so physicalism is explicitly formulated as the
inconceivability of a physical duplicate of our world that is not a duplicate simpliciter. Jackson
subscribes to the a priori entailment commitment of physicalism as well, and we agree with
them on the issue.
However, our agreement with them motivates our dissatisfaction with the focus of the
recent deveopments of the debate over physicalism. These developments have been
characterized by the exclusive focus on the issue of apriority and necessity. Most physicalists'
main preoccupation is to deny the move from epistemic premises to metaphysical conclusions,
while most dualists try to defend this link. We would like in this paper to show, among other
things, that these modal issues are far from being so clear, that dualists should not appeal to such
arguments not because of the feebleness of the conceivability-possibility link, but because of the
feebleness of the conceivability intuitions themselves, and that there is a classic and clearer
argument, Jackson's knowledge argument, that can do the anti-physicalist work with more
effectiveness.
2. Elements of the problem.
Once upon a time there was a fairly straightforward (but not, of course, uncontroversial)
argument against physicalism, called the `knowledge argument'. It was the most focused of the
qualia objections to physicalism. Discussion of this argument, it seems, however, has become
enmeshed with - perhaps even swallowed up by - discussion of other closely related arguments
that import extra complexities that perhaps damage the clarity of the original argument. These
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other arguments concern, for example, the conceivability of zombies, the explanatory gap that
there is between physical theory and mental phenomena, and the question of whether mental
concepts can be conceptually analysed in physicalist terms. Our objective is to investigate what
difference, if any, these sophistications make to the knowledge argument, and we shall do this
by considering three important papers that have contributed to this diversification. (In fact the
locus classicus for bringing these things together is chapter 3 of David Chalmers' The Conscious
Mind, but we think it is in (some) discussions of Chalmers, rather than the original, in which
they get run together as if there was no significant difference.)
To clarify the situation, we will set out a brief taxomony of the various arguments
involved. There are now, in the arena together, the following beasts threatening to devour the
poor physicalist.
The Explanatory Gap (EG): That no amount of information about the working of the brain etc
can explain how there come to be conscious states associated with it.
Conceptual Analysis Thesis (CAT): That (i) the gap between brain and consciousness could
only be closed if there were available a (correct) conceptual analysis of mental concepts in
something like functional terms, and (ii) there is no such correct analysis.
The Knowledge Argument (KA): This argument purports to prove that total physical knowledge
does not constitute total knowledge of the empirical realm, so there is something in experience
which is non-physical.
The Conceivability of Zombies Argument (CZ) : Because there is no conceptual analysis of
conscious or phenomenal states in physicalist or topic neutral (eg. functional) terms, we can
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conceive of our having physical twins which lack conscious or phenomenal states. The
possibility of such `zombies' shows the falsehood of physicalism.
In an obvious way, all these arguments are making the same point, namely that there are
fundamental features of consciousness that physicalism cannot accommodate: they are all
arguments for property dualism. How they are interconnected is intuitively clear. But is it not the
KA that provides the argumentative force behind all the others? Let us remind ourselves of the
argument.
Harpo is a scientist who has been stone deaf from birth, but who has become the
supreme authority on all physical aspects of the hearing process, from sub-atomic physics,
through neurology, to computational and behavioural analysis. But he still does not know what it
is like to hear, or what the phenomenal nature of sound - eg. C-sharp - is. And when, by the
wonders of a new surgery - perhaps developed by himself - he gets hearing for the first time, he
learns something new that no amount of physical knowledge could have given him. The subject
matter of this new knowledge, therefore, must fall beyond the range of the physical. It is what
the KA, says is left out by or from physical knowledge is also that which cannot be conceptually
analysed in the appropriate way, and the fact that it cannot be captured in this way is what
produces the explanatory gap. It is also because it cannot be captured by physical knowledge or
by analysis that we can imagine it absent and so conceive of zombies. What are the other
arguments adding?
In order to understand this, it will help to formulate a more cautious version of CAT.
Weak Conceptual Analysis Thesis (Weak CAT): That (i) the gap between brain and
consciousness can be closed only if it is possible to infer a priori from the physical facts to the
presence of psychological ones, given that one possesses the psychological concepts: (ii) in fact,
this cannot be done.
The difference between the original and the weak versions is rather like that between a
reductive behaviourism that thinks that a strict analysis of individual concepts in behavioural
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terms can be given, and a Wittgensteinian behaviourism that holds that the behaviour is logically
sufficient for the psychological, but piecemeal reduction is not possible. In fact, the weak
version allows for a general behaviouristic gloss of concepts, and if one is prepared to call that
an analysis, there is no significant difference between the theses. Armstrong, for example, insists
that his causal theory of the mind does not give meaning, in any strict sense, of psychological
vocabulary, but ageneral rationale or gloss. From now on I shall use CAT to refer to the weaker
thesis.
CZ can be treated simply as a separate argument towards the same conclusion. Most of
David Chalmers work on possibility and conceivability is perhaps best seen in this way. But
there is a tendency in at least some of the literature to treat them as standing or falling together,
which would not be the case if they were different arguments to the same conclusion. The
tendency is to treat CZ as 'where it is at' in discussing KA. How does this connection work? I
think it is as follows.
One response to KA is to say that Harpo acquires when he gets his hearing is a form of
knowledge how, not a form of knowledge that. This is the behaviourist/functionalist response,
and currently the consensus is that this will not do1. So the context of developments is an
acceptance that the KA is sound in the sense that it establishes that Harpo gains some new real
knowledge, which is factual in at least the negative sense that it is not just a capacity, then to try
to reconcile this with physicalism.
We can now explain how the arguments relate in the following way.
(1) KA presents a very strong threat to physicalism because it seems to require property dualism.
But
(2) it presents such a threat only if physicalism entails that there is a conceptual analysis, in the
weak sense.
1
Though one of us believes that this consensus is unjustified. See Aranyosi (2004a, chapter 3)
for a defense of the commonsense functionalist response to KA.
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This is so because
(3) in the absence of an analysis - entailment from physical facts to mental - there is bound to be
some kind of explanatory gap and, hence, scope for something new for Harpo to learn when he
starts to hear.
But, therefore,
(4) if physicalism does not require analysis, it will not be afraid of the consequences of the lack
of an analysis, that is the existence of an explanatory gap, and the conclusion of KA.
The suggestion is that a physicalist need not be threatened by a weak explanatory gap. It
is at this point that the anti-physicalist is tempted to fall back on the conceivability of Zombies,
for that involves a real property dualism. So
(5) if one can show that zombies are a real possibility, the conclusion of KA must be strong
enough to establish property dualism.
There has, therefore, been a scuffle between those defending zombies and those intent on
showing that physicalism does not require an a priori component. But proving that there could
be zombies is not the only way of showing that the KA's conclusion is strong enough. It would
also do to show that physicalism is really committed to weak analysis (Weak CAT), for
everyone agrees that KA is incompatible with that.
We want to consider three papers that have as their common thread the notion that the
physicalist is not obliged to provide some kind of analysis of mentalistic language in order to
accomodate it to his ontology, however austere the latter may be. The strategy of the first paper,
by Block and Stalnaker (1999), is to deny that reduction in general involves conceptual analysis
and hence to claim that its absence in the case of mind signifies nothing. The next two, by Balog
and Loar, respectively, have a more precise common thread. Their authors hold that the
physicalist can treat phenomenal concepts in a purely demonstrative fashion, as does the dualist.
They do not claim, as do Block and
Stalnaker, that there is not a conceptual analysis
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requirement for normal scientific reductions: it is the special demonstrative nature of the
experiential case that does the work. The argument for this really comes in Loar's paper, though
they both rely on it. Balog's paper argues that CZ is too promiscuous, as it could be used to
prove things that are ex hypothesi false. Loar's paper attempts to close the explanatory gap by
refuting the knowledge argument. It is the only one of the papers that deals with the KA as an
independent argument.
(3) Block and Stalnaker on why explanatory gaps are harmless.
It is a principle adhered to by Smart, Armstrong and functionalists that, if one is to claim that
mental states are physical, one must give an analysis - or at least a gloss - of mentalistic terms
which makes it intuitively clear how something physical could qualify as mental. If this is
required in the case of the reduction of the mental to (or its identification with) the physical, it
must be a general requirement for similar identifications or reductions. Such a requirement
would be equivalent to the provision of a topic neutral account of the concept to be reduced. In
the case of mental states that would most probably be something along the lines of
Mental state M is that state - whatever it is - that is typically brought about by stimulus S
or
...typically causes response R.
In the case of other states - for example being water, it might be something of the form
Water is that kind of stuff, whatever it is, that underlies the stereotype that, on Earth, we call
'water'.
Block and Stalnaker deny CAT(i), claiming instead that:
(i) The absence of conceptual analysis does not, in general, entail the presence of an explanatory
gap.
(ii) There is no conceptual analysis involved in purely physical cases - eg water = H2O.
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We would like to first point out that (ii) could be interpreted in two ways, the first of which
makes the qualia/water analogy be irrelevant from the point of view of defending physicalism,
and the second self-refuting. The first interpretation could be that we have only a weak analysis
or just a gloss on how water-truths are determined by the totality of physical truths This
interpretation is of no use for defending physicalism, because the qualia objection is precisely
that we lack even this weak analysis or gloss over how physical or neural states can
metaphysically determine phenomenal truths. The second interpretation could be that even
though the water-truths are purely physical we lack an analysis of them in physical terms. This
interpreatation is even more problematic. You cannot really say both that:
(a) The water = H2O case is purely physical
and
(b) We do not know with certainty, given by an a priori deduction, but only by fiat that the
identity holds.
If the argument is meant to show that there are the same explanatory gap problems with
standard scientific identities as in the mental-physical case, than that is an argument at most to
the non-physicality of scientific identifications. We agree here with David Lewis, who pointed
out, against this kind of argumentation, that it implies that we are not sure about the physical
nature of, say, boiling, which is absurd. As Lewis puts it ([1994] 1999, p. 296):
“It may seem that when supervenience guarantees that there are physical
conditions sufficient for the presence or absence of a given mental item, the
sufficiency is of the wrong sort. The implication is necessary but not a priori.
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You might want to say, for instance, that black-and-white Mary really did
gain new knowledge when she first saw colour; although what she learned
followed necessarily from all the physics she knew beforehand, she had
remained ignorant because it didn't follow a priori.
A short reply to this objection from necessity a posteriori is that if it
did show that boiling was irreducible to fundamental physics, it would
likewise show that boiling was irreducible to fundamental physics – which is
absurd. For the identity between boiling and a certain process described in
fundamental physical terms is necessary a posteriori if anything is.”
As a general observation, we should also point out a difference between Block and
Stalnaker's approach to the issue and that of the classic identity theory of J. J. C. Smart (1959).
While the latter appealed to Occammist considerations for establishing identities, but these were
taken, precisely because of these considerations as contingent identities, and the approach was
coherent, the former seem to hold a hard to understand and even incoherent view, according to
which we should assert that the water- H2O case is a necessity, yet we should also assert that we
don't know for sure that it holds. We believe one cannot have it both ways: once you commit
yourself to asserting that there is a necessity, you cannot appeal to Occamist considerations and
assert that you don't know it for sure. As we said, Smart's theory was at least coherent on this
point.
The scientific identities are postulated on grounds of general method - simplicity. This
can be done, according to Block and Stalnaker just as well for mental state-brain state identities.
The implication is that, in so far as KA establishes emergent properties, they can be integrated
into the body of science by nomological fiat, as happens in other cases. Their position is, in this
respect, similar to Searle's.
They argue this, partly with Levine in mind, but mainly with Jackson and Chalmers as
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their target. To set up what they are attacking they quote and paraphrase Levine as follows.
Levine holds the following, in common with Jackson and Chalmers.
"While it is conceivable that something other than H2O shuld manifest the superficial
macro properties of water...it is not conceivable...that H2O should fail to manifest these
properties (assuming, of course, we keep the rest of chemistry constant)."
In other words, there cannot be such a thing as 'zombie water' - something like water in all its
micro physical properties (with the same laws and conditions) and lacking the same manifest
properties.
By contrast, about pain, he holds (in Block and Stalnaker's words):
"However, according to Levine, one cannot say the analogus thing about conscious
states and their neural correlates. Even if pain turns out to be perfectly correlated with
pyramidal cell activity, and even if we decide that pain is (necessarily) pyramidal cell
activity, it will remain possible (Levine contends) to conceive of pyramidal cell activity
without pain."
Part of this - namely the contrast with water - is common with Jackson and Chalmers, but the
possibility that there is nevertheless identity and hence necessity is particular to him. For present
purposes, we shall ignore it.
It seems to us that Block and Stalnaker's response to the core argument rests on a fairly simple
mistake, namely that they are confused about what is involved in there being a conceptual
connection between micro and macro. Their claim is that there is no analysis of water such that
it follows a priori that H2O, given its properties, is or constitutes water. Let us look first at the
arguments and conclusion found on 8-9, during their discussion of Levine.
Their first argument is as follows.
“Let C be a complete description, in microphysical terms, of a situation in
which water (H2O) is boiling, and let T be a complete theory of physics. Can
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one deduce from T, supplemented with analytic definitions, that H2O would
boil in circumstances C? To see that one cannot, suppose that the deduction is
taking place on Twin Earth. The stuff they call "water" is XYZ, and the
process they call "boiling" is a process that superficially resembles boiling,
but that involves a different physical process. Just as they would say (truly)
"water is XYZ, and not H2O (and if there were H2O, it wouldn't be water),"
so they would say, truly, "If there were H2O, and it were behaving like that, it
wouldn't be boiling." They could hardly deduce ‘H2O would boil in
circumstances C’ if on their meaning of ‘boil’, H2O can’t boil at all. (We
assume that boiling is a natural kind concept. If you don’t agree, substitute
some other process term that does express a natural kind concept.)”
The argument appears to be that 'one' - i.e. we - cannot deduce that H2O boils in C because a
Twin Earthian could not deduce that it twin-boils in C; and the slippage from boiling to twinboiling is legitimated by the fact that 'boil' is a natural kind concept. This seems wrong in at least
two ways.
(i)If boil is a natural kind concept, twater does not boil, so the slippage is not legitimate. That is,
the fact that H2O does not twin-boil does not mean that it does not boil and it does not mean that
a Twin-Earthian acquainted with the concept of boiling could not work out that H2O boils.
(ii)Natural kinds are irrelevant. A description of what both water and twater do is enough. There
must be such a description, otherwise there would be no sense in calling the other earth our twin.
What can be deduced, even by a properly informed twin-earther, is that H2O will do that under
C.
Their second argument is as follows.
“We don't really need a Twin Earth story to make our point. Consider a person
on actual Earth, who does not know the story about how water boils -- perhaps
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she doesn't even know that water is made up of molecules. One presents her
with the theory T, and a description (in microphysical terms) of a water boiling
situation. Can she then deduce that if T is true and a situation met conditions
C, then the H2O would be boiling? No, since for all she knows the actual
situation is like the one on Twin Earth. Perhaps, if she were told, or could
figure out, that the theory was actually true of the relevant stuff in her
environment, she could then conclude (using her knowledge of the observable
behavior of the things in her environment) that H2O is water, and that the
relevant microphysical description is a description of boiling, but the
additional information is of course not a priori, and the inference from her
experience would be inductive. (i) The appeal to her ignorance about whether
she is on Twin Earth is ineffective because the Twin Earth version of the
argument has been shown to be hopeless, and because B. and S. provide their
own reply to it.”
(ii) There is a mistake about what has to be shown a priori. It is not that H2O under C is water
boiling, but that it manifests all the properties we believe water to possess when it boils. This is
an important point to which we will recurr. Immediately so, because of what B and S say in their
conclusion.
All we reject is the a priori, purely conceptual status attributed to the bridge
principles connecting the ordinary description of the phenomena to be
explained with its description in the language of science. What is actually
deduced in such an explanation is a description wholly within the language of
science of the phenomenon to be explained. For this to answer the original
explanatory question, posed in so--called folk vocabulary, all we need to add is
the claim that the phenomenon described in scientific language is the same
ordinary phenomenon described in a different way. But if the closing of an
explanatory gap does not require an a priori deduction of the folk description of
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the phenomena, then it has not been shown that unavailability of a conceptual
analysis of consciousness need be an obstacle to the closing of the explanatory
gap between consciousness and the physical. B. and S. are right that it cannot
be deduced a priori from science and the properties of H2O that H2O is water.
But it can be deduced a priori that H2O is an adequate candidate to be water: ie,
if H2O were water it would explain all the relevant observable facts about
water. This kind of adequacy is precisely what neuroscience lacks in respect of
consciousness: we cannot deduce from the nature of pyramidal cell activity, as
characterised within neuroscience, that, were there to be something of that sort,
it would it would give rise to or constitute a pain-like sensation. B and S
confuse the non-deducible brute fact, asserted on the grounds of general
scientific simplicity, that it is H2O (not, eg, XYZ) that is the waterish stuff in
our vicinity, with a supposed brute fact, supposedly asserted on general
scientific grounds, that H2O manifests itself in a waterish way under certain
conditions. The latter is not brute, nor asserted on general scientific grounds,
but is deducible from the properties of H2O, the laws of nature and the
conditions.
These considerations enable us to answer B and S's objections to Jackson and Chalmers,
we think. Perhaps Chalmers invites B and S to make their mistake by the way he states the
relationship between macro properties and micro base. He supports the full CAT, when all that
is needed is Weak CAT. Chalmers initially defines logical supervenience as follows:
B-properties supervene logically on A-properties if no two logically possible situations are
identical with respect to their A-properties but distinct with respect to their B-properties.
(The CM, 35)
The problem with this is that there may be 'ghostly' B-properties, in some world, over and above
those that supervene on the A-properties. The brunt of the rather obscure arguments in B and S
16-20 is that there can be no a priori argument from microphysical facts to the absence of such
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ghostly properties, so there is no general a priori move from how things are at the micro level to
how they are at the macro. But the situation is that such micro facts are a priori sufficient to
guarantee the presence of the macro facts. Whether they are the actual explanation of all the
macro facts of the relevant kind is an empirical matter.
I would reformulate Ch's definition:
B-properties supervene logically on A-properties (holding the A-level laws of nature
constant) iff the presence of A-properties is a priori sufficient for the presence of Bproperties [the presence of B-properties can be deduced from the presence of Aproperties] and the A-properties provide an a priori explanation of the presence of those
B-properties for which they are sufficient / the existence of which can be deduced from
them.
There is no longer any need to deduce the whole macro set up, including negative conditions
from the micro facts.
So Block and Stalnaker's arguments may show that there is no adequate conceptual
analysis of 'water', such that it follows that there is no more to water than H2O. It does not show
that we cannot work out a priori that the properties of the base - H2O - are sufficient to explain
all the observable properties of water, or ones indistinguishable from them. Given this, we are
methodologically free to assert identity. This a priori sufficiency is absent in the mind-brain
case, so the assertion of identity is not warranted on general methodological grounds - certainly
not with as solid a rationale as in the case of water.
(4) Balog's reductio of the zombie argument.
Balog's strategy is to show that an argument exactly parallel to Jackson's would allow Zombie's
to prove that they are not purely physical. As it is ex hypothesi that they are, there must be
something wrong with this general form of argument.
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Jackson's Argument
(1) If physicalism is true, then for any true T, statements of the form K -> T are conceptual
truths. (K is the total of true descriptions in physics.)
(2) There are some true statements Q to the effect that phenomenal conscious experience
occurs...
(3) If Q is a phenomenal statement then `K -> Q' is not a conceptual truth.
So
(4) Physicalism is false.
Zombie-Jackson's Argument
(1*) If physicalism is true, then for any true T, statements of the form K -> T are conceptual
truths.
(2*) There are some true statements Q+ to the effect that a phenomenal+ state occurs...
(3*) If Q+ is a phenomenal+ statement, then `K -> Q+' is not a conceptual truth.
So
(4*) Physicalism is false.
As it is ex hypothesi that physicalism is not false for zombies, the original argument must be
somehow flawed. (2) and (3) are not in dispute, so (1) can be rejected.
The natural objection to this argument is that (3*) is false, because the only sense that could be
given to a zombie's `phenomenal+' states would be a functional one and functional statements
are entailed by K. Balog denies this, because what is and what is not a conceptual truth depends
on the conceptual role of their constituents, and the conceptual role of the elements in zombie
thoughts are just the same as those in ours. This raises two questions. First, whether conceptual
role semantics is correct and second whether there really is an identity of role between the
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zombie and human concepts. Balog does not supply much argument here. On the former of
these two points she says
If a prioricity did not so supervene...[end para]
Of the latter
...Jackson's phenomenal concepts and zombie-Jackson's phenomenal+ concepts have parallel
conceptual roles. Q+, like Q, lacks conceptual links to physical,functional, and
behavioural concepts sufficient to ground the a prioricity of `K -> Q+'.
It is this latter assertion that seems controversial. It is natural to think that the meaning of the
human Q depends essentially on its connection with the real phenomenal qualities that zombies
lack, and that, therefore, any parallel concepts that we might be prepared (if only for purposes of
argument) to admit that zombies possessed, would have to have another source of meaning, and
this could only be functional role2.
The crux can be brought out by comparison with what Balog calls `yogic' concepts which are the same as blindsight ones. A yogic concept is one by which we can refer to
something without knowing anything about the nature of that to which we refer and is, in a
sense, the kind of concept that a zombie would possess. It is a form of topic neutrality without
anything that guides the reference contextually. Yogic concepts (as opposed to yogic access to
states we otherwise understand - as with blindsight) are peculiarly empty. In fact without some
kind of associated content, they are no better than dispositions to meaningless utterances.
We want to make three points about yogic concepts.
Balog’s argument is yet another point of both agreement and disagreement between the
authors of this paper. Both of us agree on this interpretation of Balog’s thought experiment as
the correct one, namely, that the parallel zombie concepts that we would be prepared to
accept should be thought of as functional ones. The disagreement is that one of us (HR)
thinks this points to property dualism, while the other (IA) that this shows that deep down
zombies are not conceivable since we cannot avoid functional role concepts in analyzing the
situation, so that commonsense functionalism can safely be concluded from the thought
experiment.
2
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(1) Balog says that they can be treated in the same way as zombie concepts, giving a restricted
version of the 'zombie argument'. But these concepts are topic neutral - that is, the yogis have the
resources to realise that they know nothing about the reference of these terms and so nothing
rules out that reference being in fact physical. And the physical facts do entail that they make the
reports. So the physical is sufficient and the conceptual analysis thesis is not avoided.
(2) Blindsight concepts, in so far as they actually occur, have their sense from the context in
which the subject is not blindsightedly but naturally perceiving. It is not obvious to me that there
could be purely direct referential blindsight concepts - which is what yogic concepts are.
Without either contextualising descriptive gloss or a qualitative nature to the reference, they are
peculiarly empty: so empty, I think, as to be meaningless.
(3) How does Balog think that phenomenal concepts, on her account, differ from yogic ones?
They are directly referential, are not explicitly of something physical and do not invoke nonphysical qualities. How does this differ from yogic concepts? To understand this, let us consider
Loar's classic paper.
(5) Loar's account of concepts that are both phenomenal and demonstrative.
Loar's position can be stated as follows.
(i) The new knowledge Harpo gets deploys special phenomenal concepts but does not relate to
new properties or qualities.
(ii) These concepts are ostensive, not given descriptively, and this explains why there is no
functionalist analysis of them.
(iii) It thereby also explains why no account in terms of physical theory - into which these
ostensive concepts are not integrated - can explain the role of these phenomenal concepts.
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So this answers the KA and shows why no conceptual analysis is required, and the EG either
harmless or nonexistent, depending on how you construe it. If correct, it would also undermine
the zombie argument. That argument, as currently expressed, depends on Chalmer's distinction
between the primary and secondary intension of terms. The primary intention of 'water', for
example, is what 'water' shares with 'twater'; the waterish stereotype that can be the face of either
H2O or XYZ, or an infinity of other things in other worlds. The secondary intention is H2O or
XYZ, or whatever, depending on the world. The role of this distinction is to show that Kripke's a
posteriori necessities cannot really restrict the range of metaphysical possibilities. There is no
possible world in which water is not H2O, but this is only a semantic restriction, not one which
restricts the range of possible combinations of properties: there are waterish things that are not
H2O, but you cannot call them 'water'. Physicalists argue that the relation between eg. pain and
some brain state is necessary a posteriori, like that of water and H2O. Developing Kripke's
arguments, and deploying the notions of primary and secondary intentions, Chalmers shows that
it cannot be. But if the primary intention is topic neutral, without a contextualising description,
then it does not present a face which could be the face of a variety of possible worlds. Its hidden
real essence - its secondary intention - is the only positive content that it possesses. Everything
turns, therefore, on the legitimacy of this bare notion of topic neutrality.
6. Three Problems for the Loar Solution.
(i) Does his theory, even if correct, solve the problem? Loar's solution is, in some ways at least,
a variant on a solution already proposed by others, namely that what Mary originally lacked and
came to possess was a new mode of access to something about which she already knew in
another way. The replies to this are well-known. In Frank Jackson's words; ' What is
immediately to the point is not the kind, manner, or type of knowledge [DS] has, but what [he]
knows.' Richard Warner illustrates the point: we may either see or hear that a certain person is
19
in the room and which we do is indifferent to the content of our discovery.
It is not difficult to appreciate the prima facie appeal of the idea that a difference of mode in
knowledge could explain DS's case. The idea behind the 'mode' theory is, presumably, that if
the phenomenal is merely another mode of access to respectable physical facts, then it does not
itself constitute an extra fact: it is not an addition to ontology, but an extra mode of access to
part of the previously accepted ontology. A moment's reflexion will, however, show this to be
sophistical. Call the set of physical facts P and the scientific modes of access which DS has to
these facts S, and the experiential mode of access he lacks H. If we regard S and H as external
to P, then the addition of a new mode of access will not alter P. But the physicalist hypothesis is
that everything relevant is included in P: modes of access to physical facts are themselves
simply physical processes and are included in physical facts. Therefore, if DS knows all the
relevant members of P, he should know all the facts about H: he should know, that is, all that is
real about applying phenomenal concepts.
Can Loar avoid this objection by appealing to the particular nature of phenomenal concepts, as
he explains them? This would involve arguing that one can apply such concepts only if one has
the experience oneself, so only those who have the experience can have the knowledge which is
cast in that way.
There is an ambiguity or equivocation here. The early Mary's defecit was not simply that she
lacked certain pieces of information, but that there was a certain type of proposition which she
was not in the position to properly understand: she lacked the concepts, not merely the
knowledge. Uncontroversially, one cannot exercise these concepts to gain knowledge through
them unless one has the experiences. But knowledge about the process of applying phenomenal
concepts - how they work and why - is, if physicalism is correct, something that Mary knew
about all along. Only if there is something about how those concepts work which is only
available from the first personal perspective, should she have lacked any understanding. But this
is the sort of thing the physicalist cannot allow. Only if the first-personal perspective reveals
something essential about their reference not otherwise available would understanding be so
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dependent. (longer footnote on Nagelian approaches, see my chapter II)
(ii) Is it possible to locate Loar's position?
There are three accounts, which I can understand, of how reference to phenomenal states might
work, and which are brought into the discussion.
(a) One identifies them by some quale they present, or which constitutes them.
(b) One identifies them by a kind of bare reference that is analogous with blindsight.
(c) One identifies them by some description which locates them in virtue of a contextual (eg
stimulus - response) property.
It is agreed that the first of these is the dualist option that the physicalist is trying to avoid. The
second, it is agreed, leaves out the experiential element altogether. The third, it is agreed, is what
Kripke refutes.
Loar's own theory seems to be a mysterious combination of (a) and (b): it omits the quale,
without omitting consciousness of the experience. I cannot detect the tertium quid between these
theories. By contrast, Loar finds it obvious.
The main point is by now more than obvious. Whatever the antiphysicalist has said about these
[ie phenomenal qualitites, feelings of them and blindsight] cases the physicalist may say as well.
The way that one picks out the phenomenal quality cramp feeling by way of a particular feeling
of cramp (or image, etc) is hardly incompatible with holding that that phenomenal quality is a
physical property. The contrast between phenomenal concepts and self-directed blindsight
concepts and cramp concepts finds physicalist and antiphysicalist equally able to say something
sensible.(604-5)
The only sense that I can make of this is that the difference between normal awareness
and the blindsight kind of case, is that the grasp in the former is via something that involves a
feeling or image, the latter does not. But do not feelings and images fall within the range of
those qualia-type entities that we are supposedly explaining? It is, after-all, the difference
21
between these two cases that constitutes the difference between 'lights on' and 'lights off', as far
as consciousness is concerned. If I understand him, Loar is making the very mistake Kripke
criticises. (The pain is not what lies behind the feeling, it is the feeling.) He is treating the
phenomenal quality as something that lies behind the experiential states. The quality, as Loar
conceives it, is common to `blindsight' and full consciousness, and what constitutes the latter is
treated as a form of imagistic conceptualisation, which he also describes as `a particular feeling
[of cramp]'. But, (a) there is no adequate account of imagery possible in this context. (`Adequate'
meaning that it is both physicalistically pure and will do the job of constituting what the
`blindsighter' lacks). (b) This means that the imagistic conceptualisation is the phenomenon.
Recent discussion of one of us (HR) with Kati Balogh has shown that the following is
her position, and perhaps it is Loar's. The difference between the phenomenal case and the
yogic/blindsight case is that in the former, but not in the latter there is a phenomenal quality
present, but that quale simply is identical with a brain state. There is, I think, no reduction of the
quality involved here, and no topic neutrality in our knowledge of the phenomenal aspect of the
quale. I think this takes us back to B and S, with the assertion of brute identities between
qualities on grounds of simplicity alone. This will seem plausible only if this is how other
reductive identities operate, and we have seen how it is not.
(iii) The direct anti-physicalist approach that we favour, and which we will expound in the next
section, consist of our having a clear and distinct, to use some good old Cartesian phrase, idea of
a conceptual disparity between physical and phenomenal notions, namely the former being
connected to properties of the dispositional and relational logical type, while the latter to those of
the categorical and monadic logical type. If Loar wants to accommodate the directness, and by
that transparency of phenomenal reference, and to also be a realist about phenomenal properties,
then he has to assert that one and the same property is of both logical types that the two kinds of
concepts conceptualize it, which is contradictory. Therefore, we do not see how to be a
22
phenomenal realist and assert physical/phenomenal property identities3.
7. Why modalization is problematic
In this section we would like to be more explicit about why modalization of the
physicalism/anti-physicalism debate is not desirable, and why the what we call ‘direct or nonmodal arguments’, KA being one of them, should better be focused on, in order to avoid lack of
clarity.
In one of his recent papers Chalmers (2002) merges the KA and the ZA under the same
heading of “conceivability arguments”. As he formulates it, the KA is an argument requiring a
weaker premise, the negative conceivability of zombies, while the ZA a stronger one, the
positive conceivability of zombies. Positive conceivability is a strong kind of conceivability,
similar to Descartes clear and distinct perception. It requires an act of clear imagination of a
scenario, as opposed to negative conceivability, which only requires the lack of a defeater of a
scenario.
We do not agree with this merging. Before arguing why the KA is not a negative
conceivability of zombies argument, we touch upon the original ZA. The main issue that has
been discussed in connection with the soundness of the argument is whether conceivability
entails possibility. Positive conceivability is the kind of conceivability that presumably entails
3
Correspondence of one of us (IA) with David Chalmers revealed that the principle that
direct reference to qualia imply transparent reference to them, with the consequence that the
type of conceptualization should be isomorphic to the type of property referred to, would in
fact be easily denied by one who follows Loar’s approach. We don’t think a good case can be
made for this. The only counterexample to this principle seems to be the kind of bare
demonstrative reference, when a cognizer has no idea whatsoever what she is referring to by
a term, that is, does not associate any property to the property she is referring to. This is not
the case with qualia: here we implicitly associate properties that make them fit for being
subsumed unde more general logical categories, e.g. monadicity and categoricalness. For
another problem of conflict between qualia realism and physical/phenomenal identities see a
recent article by Jose Louis Bermudez (2004), where he points out vagueness – which is
characteristic to the phenomenal and is absent in the case of physical properties-- as a factor
that makes impossible such identification.
23
possibility. At the same time, it puts a lot more burden on anti-physicalists, since it is a
demanding notion of conceivability, namely imaginability4. This is one reason we would advise
dualists not to appeal to the ZA. But the positive conceivability based ZA should also be less
appealing to defenders of phyhsicalism. There are two main approaches within the physicalist
camp, a posteriori and a priori physicalism, and it seems that none of them can gain too much
from properly attacking the ZA. The proper attack on ZA is, we believe, the denial of positive
conceivability, since once one accepts that zombies are positively conceivable, one should also
accept entailment of possibility5. But attacking positive conceivability is not something either of
the two kinds of materialists would find comfortable doing. The a posteriori materialist is
committed to the denial of the conceivability-possibility entailment in the case of zombies, so
she has to attack that premise rather than the conceivability premise. The a priori materialist will,
of course, attack the positive conceivability premise, but as a result of his much stronger
commitment to denying even negative conceivability. According to a priori materialism,
phenomenal properties and physical/functional properties are analytically related, so she will not
bother with only attacking one of the terms of such a fine-tuned distinction like the
positive/negative conceivability distinction. She will deny conceivability in its weakest form.
Therefore, the modal approach represented by ZA is not very advantageaous from the point of
view of either physicalism or dualism, since it makes things more confused.
Let us then turn to the KA. As we have mentioned, we do not agree with David
Chalmers’ putting the KA under a negative conceivability of zombies argument. The KA’s two
important parts are: (1) that one could know alll the physical facts about colour experience, and
(2) that one would not thereby know everything about colour experience. From these it follows
that there is something left out by physical knowledge. The fact that something is left out by the
complete physical knowledge is pretty clearly equivalent with the fact that there are non-
4
On how demanding this kind of conceivability can be see Stephen Yablo (1993) and Peter
Van Inwagen (1999).
5 This is because positive conceivability is precisely a notiion elaborated for the purpose of
possibility entailment.
24
physical facts, which is just the negation of physicalism. First, the KA does not even implicitly
require any act of conceiving of a non-actual world. Second, it does not have to appeal to
principle of modal cognitive reliability. Third, the fact that one could augment the argument or
alter it to include the negative conceivability of zombies, does not mean that the argument needs
such an augmentation or alteration in order to be effective.
We argue, in fact, that the KA is independent from the ZA, and it can be put under the
heading of direct or non-modal arguments against physicalism. An alternative direct argument
against physicalism that could be formulated is a reformulation of point (iii) that we used to
criticise Loar’s position in the previous section. The reformulation would mainly consist in
drawing a clearly property dualist conclusion from the disparity of physical/phenomenal
concepts/properties, according to which no physical property can be identical to any
phenomenal property. This sort of argument is, we believe, more effective than the
conceivability arguments in attacking physicalism, and also clearer than the conceivability
arguments, so that they can be more properly discussed by physicalists6.
8. Conclusion.
Starting, as is our intuition, from the KA, we shall try to piece together the area. Let us begin by
asking
(1) What does the knowledge argument show?
Two possible responses to this are
(2) That some concepts are not integratable into science.
(3) That some properties are not integratable into science.
6
For more advantages of theis kind of property dualist arguments over the classical ones,
see Aranyosi (2004b).
25
Physicalists need to deny the latter. But they can hardly rest content with affirming the former
because of the following is hard to deny
(4) The phenomena - qualia as they are experienced - are not just concepts or ways of
conceiving, but things or states that get conceptualised, ie. the objects of concepts.
If one accepts (4), as one must, how might one avoid (3)? The traditional answer has been
(5) The objects/contents of phenomenal concepts are grasped topic neutrally via some
contextualising analysis, gloss or paraphrase.
In the present context, this is something everyone agrees to reject, for this is what is proposed by
those who think there is a conceptual analysis available. So one might try
(6) The contents are grasped topic neutrally without any analysis etc.
This was the solution that lead us to wonder (a) how they had any content at all and (b) how they
differed from `yogic' concepts. The reply appears to be
(7) The contents are not grasped neutrally, but as having a qualitative content, but this content is
(token?) identical with a brain state.
(8) But how can there be brute identities between non-neutrally and non-contextually conceived
properties?
(9) At least we can say that if the Conceptual Analysis Thesis was false, in the sense that there
was no a priori sufficiency of the base in normal, non-controversial cases of reduction (as Block
and Stalnaker affirm) then it would be difficult to see anything special about mind-brain
relations. So KA does require that version of CAT.
9. General reflections.
There seems at first sight to be a wide range of contemporary physicalisms, stretching from
26
eliminativism at one extreme, through Dennett, functionalism, and Searle, to those who regard it
as true but essentially mysterious - McGinn, Strawson, Nagel. In fact there seems to me to be a
lot more in common here than one might think at first sight: at least in the forms these theories
have come to adopt as the discussion has developed. A surprising range of philosophers accept
the following three propositions.
(1) Of course, there are the mental states - conscious and intellectual - that we think there are,
and they are broadly as they seem to us. We are not denying the obvious. (Even Patricia
Churchland says this about consciousness.)
(2) What these states in fact are, are complex micro structures that realise the behaviourinfluencing role of the mental states in question. There is serious disagreement about whether
complex micro structures with these functional roles have to be in certain kinds of matter or can,
in principle, be in anything, but there is agreement that functional organisation in something however restricted or not it must be - is all there is to mental states.
(3) There is an endemic failure of imagination that makes it impossible - or more or less so - for
us to see how what is described in (2) can amount to what is described in (1). It at least seems to
us that we can conceive things as in (2) without their amounting to (1). There is a real
emergence relative to our understanding; a kind of epistemological emergence. This is why
Mary learns something new. But this is due to a lack in our understanding - a conceptual gap
between two ways we have of thinking about things - not to there being two forms of reality.
There are various accounts of what underlies this endemic failure of ours, some making it less
insuperable than others.
To support our claim that belief in these principles is quite general...
(1) Even Patricia Churchland claims to believe this with respect to consciousness. The common
affirmation is that, as far as our experience of life is concerned (if not all our `theories' for
explaining our behaviour), it is as it seems. Whether this really makes sense for an eliminativist
is another matter.
27
(2) Not only functionalists, (which includes computationalists and eliminativists) believe this.
Searle does not deny closure under physics, and is an internalist, so he believes that neural
micro-structres drive behaviour, and that the presence of structures of the right kind, in the right
kind of stuff, is all there is to the existence of mind. He simply holds the odd view that
emergence of conscious and intentional states allows an interactionism that does not threaten
that closure, because such emergences are not peculiar or threatening.
(3) is the new-ish one, and stems from the now almost universal belief that no reductive analysis
- however broad, loose or schematic - will seem intuitively to capture the nature of
consciousness from the first person perspective. Trying various ways of living with this fact
whilst sticking to physicalism is now the name of the game.
Searle, and Block and Stalnaker believe that the `emergence' is a harmless feature of the
general relations between `levels', which explain qualitiative emergence only in a brute way that is, via a theory which simply says it does.
Balog and Loar explain it as a feature of the bare demonstrative nature of phenomenal
reference., though perhaps also relying on the same point as S, B and S.
McGinn says it is because the eye cannot see itself. And Galen Strawson and Nagel
think we need a radically new understanding of physics. They alone think that physical science
itself must change radically for the problem to be solved.
The relation of ZA to EG and CAT is also supposed to be clear: ZA says that, if there is no
conceptual analysis of the mental in physical-compatible terms, there follows not only an
explanatory gap from physical to mental, but also that the existence of the one without the other
is conceivable.
We can express these two points as follows
(1) KA -> CAT & CAT -> EG
28
and
(2) CAT -> EG & ZA
From this it follows
(3) KA -> ZA
In other words, the Zombie (or Conceivability) Argument follows from the Knowledge
Argument, and, therefore, if the Zombie/Conceivability Argument can be refuted so can the
Knowledge Argument. Similarly, if the Conceptual Analysis Thesis or the Explanatory Gap can
be refuted, so is the Knowledge Argument. This explains how the discussion has developed.
But are these entailments correct? In particular, do the others really entail the zombie argument?
ZA takes us from the philosophy of mind to the philosophy of modality, and one might well
want to stay as clear of that as possible: or, to speak more carefully, be discriminative about
those aspects of the issue that are strictly relevant to the mind-body problem, and those that
more properly belong with issues on modality. For example, the proponent of the KA might
want to resist the ZA because he thinks he can make his basic point without getting into the deep
and muddy waters that surround issues of conceivability and the relation between metaphysical
and logical possibility. Or he might hold something like Strawson's view of the person, which
rules out zombies but would acknowledge the force of KA against physicalism. In neither case
would CAT imply ZA.
The general structure of the reservations about the connection between the knowledge
argument and the conceivability of zombies could be put as follows. Let us assume that the KA
works, in that it shows that there are qualia and their nature qua qualia - what it is like to have
them - cannot be worked out from knowledge of physical states. Someone who thinks that the
KA entails ZA thinks that the very fact that there is this qualitiative nature with no kind of a
priori connection with the physical shows that there is a possible world in which the physical can
occur without the quale. But someone might accept the KA, as establishing property dualism
and still maintain either:
29
(a) Qualia have other essential properties than those they seem to have and these other properties
could be physical, and the relation between the qualia and those physical properties is such that
neither could, metaphysically, occur without the other.
(b) Having a quale has other properties essentially than those given in introspection, and these
could be physical and neither the state of having the quale nor those physical properties could,
metaphysically, occur without the other.
Whether there could be such an association between a quale, understood as something
the nature, qua quale, of which Mary only came to know after she left the laboratory, and
physical properties, is further question from that of whether there are qualia that instantiate nonphysical properties. Some philosophers hold, for example, that metaphysical necessity is
constrained by natural necessity, so that natural necessities are held to be metaphysical
necessities. A nomological connection between qualia or and brain states would then establish
(a), but the KA would still succeed in showing property dualism. One might want to treat the
correct account of metaphysical necessity as another matter. (b) is different from (a), in that it
ties the connection to the act of having the state, not the content: but the same considerations
arise. I mention it because it might seem more plausible than (a). A physicalist who accepts
Mary but who wants to deny property dualism would have to affirm
(c) Qualia have other properties essentially associated with them than those they seem to have,
these could be physical, and the qualia could be nothing over and above these other properties:
that is, the qualia could be identical to the physical properties.
The attempt to combine (c) with accepting Mary's revelation, is Balog and Loar's position. (a) or
(b) without (c) is a form of dual aspect theory, with metaphysically necessary supervenience: (c)
alone is physicalism proper. This does, however, expose another reason for transfering the
weight of argument from KA to ZA. One might argue that only the success of ZA would show
that (c) cannot be true. Once, that is, there is any dispute about what KA really proves, (granted
its success in showing that Mary learns something) only ZA can show that the conclusion is a
30
genuinely anti-physicalist one. To put it another way, only ZA can show that the content of
Mary's new knowledge involves a new property and not just the exercise of a new concept. ZA
is certainly, in context, a sufficient condition for making the strong interpretation of KA's
conclusion, ruling out all of (a), (b) and (c). But it is not a logically necessary one and it is
certainly not necessary for ruling out (c) and one might hope to defend that on other grounds,
having no faith in showing anything conclusive in the philosophy of modality.