Category: Mind

Am I a Body or Do I Have a Body?

In his latest and last book, Mortality, Christopher Hitchens writes, "I don't have a body, I am a body." (86) He goes on to observe that he has "consciously and regularly acted as if this was [sic] not true."  It is a curious fact that mortalists are among the worst abusers of the fleshly vehicle.  But that is not my theme.

Is a person just his body?  The meditation is best conducted in the first person: Am I just my body?  Am I identical to my body?  Am I one and the same with my body, where body includes brain?  Am I such that, whatever is true of my body is true of me, and vice versa? Let's start with some 'Moorean facts,' some undeniable platitudes.

1. I am not now identical to a dead body, a corpse.  There is, no doubt, a dead body in my future, one with my name on it.  But that lifeless object won't be me.  I will never become a corpse.  I will never be buried or cremated.  I am not now and never will be identical to a dead body.  For when the corpse with my name on it  comes to exist, I will have ceased to exist; and when I cease to exist, it will still exist.  This property difference via the Indiscernibility of Identicals entails the non-identity of me and 'my' corpse. 

'My' corpse is the corpse that will come into existence when I cease to exist, or, if mortalism is false, when I am separated from my body.  Strictly speaking, no corpse is my corpse: hence the scare quotes around 'my.'  But I can speak strictly of my body: my body is the body that is either identical  to me, or is related to me in some 'looser' way. 

2.  I am obviously not identical to a dead body.  And I have just argued that I will never become identical to a dead body.  Am I  then identical to a  living body?  Not if the following syllogism is sound: My living body will become a dead body;  I will never become a dead body; therefore, I am not identical to a living body. 

This argument assumes that if x = y, then whatever is true of x is true of y, and vice versa.  Little is self-evident, but surely this principle is self-evident.  There is something true of my living body that is not true of me, namely 'will become a dead body.'  Therefore, I am not identical to a living body.  And since the only living body I could be identical to if I were identical to a living body would be my living body, I am not identical to my living body.  Of course, I have a living body in some to-be-explored sense of 'have'; the point is that I am not identical to it.

3. Consider now the following rather more plausible identity claim:  I am (identically) a self-conscious animal.  Let's unpack this.  I am a living human animal that says 'I' and means it; I am a thinker of I-thoughts, an example of which is the thought *I am just a self-conscious animal.*  I am self-aware: aware of myself as an object, both as a physical object, a body, through the five outer senses, and as psychological object, a mind, through inner sense or introspection.  Both my body and my mind are objects for me as subject.  As such a self-aware animal, I am aware of being different from my body.  In some sense I must be different from my body (and my mind) if  they are my objects.  'My objects' means 'objects for me as subject.'

Now if you were paying attention you noticed that I made an inferential move the validity of which demands scrutiny.  I moved from

a. I am aware of being different from my body

to

b. I am different from my body.

The materialist is bound to resist this inference.  He will ask how we know that the awareness mentioned in (a) is veridical.  Only if it is, is the inference valid.  He will suggest that it is possible that I have an non-veridical, an illusory, awareness of being different from my body.  I can't credit that suggestion, however.  It cannot be an illusion that I am different from anything I take as object of awareness including my brain or any part of my brain.  That is a primary and indubitable givenness. Awareness is by its very nature awareness of something: it implies a difference between that which is aware, the subject of awareness, and the object of awareness.  Without that difference there could be no awareness of anything.  If the self-aware subject were identical to that object which  is its animal body, then the subject would not be aware of the body. 

4.  Will you say that the body is aware of itself? Then I will ask you which part of the body is the subject of awareness.  Is it the brain, or a proper part of the brain?  When I am aware of my weight or the cut on my arm, is it the brain or some proper part of the brain that is aware of these things?  This makes no sense.  My brain is no more the subject of awareness than my glasses are.  My glasses don't see the wound; I see the wound by the instrumentality of the glasses.  Similarly, my brain doesn't see the wound; I see the wound by the instrumentality of the brain (and the visual cortex, and the optic nerves, and the glasses, etc.)  The fact that my visual awareness is causally dependent on my having a functioning brain does not show that my brain or any part of it is the subject of awareness.  I am not identical to my brain or to any bodily thing.

5.   Who or what asks the question:  Am I identical to this body here?  Does the body ask this question?  Some proper part of the body such as the brain?  Some proper part of this proper part?  How could anything physical ask a question?

"Look, there are are certain physical objects that ask themselves whether they are identical to the physical objects they are, and entertain the (illusory) thought that they might not be identical to the physical objects they are."

This little materialist speech is absurd by my lights since no physical object — as we are given to understand 'physical object' by physics — could do such a thing.   If you insist that some physical objects can, then you have inflated 'physical' so that it no longer contrasts with 'mental.' 

So with all due respect to the late Mr Hitchens, brilliant talker about ideas whose depth he never plumbed, I think there are very good reasons to deny that one is identically one's body.

Further questions:  If I am not identical to any physical thing, can it be inferred that I am identical to some spiritual thing?  If I am not identical to my body or any part thereof, do I then have a body, and what exactly does that mean? 

A Theism-Materialism Combo?

If the reality of spirit and the reality of free will cannot be encountered in ourselves, in the depths of our subjectivity, why should we think that they  can be encountered outside ourselves — in God, for example?

I don't understand those who attempt to combine theism with materialism about the human mind.  I don't deny that it is a logically possible combination.  But mere absence of formal-logical contradiction is no guarantee of metaphysical coherence.  (I develop the thought in "Could a Classical Theist be a Physicalist?" Faith and Philosophy, vol. 15, no. 2, April 1998, pp. 160-180.)

If reality has a spiritual core we will be able to learn about it only by studying ourselves, by plumbing our subjective depths, not by reducing self to not-self, not by trying to understand spirit and consciousness in material terms.  They cannot be understood in those terms, and attempts to do so end up eliminating the very means of access — mind and language — to the material world.

On the Logical Possibility of Reincarnation

London Ed says that reincarnation is logically possible.  I agree.  For my use of the first-person singular pronoun does not refer to my (animated) body alone.  Surely I am not identical to my body.  If I were, then reincarnation would be logically impossible.  As Ed says, there is nothing in the sense or reference of 'I' that entails such an identity.  But then Ed says this:

That's not to countenance disembodied egos or anything like that.  The possibility of reincarnation does not require there to be a disembodied referent for 'I'.  But if there are no disembodied egos, and if reincarnation takes place some time after the death of the previous body, there has to be a time when the 'I' does not exist.

There is a problem here.  Suppose I existed 100 years ago with body B1, but I now exist with a numerically different body B2. After B1 ceased to exist, I ceased to exist, but then I began to exist again when B2 came into existence.  It would follow that I had two beginnings of existence.  But it is not plausible to suppose that any one thing could have two beginnings of existence.  John Locke famously maintained (emphasis added):

When therefore we demand whether anything be the same or no, it refers always to something that existed such a time in such a place, which it was certain, at that instant, was the same with itself, and no other. From whence it follows, that one thing cannot have two beginnings of existence, nor two things one beginning; it being impossible for two things of the same kind to be or exist in the same instant, in the very same place; or one and the same thing in different places.

The problem can be cast in the mold of an aporetic triad:

1. It is logically possible that one and the same self (ego, I) have two consecutive but non-overlapping numerically distinct bodies.

2. There are no unembodied or disembodied referents of uses of the first-person singular pronoun.

3. It is not logically possible that one and the same thing have two beginnings of existence.

Each of the limbs of the triad is plausible and yet they cannot all be true.  Any two, taken together, entails the negation of the remaining one.  Thus (2) and (3), taken in conjunction, entails the negation of (1).

If Ed wants to hold both (1) and (2), then he must reject (3).  I would hold (1) and (3) and reject (2).

But is there any good reason to prefer my solution over Ed's? 

(1) makes a very weak claim, merely one of logical possibility.  So I don't see that it can be reasonably denied.  Admittedly, this needs further arguing.

Both 'I' and 'ego' are pronouns.  Both both Ed and I are using them as nouns.  Is there are problem with that? 

Suppose You Build a Conscious Robot. . .

 . . . would that solve the mind-body problem?

One aspect of the mind-body problem is the problem of the subjectivity of conscious experience. As I have argued on numerous occasions, the subjectivity of conscious experience and the manner in which it  connects to its physical substratum in the brain cannot be rendered intelligible from an objectifying 3rd-person point of view. Even if we had in our possession a completed neuroscience, we would not be able to understand how conscious experiences arise from the wetware of the brain.

But suppose someone objects as follows:

Robotics is making tremendous strides. In the future we may be able to build robots that are behaviorally indistinguishable from human beings. They will walk, talk, and look like human beings. One can even imagine them being made so human-like that a superficial physical examination would not reveal their robotic status. Imagine a 'female' robot that could pass a cursory gynecological     examination and fool a gynecologist or a 'male' robot that could pass a superficial prostate exam and fool a urologist . . .

Suppose further that such a robot not only passes all linguistic and non-linguistic behavioral  tests for being conscious, but really is conscious, really does feel ill at ease in the physician's office, even though the  physical substratum of the feelings is silicon-based. Suppose, in other words, that consciousness and indeed self-consciousness  emerge in this robot.

We will then have an answer to the mind-body problem: we will know that consciousness is nothing special and nothing mysterious. We will know that it does not have a higher, meta-physical or super-natural origin, but is simply the byproduct of the functioning of a sufficiently complex machine, whether the machine be an artifact of a human artificer or the 'artifact' of natural selection.

But if we think about this carefully, we realize that even if this sci-fi scenario were realized, we would still not have a solution to the mind-body problem. For the problem is to render intelligible to   ourselves, to understand, HOW consciousness can arise from matter. Building a robot in which consciousness DOES arise or manifest itself  does nothing to render understandable how the arisal occurs.  Nor does it show that the arisal is an emergence from matter.    The mere fact of consciousness is no proof that it has emerged from a physical substratum, and the mere claim that it has so emerged is an empty asseveration unless the exact mechanism of the emergence can be laid bare.  And good luck with that.

Suppose that there is a group of philosophizing robots.  These machines are so sophisticated that they ask Big Questions.  One of the problems under discussion might well be the mind-body problem in robots. The fact that they know that they had been constructed by human robotics engineers in Palo Alto, California would do nothing to alleviate their puzzlement. In fact, one of the philosophizing robots could propose the theory that the emergence of consciousness in their silicon brains is not to be interpreted as an emergence from matter  or as a dependence of consciousness on matter, but as a Cartesian mind's becoming embodied  in them: at a point of sufficient complexity, a Cartesian mind embodies itself in the robot.

In other words, what could stop a philosophizing robot from rejecting emergentism and being a substance dualist? He knows his origin, or at least the origin of his body; but how does knowing that he is a robot, and thus a human artifact prevent his considering himself to be an artifact housing a Cartesian mind?  He might trot out all the standard dualist arguments. 

Our philosophizing  robot would be able to exclude this Cartesian possibility only if he understood HOW consciousness arises from matter. If he knew that, he would know that he does not have a higher origin.  And let's not forget that our philosophizing robot is very smart: so smart that he sees right  through the stupidity of eliminative materialism.

In sum, even if we knew how to build (really) conscious machines, such know-how would not be the knowledge necessary to solve the mind-body problem.

Are There Indexical Facts? Are They a Threat to Materialism?

1. Ernst Mach Spies a Shabby Pedagogue. In The Analysis of Sensations (Dover, 1959, p. 4, n. 1) Ernst Mach (1838-1916) offers the following anecdote:

     Not long ago, after a trying railway journey by night, when I was
     very tired, I got into an omnibus, just as another man appeared at
     the other end. 'What a shabby pedagogue that is, that has just
     entered,' thought I. It was myself; opposite me hung a large
     mirror. The physiognomy of my class, accordingly, was better know
     to me than my own.

When Mach got on the bus he saw himself, but not as himself. His first thought was one expressible by 'The man who just boarded is a shabby pedagogue.' 'The man who just boarded' referred to Mach. Only later did Mach realize that he was referring to himself, a thought that he might have expressed by saying, 'I am a shabby pedagogue.'

Clearly, the thought expressed by 'The man who just boarded is shabby' is distinct from the thought expressed by 'I am shabby.' After all, Mach had the first thought but not the second.  So they can't be the same thought.  And this despite the fact that the very same property is ascribed to the very same person by both sentences.  The difference emerges quite clearly if we alter the example slightly. Suppose Mach sees that the man who has just got on the bus has his fly open. He thinks to himself: The man who has just boarded has his fly open, a thought that leads to no action on Mach's part. But from the thought, I have my fly open, behavioral consequences ensue: Mach buttons his fly. Since the two thoughts have different behavioral consequences, they cannot be the same thought, despite the fact that they attribute the very same property to the very same person.

But if they attribute the same property to the same person, what exactly is the difference between the two thoughts?

Linguistically, the difference is that between a definite description ('the man who just boarded') and the first person singular pronoun 'I.'   Since the referent (Frege's Bedeutung) is the same in both cases, namely Mach, one will be tempted to say that the difference is a difference in sense (Frege's Sinn) or mode of presentation (Frege's Darstellungsweise). Mach refers to himself in two different ways, a 3rd-person objective way via a definite description, and a 1st-person subjective way via the first-person singular pronoun.

If this is right, then although there are two different thoughts or propositions, one indexical and the other non-indexical, it might seem  that there need only be one fact in the world to serve as truth-maker for both, the fact of Mach's being shabby.  This is a non-indexical fact.  It might seem that reality is exhausted by non-indexical facts, and that there are no such indexical or perspectival facts as those expressed by 'I am shabby' or 'I am BV' or 'I am the man who just got on the bus.' Accordingly, indexicality is merely a subjective addition, a projection: it belongs to the world as it appears to us, not to the world as it is in reality.  On this approach, when BV says or thinks 'I,' he refers to BV  in the first-person way with the result that BV appears to BV under the guise of 'I'; but in reality there is no fact corresponding to 'I am BV.'

2. But is this right? There are billions of people in the world and one of them is me. Which one?  BV. But if the view sketched above is correct, then it is not an objective fact that one of these people is me. That BV exists is an objective fact, but not that BV is me.  BV has two ways of referring to himself but there is only one underlyingobjective fact.  Geoffrey Maddell strenuously disagrees:

     If I am to see the world in a certain way, then the fact that the
     world seen in this way is apprehended as such by me cannot be part
     of the content of that apprehension. If I impose a subjective grid
     on the world, then it is objectively the case that I do so. To put
     it bluntly, it is an objective fact about the world that one of the
     billions of people in it is me. Mind and Materialism, 1988, p.
     119.)

Maddell's point is that the first-person point of view is irreducibly real: it itself cannot be a subjective addition supplied from the first-person point of view. It makes sense to say that secondary qualities are projections, but it makes no sense to say that the first-person point of view is a projection. That which first makes possible subjective additions cannot itself be a subjective addition.

Consider the phenomenal redness of a stop sign. It makes sense to say that this secondary quality does not belong to the sign itself in reality, but is instead a property the sign has only in relation to a   perceiver. In this sense, secondary qualities are subjective. But to say that subjectivity itself, first-person perspectivity itself, is a subjective projection is unintelligible. It cannot belong to mere   appearance, but must exist in reality. As Madell puts it, "Indexical  thought cannot be analysed as a certain 'mode of presentation', for the fact that reality is presented to me in some particular way cannot be part of the way in which it is presented." (p. 120)

3. Trouble for materialism. According to materialism, reality is exhausted by non-indexical physical facts. But we have just seen that  indexical thoughts are underpinned by indexical facts such as the fact of BV's being me. These facts are irreducibly real, but not physically real. Therefore, materialism is false: reality is not exhausted by  non-indexical physical facts.

Jaegwon Kim on Reductionism and Eliminativism

I've been studying Jaegwon Kim's Physicalism, or Something Near Enough (Princeton UP, 2005).  Here are some notes and questions.

1. It's clear that mental causation must be saved.  If Kim is right that nonreductive physicalism is not viable, then by his lights our only hope of saving mental causation is via "physical reductionism." (159).  It is of course easy to see how such reductionism, if true, would save mental causation.  Surely my desire for a beer together with my belief that there is beer in the reefer are part of the etiology of my getting out of my chair and heading to the kitchen.  If beliefs and desires are physical states, then there is no in-principle difficulty in understanding the etiology of my behavior.  Reductionism insures the physical efficacy of the mental.  What was a thorny problem on dualist approaches is no problem at all for the physical reductionist. 

2. At this point some of us are going to wonder whether reductionism collapses into eliminativism.  I tend to think that it does.  Kim of course must disagree.  His project is to find safe passage between  nonreductive physicalism and eliminativism.  But first I want to concede something to Kim.

3. Kim rightly points out (160) that we cannot assume that the mental cannot be physical in virtue of the very meaning of 'mental.'  We cannot assume that 'mental' means 'nonphysical.'  The following argument is not compelling and begs the question against the physicalist:

Beliefs and desires are mental
Whatever is mental is nonphysical
Ergo
Beliefs and desires are not physical.

The physicalist finds nothing incoherent in the notion that what is mental could also be physical.  So he will either reject the second premise, or, if he accepts it, deny the first and maintain that beliefs and desires are not mental in the sense in which his opponents think they are.  It seems clear, then, that one cannot mount a merely semantic argument against the physicalist based on a preconceived  meaning of 'mental.'

4.  Is my present state of consciousness real and yet reducible to a pattern of electrical activity in a network of neurons?  Can we secure reduction without elimination?  Reductionist: there are Fs but what they are are Gs.  Eliminativist: There are no Fs.  There at least appears to be a difference in these two sorts of claims.  Kim claims that "There is an honest difference between elimination and conservative reduction."  (160) Phlogiston got eliminated; temperature and heat got reduced.  Witches got eliminated; the gene got reduced. The reductionist thinks he can secure or "conserve" the reality of the Fs while reducing them to the Gs.  In the present case, the physical reductionist in the philosophy of mind thinks that he can maintain both that mental states are real and that they reduce to physical states.

5.  Let's note two obvious logical points.  The first is that identity is a symmetrical relation.  The second is that reduction is asymmetrical.  Thus,

I.  Necessarily, for any x, y, if x = y, then y = x.
R. Necessarily, for any x, y, if x reduces to y, then it is not the case that y reduces to x.

It is clear, then, that identity and reduction are not the same relation.  And yet if particular a reduces to particular b, then a is nothing other than b, and is therefore identical to b.  If you think about it, reduction is a strange and perhaps incoherent notion.  For if a reduces to b, a is identical to b, but, since reduction is asymmetrical,  b is not identical to a!  Reduction is asymmetrical identity.  Amd that smacks of radical incoherence.   This is what inclines me to say that reduction collapses into elimination.  For if a reduces to b, and is therefore identical to b, while b is not identical to a, then it follows that there simply is no a.  And so if my present mental state reduces to a pattern of electrical activity in a network of neurons, then my mental state does not exist; all that exists is the electrical activity.

6.  Kim wants to have it both ways at once.  He wants mental states to be both real and reducible.  He wants to avoid both eliminativism and dualism. My claim is that it is impossible to have it both ways.  Kim thinks that reduction somehow "conserves" that which is reduced.  But how could it?  If my desire for a beer is nothing other than a brain state, then then it is a purely physical state and everything mental about it has vanished.  If 'two' things are identical, then there is only one thing, and if you insist that that one thing is physical, then it cannot also be mental.

7.  My present thinking about a dog is intrinsically intentional, intrinsically object-directed.  But no physical state is intrinsically object-directed.  So, by the Indiscernibility of Identicals, my present thinking about a dog simply cannot be identical to any brain state, and so cannot reduce to any brain state. Kim of course thinks that intentional properties are functionalizable.  I have already  argued against that view here.  Whatever causal role my thinking about a dog plays in terms of behavioral inputs and outputs, causal role occupancy cannot be make makes my thinking  intentional.  For it is intentional intrinsically, not in virtue of causal relations.

8. Kim speaks of the functional reducibility of intentional/cognitive properties.  But surely it is not properties that need reducing but particular meetal acts.  Properties are not conscious of anything.  Nor are causal roles.  It is the realizers of the roles that are bearers of intentionality, and it simply makes no sense to think of these as purely physical.

9. Once one starts down the reductive road there is no stopping short of eliminativism.  The latter, however, is surely a reductio ad absurdum of physicalism as I explain in this post on Rosenberg's eliminativism. 

The Irreducibility of Intentionality: An Argument From the Indeterminacy of the Physical

If it could be made to work, materialism would be attractive simply on grounds of parsimony. We all agree that entities, or rather categories of entity, ought not be multiplied beyond necessity.  There are those who will intone this Ockhamite principle with great earnestness as if they are advancing the discussion when of course they are not: the real issue concerns what is needed (necessary) for explanatory purposes.  If you agree that philosophers are in the business of explanation, then I hope you will agree that a good explanation must be categorially parsimonious but not at the expense of explanatory adequacy.

So we ought not introduce irreducibly mental items and/or abstracta if we can  get by with just material items By 'get by' I mean explain in adequate fashion all that needs to be explained: consciousness, self-consciousness including self-reference via the first-person singular pronoun, qualia, intentionality, conscience,  mystical and religious experience, the applicability of mathematics to the physical world, the normativity of logic, normativity in general, the existence of anything in the first place, the emergence of life . . . .

My main interest is negative: in showing that materialism doesn't work. Please don't respond by saying that some other theory (substance dualism, say) doesn't work either. For the issue is precisely: Does   materialism work? If theory T1 is explanatorily inadequate, its deficiencies cannot be made good by pointing out that T2 is also inadequate. This is an invalid argument: "Every alternative to materialism is inadequate; therefore we should embrace materialism despite its inadequacies." Wouldn't it be more reasonable under those circumstances to embrace no theory?

One more preliminary point. If materialism is explanatorily adequate, then we ought to embrace it, and dispense with God, the soul, and the denizens of the Platonic menagerie. For if materialism were adequate, there would be no reason to posit anything beyond the material. But if materialism is not adequate, then we do have reason for such posits.

The following argument is my interpretation of remarks made by Edward Feser in his Philosophy of Mind: A Short Introduction (One World, 2005), pp. 156-159)

1. Consider a representation such as a picture. You draw a picture of your mother. The picture represents her: it is of or about her, and it would remain about her even were she to cease to exist. The picture is a physical object with physical properties: the paper is of a certain size and shape and texture, the ink of a certain chemical composition, the lines have a definite thickness, etc. Now I would insist that these physical features cannot be that in virtue of which the picture represents your mother: they cannot be that in virtue of which the physical item is a representation. For it makes no sense to ascribe intrinsic semantic or intentional properties to merely physical items.  But even if I am wrong about this, there remains a problem for a materialist theory of representation.

2. Suppose a 'copycat' comes along and makes an EXACT copy of your picture of your mother. The copycat's intention is not to represent your mother; his intention is merely to represent your representation of your mother. Now there are two pictorial representations, call them R (the original) and R' (the copy). The question arises: Is R' a  representation of your mother, or is R' a representation  of R? Suppose a second copycat comes along and produces a second copy R''.   Does R'' represent R' or R or your mother? The situation is obviously iterable ad infinitum.

3. Clearly, there is a difference between saying that R' represents your mother, a human being, and saying that R' represents R, a nonhuman drawing of your mother. The reference is different in the two cases. But the reference is indeterminate if we go by the physical properties of the representations alone. Suppose I hand you two drawings of your mother, one an exact copy of the other, but you do not know which is the orignal and which is the copy. You cannot, by inspection of these drawings, tell which is which. Thus you cannot  determine the reference from the physical properties.

4. The point is generalizable to other types of representations.  Suppose I say 'cat' to refer to a cat and my copycat brother says 'cat' simply to copy me. If my brother mimics me perfectly, then it will be impossible from the physical properties of the two word-sounds to tell which refers to a cat and which does not.

Please do not say that we are both referring to a cat. For my copycat brother is a mere copycat: his intention is merely to reproduce the word-sound I made. To make it even clearer, replace my brother with a parrot who happens to be a perfect mimic. No one will say that the 'cat'-token produced by the parrot refers to a cat. The parrot is just an animate copy machine.

The same goes for any physical representation. Suppose a pattern of neural firings is taken to be a representation of X. An exact copy of  that pattern needn't be a representation of X; it could be a
representation of the original pattern. In general, no material representation of X is such that its physical properties suffice to make it a representation of X as opposed to a representation of a
representation of X.

5. Here is the argument:

P1. All thoughts have determinate objects.
P2. No purely material representation has a determinate object.
 —–
C. No thought is a purely material representation.

6. Let's consider an objection. "Granted, material representations on their own lack determinate reference, but that can be supplied by bringing in causal relations. Thus what makes a tokening of 'cat' refer to a cat rather than to a word is the fact that there is a causal chain starting with a furry critter and terminating with an utterance of 'cat.'"

But causal connections cannot secure determinacy of reference, as Hilary Putnam appreciates (Renewing Philosophy, Harvard UP, 1992, p. 23):

     One cannot simply say that the word "cat" refers to cats because
     the word is causally connected to cats, for the word "cat," or
     rather my way of using the word "cat," is causally connected to
     many things. It is true that I wouldn't be using "cat" as I do if
     many other things were different. My present use of the word "cat"
     has a great many causes, not just one. The use of the word "cat" is
     causally connected to cats, but it is also causally connected to
   &#0
160; the behavior of Anglo-Saxon tribes, for example. Just mentioning
     "causal connection" does not explain how one thing can be a
     representation of another thing, as Kant was already aware.

Related Post:  Representation and Causation, With Some Help from Putnam

Searle, Subjectivity, and Objectivity

John Searle is a marvellous critic of  theories in the philosophy of mind, perhaps the best.  He makes all sorts of excellent points in his muscular and surly way.  But his positive doctrine eludes me, assuming it is supposed to be a coherent doctrine.  The problem may reside with me, of course.  But I am not ready to give up.

So I take yet another stab at making sense of Searle. (The exegetical equivalent of squaring the circle?) His aim is to find a via media between the Scylla of dualism and the Charybdis of materialism.   Dualism, whether a dualism of (kinds of) substances or a dualism of (kinds of) properties, makes of mind something mysterious and supernatural and therefore intolerable to naturalists. But materialism, as Searle understands it, issues in the conclusion that "there really isn't such a thing as as consciousness with a first-person, subjective ontology." (Mind, Language, and Society, Basic Books, 1998, p. 45)

What Searle wants to say is that there can be a natural science of consciousness, but one that does not end up by denying its existence, a natural science that is adequate to consciousness in its very   subjectivity. But (1) science is objective: it aims at an underlying reality 'beneath' subjective appearances. (2) Consciousness, however, is essentially subjective. It seems, therefore, that (3) there can be no natural science of consciousness.

To defeat this argument, Searle makes a distinction between epistemic subjectivity and ontological subjectivity, and a distinction between epistemic objectivity and ontological objectivity. Compare a pain and  a mountain. A pain has a subjective mode of existence whereas a mountain has an objective mode of existence. The difference is that the appearing of the pain is identical to the being of the pain unlike the mountain whose appearing and being are distinct. A pain cannot exist unless it is experienced, whereas a mountain can exist without being experienced. So far, so good.  But then Searle maintains that what is ontologically subjective can be studied by a science that is epistemically objective. If this is right, then the argument above falls victim to a failure to distinguish the two senses of 'subjectivity' and the two senses of 'objectivity.'   Here is the argument again:

1. Science is objective:  it aims at an underlying reality 'beneath' subjective appearances.
2. Consciousness is essentially subjective.
Therefore
3. There can be no natural science of consciousness.

Searle's contention is that there is nothing to prevent a science that is epistemically objective from studying consciousness which is ontologically subjective. Here is the crucial passage (ML&S, pp. 44-45):

     The pain in my toe is ontologically subjective, but the statement
     "JRS now has a pain in his toe" is not epistemically subjective. It
     is a simple matter of (epistemically) objective fact, not a matter
     of (epistemically) subjective opinion. So the fact that
     consciousness has a subjective mode of existence does not prevent
     us from having an objective science of consciousness.

Searle's argument goes like this:

   4. The pain in JRS's toe is ontologically subjective.
   5. That JRS has a pain in his toe is a matter of epistemically
   objective fact.
   Therefore
   6. That consciousness has a subjective mode of existence is consistent
   with there being an epistemically objective science of it.

Although both premises are true, the conclusion does not follow from them. Searle is confusing the objective reality of his pain with its objective accessibility to science. This confusion is aided and
abetted by the ambiguity of 'object' and 'objective.' From the fact that the pain exists in itself and is in that sense objective, it does not follow that the pain is exhaustively knowable by science, that it
is an object of scientific knowledge.

Consider a different example. Mary says, "The room is cold!" Bill says, "The room is not cold." Clearly, there is no fact of the matter as to whether or not the room is cold or the opposite. It is a matter of perception: Mary feels cold, while hot-blooded Bill does not. The objective fact is that the room temperature is 68 degrees Fahrenheit, a fact  perceived differently by Bill and Mary.

Note that it is also an objective fact that Mary feels cold and that Bill does not. But how is it supposed to follow that Bill's sensation, or Mary's, are exhaustively understandable in natural-scientific terms? The fact that the sensations themselves exist in reality and not relative to perceivers does not show that they are wholly accessible to science.  It is precisely their "first-person ontology"  that keeps them from being wholly accessible to science. 

The mistake Searle is making is to think that what is objectively real (in the sense of that which exists in itself and not relative to perceivers) is exhausted by what is natural and therefore accessible to natural science. He mistakenly identifies reality with nature. It is undoubtedly true that sensations (and mental data generally) exist in observer-independent fashion: they are not mere appearances but   appearances in which appearance and reality coincide. Thus Searle is right to say that they are ontologically subjective. Searle is also right to say that this ontological subjectivity is consistent with mental data's existing in themselves and not merely for an observer.

But as far as I can see it is a howling non sequitur to conclude that mental data are objects of scientific knowledge. To be objectively real (in the sense of existing an sich and not merely for observers) is not the same as being an object of scientific knowledge. Beware the ambiguity of 'object'!  It appears that Searle has fallen victim to it.

But why does Searle mistakenly identify reality with the objects of scientific knowledge — especially given his clear insight into the ontological subjectivity of mental data? Because he is in the grip of
the IDEOLOGY of scientific naturalism. This prevents him from properly exploiting his insight. But to make this allegation stick will require further citations and considerations.

My Searle posts are in the aptly-named  Searle category.

Could Intentionality be an Illusion? A Note on Rosenberg

Could intentonality be an illusion?  Of course not.  But seemingly intelligent people think otherwise:

A single still photograph doesn't convey movement the way a motion picture does. Watching a sequence of slightly different photos one photo per hour, or per minute, or even one every 6 seconds won't do it either. But looking at the right sequence of still pictures succeeding each other every one-twentieth of a second produces the illusion that the images in each still photo are moving. Increasing the rate enhances the illusion, though beyond a certain rate the illusion gets no better for creatures like us. But it's still an illusion. There is noting to it but the succession of still pictures. That's how movies perpetrate their illusion. The large set of still pictures is organized together in a way that produces in creatures like us the illusion that the images are moving. In creatures with different brains and eyes, ones that work faster, the trick might not work. In ones that work slower, changing the still pictures at the rate of one every hour (as in time-lapse photography) could work. But there is no movement of any of the images in any of the pictures, nor does anything move from one photo onto the next. Of course, the projector is moving, and the photons are moving, and the actors were moving. But all the movement that the movie watcher detects is in the eye of the beholder. That is why the movement is illusory.

The notion that thoughts are about stuff is illusory in roughly the same way. Think of each input/output neural circuit as a single still photo. Now, put together a huge number of input/output circuits in the right way. None of them is about anything; each is just an input/output circuit firing or not. But when they act together, they "project" the illusion that there are thoughts about stuff. They do that through the behavior and the conscious experience (if any) that they produce. (Alex Rosenberg, The Atheists' Guide to Reality: Enjoying Life Without Illusions.  The quotation was copied from here.)

Rosenberg is not saying, as an emergentist might, that the synergy of sufficiently many neural circuits gives rise to genuine object-directed thoughts.    He is saying something far worse, something literally nonsensical, namely, that the object-directed thought that thoughts are object-directed is an illusion.  The absurdity of Rosenberg's position can be seen as follows.

1. Either the words "The notion that thoughts are about stuff is illusory"  express a thought — the thought that there are no object-directed thoughts — or they do not. 
2. If the latter, then the words are meaningless.
3. If the former, then the thought is either true or false.
4. If the thought is true, then there there are no object-directed thoughts, including the one expressed by Rosenberg's words, and so his words are once again meaningless.
5. If the thought is false, then there are object-directed thoughts, and Rosenberg's claim is false.
Therefore
6. Rosenberg's claim is either meaningless or false.  His position is self-refuting.

As for the analogy, it is perfectly hopeless, presupposing as it does genuine intrinsic intentionality.  If I am watching a movie of a man running, then I am under an illusion in that there is nothing moving on the movie screen: there is just a series of stills. But the experience I am undergoing is a perfectly good experience that exhibits genuine intrinsic intentionality: it is a visual experiencing of a man running, or to be perfectly punctilious about it: a visual experiencing AS OF a man running.  Whether or not the man depicted exists, as would be the case if the movie were a newsreel, the experience exists, and so cannot be illusory.

 To understand the analogy one must understand that there are intentional experiences, experiences that take an accusative.  But if you understand that, then you ought to be able to understand that the analogy cannot be used to render intelligible how it might that it is illusory that there are intentional experiences.

What alone remains of interest here is how a seemingly intelligent fellow could adopt a position so manifestly absurd.  I suspect the answer is that he has stupefied himself  by  his blind adherence to scientistic/naturalistic ideology.

Here is an earlier slap at Rosenberg.  Peter Lupu joins in the fun here.

Memory, Memory Traces, and Causation

Hippy-trippyPassing a lady in the supermarket I catch a whiff of patchouli.  Her scent puts me in mind of hippy-trippy Pamela from the summer of '69.  An olfactory stimulus in the present causes a memory, also in the present, of an event long past, a tête-à-tête with a certain girl.  How ordinary, but how strange! Suddenly I am 'brought back' to the fantastic and far-off summer of '69.  Ah yes!  What is memory and how does it work?  How is it even possible? 

Let's start with the 'datanic' as I like to say:

1. There are (veridical) memories through which we gain epistemic access to the actual past, to events that really happened.  The above example is a case of episodic personal memory.  I remember an event in my personal past.  To be precise, I remember my having experienced an event in my personal past.  My having been born by Caesarean section is also an episode from my personal past, and I remember that that was my mode of exiting my mother's body; but I don't remember experiencing that transition.  So not every autobiographical memory is a personal episodic memory.  The latter is the only sort of memory I will be discussing in this post.  The sentence in boldface is the nonnegotiable starting point of our investigation. 

We now add a couple of more theoretical and less datanic propositions, ones which are not obvious, but are  plausible and accepted by many theorists:

2. Memory is a causal notion.  A mental image of a past event needn't be a memory of a past event.  So what makes a mental image of a past event a memory image?  Its causal history.  My present memory has a causal history that begins with the event in 1969 as I experienced it.

3. There is no action at a temporal distance.  There is no direct causation over a temporal gap.  There are no remote causes; every cause is a proximate cause.  A necessary ingredient of causation is spatiotemporal contiguity.  So while memory is a causal notion, my present memory of the '69 event is not directly caused by that event.  For how could an event that no longer exists directly cause, over a decades-long temporal gap, a memory event in the present?  That would seem to be something 'spooky,' a kind of magic. 

Each of these propositions lays strong claim to our acceptance.  But how can they all be true?  (1) and (2) taken together appear to entail the negation of (3).  How then can we accommodate them all?

Memory trace theories provide a means of accommodation.  Suppose there are memory traces or engrams engraved in some medium.  For materialists this medium will have to be the brain.  One way to think of a memory trace is as a brain modification that was caused at the time of the original experience, and that persists since that time.  So the encounter with Pam in '69 induced a change in my brain, left a trace there, a trace which has persisted since then.  When I passed the patchouli lady in the supermarket, the olfactory stimulus 'activated' the dormant memory trace.   This activation of the memory trace either is or causes the memory experience whose intentional object is the past event.  With the help of memory traces we get causation wthout action at a temporal distance. 

(Far out, man!)

The theory or theory-schema just outlined seems to allow us to uphold each of the above propositions. In particular, it seems to allow us to explain how a present memory of a past event can be caused by the past event without the past event having to jump the decades-long temporal gap between event remembered and memory.  The memory trace laid down in '69 by the original experience exists in the present and is activated in the present by the sensory stimulus.  Thus the temporal contiguity requirement is satisfied.  And if the medium in which the memory traces are stored is the brain or central nervous system, then the spatial contiguity requirement is also satisfied.

Question:  Could memory traces play merely causal roles?

Given (2) and (3), it seems that memory traces must be introduced as causal mediators between past and present.  But could they be just that?  Or must they also play a representational role?  Intuitively, it seems that nothing could be a memory trace unless it somehow represented the event of which it is a trace. If E isthe original experience, and T is E's trace, then it it seems we must say that T is of E in a two-fold sense corresponding to the difference between the subjective and objective genitive.  First, T is of E in that T is E's trace, the one that E caused. Second, T is of E in that T represents E. 

It seems obvious that a trace must represent.  In my example,the sensory stimulus (the whiff of patchouli) is not of or about the '69 event.  It merely activates the trace, rendering the dispositional occurrent.  But the memory is about the '69 event.  So the aboutness must reside in the trace.  The trace must represent the event that caused it  – and no other past event.  The memory represents because the trace represents.  If the trace didn't represent anything, how could the memory — which is merely the activation of the trace or an immediate causal consequence of the activation of the trace — represent anything?  How a persisting brain modification — however it is conceived, whether it is static or dynamic, whether localized or nonlocalized — can represent anything is an important and vexing question but one I will discuss in a later post.

Right now I want to nail down the claim that memory traces cannot play a merely causal role, but must also bear the burden of representation.

Suppose a number of strangers visit me briefly.  I want to remember them,  but my power of memory is very weak and I know I will not remember them without the aid of some mnemonic device.  So I have my visitors leave calling cards.  They do so, except that they are all the same, and all blank (white).  These blank cards are their traces, one per visitor.   The visitors leave, but the cards remain behind as traces of their visit.  I store the cards in a drawer.  I 'activate' a card by pulling it out of storage and looking at it.  I am then reminded (at most) that I had a visitor, but not put in mind of any particular visitor such as Tom.  So even if the card in my hand was produced by Tom, that card is useless for the purpose of remembering Tom.  Likewise for every other card.  Each was produced by someone in particular and only by that person; but none of them 'bring back' any particular person. 

Bear in my mind that I don't directly remember any of my visitors.  My only memory access to them is via their traces, their calling cards.  For the visitors are long gone just like the '69 experience.  So the problem is not merely that I don't know which card is from which person; the problem is that I cannot even distinguish the persons.  

Had each visitor left a differently  colored card, that would not have helped.  Nor are matters helped if each visitor leaves a different sort of trace; a bottle cap, a spark plug, a lock of hair, a guitar pick.  Even if  Tom is a guitar player and leaves a guitar pick, that is unhelpful too  since I have no access to Tom except via his trace. 

So it doesn't matter whether my ten visitors leave ten tokens of the same type, or ten tokens each of a different type.  Either way I won't be able to remember them via the traces they leave behind.  Clearly, what I need from each visitor is an item that uniquely represents him or her — as opposed to an item that is merely caused to be in my house by the visitor.  Suppose Tom left a unique guitar pick, the only one of its kind in existence.  That wouldn't help either since no inspection of that unique pick could reveal that it was of Tom rather than of Eric or Eric's cat.  Ditto if Tom has signed his card or his pick 'Tom Riff.'  That might be a phony name, or the name of him and his guitar — doesn't B. B . King call his guitar 'Lucille'?

If I can remember that it was Tom who left the guitar pick, then of course I don't need the guitar pick to remember Tom by.  I simply remember Tom directly without the need for a trace.  On the other hand, if I do need a trace in order to remember long gone Tom, then that trace must have representational power: it cannot be merely something that plays a causal role. 

Traces theories have to avoid both circularity and vicious infinite regress.

Circularity.  To explain the phenomenon of memory, the trace theory posits the existence of memory traces.  But if the explanation in terms of traces ends up presupposing memory, then the theory is circular and worthless.  If what makes the guitar pick a trace of Tom is that I remember that Tom left it, then the explanation is circular.  Now consider the trace T in my brain which, when activated by stimulus S causes a memory M of past experience E.  M represents E because T represents E.  What makes T represent E? What makes the memory trace caused by the encounter with Pam in '69 represent Pam or my talking with her?  The answer cannot be that I remember the memory trace being caused by the encounter with Pam.  For that would be blatantly circular.  Besides, memory traces in the brain are not accessible to introspection.

Infinite Regress.  Our question is: what makes T represent E and nothing else?  To avoid circularity one might say this:  There is a trace T* which records the fact of E's production of T, and T represents E in virtue of T*.  But this leads to a  vicious infinite regress.   Suppose Sally leaves a photo of herself.  How do I know that the photo is of Sally and not of her sister Ally?  If you say that I directly remember Sally and thereby know that the photo is unambiguously of her, then you move in a circle.  You may as well just say that we remember directly and not via traces.  So, to hold onto the trace theory, one might say the following:  There is a photo of Sally and her photograph, side by side.  Inspection of  this photo reveals that that the first photo is of Sally.  But this leads to regress:  what makes the second photo a photo of the first?

Conclusion:  To avoid both circularity and infinite regress, memory traces must possess intrinsic representational power.  Their role cannot be merely causal.

A later post will then address the question whether memory traces could have intrinsic representational power.  If you are a regular reader of this blog you will be able to guess my answer.

REFERENCE:  John Heil, "Traces of Things Past," Philosophy of Science, vol. 45, no. 1 (March 1978), pp. 60-72.  My calling card example above is a reworking of Heil's tennis ball example.

 

More on Intentionality as a Problem for Functionalism

1. Even if every mental state is a brain state, it is quite clear that  not every brain state is a mental state: not everything going on in the brain manifests mentality. So what distinguishes the brain states that are mental states from the brain states that are not? This question cannot be evaded.

The distinguishing feature cannot be anything intrinsic to brain states qua brain states. To put it another way, the biological, electrochemical, and other terms appropriate to the description of  brain phenomena are of no help in specifying what makes a brain state  mental. Talk of axons, dendrites, synapses, diffusion of sodium ions across synapses, etc. is not the sort of talk that makes intelligible why a particular complex state of Jones' brain is his intense elation at getting his neuroscience text accepted for publication.
  
2. To help you understand what I have just said, I offer an analogy.  Even though every valve-lifter is an engine part, it is quite clear that not every engine part is a valve-lifter. So what distinguishes  the engine parts that are valve-lifters from the parts that are not?

The distinguishing feature cannot be anything intrinsic to engine parts qua physical objects. The mechanical, chemical, electrical, metallurgical and other terms appropriate to the description of engine parts are of no help in specifying what makes an engine part a  valve-lifter. A metallurgist might tell us everything there is to know  about the physical properties of those engine parts that are valve-lifters. But knowing all of that, I do not yet know what makes the part in question a valve-lifter. Similarly, I don't know what makes a certain heavy object under my hood a battery just in virtue of knowing all the electrochemistry involved in its operation.

3. The obvious thing to say at this point is that what make an engine part a valve-lifter or a battery or a generator or a transmission is its function. Physical composition is irrelevant. What makes a part a valve-lifter is the causal role it instantiates within the 'economy'  of the engine. A thing is a valve-lifter in virtue of the job it does  when properly connected to valves, cams, etc. Its being a valve-lifter is not intrinsic to it. Its being is its function within a system whose parts are causally interrelated.

I stress that physical composition is irrelevant. Anything that does the job of a valve-lifter is a valve-lifter. Anything that does the job of a modem is a modem.  There is more than one implementation of the modulation-demodulation function.  The function is 'multiply  realizable' as we say in the trade. Of course, not every physical substratum supports the function: not even in Eskimo land could valve-lifters in internal combustion engines be made of ice.

Another important point is that a particular thing that functions as a valve-lifter can assume other functions, that of paper-weight for example.  So not only are causal roles typically multiply realizable, causal role occupants or realizers are typically multi-functional. 

I think we are all functionalists when it comes to things like valve-lifters, screwdrivers, switches, and modems. Anything that modulates/demodulates is a modem regardless of the stuff inside the
box that realizes or implements the function. For all we care, there is a colony of leprechauns inside the box that chop up the analog input into digital bits. If it does the job of a modem, it IS a modem.

Can we apply this functionalist model to the mind?

4. If there is nothing intrinsic to brain states that explains why some of them are mental states, then the naturalist must look to the extrinsic or relational features of brain states. How do they function? What causal role do they play? How do they stand in relation to inputs and outputs? How did they come into being? What are they good for?

One answer is the functionalist theory that causal role is what makes a brain state a mental state. What makes a mental state mental is just  the causal role it plays in mediating between sensory inputs,   behavioral outputs and other internal states of the subject whose state it is. The idea is not the banality that mental events have causes and effects, but that it is causal role occupancy, nothing more and nothing less, that constitutes the mentality of a mental state. The intrinsic nature of what plays the role is relevant only to its fitness for instantiating mental causal roles but not at all relevant to its being a mental state.

That's the basic idea. What makes a brain state a desire is the causal role that state plays. There is nothing intrinsic to the brain state itself that could tell you that it was a desire for a beer rather than
an intention to paint the bathroom, or a memory of a trip to the Grand Canyon.  In their intrinsic nature mental states are just brain states; it is only their external relations that confer upon them mentality.

5. Here is one problem. It seems clear that my intention to clear brush could not have been a desire for a cold beer. Nor could it be an intention to paint the bathroom. The act of intending is individuated by its intentional content (to clear brush; to pain the bathroom): the content enters into the description of the act. This entails that the act could not have been an act having a different content.

But if it is causal role occupancy that makes brain state B an intention to clear brush, then B could have been an intention to paint the bathroom, had its causal relations been different.  Since this is absurd, it cannot be causal role occupancy  that makes B an intention to clear brush.  The fact of intentionality refutes functionalism.

Compare the valve-lifter. A particular engine part is a valve-lifter in virtue of the causal role it plays in the engine. But that part might not have been in the engine; it might have been on my desk weighing down papers, in which case it would have been playing a different causal role. There is no problem in this case because valve-lifters lack content, or directedness to an object. A valve-lifter is not about anything. But an intention is. And this aboutness is intrinsic to it, which is why it cannot be captured extrinsically in terms of functional role.

So one should not suppose that qualia are the only problems for functionalism.  Intentionality is just as much of a problem.  Compare the Martian neuroscientist argument given earlier.

Besides, one is superficial and thoughtless if one imagines that a clean separation can be made between qualia and intentional phenomena.  But that's a separate post.

Intentionality Not a ‘Hard Problem’ for Physicalists?

The qualia-based objections are supposed to pose a 'hard' problem for defenders of physicalism.  The implication is that the problems posed by intentionality are, if not exactly 'easy,' then at least tractable.  An earlier post discussed a version of the knowledge argument, which is one of the qualia-based objections.  (Two others are the absent qualia argument and the zombie argument.)  It seems to me, though, that intentionality is also a damned hard problem for physicalists to solve, so hard in fact as to be insoluble within physicalist constraints and another excellent  reason to reject physicalism.

Before proceeding I want to make two preliminary points. 

The first is that the untenability of physicalism does not entail the acceptability of substance dualism. Contrapositively, the unacceptability of substance dualism does not entail the tenability of physicalism.  So if a physicalist wishes to point out the problems with substance dualism,  he is free to do so.  But he ought not think that such problems supply compelling reasons to be a physicalist.  For it is obvious that the positions stand to each other as logical contraries; hence both could be be false.

My second point is that considerations of parsimony do favor physicalism over dualistic schemes — but only on condition that the relevant data can be adequately accounted for.  And that is one big  'only if.'  (See The Use and Abuse of Occam's Razor: On Multiplying Entities Beyond Necessity.)

An Argument Sketched.  Mary, Meet Marty.

We were talking about Frank Jackson's Mary.  Now I introduce Marty, a Martian scientist who like Mary knows everything there is to know about human brains and their supporting systems.  So he knows all about what goes in the human brain and CNS when we humans suffer and enjoy twinges and tingles, smells and stinks, sights and sounds, etc.  We will suppose that Marty's sensorium is very different, perhaps totally different than ours.  He may have infrared color qualia but no color qualia corresponding to the portion of the EM spectrum for which we have color qualia.  Marty also knows everything there is to know about what goes on in my head when I think about various things.  We may even suppose that Marty is studying me right now with his super-sophisticated instruments and knows exactly what is going on in my head right now when I am in various intentional states.

Suppose I am now thinking about dogs. I needn't be thinking about any particular dog; I might just be thinking about getting a dog, which of course does not entail that there is some particular dog, Kramer say, that I am thinking about getting. Indeed, one can think about getting a dog that is distinct from every dog presently in existence! How? By thinking about having a dog breeder do his thing. If a woman tells her husband that she wants a baby, more likely than not, she is not telling him that she wants to kidnap or adopt some existing baby, but that she wants the two of them to engage in the sorts of conjugal activities that can be expected to cause a baby to exist.  Same with me.  I can want a dog or a cat or a sloop or a matter transmitter even if the object of my wanting does not presently exist.

So right now I am thinking about a dog, but no presently existing dog.  My thinking has intentional content. It is an instance of what philosophers call intentionality.  My act of thinking takes an object, or has an accusative. It exhibits  aboutness or of-ness in the way a pain quale does not exhibit aboutness of of-ness.   It is important to realize that my thinking is intrinsically such as to be about a dog:  the aboutness is not parasitic upon an external relation to an actual dog.  That is why I rigged the example the way I did.  My thinking is object-directed despite there being no object in existence to which I am externally related.  This blocks attempts to explain intentionality in terms of causation.  Such attempts fail in any case.  See my post on Representation and Causation.

The question is whether the Martian scientist can determine what that intentional content is by monitoring my neural states during the period of time I am thinking about a dog. The content before my mind has various subcontents: hairy critter, mammal, barking animal, man's best friend . . . .  But none of this content will be discernible to the Martian neuroscientist on the basis of complete knowledge of my neural states, their relations to each other and to sensory input and behavioral output. To strengthen the argument we may stipulate that Marty lacks the very concept dog. Therefore, there is more to the mind than what can be known by even a completed neuroscience. Physicalism (materialism) is false.

The argument is this:

1. Marty knows all the physical and functional facts about my body and brain during the time I am thinking about a dog.
2. That I am thinking about a dog is a fact.
3.  Marty does not know that I am thinking about a dog.
Therefore
4. Marty does not know all the facts about me and my mental activity.
Therefore
5. There are mental facts that are not physical or functional facts, and physicalism is false.

Credit where credit is due:  The above is my take on a more detailed and careful argument presented here by Laurence BonJour.  Good day!