Friday, 23 September 2016

E. Brian Davies's Empiricist Account of Real Numbers

*) This commentary is on the relevant parts of E. Brian Davies's book, Science in the Looking Glass.  


At first glance it's difficult to see how mathematics generally, and numbers specifically, have anything to do with what philosophers call “the empirical”. This is also the case for mathematicians and philosophers whom class themselves as “realists” or “Platonists”. Nonetheless, everyone is aware of the fact that maths is applied to the world. Or, at the least, that maths is a useful tool for describing empirical reality.

Nonetheless, empiricists go one step further than this by arguing that mathematics (or, in Davies's case, a real number) is empirical in nature. Or, at the least, that certain types of real number have an empirical status.

At first I had to decide whether to class E. Brian Davies's position “empiricist mathematics” or “mathematical empiricism”. The former is a philosophical position regarding maths. The latter, on the other hand, is a position on empiricism itself. In other words, in order to make one's empiricism more scientific, it would make sense to make it mathematical. Empiricist maths, on the other hand, is a philosophical position one could take on mathematics itself. Although these are different positions, I can only say that both apply to Davies's account.

Small Real Numbers

E. Brian Davies puts his position at its most simple when he says that for a “'counting' number its truth is simply a matter of observation” (81). Here there seems to be a reference to the simple act of counting; which is a psychological phenomenon. By inference it must also refer to what we count. And what we count are empirical objects or other empirical phenomena. That means that empirical objects need to be observed in the psychological act of counting.

Prima facie, it's hard to know what Davies means when he writes that “[s]mall numbers have strong empirical support but huge numbers do not” (116). Even if it means that we can count empirical objects easily enough with numbers, does that, in and of itself, give small numbers “strong empirical support”? Perhaps we're still talking about two completely different/separate things: small numbers and empirical objects. Simply because numbers can be utilised to count objects, does that - on its own - confer some kind of empirical reality on them? We are justified in using numbers for counting; though that may just be a matter of practicality. Again, do small numbers themselves have the empirical nature of objects passed onto them simply by being used in acts of counting?

Did these small numbers exist before “assenting to Peano's axioms”? Davies make it seems as if accepting such axioms is a means to create or construct small numbers. That is, we take the axioms; from which we derive all the small numbers. However, before the creation of these axioms, and the subsequent generation of small numbers as theorems, did the small numbers already exist? A realist would say 'yes'. A constructivist, of some kind, would say 'no'.

Davies appears to put the set-theoretic or Fregean/Cantorean position on numbers in that he writes that that “'counting' numbers exist in some sense” (82). What sense? In the sense that “we can point to many different collections of (say) ten objects, and see that they have something in common” (82). I say Fregean/Cantorean in the sense that the nature of each number is determined by its one-to-one correspondence with other members of other sets.

Prima facie, I can't see how numbers suddenly spring into existence simply because we 'count' the members of one set and them put the members of equal-membered sets in a relation of one-to-one correspondence. How numbers are used can't give them an empirical status. Something is used, sure; though that use doesn't entirely determine its metaphysical nature. (We use pens; though that use of a pen and the pen itself are two different things.)

The other problem is how we 'count' without using numbers? Even if there are "equivalence classes", are numbers still surreptitiously used in the very definition of numbers?

In any case, what these “collections” have in common, according to Davies, is the number of members, which we “see” (rather than count?).

Davies goes on to argue a case for the empirical reality of small real numbers. There is a logical problem here, which he faces.

Davies offers a numerical version of the sorites paradox for vague objects or vague concepts. Let me put his position in argument-form. Thus:

 i) “If one is prepared to admit that 3 exists independently of human society.
ii) “then by adding 1 to it one must believe that 4 exists independently...”
         iii) “[Therefore] the number 1010100 must exist independently.” (82)

This would work better if Davies hadn't used the clause “exists independently of human society”. I say that because it's empirically possible, or psychologically possible, that there must be a finite limit to human counting-processes. Thus counting to 4 is no problem. But counting to 1010100 may not be something “human society” can do.

I mentioned the simpler and more effective argument earlier. Thus:

i) If 3 exists.
ii) Then by adding 1 to 3, 4 must exist.
iii) Therefore, by the repeated additions of 1 to the previously given number, the number 1010100 must also exist.

It may exist; though Davies thinks that mathematics tells us “it is not physically possible to continue repeatedly the argument in the manner stated until one reaches the number 1010100 ” (82).

Extremely Large and Extremely Small Real Numbers

Davies begins his case for what he calls the “metaphysical” or “questionable” nature of extremely large numbers by saying that they “never refer to counting procedures” (67). Instead, “they arise when one makes measurements and then infers approximate values for the numbers”.

The basic idea is that there must be some kind of one-to-one correlation between real numbers and empirical objects. If this isn't forthcoming, then certain real numbers have a “questionable” or “metaphysical” status. (Again, this is like the idea of a one-to-one correspondence between members of one set and the members of another set. This is – or was - a process used to determine the set-theoretic status of numbers.)

From his position on small numbers, Davies also concludes that “huge numbers have only metaphysical status” (116). I don't really understand this. Which position in metaphysics is Davies talking about? His use of the word “metaphysics” makes it sound like some kind of synonym for “lesser” (as in a “lesser status”). However, everything has some kind of metaphysical status, from coffee cups to atoms. Numbers do as well. So it makes no sense to say that “huge numbers have only metaphysical status” until you define what status that is within metaphysics. The phrase should be: “huge numbers only have a … metaphysical status”; with the three dots filled in with some kind of position within metaphysics.

Davies goes on to say similar things about “extremely small real numbers” which “have the same questionable status as extremely big ones”. I said earlier that the word “metaphysical” (within this context) sounded as if it were some kind of synonym for 'lesser'. That conclusion is backed up by Davies using the phrase “questionable status”. Thus a metaphysical status is also a “questionable status”. Nonetheless, I still can't see how the word “metaphysical” can be used in this way. Despite that, I'm happier with the latter locution (“extremely small real numbers have the same questionable status as extremely big ones”), than I am with the former (i.e., “huge numbers have only metaphysical status”).

Since there must be some kind of relation or correspondence between real numbers and empirical things, Davies also sees a problem with extremely small real numbers. It seems that physicists or philosophers may attempt to set up a relation between extremely small numbers and “lengths far smaller than the Planck length” (117). Thus the idea would be that Planck lengths divide up single empirical objects. Small numbers, therefore, correlate with individual empirical objects; whereas extremely small numbers correlate with the various Planck lengths of an object (rather than with objects in the plural).

Davies doesn't appear to think that this approach works. That is because Planck lengths “have no physical meaning anyway” (117). This means that extremely small numbers don't have any empirical support. They have a “questionable” or “metaphysical status”.

Models, Real Numbers and the External World

Davies's general position is that “real numbers were devised by us to help us to construct models of the external world” (131). As I said earlier, does this mean that numbers gain an empirical status simply because they're “used to help us construct models of the external world”? Perhaps, again, even though real numbers are used in this way, that still doesn't give them an empirical status. Can't numbers be abstract platonic objects and still have a role to play in constructing models of the external world? Why do such models and numbers have to be alike in any way? (Though there is the problem, amongst others, of our causal interaction with abstract numbers.)

In terms of a vague analogy. We use cutlery to eat our breakfasts. Yet breakfasts and cutlery are completely different things. Nevertheless, they're both, as empirical objects, in the same ball park. What about using a pen to write about an event in history? A pen is an empirical object; though what about an historical event? Can we say that the pen exists; though the historical event no longer exists? Nonetheless there is a relation between what the pen does and a historical event even though they have two very different metaphysical natures.

As non-physicists, we may also want to know how real numbers “help us to construct models of the external world”. Are the models literally made up of real numbers? If the answer is 'yes', then what does that mean? Do real numbers help us measure the external world via the use of models? That is, do the numbered relations of a model match the unnumbered relations of a object (or bit of the external world)? Would that mean that numbers belong to the external world as much as they belong to the models we have of the external world? Is the world, in other words, numerical? Thus, have we the philosophical right, as it were, to say of the studied objects (or bits of the external world) what we also say about the models of studied objects (or bits of the external world)? Platonists (realists) would say 'yes'. (Perhaps James Ladyman and Donald Ross, or ontic structural realists, would say 'yes' too.)


E. Brian Davies puts the empiricist position on mathematics at its broadest by referring to von Neumann, Quine, Church and Weyl. These mathematicians and philosophers “accepted that mathematics should be regarded as semi-empirical science” (115). Of course saying that maths is “semi-” anything is open to many interpretations. Nonetheless, what Davies says about real numbers, at least in part, clarifies this position.

Davies then brings the debate up to date when he tells us that contemporary mathematicians are “[c]ombining empirical methods with traditional proofs” (114). What's more, “the empirical aspect [is often] leading the way”. Indeed, Davies says, this position is “increasingly common even among pure mathematicians”.

Thursday, 15 September 2016

Kenan Malik's Extended Mind

This is a commentary on Kenan Malik's 'Extended Mind' chapter of his book, Man, Beast and Zombie (2000).

*) Malik offers a syllogistic argument thus:

i) The “human mind is structured by language”.
ii) “Language is public.”
iii) Therefore “the mind is itself is public”.

Kenan Malik characterises “computational theory” as one that “suggests that everything that is necessary for the use of language is stored in each individual mind” (327).

Here we must make a distinction between necessary and sufficient conditions “for the use of language”. It may indeed be the case that “everything that is necessary for the use of language is stored in each individual mind”; yet it may also be the case that such things aren't sufficient for the use of language. In other words, the mechanics for language-use are individualistic; though what follows from that may not be. And what follows from the mechanics of language is, of course, language itself.

Thus Malik's quote from Putnam, that “'no actual language works like that [because] language is a form of cooperative activity, not an essentially individualistic activity'” (328), may not be to the point here. Indeed I find it hard to see what an non-cooperative and individualistic language would be like – even in principle. That must surely imply that Malik, if not Putnam, has mischaracterised Fodor's position. Another way to put this is to say that Fodor is as much an anti-Cartesian and Wittgensteinian as anyone else. The Language of Thought and “computational theory” generally are not entirely individualistic when we take them beyond their physical and non-conscious reality. How could they be?

There's an analogy here between this and the relation between DNA and its phenotypes. Clearly DNA is required for phenotypes. However, DNA and phenotypes aren't the same thing. In addition, environments, not only DNA, also determine the nature of the phenotype.

As I hinted at earlier, Malik's position hints at a debate which has involved Fodor, Putnam and Chomsky.

Malik rejects Fodor's internalism or individualism, as has been said. It was said that Fodor believes that something must predate language-use. So let Fodor explain his own position. Thus: “My view is that you can't learn a language unless you already know one.”

Fodor means something very specific by the clause “unless you already know one”. As he puts it:

It isn't that you can't learn a language unless you've already learned one. The latter claim leads to infinite regress, but the former doesn't.” (385)

In other words, the language of thought isn't learned. It is genetically passed on from previous generations. It is built in to the brains of new-born Homo sapien babies.

Putnam gives a more technical exposition of Fodor's position. He writes:

[Fodor] contends that such a computer, if it 'learns' at all, must have an innate 'programme' for making generalisations in its built-in computer language.”

Secondly, Putnam tackles Fodor's rationalist - or even platonic - position which argues for innate concepts. Putnam continues:

[Fodor] concludes that every predicate that a brain could learn to use must have a translation into the computer language of that brain. So no 'new' concepts can be acquired: all concepts are innate.” (407)

Meanings Ain't in the Head

Because Malik argues that reference to natural phenomena is an externalist affair, and sometimes also scientific, it may follow that non-scientific individuals may not know the full meanings of the words, meanings or concepts within their heads. As Putnam famously put it: “Meaning just ain't in the head.”

Malik gives the example of the words (or mental representations?) 'ash' and 'elm'. Ash and elm trees are natural phenomena. In addition, their nature is determined and perhaps defined by their scientific nature. In other words, the reference-relation is not determined by the appearances of elm and ash tress. This results in a seemingly counterintuitive conclusion. Malik writes:

Many Westerners have a distinct representation of 'ash' and 'elm' in their heads, but they have no idea how to distinguish ash and elm in the real world.”

I said earlier that references to ash and elm trees can't be fully determined by appearances. However, they can be fully distinguished solely by appearances. But that distinction wouldn't be enough to determine a reference-relation. The scientific nature of ash and elm trees must also be taken into account. Thus when it comes to the reference-relation to what philosophers call 'natural kinds' and other natural phenomena, the

knowledge of gardeners, botanists, of molecular biologists, and so on, all play a crucial role in helping me refer to [in this instance] a rose, even though I do not possess their knowledge” (333).

Malik backs up his anti-individualistic theory of language and mind by offering an account of reference which owes much to Kripke and Putnam – certainly to Putnam.

Prima facie it may seem that reference is individualistic or internalist. That is, what determines our words is some kind of relation between it (as it is the mind), and that which it refers to or represents. This means that reference isn't only a matter of the individual mind and the object-of-reference.

Malik, instead, offers what can be seen as a scientific account of reference.

Take his example of the “mental representation” of, as he puts it, 'DNA'. (Does Malik mean word here?) The reference-relation between 'DNA' and DNA is not only a question of what goes on in a mind (or in minds). Indeed “your mental representation of DNA (or mine) is insufficient to 'hook on to' DNA as an object in the world” (328). There's not enough meat, as it were, to make a sufficient reference-relation between 'DNA' and DNA in individual minds alone. Instead the scientific nature of DNA determines reference for all of us – even if we don't know the science.

Malik quotes Putnam again here. Reference for 'DNA' is "socially fixed and not determined simply by conditions of the brain of an individual” (329). Of course something that is scientifically fixed is also “socially fixed”. DNA may be a natural phenomenon; though the fixing of reference for 'DNA' to DNA is a social and scientific matter.


Fodor, Jerry. (1975) 'How There Could Be a Private Language and What It Must Be Like', in (1992) The Philosophy of Mind: Classical Problems, Contemporary Issues.
Putnam, Hilary. (1980) ' What Is Innate and Why: Comments on the Debate', in (1992) The Philosophy of Mind: Classical Problems, Contemporary Issues

Wednesday, 20 April 2016

Scraps of Kant (1)

Prolegomena to Any Future Metaphysics (German edition).jpg
The Unexperienced Soul

In a sense, Kant is quite at one with Hume in that he believes that we never actually experience the self; or, in Kant’s terms, the “soul” (or the “substance of our thinking being”). This is because the soul is the mode through which we experience and is not, therefore, an object of experience. Perhaps it would be like a dog trying to catch its own tail. We can, of course, experience the “cognitions” of the soul; though we can’t experience the soul which has the cognitions. Like all other substances, including the substances of objects, the “substantial itself remains unknown” (978). We can, however, prove “the actuality of the soul” through the “appearances of the internal sense”. This is a proof of the soul, however, not an experience of it.

The Antinomies and Experience

What are the “antinomies”? They are subjects of philosophical dispute that have “equally clear, evident, and irresistible proof”(982) on both sides of the argument. That is, a proposition and its negation are both equally believable and acceptable in terms of rational inquiry.

Kant gives an example of such an argument with two equally weighty sides. One is whether or not the world had a beginning or as existed for eternity. The other is whether or not “matter is infinitely divisible or consists of simple parts” (982). What unites these arguments is that none of them can be solved with the help of experience. In a sense, this is an argument of an empiricist. In addition, according to the empiricism of the logical positivists, these arguments would have been considered non-arguments precisely because they can't be settled or solved by experience. As Kant puts it, such “concepts cannot be given in any experience” (982). It follows that such issues are transcendent to us.

Kant goes into further detail about experience-transcendent (or even evidence-transcendent) facts or possibilities. We can't know, through experience, whether or not the “world” (i.e., the universe) is infinite or finite in magnitude. Similarly, infinite time can't “be contained in experience” (983). Kant also talks about the intelligibility of talking about space beyond universal space or time before universal time. If there were a time before time it would not actually be a time “before” time because time is continuous. And if there were a space beyond universal space, it wouldn’t be “beyond” universal space because there can be no space beyond space itself.

Kant also questions the validity of the notion of “empty time”. That is, time without space and objects within space. This is because he thinks that time, space and objects in space are interconnected. Perhaps Kant believed that time wouldn't pass without objects to, as it were, measure the elapsing of time (through disintegration and growth). Similarly, space without time would be nonsensical, on Kant’s cosmology.

The Unperceived Tree in Space and Time

This is very much like Berkeley’s argument.

Thus, when we imagine a tree unperceived, we are, in fact, imagining it as it is perceived; though perceived by some kind of disembodied mind. Or, as Kant puts it, to represent “to ourselves that experience actually exists apart from experience or prior to it” (983). Thus when we imagine the objects of the senses existing in a “self-subsisting” manner, we are, in fact, imagining them as they would be as they are experienced. That isn't surprising because there's no other way to imagine the objects of the senses.

Space and time, on the other hand, are “modes” through which we represent external objects of the senses. As Bertrand Russell put it, we wear spatial and temporal glasses through which we perceive the world. If we take the glasses off, then, quite simply, space and time would simply disappear. They have no actuality apart from our minds. Appearances must be given up to us in the containers we call “space and time”. Space and time are the vehicles of our experiences of the objects of the senses. In a sense, it seems like a pretty banal truism to say that “objects of the senses therefore exist only in experience” because quite evidently there are no experiences without the senses and our senses themselves determine those experiences.

Freedom and Causal Necessity

“…if natural necessity is referred merely to appearances and freedom merely to things in themselves…” [984]

This position unites Kant with Hume, who also thought that necessity is something that we impose on the world. That is, necessity only belongs to appearances, not to things-in-themselves. This could also be deemed a forerunner of the logical positivist idea that necessity is a result (or product) of our conventions, not of the world itself. Of course, just as conventions belong to minds, so too do appearances belong to minds. Freedom, that is independence from causal necessity, is only found in things-in-themselves. That is, the substance of the mind is also a thing in itself; therefore the mind too is free from causal necessitation. The only things that are subject to causal necessitation are the objects of experience. Things-in- themselves (noumena) are free.

Thus Kant manages to solve a very difficult problem: the problem of determinism. That is, “nature and freedom” can exist together. Nature is not free. However, things-in-themselves (including the mind’s substance) are free. The same things can “be attributed to the very same thing”. That is, human beings are beings of experience and also beings-in-themselves. The experiential side of human nature is therefore subject to causal laws; whereas the mind transcends causal necessitation. We are, therefore, partly free and partly unfree.

Kant has a particular way of expressing what he calls “the causality of reason”. Because reason is free, its cognitions and acts of will can be seen as examples of “first beginnings” (986). A single cognition or act of will is a “first cause”. It's not one of the links in a causal chain. If they were links in such a possibly infinite causal chain, then there would be no true freedom. First beginnings guarantee us freedom of the will and self-generated (or self-caused) cognitions. In contemporary literature, such “first beginnings” are called “originations” and what a strange notion it is! What does it mean to say that something just happens ex nihilo? Would such originations therefore be arbitrary or even chaotic – sudden jolts in the dark of our minds? They would be like the quantum fluctuations in which particles suddenly appear out of the void. Why would such things guarantee us freedom rather than make us the victims of chance?

Knowledge of Things-in-Themselves

Kant both says that we can't know anything about things in themselves, yet he also says that “we are not at liberty to abstain entirely from inquiring into them” (989). So which one is it to be? Can we have knowledge of things-in-themselves or not? Perhaps Kant means that although we can indeed inquire into things in themselves, nevertheless it will be a fruitless endeavour. Or perhaps it's the psychological need to inquire because “experience never satisfies reason fully” (989). Alternatively, though our inquiries into things-in-themselves won't give us knowledge, we can still offer, nevertheless, conjectures or suppositions about such things. That is, we can speculate about the true nature of things-in-themselves; though we'll never have knowledge (in the strict sense) of them.

There are questions that will press upon us despite the fact that answers to them may never be forthcoming. Kant, again, gives his earlier examples of evidence- or experience-transcendent issues such as “the duration and magnitude of the world, of freedom or of natural necessity” (989). However, experience lets us down on these issues. Reason shows us, according to Kant, “the insufficiency of all physical modes of explanation” (989). Can reason truly offer us more?
Again, Kant tells us that we can't be satisfied by the appearances. The

chain of appearances…has…no subsistence by itself…and consequently must point to that which contains the basis of these appearances”. [990].

Of course it's reason itself which will “hope to satisfy its desire for completeness” (990). However, it's not clear whether or not reason can satisfy our yearnings by given us knowledge of things-in-themselves. Yet “we can never cognise these beings of understanding” but “must assume them”. It is reason that “connects them” (991) with the sensible world (and vice versa). It must follow, therefore, that although “we can never cognise these beings of understanding” there must be some alternative way of understanding them. Which way is that?

*) All the notes above are readings of Kant's Prolegomena to Any Future Metaphysics.

Tuesday, 22 March 2016

A Challenge to Materialism in the Philosophy of Mind


Certain positions in contemporary physics provide anti-materialists (in the philosophy of mind) with grist for their mill. For example, are there non-physical objects that are quite acceptable to contemporary physicists? Jeffrey Poland thinks that there are. He writes:

It should be understood that the primacy of physics in ontological matters does not mean that everything is an element of a strictly physical ontology… physicalism… allows for non-physical objects, properties, and relations… physicalism should not be equated with the identity theory in any of its forms… I prefer the idea of a hierarchically structured system of objects grounded in a physical basis by a relation of realization…” [813]

All the above is quite acceptable, even on a physicalist picture of the world. However, does any of the above help in the mind-body problem or does it somehow justify attacks on materialism?

For a start, the non-physicality of (abstract) objects, properties and relations aren't of the same logical order as the ostensible non-physicality of mind or consciousness. The above can be seen as abstract objects, properties or abstract relations. We surely can't say that mind or consciousness is abstract in nature. Sure, they're non-spatial, and perhaps non-temporal; though does this make them equivalent to abstract objects like propositions, universals, etc.? Even Quine (an arch-naturalist and physicalist) accepted the existence of numbers. And if anything is an abstract object, a number is!

Thus I think that Poland has actually set up a disanalogy between the abstract objects, properties and relations accepted in physicalist philosophy and the putatively abstract nature of mind or consciousness.

The passage above finishes off with a statement of Poland's belief that he prefers the “idea of a hierarchically structured system of objects grounded in a physical basis by a relation of realization”. This too is acceptable to most philosophers of the physicalist kind. Perhaps, more importantly, it's acceptable to scientists because there is a way in which (like mentality) we can see meteorology, biology, anthropology, palaeontology, geology, anatomy, etc. as ‘higher-level’ sciences – or at least sciences which study higher-level phenomena. How does this concern the scientific question of consciousness or mentality? John Heil writes:

If you threw out “higher-level” mental states or properties solely on the grounds that they depend in a mysterious way on lower-level material phenomena, you would have to toss out all the special sciences as well. [813]

Yes, the sciences mentioned above do grow out of physics, as, for example, chemistry does and biology grows out of chemistry to a large extent: though does consciousness or mentality really grow out of the physical in the same - or even in a similar - way to all these acceptable scientific examples? Are these higher-level states and properties of the special sciences ‘emergent’ states and properties in the way that the states and properties of mentality can be seen as emergent or, at least, ‘supervenient’? Surely the parallel is far from exact.

Saturday, 19 March 2016

John Heil on the Mind-Body Problem

John Heil | Proceedings of the Aristotelian Society | Philosophy in London Since 1880

Colin McGinn is known for arguing that the problem of consciousness may well be insoluble in principle. He once wrote the following:

It could turn out that the human mind is constitutionally unable to understand itself.” [756]

We can ask how McGinn (or anyone else for that matter) could know that. Perhaps he's arguing that it could be the case that we are constitutionally incapable of understanding mind and consciousness: not that we actually are.

Take this case. If mind-brains are ‘formal systems’, it may be the case that they could not have complete knowledge of themselves. Heil writes:

Gödel showed us that formal systems rich enough to generate the truths of elementary arithmetic were, if consistent, in principle incomplete. (A system is incomplete if there are truths expressible in and implied by the system that cannot be proven true in the system.) The incompleteness of mathematics reflects an established fact about the make-up of formal systems generally. Now, imagine that we finite human beings are, as we surely are, constitutionally limited as to the kinds of thought we could entertain. Imagine, further, that our cognitive limitations were such that we could not so much as entertain the deep truth about our own minds.” [756]

Intuitively, the idea that we are constitutionally and cognitively limited in many, or some, ways is easy to accept. And if we accept this, then McGinn’s arguments seem acceptable, if not palatable. But are mind-brains formal systems? Is it right to compare the mind to an arithmetical formal system, as Heil does? (The argument is similar to the ‘what-is-it-like-to-be-a-bat/an x’ argument. In that case, we're constitutionally unable to imagine what it is like to be a bat (e.g., to have its sonar abilities).)

It is indeed quite wrong to simply assume that the ‘deep truth’ or truths of mind will some day be available to us (as many scientists may imagine). Heil writes:

“Indeed, we should be hard put to establish in advance that the deep truth about anything at all – including the material world – is cognitively available to us. To think that it must be is to exhibit an unwarranted degree of confidence in our finite capacities, what the ancients called hubris.” [756]

Doesn’t the (C.S.) Peircian notion of the “scientific convergence on the truth” assume that, at some point in the future, we will know everything about both the mind and the world? Don’t many scientists daily display such an example of scientific hubris? However, on the other side of the argument, deep pessimism may also be unwarranted. Heil writes:

“… we cannot positively prove that we are cut off from a deep understanding of mental phenomena.” [756]

Just as many scientists and philosophers display positivism on this issue, so many philosophers, such as McGinn, Nagel, etc. display a deep pessimism which is often disguised under the clothing of modesty or humility. Perhaps the problem of consciousness is not one of insolubilia; but one of incompletability.



Tuesday, 23 February 2016

Consciousness: Sapience & Sentience

David Chalmers makes a terminological distinction between sentience and sapience:

       sentience = phenomenal consciousness
       sapience = psychological consciousness

What does this distinction amount to?

For a start, a conscious creature “senses and feels”. That is, it is sentient. This is Chalmers ‘hard problem’:

Chalmers points out that psychology and neuroscience have made significant progress toward increasing our understanding of sapience – psychological consciousness… In contrast, we seem to have made little or no progress in understanding sentience. What understanding we do have consists mainly in the discovery of brute correlation between conscious episodes and neurological events. The identification of correlation represents at most a starting point for explanation, however, not a settled goal. Unlike the case of sapience, where it is reasonable to expect incremental progress, it is hard to see what we could do to move ahead in our understanding of the basis of consciousness.” - John Heil

One way we can appreciate our progress with sapience is with the fantastic growth of the cognitive sciences (as well as cognitive psychology). The language of thought hypothesis (LOT) is also an example of this; along with neuro-computationalism and connectionism. All are concerned with sapience – or psychological consciousness. But what about sentience? Where are the research projects in sentience? Could there even be such things as research projects in sentience?

Chalmers is correct to argue that the discovery of brute correlations (or connections) between conscious states and physical states is only the beginning of the story – or, at the least, a different story to the story of sentience altogether. Chalmers last point is very telling, if not overtly pessimistic. He writes that

it is hard to see what we could do to move ahead in our understanding of the basis of consciousness”.

Perhaps this word ‘basis’ is incorrectly used here. We do indeed partly know the basis of consciousness. What we don’t know is the why-of-consciousness. What we can't explain is why a conscious state should arise out of such a physical basis in the brain. The correlates are known; though not why they are correlated.

Some philosophers seem to offer a way out of this impasse that is, quite frankly, little more than a cop-out. In general terms, they “hope that sentience [will be] reducible to sapience” [601]. Surely this couldn’t be the case.

This is the position on offer:

"… all there is to being conscious is acting and interacting intelligently in a complex environment (see e.g. Dennet 1991)."

Acting thus and so is to be conscious. What of feelings and other sensuous states? These are species of sapient state. Functionalists, for instance, may hold that, to be in pain is to be in a state with the right sorts of cause and effect. Pains are caused by tissue damage and result in aversive behaviour (including the formation of various beliefs and desires).

This is indeed a reductive explanation of consciousness. It seems, to me, to be obviously false and even disingenuous in nature. How could anyone really believe that consciousness is our acting and interacting in a complex environment? How could anyone believe that acting thus and so is to be conscious? No. Consciousness comes along with interacting intelligently. Consciousness comes along with functional roles as well. Pain, on the functionalist picture, is indeed caused by tissue damage. And it's true that pain results in the right sorts of aversive behaviour (including the formation of various beliefs and desires about pain and ways of escaping pain). But all these causes and effects are accompanied by consciousness. They aren't examples of consciousness. They may even be the necessary accompaniments of consciousness; though they aren't sufficient for it. It's is incredible, again, that any philosophy could uphold these reductive (or functionalist) explanations of consciousness. And yet they do!

Friday, 19 February 2016

Frank Jackson’s ‘Epiphenomenal Qualia’ (1982)

Firstly, Frank Jackson introduces us to the case of Fred. Fred can see two colours in a given areas; whereas we can see only one. The problem is that he's unsuccessful when it comes to teaching the rest of us the difference between red1 and red2. We can't make the distinction. Fred, therefore, concludes that “the rest of the world is red1 – red2 colour-blind”. The point is that Fred has a different phenomenal experience than the rest of us. He has the “ability” to distinguish two shades of red which we can't distinguish. We can, initially, accept this hypothesis. Jackson concludes that it won't help us to understand the difference between red1 and red2 even if we were to know everything there is to know, physically, about both red1 and red2. There must therefore be a phenomenal gap between the physical and either red1 or red2 (perhaps both). Either one or both must run free (as it were) of any physical underpinning. Despite all that, researchers do find a physical explanation as to why Fred can distinguish between red1 and red2. In this hypothetical situation we

find out that Fred’s cones respond differentially to certain light waves in the red section of the spectrum that make no difference to ours (or perhaps he has an extra cone) and that this leads in Fred to a wider range of those brain states responsible for visual discriminatory behaviour”. [1982]
Yes, you guessed it, this imaginary state of physical affairs doesn't have the slightest impact on Jackson’s argument. It's indeed the case that red2 has it own physical underpinning. It is the case that we have full physical knowledge as to why Fred can distinguish between red1 and red2.; though we still can't distinguish red1 from red2. We still can't read-off the extra colour from the new physical information we've acquired of Fred’s brain, eyes, etc. And nor can we infer or deduce what red2 is like from these physical facts. There's still a gap between our knowledge of the physical and our knowledge (or lack of knowledge) of the phenomenal (i.e., if we can call phenomenal knowledge, knowledge at all).

The Modal Argument

Jackson then brings on board a modal argument; as well as giving attention to the possibility of zombies. In fact the zombie-possibility starts of with a logical argument - or at least a statement about the limits of logical entailment.

Mary may well have all the physical information about red or about red’s physical underpinnings. Similarly, we may have all the physical information about what seems to be another person. Jackson argues that no
“amount of physical information about another logically entails that he or she is conscious or feels anything at all”.
This is an incredible conclusion. It's not only about the possibility of zombies: it also applies to all our fellow human beings. Perhaps it's a new take on the “problem of other minds” in that Jackson argues that a complete physical picture won't tell us whether or not another being is conscious or feels anything at all. As with other-minds arguments, we infer, perhaps inductively, that other people have minds and feel pain because of their behaviour and what they say. Though, again, we can't say that behaviour alone logically entails consciousness or pain. However, we have good reasons to believe that others do suffer pain, etc. (though that’s another story). In the case of zombies, we can say that a zombie is physically and behaviourally identical to us, yet he won't be conscious and he won't feel pain. More technically, he may have the same “functional states” too. Jackson concludes this by asking a very telling and simple question:

“But then what is it that we have and they lack?”
Of course he answers his own question thus:

Not anything physical…”
Jackson concludes from his self-questioning that “[c]onsequently there is more to us than the purely physical. Thus Physicalism is false.”

As it stands, this seems to beg the question that the phenomenal, by definition, must be non-physical. Many philosophers reject this. Indeed, according to certain physicalists (such as Lewis), they do think that the phenomenal is something over and above the physical – or, at the least, above the physical as we currently describe it. (The point is that we can't have new knowledge of an experience of red, etc.) Jackson tells us that certain philosophers

sincerely deny that there cannot be physical replicas of us in other possible worlds which nevertheless lack consciousness”.


Perhaps we can say here that such beings couldn't exist according to the physical laws of our world. Aren’t philosophers usually talking to us about the possibility of zombies in our world? Or, at the least, about zombies at a possible world which nevertheless still shares our laws of nature? However, isn’t it logically possible that zombies could exist not only at other possible worlds but also in our own? Is this scenario metaphysically possible? (It depends on what metaphysical possibility actually is.)

What is it Like?

T. Nagel offered us something very special to this general debate when he published his paper, ‘What is it like to be a Bat?’ Very generally, S can't tell us what it is like “from a bat’s point of view”. The bat’s point of view is “not our point of view” [443]. In addition, the bat’s point of view

“is not something captureable in physical terms which are essentially terms understandable equally from many points of view”

All this is pretty much incontestable.

David Hume, according to Jackson, offered an argument that goes against the general position (at this time). Hume argued that “from knowledge of some shades of blue we can work out what it would be like to see other shades of blue”. That is, did Hume think that we could deduce or infer what a new shade of blue is like simply by studying the physical basis of the given shades of blue? Or did Hume mean that we could work out a new shade of blue from the shades of blue we've already seen, not from the physical substructure of our known shades of blue? These two claims are quite different. For example, we could work out the physical substructure of another shade of blue by examining it. But we still couldn't imagine another shade of blue. As for inferring another shade of blue simply from our previous experiences of known shades of blue; this is equally contestable and probably untrue. Indeed both hypotheses seem untrue, at least prima facie. At the phenomenal level, only, we couldn't do so, according to Nagel (if not Jackson), because bats, for one, are simply “too unlike us”.

The Bogey of Epiphenomenalism

Jackson now introduces epiphenomenalism into the debate.
What is epiphenomenalism? Well, for a start, epiphenomenalists don't deny qualia. However, they do “countenance the idea that qualia are causally impotent with respect to the physical world”. They don't necessarily deny that there are qualia. They believe, or some of them do, that it's “possible to hold that certain properties of certain mental states” can indeed be seen as qualia. However, “their possession or absence makes no difference to the physical world”. They are ‘causally impotent’.

Perhaps, however, an epiphenomenalist can accept that the “instantiation of qualia makes a difference to other mental states though not to anything physical”. One can immediately ask here whether or not it's coherent to deny qualia causal efficacy at the same time as allowing that they may well make a difference to other mental states (regardless of their effect on anything purely physical).

There are good reasons for holding that qualia are indeed causally efficacious. For example, “a quale like the hurtfulness of pain must be causally efficacious in the physical world”. A pain is a phenomenal process that can cause us, for example, to remove our hand from the fire. This is a causal relation or link between phenomenal pain and the physical movement of a hand. Surely this causal link is real. However, there's a Humean argument against believing this which makes use of a general position taken from Hume’s well-known stance on causality. Jackson writes:
"No matter how often B follows A, and no matter how initially obvious the causality of the connection seems, the hypothesis that A causes B can be overturned by an overarching theory which shows the two as distinct effects of a common underlying causal process.”
We can rewrite the passage above by making it germane to our current debate. Thus:

No matter how often the removing of one’s hands follows the hand’s experience of intense heat, and no matter how initially obvious the causality of the connection seems, the hypothesis that the intense heat causes the removal of the hand can be overturned by an overarching theory which shows the two as distinct effects of a common underlying causal process.
In that case, what would that common underlying causal process actually be? Why augment entities at all by positing yet another causal process to account for the feeling of heat and the removal of the hand? The epiphenomenalist argument would of course be that instead of the feeling of intense being itself a physical cause of the moving of the hand, there would be a causal process which subserves the feeling of intense heat. It would be that underlying cause that prompts the sudden movement of the hand. The feeling of pain, or the quale, simply “rides on the top” of this so far undiscovered underlying causal process.

So why the quale or the feeling at all? What point does it serve? Why not simply do without it? Why not give a fully physical and behaviourist account of what happens? And if there is such an account, then what point is pain from an evolutionary point of view? Jackson alights on this last point. He asks:

We may assume that qualia evolved over time… and so we should expect qualia to be conducive to survival. The objection is that they could hardly help us to survive if they do nothing to the physical world.”
The assumption here is that everything about the human body and mind has its evolutionary value in the precise sense that it helps us survive in some shape or form. This is wrong, according to Darwinians.

Take the well-known case of a coat being both warm and heavy, which Jackson cites. A warm coat was clearly once conducive to survival for all kinds of animal (including man). The problem is that warm coats are also heavy coats. The coat’s heaviness was not conducive to survival (for obvious reasons). However, this example of both pro and con is adequately explained by evolutionists, and indeed by Jackson. He writes:

Having a heavy coat is an unavoidable concomitant of having a warm coat… and the advantages for survival of having a warm coat outweighed the disadvantages of having a heavy one.”
What has this to do with the qualia debate? The epiphenomenalist argues that qualia “are a by-product of certain brain processes that are highly conducive to survival”.

As is often the case in many debates in the philosophy of mind, the problem of other minds also raises its head. In terms of qualia, we can ask the following question:

… how can a person’s behaviour provide any reason for believing he has qualia like mine, or indeed any qualia at all, unless this behaviour can be regarded as the outcome of the qualia.”
Clearly another person’s physical behaviour doesn't point directly, or even indirectly, to the existence of qualia (like or unlike our own). So what's the point of qualia? Even if that question was answered a moment ago, can’t we still see this lack of behavioural evidence for qualia, as well as their very existence, as pointing us to the conclusion that behaviour must indeed be the outcome of qualia? Clearly an epiphenomenalist can't accept this conclusion.

Jackson then reiterates the basic epiphenomenalist position on qualia. He writes:
“Now the epiphenomenalist allows that qualia are effects of what goes on in the brain. Qualia cause nothing physical but are caused by something physical.”
We know this position by now. However, the epiphenomenalist can still give a physical or behaviourist account of qualia. He does so in the following way:

Hence the epiphenomenalist can argue from the behaviour of others to the qualia of others by arguing from the behaviour of others back to its causes in the brains of others and out again to their qualia.”
The epiphenomenalist has already accepted qualia and he gives a physical account of them. Thus if the epiphenomenalist accepts that he indeed has qualia, he must make sense of this in terms of the behaviour of other people. If other people behave like him, and he admits to his own qualia, then he can happily accept that because others behave like him, then they (probably?) also have their own qualia. And because he has already argued that qualia are caused by the brain, the brains of other people must cause their qualia as well. Thus qualia are given a physical or behaviourist explanation, even if qualia are still seen as being inefficacious physically.

Many, if not all, epiphenomenalists argue that the supposed causal impotence of qualia is a godsend for die-hard (neo) dualists. They merely “sooth” their “intuitions”. The fact remains, however, that they are an ‘excrescence’:

They do nothing, they explain nothing…”
At least they do nothing and explain nothing if one accepts the general epiphenomenalist position, which many philosophers of mind – sometimes vocally – don't!

We talked earlier about the relevance of evolutionary theory on the qualia debate. What about an evolutionary account of our knowledge, or lack thereof, with regards to the reality of qualia? Perhaps our lack of knowledge about qualia can also be explained in evolutionary terms. Jackson states that

it is very likely that there is a part of the whole scheme of things, maybe a big part, which no amount of evolution will ever bring us near to knowledge about or understanding of”.
Perhaps the simple reason for this is that “such knowledge and understanding is irrelevant to survival”. This may account for this epistemological dearth on our part. Similarly, it has been argued, by, for example, Donald Davidson, that certain false beliefs are quite helpful for survival in certain contexts! In addition, Jackson’s position is a little like Colin McGinn’s position in that he talks in terms of “cognitive closure”. That is, we are (or we may be) cognitively incapable of acquiring a complete knowledge of consciousness (or qualia). Perhaps McGinn’s position can also be given an evolutionary explanation. 


Jackson, Frank. (1982) 'Epiphenomenal Qualia'.
-- (1986) 'What Mary Didn't Know'.
McGinn, Colin. (1989) 'Can We Solve the Mind-Body Problem?'