David Chalmers on Type-A Materialism

 

Type-A materialists (David Chalmers' term) claim that it isn't conceivable

“that there be duplicates of conscious beings that have absent or inverted conscious states”.

This can't be a logical argument because surely this could happen. It must be a scientific or physical argument that states that if P, then Q.
 

Type-A materialists also claim that Mary isn't ignorant of any phenomenal ‘truths’ inside her black and white room. As with ‘facts’, what does Frank Jackson mean by ‘phenomenal truths’? There are some things Mary is ignorant of; though are they ‘facts’ or ‘truths’? And what does it mean to say that she “gains an ability”? Does it mean the ability to, say, discriminate red from green?

 

The materialist can accept that there's such a thing as consciousness; it’s just that he can define ‘consciousness’ in his own peculiar technical way.
 

For example, analytic functionalists or logical behaviourists define ‘consciousness’ in terms of “wholly functional or behavioural terms”. More specifically, they talk in terms of “certain sorts of access to information, and/or certain sorts of dispositions to make verbal reports”. Of course intuitively these definitions are far from acceptable and they simply leave out - amongst other things - the question of what it is like to be conscious – that is, they leave out entirely the first-person reality of conscious states.
 

How can consciousness only be about behaviour or functional states because a zombie or a machine could – at least in principle - replicate our behaviour and functional states. Similarly with accessing information and ‘overt behaviour’.
 

Thus this seems like a simple stipulative definition of ‘consciousness’ on the analytic functionalist or logical behaviourist’s part. And why not?
 

More relevantly, type-A materialists believe that there's nothing further to be explained about consciousness over and above explaining the various functions. If this is the case, then Daniel Dennett, for one, has indeed explained consciousness! Though only by stipulating that there's nothing, in fact, to be explained!
 

To be clear: what precisely are these functions?
 

They include the “capacities for access, self-monitoring, report, control, and their interaction”. Importantly, a being’s environmental relations and neurobiology will also be of importance to such materialist accounts of consciousness.
 

There are three responses to the above:

1. Such functions are irrelevant to an explanation of consciousness.
2. Functions are relevant to a story of consciousness; though there's something above and beyond functionality to also explain.
3. Functions, neurobiology and environmental relations will tell us all we need to know about consciousness.

Is consciousness like everything else in nature? Type-A materialists argue that it is and they argue by analogy.

 

For example, in explaining life “the only phenomena that present themselves as needing explanation are adaptation, growth, metabolism, reproduction, and so on”. We can now say:

 

life = adaptation, growth, metabolism, reproduction, etc.

Though can we say? -

 

consciousness = mental access, control, report, self-monitoring and environmental relations, neurobiology, etc.

The vitalist, of course, argued that there's more to life than the list above. What about consciousness? Is there more to the list above? What if consciousness is somehow unique? What would make it unique? Phenomenal experience? And is this over and above the list above?

 

Dennett seems to argue that if the old-fashioned vitalist was wrong about life, perhaps non-materialist philosophers are wrong about consciousness. Is the analogy exact? David Chalmers cites Broad (who was a vitalist about life). Broad believed that the (biological?) functions “would require a non-mechanical explanation”. Broad also had something to say about the analogy with consciousness and argued that life and consciousness aren't the same. Indeed his position on life appears to be behaviourist in orientation. He

“held that in the case of life, unlike the case of consciousness, the only evidence we have for the phenomenon is behavioural, and that 'being alive' means exhibiting certain sorts of behaviour”.

This seems a thoroughly behavioural account, as I've already said. Why did he also say that “functions would require a non-mechanical explanation”? This isn't really explained in Chalmers’ paper.
 

We can also see an explicit behaviourist account of qualia.
 

Rey argues, for instance, “that there is no reason to postulate qualia, since they are not needed to explain behaviour” (12). The obvious and immediate riposte to this argument is the question: Why should we see behaviour as everything that is the case? And even if qualia aren't needed to explain behaviour (or don't even cause behaviour), why should this be the end of the story? There's still something it is like to taste milk or experience an orgasm.

 

Dennet offers a similarly behaviourist account of consciousness. It is verbal reports that are of prime importance to Dennett. And, of course, overt behaviour is behaviour.
 

Again, why stop at verbal reports? Isn’t there something else to add to this story of consciousness? Even Quine was only a semantic behaviourist in that examples of overt behaviour were the sole grounds of meaning and other semantic properties. The semantic can only be known through what is said and what is written. Though this isn't psychological behaviourism. Would Quine have rejected the need for an explanation - or even an acknowledgement - of qualia and other non-semantic phenomena? Is Wittgenstein’s ‘private language argument’ also applicable to the phenomena we call ‘qualia’?

Chalmers on the Explanatory, Conceivability & Knowledge Arguments

The Explanatory Argument

David Chalmers says that the “easy problems” of consciousness explain “only structure and function”. They don't explain consciousness. Therefore “no physical account can explain consciousness”.

The Conceivability Argument

We can conceive of a physical system that is note-for-note identical to us but which doesn't have consciousness. (Though what has the psychological notion of conceivability got to do with the problem of consciousness?)

Such as system would therefore be a zombie. Alternatively, it may be a zombie-invert in that some of its experiences are inversions of those of human beings.

The invert-zombie has the same nuts and bolts as us; though nevertheless it has different experiences. So the inverted zombie is still allowed his experiences.

There is also the conceivability of a partial zombie who also has experiences; though not as many as those of human beings – perhaps he can only feel pain.

The point is that all these zombies are physically identical to us from the third-person point of view and their behaviour will also be indistinguishable.

What about their first-person point of view? What is it like to be a zombie of whatever kind? Well, there's nothing it is like to be a bona fide zombie!

On a larger scale. What about a physically identical universe that doesn't, however, give rise to consciousness; though which does give rise to zombies? We can say that such zombies are indeed "naturally possible". However, according to our laws of nature, they probably couldn't exist. That is, given identical physical and bodily facts, then such a universe couldn't help but give rise to consciousness. (This is what some non-reductive physicalists and supervenience theorists believe.)

Let’s take this further.

There could be an identical universe that didn't give birth to consciousness. If this were the case, then consciousness must be something above and beyond the physical if such a counterfactual scenario were possible. In addition, if we can conceive of such zombies in our world or at other worlds, then Chalmers claims that it is "metaphysically possible" that there could be zombies.

What does metaphysical possibility add to the notion of conceivability?Chalmers codifies and simplifies this with a logical argument:

i) It is conceivable that P & not-Q.
ii) If it is conceivable that P & not-Q, then it is metaphysically possible that P and not-Q.
iii) If it is metaphysically possible that P & not-Q, then materialism is false.
iv) So materialism is false.

(Can a mere possibility make materialism false?)

Again, we can see Chalmers’ slide from conceivability to metaphysical possibility. Why should it be that simply because we can conceive of something then that something is metaphysically possible? This has an almost empiricist ring to it in that all conceivables (or ‘ideas’) must come from somewhere or entail metaphysical possibility.

Can we conceive a round square? No. Then it isn't metaphysically possible. Can we imagine a man with five legs? Yes. Then it's metaphysically possible.

The Knowledge Argument

To put the case simply. We could never, and have never, deduced or inferred consciousness from the sum of all physical facts. Though, then again, the same can be said about water. We could study H2 O until the cows come home; though we would never deduce (or infer) the reality of water - its wetness and drinkability - from such physical facts. We can only do so a posteriori – in this case, through science, which tells us that water is indeed H2 O. Though no scientist has ever (or could ever) infer or deduce water’s wetness, etc. a priori. (Or could they? Is water’s transparency an emergent property?)

Does Mary lack knowledge about red? She obviously lacks the experience of red. Is the experience of red a ‘fact’? What sort of fact would it be? Frank Jackson argues that if she finally came to actually experience red, she would learn a ‘new fact’ about red which must be over and above her knowledge of its physical basis and even beyond her powers of deduction from such facts. That is, experience emerges from the physical; though it can't be read off from the physical. That is the essence of emergentism.

Jackson concludes that Mary does indeed know all the physical facts; though not all the facts. There must be non-physical facts (one of which is consciousness).

The strong conclusion to all this is that

i) If there are more than physical facts

ii) and that these things can't be deduced from physical facts

iii) then materialism must be false.

That's because materialism only allows physical facts in its world-picture.

The Shape of the Arguments

Chalmers then attempts to codify and simplify the arguments in strictly logical terms.

Firstly we can think in terms of epistemic entailment, deducibility, explicability and conceivability.

Let us take epistemic entailment.

This is a priori entailment or implication in that it doesn't depend on (further) experience. If we have

P ⊃ Q

we have a material conditional from the physical facts to an arbitrary phenomenal fact. When we know that P is the case, then we must also know that Q is the case without further experience.

In the case of consciousness, P doesn't entail or imply Q a priori. We can't deduce Q from P. Similarly, we can conceive of P without thereby also conceiving of Q. Or, in functional terms, if P is functional, then we can't deduce Q from P because consciousness “is not a functional concept” (as we saw earlier in this debate).

These logical uses of the material conditional can also be applied to the conceivability argument, the knowledge argument and the explanatory argument.

Taken one by one.

If we can conceive of zombies, then zombies are metaphysically possible. If we can't deduce consciousness from all the physical facts, then some facts - those of consciousness - aren't physical. If physical explanations aren't adequate, then there must be non-physical facts that require non-physical explanations.

Now we can talk of another kind of entailment: ontological necessitation.

We can say that P necessitates Q. In the material conditional P ⊃ Q, we can say that P can't hold without necessitating Q. It is ontologically necessary that P necessitates or entails Q. Again, if this were the case, then materialism would be false.

The other interesting point about these arguments is the movement from an epistemic gap to an ontological gap. More precisely, we can argue that:

1. There is an epistemic gap between physical and phenomenal truths.
2. If there is an epistemic gap between physical and phenomenal truths, then there is an ontological gap, and materialism is false.
3. Materialism is false.

The obvious point to make here is the slide from the epistemic gap to an ontological gap. What does that mean?

If we can't slide from our knowledge of P to Q, then that must be because P and Q are ontologically different. If P and Q were ontologically of the same order, then we could move, epistemically, from P to Q.

Why does a lack of epistemic movement from P to Q entail ontological difference? Couldn’t that epistemic gap be accounted for simply in terms of our epistemic limitations or our inadequate knowledge or physical devices? We at one time couldn't move from H2 O to the wetness of water. That epistemic or scientific gap didn’t engender an ontological difference between H2 0 and water or even water’s wetness. Does a lack of knowledge about X entail the fact that X is ontologically weird or irreducible?

David Chalmers on the Hard & Soft Problems of Consciousness

 

David Chalmers makes the helpful distinction between the ‘hard’ and ‘soft’ problems of consciousness.

The soft problem includes the ability to discriminate stimuli, or to report information, or to monitor internal states, or to control behaviour. Prima facie, you can see that these problems can be accounted for in third-person or scientific terms. For example, someone can tell us how they discriminate stimuli with his verbal reports. All this can also be explained neurobiologically. The same goes for the reports of information that we can achieve or carry out. (The problematic ‘easy problem’ is the monitoring of internal states which, prima facie, doesn't seem scientifically kosher.)

 

The ‘hard problem’ is the problem of experience. There is something it is like to experience this, that or the other. What does that mean? It means that we are phenomenally conscious of this, that or the other. Mental states also have their own feel, as it were. When we are having a mental state (if we do indeed have distinct mental states), there is something it is like to be in that state.

What are conscious states in the first place? They include states of perceptual experience, bodily sensation, mental imagery, emotional experience, occurrent thought, etc. There is something it is like to perceive a red apple. There is something it is like to feel a toothache. There is something it is like to imagine Tony Blair. There is something it is like to feel depressed about something. There is even something it is like to make an arithmetical calculation. Of course we will now need to explain what exactly we mean by saying that ‘there is something it is like to…’ and why this makes consciousness ‘unique’ and something non-reducible to the physical.

Chalmers is more precise about this phrase ‘what it is like’. He introduces explanatory technical terms to do so.

For example, conscious states have a phenomenal character with phenomenal properties that characterise what it is like to be in that state.

What, then, are phenomenal properties? The conscious state of perceiving a red apple has phenomenal properties. The properties include the experience of the colour red or the feel of the apple. A toothache can be ‘nagging’ and other pains can be sharp or blunt. The mental image of Tony Blair will have certain phenomenal properties, such as the redness of his face or the emotional responses to the image. Similarly, depressions may be painful or tiring and may engender other phenomenal properties such as lethargy or anger. And even an arithmetical cognition can be accompanied by certain emotions such as that of excitement or tedium.

Chalmers then asks a fundamentally different and equally important question about consciousness.

“How and why do physical processes give rise to experience?”

Intuitively, consciousness, experience or mentality doesn't seem physical at all. How is my mental image of Tony Blair in any way physical? Is my sensation of the red of a red apple in any way physical? And so on. The relation between the physical and the mental is problematic because we can imagine that all the physical processes and events could happen without giving rise to any conscious experience. Such functions and processes “could occur in the dark”. Chalmers calls this problem the “central mystery of consciousness”.

Let's get back to the ‘easy problems’.

What are the easy problems and why are they easy?

These problems are about certain behavioural or cognitive functions. If we lift one leg and are conscious of lifting one leg this can be explained in neurological and neurophysiological terms. As for cognitive functions, these too can be explained in neurological terms, or at least in principle they could be. More explicitly, we can talk in terms of the causal role of a function in a cognitive system and how such causal roles, within the brain, cause us to lift one leg or make a logical inference from p to q. The function takes on the form of a causal role in the production of behaviour and we need only see what exactly the mechanisms within the brain and body are that carry out such causal roles.

In terms of the brain, Chalmers states that such mechanisms are neural or computational in nature (why computational?). As for examples of these functions or causal roles, we can site discrimination, integration, access, report and control. We can intellectually distinguish a cow from a horse. We can integrate new knowledge with old knowledge. We can access our memory system or even past mental images. We can report internal states and past perceptions. We can control our behaviour through cognition as when we build a house. Though, alas, why are any of these mental functions accompanied by experience?

And so we have ventured on to the hard problem of consciousness.

What is the relation between these physical functions in the brain and experience? Such a relation would need to abide by ‘natural principles’ if it is to stand the test of materialism or physicalism. What is it about physical processes that bring about states of consciousness? Why do they do so in the first place?

Bertrand Russell’s Theory of Types

Theory of Types 1

Bertrand Russell’s theory of types seems quite commonsensical at a prima facie level.

That is, different objects, or their many types, can't be treated in the same way within any philosophical or logical system. In Russell’s case, the important thing is that the predicates applicable to different types of objects will differ depending on the type under scrutiny. More specifically, these predicates will be true or false of particular objects depending on the type of object that is predicated.

In Russell’s scheme, objects are arranged in some kind of hierarchy from objects of the least generality to objects of the most extreme generality. In terms of statements, this means that if predicates change according to their types of objects, then statements will likewise change in according to the type of objects they are statements about. So the statements we make about individuals or particulars can't be made about classes. Similarly, the statements we make about classes can't be made about classes of classes. And so on into indefiniteness.

What of different types of individuals? Is this theory true of these types too?Clearly, this theory has relevance to the class of all classes that do not belong to themselves. According to Russell, the theory of types is intended to prevent the paradox discovered in the said class of classes. It was said these classes both are and aren't members of themselves. The original assertion was about classes, not classes of classes. That is, it is said of classes that they either are or aren't members of themselves. This part doesn't result in paradox.

For example, the class of abstract entities is itself an abstract entity. Therefore it's a member of itself. On the other hand, the class of pink shoes is not a pink shoe. Therefore it's not a member of itself. So such classes don't generate any paradoxes.

We introduced another class that is a class of classes. It was, therefore, of a higher logical order than first-order classes. We talked of the class of all classes that aren't members of themselves. This class generated a paradox: it is both a member of itself and not a member of itself. This is the paradox that Russell attempted to solve or prevent. How did he attempt it?

He created his theory of types. And, according to this theory, the predicates and statements we apply to objects depend on the nature of the type of objects being talked about. Clearly, a class of classes is not of the same logical order than a basic class; just as basic classes are of a different logical order than individuals.

We've said that classes can either be members of themselves or not members of themselves. That’s fine. However, we also asked whether or not a class of classes, the class of classes that aren't members of themselves, is a member of itself. It was concluded that it both is and isn't a member of itself. This, of course, is paradoxical. So how does Russell’s theory prevent this paradox from occurring?

Again, different objects have different predicates and statements made about them. A class is a different ‘object’ than a class of classes. It follows that we can't predicate or assert about this class of classes the same kind of things we predicate and assert about first-order classes. We said that the predicate ‘a member of itself’ is either true or false of the classes that either are members of themselves or not. However, our main concern is a class of classes: the class of all classes that aren't members of themselves. So we can't ask of this class the question whether or not it's a member of itself because that kind of question can only be made of classes, not classes of classes. And if these questions can't be asked in the first place, then this class of classes is not in fact paradoxical after all.

A.J. Ayer writes that it is “nonsensical” to even ask if the class of all classes that aren't members of themselves is itself a member or not a member of itself. This question can only be asked of first-order classes, not of second-order classes or classes of classes.

                                                   The Theory of Types 2

It's not only classes, predicates and expressions that differ depending on the objects they're applied to: the theory also applies to ‘numerical expressions’. These expressions, according to Russell and/or Ayer, change their ‘sense’ depending on whether or not they count individuals, classes or classes of classes.

This is an interesting use of the term ‘sense’ if we bear in mind Frege’s notion of sense and reference and all the later theories about reference. Usually proper names, for example, are not supposed to have a sense. So it seems strange, prima facie, that the theory of types claims that numerical expressions have different senses depending on what they are applied to.

However, it may not be numbers themselves that have different senses; but the expressions in which they are constituents. It also seems strange that the way we ‘count’ different types of objects will also be different, regardless of the ‘senses’ of the numbers within the expressions. Again, perhaps I need to know what is meant by ‘numerical expressions’ and whether such expressions have constituents that somehow are relevant to the notion of ‘sense’.

There is a problem with the theory of types. In traditional class theory, the same object can belong to different classes. Though in the theory of types, we must be careful to treat different objects in different ways. This may result in certain classes becoming smaller than they originally were because many classes contain different types of objects as members. This will result in both a proliferation of classes, and also the numerical shrinkage of the classes that are deemed to already exist.

Though, according to set-theory, we define the natural numbers by reference to classes. That is, the class of all two-membered classes is in fact the class we call the number 1. So if class membership, the number of members, defines the natural numbers, then the shrinkage of classes that results from the theory of types may result in their being classes that aren't large enough - in terms of members - to define the higher natural numbers. That is, the higher numbers may not be able to correspond with any classes because there aren't enough classes with correlative higher memberships. The classes needed to account for the higher numbers may simply run out. The may not be enough classes with higher enough memberships to account for the higher natural numbers.

Another way of putting the theory of types - in this class-membership and numbers sense - is that the conditions that allow objects to belong to certain classes becomes more stringent. Classes become better defined, as it were. And if the conditions of class membership are more stringent, then clearly many previous classes will effectively become smaller in terms of their numbers of members. And, again, if this is the case, then certain higher numbers may not find their correlative classes in set-theory. This is clearly a problem for set-theory and the theory of types. Rather than reject a set-theoretic account of numbers, many logicians in Russell’s day and after simply rejected his theory of types. Other theories, of course, were created and adopted after the period in which Russell formulated his theory of types.

D.H. Mellor on Ontological Pluralism

Rather than adopt a position of monism or dualism when it comes to properties, D.H. Mellor adopts what he calls a ‘pluralist’ approach to properties.

It would be strange that in this huge universe of ours, and amongst its infinite properties or objects, that there were only two kinds of entities – mental and physical. Indeed I would more likely go for one kind of entity or property rather than the rather-too-neat postulation of two. Or, as with Hugh Mellor, go for a plurality of properties or objects.

This multiplicity or plurality of kinds of objects or properties seems to go against the scientific search for simplicity and the metaphysical desire for ontological parsimony. However, we can't reject the possibility of a plurality of different properties simply because it will complexify our scientific and philosophical endeavours. Perhaps the world simply is complex and it's complex because it's made up of a plurality of different objects or properties.

Of course scientists will happily accept the fact that there “is a great plurality of properties” (109). It's just what we conclude from this scientific acceptance of a prima facie plurality.

For instance, does this mean that a distinct property can't be reduced to another distinct property? Are these properties basically irreducible? If they aren't, then are they genuinely distinct at all?

Take Mellor’s own list of properties: electrical, gravitational, chemical, biological, psychological. Many philosophers will argue that the psychological is indeed reducible to the biological; though also to the chemical, electrical and even the gravitational.

The biological is essentially made up of the chemical; though it isn't strictly reducible to the chemical (for many reasons). Perhaps the chemical can be (fully?) reduced to the electrical and even the gravitational.

Mellor himself says that “there is no fundamental distinction of kind amongst them” (109). Rather, there “are lots of little distinctions, and interesting questions about which are reducible to which” (109). What Mellor is saying here doesn't make what he says any different to what the average scientist says and not even to the scientific reductionist. So how does this play on his ontological ‘pluralism’ at all?

Scientists are reductionists who also accept that “there is no fundamental distinction of kind amongst them” (109). They will also say that there are (only) “lots of little distinctions” to be made about them. Mellor even accepts reduction when it comes to (some of) these properties. What does his ontological pluralism amount to and how is it different to ontological monism and ontological dualism?

Mellor accepts that it may be possible to reduce “a lot of sciences... in some non-trivial sense to one basic science” (109); though he also says that this is “not a very fundamental one” (109). He then stresses what it is that all the sciences share and how it is they differ.

For a start, all the natural sciences “are involved with phenomena” (109). These phenomena “can be physical, chemical, biological, psychological, or whatever” (109). Not only that: these different phenomena “are all studied in ways that are methodologically similar” (109). However, all these disciplines will “differ in detail according to their subject-matter” (109). So if there are differences, these differences will be brought about by the different subject-matters of the natural sciences. Despite that, their methodologies will be 'similar' regardless of the differences ‘in detail’. As in the case of Mellor’s ontological pluralism, he says little that is controversial or even interesting here.

D.H. Mellor or Parapsychology

Hugh Mellor offers a very interesting criticism of parapsychology. It's similar to Karl Popper’s view that ‘pseudo-sciences’ - such as Freudianism and Marxism - make it the case that they can't be falsified. Parapsychology goes a step further than this. Its failure to prove something counts “as a kind of success” (110). Mellor writes:

“What’s wrong with parapsychologists is that they count failure as a kind of success; that is, they think that failure to understand a phenomenon bestows a kind of glamour upon it, makes it something special, a paraphenomenon. It does nothing of the sort: all it means is that there’s something we still don’t understand.” (110)

Of course this “failure to understand a phenomenon” - and the concomitant bestowing of “a kind of glamour upon it” - is something that can be applied to what people believe about UFOs, extra-terrestrials, astral travelling, ley lines, ‘the stars’ and all the rest. One gets the feeling that a lot of true believers in this stuff wouldn't even like their darling subjects to be proved by science – that would take away the glamour and the mystique (which is at the heart of all these subjects and pursuits).

Of course it's also the case that, as with Marxism and Freudianism, claims about UFOs, extra-terrestrials, astrology, and the like are also unfalsifiable in principle because the believers in such stuff always rely on some ‘auxiliary hypothesis’ to counteract any evidence that works against what it is they believe. (For example, non-believers never see UFOs because they are brainwashed by the CIA or extra-terrestrials keep well away from all sceptics.)