Wednesday, 11 October, 2000
What version, if any, of the psycho-physical identity theory is acceptable? What reasons are there to believe such a view?
Description of Davidson by Smart in the Stanford Encyclopaedia Identity theory article:
An interesting form of token identity theory is the anomalous monism of Davidson (1980). Davidson argues that causal relations occur under the neural descriptions but not under the descriptions of psychological language. The latter descriptions use intentional predicates, but because of indeterminacy of translation and of interpretation, these predicates do not occur in law statements. It follows that mind-brain identities can occur only on the level of individual (token) events.
the mind is the brain: mental states are states of the brain
ID theory avoids the problem of the interaction between mind + body/matter by simply seeing it as �interaction between subsets of material states�
neuroscience will eventually reveal the secrets of the mind in the same way that the theory of electricity reveals the secrets of lightning
The thing about sound waves, heat, colour and the like, is that they are all separate sensory modalities whose physical principles and physiology we now understand.But we don�t understand any better why a noise sounds the way it does, why a fire feels hot, or indeed any of the phenomenology whose cause has troubled philosophy since the Ancient Greeks. To say that we undestand them by virtue of the reductionist�s scalpel is to answer �How can we understand and predict this physical phenomenon?�, but misses the difficult half of the original question, �And why does it feel like this to me?�.
Indeed, glossing over these questions in the same fashion with mind is to gloss over the grand-daddy question underlying them all. For all of these intertheoretic reductions are, at their root, problems of mind, not matter. Understanding the physics of a soundwave tells us nothing about the noise we hear. We cannot attempt the same reductionist approach in philosophy of mind that worked on these problems, because reductionism fails to explain (or often even recognise) phenomenology. Phenomenology is the great problem in philosophy of mind.
Nagel is right in identifying parallels between pre-scientific notions of his �a posteriori necessary truths� like water, lightning, sound and heat, and current philosophy of mind. The problems suffer from what he expressively terms an �explanatory gap�, characterised by an ineliminable vagueness in our discussions, because we have an inadequate conceptual toolbox for the problem. Understanding sound in terms of soundwaves, or mind in terms of brain, involves bridging two terminologies and levels of explanation which cannot initially be explained or even imagined in terms of the other.
And he is right in largely eschewing guesses in the dark as to what form that conceptual gap might take. For history has shown that philosophy orders the landscape we have traversed, but laps and breaks against formatting a framework in the formless blackness ahead.
arguing against the last 3-4 lines of �Historical parallels�, pg 26 in Matter & Consciousness - Churchland
Having said all this, I do see hope for an identity theory of sorts. In all the cases of explanatory gaps being bridged in the past, one theory wholly superceded another. The (usually mental appreciation of the phenomenon being studied) was described wholly and in more detail ( as well as in quantified predictive fashion) by laws of physics determining the behaviour of matter. The mind-bogglingly immense capacity and distributed nature of neural networks� representation is too low-level and alien-seeming relative to the abstract, high-level designs our pattern-matching brains are best used to. This gives cause for hope that the behaviour of matter might even be enough, might even account for the minds of which we are so proud. Indeed, just as nature harnesses bootstrapping and emergent systems like evolution and the self-organising properties of neural networks, mankind is able to do the impossible: by building machines more powerful than ourselves, we may be able to understand ourselves, mind exploring itself, brain�s capacity exceeding itself vicariously (through its own product, computers) to understand itself in terms it can understand.
There may in fact be another encouraging point to make. I don�t think consciousness is binary (you have it or you don�t, e.g. we�re conscious and bacteria aren�t, with a dividing line in between. For starters, they don�t have a dislocated non-stimulus-response sensori-motor system, do they?). Consciousness is not a continuum either, for �continuum� implies a single dimension stretching to infinity, with no gaps. Consciousness is not 2- or 3-dimensional either. To give you a clue, it�s not 5-dimensional either. The idea of the 5 senses is one of the most debilitating, senseless and arbitrary hangovers from the pre-scientific past. We have far more than five sensory modalities: the �sixth� has variously been described as: scenting danger, phonetic understanding sounds + words, vestibular, pain, time, proprioception, hunger, emotion???. Even those aren�t indivisible: within touch we have pain, itchy, smooth, cold, wet etc. In vision we have: colour, writing, background/foreground object, focus + double-vision, texture, perspective, motion etc. Taste is supposedly derived from the interpretations of signals from 4 or 5 taste receptors. Smell from 500. Colour from 3. Visual spatial acuity (resolution) from 100 million retinal cells. The point of all this? Our qualia/phenomenology is an n-dimensional space, with n a large number of modalities, of blurred distinction. Not the number of neurons. Or even their connections. But something along those lines.
Which brings us back towards functionalism. But, as Jackson�s colour scientist showed us, we intuitively shrink from an array of mathematically-describable snooker balls ricocheting off each other giving rise to consciousness, knowing what it is like for them to be that trumped up snooker table, just as we object to their more complex cousins (neurons) being conscious by virtue of the complexity and orderliness of arrangement. This is why Nagel and Davidson are plausible, because they don�t seek to describe the mental any more exactly than as a huge and kaleidoscopic cloud, floating dislocated and distant from the physical Earth; the cloud appears from the corporeal perspective as white, fluffy and unitary (cf Descartes) despite beign composed of a colossal number of little droplets together, and to the cloud the corporeal is as distant and confused as the scurrying of ants (which is why we cannot control the firing of our neurosn precisely simly by altering miniscule details in our thoughts + ideas).
humans are physical organisms, whose entire physiology (we have no reason to doubt) is explicable and compsed entirely by the behaviour of matter
evolution appears to be an adequate explanation for us and animals (despite its initial implausibility, the expectation that such a method could only give rise to incremental changes of adaptive value and not teleological large changes with seemingly no intermediary adaptive stages) and an ID theory would be consistent with, and explicable in terms of, evolution
there appears to be systematic neural dependence of the mental, i.e. it appears that a change in brain state always occurs in conjunction with a change in mental state, and vice versa
progress in neuroscience so far has been rapid and encouraging. hmmm, maybe.
ID theory = claims a 1-1 correspondence between taxonomies of neural + mental states
mental states appear very different (qualititatively) to neurophysiological states � qualia can�t seem to be explained in terms of any matter-based physical laws
category error � Leibniz�s Law of Identity (x = y if they share exactly the same properties), e.g. the brain is spatially located but mind is not, or brain cannot be ascribed semantic properties
(N.B. the comment about Copernicus� statement that the eart moves around the sun is �an abuse of language� because �movement� is by definition relative to the earth). however, the brain does have propositional content though = the inferential (relational) role it plays (in the cognitive economy)
the mental is knowable to me, while my brain is not. it could just be a different name for something familiar.
but knowing something is a property of the knower, not of the object (= the �intensional fallacy�)
introspectible, i.e. knowable, IS a property of the object, though.
refutation: e.g. temperature is knowable by feeling but the mean molecular kinetic energy is not. I think I agree with this.
what Mary doesn�t know about the sensation of red shows that there are different types of knowing, e.g. prelinguistic
experiences are defined by their causal roles
physics + its laws will eventually be able to explain all physical phenomena
(given that experiences interact causally with physical events, they must be physically explicable) (though they may have a causally inert non-physical component, experiences are physical phenomena � in which case, they must be neural states, if they�re going to be anything physical)
2 good examples � unlocking a bike lock < the locking slots being aligned
the power-on LED !�/span> the computer/motor is turned on
epiphenomenal non-physical component to experience? NO, spurious caused role
this sort of dualism is empirically irrefutable, and such parallelism is inconsequential
can�t accept any of the ID/reductionist theories (because they ignore what separates the M-B problem from other intertheoretic reductoins of scientific past in whose familiar terms they are trying to understand it) if they are compatible with the absence of the subjective character of consciousness, the subjective feeling of what it is like to be that organism for that organism
zombies of any kind may be impossible because producing behaviour of a certain complexity might be impossible without the subjective character of experience
he agrees that the usual scientific reduction is different to psychophysical reduction because they can discard the �effect on the human observer� as irrelevant to the problem, whereas the M-B problem is the problem of phenomenology, of �how it all seems to us as human observers� � he sees this, though, as a problem of accommodating the purely subjective in terms of the purely objective. Remove the observer and you remove the problem itself. To an external observer, there is no effect on a human observer.
Bats are phylogenetically close, yet still very alien to us as a form of life. Their sensory apparatus and behaviour are so very different to ours that we can barely imagine being a bat. But even tehn, we are at best imagining what it would be like for me/us to be a bat, not what it is like for a bat. We can only imagine (incremented???) modifications to our experiences as ourselves
�what it is like� is not: what (in our experience) it resembles
������ but:����� how it is for the subject himself
just because the subjective character of our/bats�/Martians� experience is so specific as to be indescribable in non-specific terms, or terms specific to those whose subjective character of experience is different to ours, does not ( as our own mental states are undeniable evidence of) mean that it is not like anything to be us, i.e. human/a bat/an alien
crude cognitive dissonance to ignore the possibility of cognitive closure
phenomenological facts are sort of objective to those who share similar subjective char of experience � Nagel is not just talking about the first-person privacy of the mental � we can imagine what it is like to be a bat, but our success depends on our ability to adjust our PoV
how could objective physical facts help us understand subjective facts?
since, if you take away the subjectiveness of experience, what is left? usually, especially in science, subjective � objective is appearance � reality. in the case of experience, there is an irreducible PoV; we cannot better undersatnd what it is like to be a bat except from the viewpoint of a bat
�if mental processes are indeed physical processes, then there is something it is like intrinsically to undergo certain physical processes� (pg 172) � this would have to be a non-contingent relationship
we cannot currently conceive how physicalism could be true. we cannot imagine/conceive of ANY non-contingent way of relating them � we need a theoretical framework.
if we try and draw parallels or analogies with/from the usually intertheoretic identifications, we either:
find that subjectiveness rearises when we relate the mental to the phsyical
you get inadequate/false accounts, like causal behaviourism
we may have evidence for the truth of something we cannot understand, e.g. locking a caterpillar in a safe, then opening it to find a butterfly in its place
3 types of imagination � perceptual, symbolic and sympathetic
Davidson: if mental events have physical causes and effects, they must have physical description. though we do not (and could not) have a general psychophysical theory to explain them
certain phys events have irreducibly mental properties
- but we cannot conceive this, or even conceive of what/how such a conception would be like
does it make sense to talk of experiences having an objective character at all?
i.e. what they are really like, not just how they appear to me
this is necessary before we can attempt to capture them with a physical, objective description
without a means of downward causation, if you recognise that the subjective phenomonology of mental states is a critical component in mind-body, then you have to be an epiphenomenalist
unless, like Penrose and Nagel, you want to expand the physical (by QM or panpsychism), otherwise the causal intertness of the non-physical in a physical world leaves neural states as the final word
Put simply, the psychophysical ID theory: identifies mental states and processes with brain states and processes. Mental experiences just are brain processes, not merely correlated with them, though this is not the same as simply equating mind and brain.
The ID theory denies qualia, i.e. non-physical, non-localised, non-extended, private and powerful psychical phenomena
central state materialists � mental states are actual brain states
(physicalists � look for explanation in terms of physical laws, but often posit non-material entities)
ID theory = physicalist (ontologically, obviously not translational (i.e. word-for-word)). they deny strong emergence
Furthermore, he denies the possibility of �strong emergence�. The scientific term �emergence� refers to where low-level local interactions give rise to a complex, high-level collective behaviour, as in the case of hive minds, flocking or neural networks. I take it by �strong emergence� that he has in mind an extended idea of emergence, which might be used in an attempt to explain our phenomenological consciousness as arising out of the complexity of our own neural networks.
dualists = �nomological danglers� � excrescences on the fair face of science
constitution vs identity � �this table is an old packing case�
������ we see �lightning�, but we experiment on �electrical discharges�
mental + brain states/processes are extensionally identical, but intensionally (in terms of how we perceive/identify them) different
meaning vs referencee (Hesperus vs Phosphorus, the Evening Star)
does Smart believe/require that the identity is a necessary (a priori) one?
by Hume�s principle: sensation and my putative awareness of the sensation can occur separately because are distinct existences
though sensations and brain processes may be identical, don�t they have different properties? e.g. introspected non-physical properties of sensation?
Smart: the properties of experiences are topic-neutral, neutral between physicalism + dualism
i.e. neutral as to whether the properties of the experience are physical or irreducibly �psychical�
Place, �phenomenological fallacy�: a green sense datum is not itself green
Rosenthal: �we lose the distinctively mental if we construe these properties as neither physical nor mental�
Smart argues that the whole point of topic-neutrality is that it straddles both
but this is circular � he is arguing that experiences are topic-neutral because they can be described without specifically dualist or physical terms, and then refuting Rosenthal by saying that experiences straddle both the physical and mental because (as he�s just told us) they�re topic neutral
Lewis: �definitive characteristic of any experience � is its causal role�
but materialists believe that these causal roles belong in fact to certain physical states. since these physical states possess the definitive character of experiences, they must be experiences
can attack the premise about the definitive characteristic of experiences being causal role
he must be saying here that the causal role is enough to identify something as an experience, as well as exclude it from being anything else (otherwise it could be that the causal role is a necessary condition for something besides experience)
we need downward causation to be able to attack the second premise that physical states possess completely the causal role
token ID theory = a particular pain is identical to a particular brain process
this is acceptable to functionalists (mental states = defined in terms of functional properties)
a single functional state can be realised by >1 brain states
anomalous monism = a token identity theory
physicalism = all factual knowledge can be formulated as a statement about physical objects and their activities
confusion over physicalism vs materialism (often used interchangeably)
ID theory = every mental property is identical with some physical property
What is a/the psycho-physical theory?
What versions are there?
Is functionalism one?
How could states that seem so different be one and the same?
Would looking at the squishy brain be able to show you thoughts?
When we report on our mental states, what are the feeling we are reporting on? � our brains?
What are the properties of mental states besides causal role?
What does Smart mean by �strong emergence�?
What�s an intertheoretic reduction?
relates to �a posteriori necessary truths�?
What is the terminology that Bernard Williams uses in his RIP 2000 lecture for one theory wholly superceding another? � vindicatory
There is of course a real question of what it is for a history to be a history of discovery. One condition of its being so lies in a familiar idea, which I would put like this: the later theory, or (more generally) outlook, makes sense of itself, and of the earlier outlook, and of the transition from the earlier to the later, in such terms that both parties (the holders of the earlier outlook, and the holders of the later) have reason to recognise the transition as an improvement. I shall call an explanation which satisfies this condition vindicatory. In the particular case of the natural sciences, the later theory typically explains in its own terms the appearances which supported the earlier theory, and, furthermore, the earlier theory can be understood as a special or limited case of the later. But � and this is an important point � the idea that the explanation of a transition from one outlook to another is "vindicatory" is not defined in such a way that it applies only to scientific enquiries.
What is a modality?
property dualism = systematic neural dependence???
has anything of lower complexity ever evolved, i.e. has evolution regressed over a reasonable period of time?
what�s the difference between systematic dependence and supervenience?
is supervenience symmetrical?
in a psycho-physical ID theory, why can�t we learn to control the activity of individual neurons by altering the content of our thought in tiny ways?
is allowing the possibility of this the criteria for an epiphenomenalist vs identity theory?
ID theory = claims a 1-1 correspondence between taxonomies of neural + mental states � what does taxonomies mean? (Classification, esp. in relation to its general laws or principles; the branch of science, or of a particular science or subject, that deals with classification; esp. the systematic classification of living organisms)
don�t understand Churchland�s refutation of qualia being impossible to explain in physical terms
is the ID theory materialistic? surely not, because it recognises that there are mental states, it�s just that these mental states only play a causal role when viewed through the lens of the physical. This is Davidson�s claim, right??? no, the ID theorists really believe that the mental and physical states/taxonomies are the same
what�s the difference between parallelism and epiphenomenalism and determinism?
syncategorematic = Of a word: having no meaning by itself, but only in conjunction with one or more other words or concepts. Opp. categorematic
how does topic-neutrality of experience (if true) help with the mental having different properties to the physical
I suppose if experiences were topic-neutral, that would mean that they can be described independent of the specifically mental or physical � so the question becomes, not �do the mental and physical have the same properties?�, but �are experiences topic neutral?�
if Smart can recognise and talk about the �irreducibly psychical�, doesn�t that pull the carpet out of the �topic neutrality of experiences�?
sensation statements = incorrigible, but brain statements = corrigible???
avowals = more trustworthy somehow, like a reflex (due to the immediate access we have to the subjective)
Ramseyfication of folk psychology???
Kirk : impossibility of zombies???
2nd order type theory???
Nagel + Davidson start from the premises, which we are not prepared to dismiss in an acceptable theory, and then see what�s left � Smart looks to explain the mental in terms of what we can understand, even if it means cutting off the bits that don�t fit
qualia �feel� unitary because that is the nature of a distributed representation, as in NNs
could it be that (since/just as a computer can�t wholly represent itself (let alone a domain larger + more complex than itslef, like the Universe)), our brain has invented mental states as a way of representing (in compressed, but rich form) itself (the salient, survival-criticial bits (i.e. adaptive)) to itself � i.e. a virtual machine/internal model, which the whole brain is acting upon, a construct which gives us the homunculi in the Cartesian Theatre illusion
I don�t think you can have a non-conscious mental state
2 parts: intro and standard args for the theories. state why I think they�re inadequate. Then state why there may be hope, and which theories fit this hope (cf Nagel RIP 98).
add in phenomenology
take away causal role
epiphenomenalism (Blakemore/Dennett ???)+ Davidson
token vs type
bring back causal role (with phenomenology)
Penrose + Nagel
 I have avoided the term, �consciousness�, because it is overly associated with human, linguistic awareness of higher thought processes. I am trying to focus on the �subjective character of experience� that Nagel is prepared to ascribe, at different
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a ���������� The fact of being a modal proposition or syllogism. Also, a qualification which makes a proposition modal. e17.
b ���������� The feature of a judgement defined by its classification as problematic, assertoric, or apodictic. m19.
3 ���������� Psychol.
a ���������� A category of sensation, a sense (as sight, hearing) . Formerly also, a qualitative aspect of a particular category of sensation. l19.
b ���������� An attribute or trait of personality. m20.
4 ���������� Gram. The property of a verb or verbal form that is represented or distinguished by its mood. e20.
5 a ������� Med. A method or technique of treatment, esp. one not involving drugs. m20.
b ���������� In diplomacy, politics, etc.: a procedure, a method. m20.
c ���������� A mode of action or behaviour. m20.