Philosophers Index Abstract
This paper is a defense of qualia freakery. The author advances what he calls the knowledge argument to show that physicalism leaves qualia out of account. He then contrasts the knowledge argument with what he calls the modal1 argument and the 'what-is-it-like-to-be' argument. Finally he discusses whether qualia are causally efficacious, and argues that it is at least a possible view that they are not.
Write-up2 (as at 10/04/2017 23:38:24): Jackson - Epiphenomenal Qualia
This note3 provides my detailed review of "Jackson (Frank) - Epiphenomenal Qualia".
Frank Jackson – Epiphenomenal Qualia: Summary & Aims
- The aim of Jackson’s paper is to overthrow the doctrine of physicalism, and to show that the best argument against it is the knowledge argument rather than the modal or what it is like arguments.
- Worries about qualia having causal powers are allayed by espousing epiphenomenalism.
- Much physical information of the physical, chemical and biological kinds is provided by the natural sciences. For example medical science may tell us much about the central nervous system and how processes going on in it relate to the happenings in the world around, past and future and to other organisms, leading to an understanding of the functional role of these processes.
- There are problems giving a precise definition of the notions of physical information, processes and property and therefore of the thesis of Physicalism; that all correct information is physical information.
- Jackson is a qualia freak. He thinks that no amount of physical information can include certain features of bodily sensations and perceptual experiences. Whatever I know about the physical brain, its states and their functional roles and relations, is not enough to tell me anything about the itchiness of itches or the experience of smelling a rose, etc.
- Some qualia freaks say the rejection of physicalism is just an unargued intuition, but this is inadequate, for there are knock-down arguments available. Nothing of a physical sort captures the smell of a rose, so physicalism is false. The argument is perfectly good, though not logically valid, and the premise is intuitively obvious.
- However, such an argument is polemically weak because not everyone does find the premise intuitively obvious. We need to find an argument with premises obvious to as many as possible. Jackson thinks the Knowledge argument is the best bet, in contrast to the Modal and What is it like to be? arguments. The major objection to the existence of qualia is the supposed causal role they would have, but Jackson thinks that the view that qualia are epiphenomenal is adequate.
- The Knowledge Argument for Qualia
- Jackson starts with an example of exceptional colour discrimination – Fred can finely distinguish things of different colours, demonstrated by his objective ability to sort red tomatoes repeatedly and identically into two groups.
- He sees two colours, red1 and red2, where we see one. He cannot teach this discrimination, which he takes to be red1 / red2 colour-blindness in the rest of us. Physiological investigation shows that Fred’s optical system can distinguish two groups of wavelengths in the red spectrum as well as we can distinguish yellow and blue.
- We must admit that Fred can really see one more colour than the rest of us. To resist this view is to be like those in H G Wells’ The Country of the Blind where the faculty of sight on the part of those who could see was ridiculed and the advantages conferred by sightedness (not falling into ditches, for instance) being put down just to those special skills themselves.
- We do not know what kind of experience Fred has when he sees red1 and red2, and no amount of physical information about Fred’s brain or optical system can tell us. Information about cones tells us nothing about his colour experience. Because, despite knowing all the physical information, including knowledge of Fred’s body, behaviour, dispositions, physiology and history, we still don’t know everything about Fred, physicalism leaves something out.
- This point is emphasised by considering that, even were we able to make everyone (or by transplantation, one particular person) see like Fred, then this would only go to show that beforehand there was something about Fred we didn’t know (because we came to know it).
- Beforehand, we had all the physical information about Fred, but after the operation, there is more we know about Fred’s visual experience, so physicalism must be incomplete.
- Jackson gives another example – Mary, the brilliant scientist, has normal colour vision, but is forced to investigate the world from a black and white room via a black and white television. She’s a specialist in the neurophysiology of vision, and knows what wavelengths of light cause us to use which colour-words, including all the mechanical workings that cause us actually to utter these words.
- However, when Mary is freed from her room, she will learn something more about the world and our experience of it. Prior thereto, despite all the physical evidence, she did not have all the knowledge, so physicalism is false.
- Similarly for other senses and for mental states with phenomenal features or qualia. So, qualia are left out. The polemical strength of the knowledge argument is that it is hard to deny the claim that we can have all the physical information without having all the information there is to be had.
- The Modal Argument
- This argument is that no amount of physical information logically entails that a person feels anything. So, there is a possible world in which they don’t, and no-one has any conscious mental life, though everything is physically the same. The difference cannot ex hypothesi be a physical one, so there is more to us than the merely physical and physicalism is false.
- While not preferring this argument, Jackson rejects one objection to it – that the physicalist only claims that physicalism is contingently true, in particular in our world. Be this as it may, if we in our world have additional features to physically identical replicas in other worlds, then we have non-physical features or qualia and the argument goes through.
- The problem with the modal argument is that it depends on a disputable, because disputed, modal intuition. We can dispute whether physically identical beings could lack consciousness.
- Our modal intuitions may arise from our rejection of physicalism on other grounds, eg. the Knowledge argument, so cannot form grounds for a conclusion that physicalism leaves something out. We might also draw a parallel with the argument that any two identical worlds would agree on aesthetic qualities, without aesthetic qualities being reducible to the natural.
- The “What is it like to be” Argument
- According to Thomas Nagel, no amount of physical information can tell us what it’s like to be a bat, because this can only be known from the bat’s perspective, which is not ours. Because something understandable in purely physical terms ought to be understandable from any perspective, the bat’s perspective cannot be captured in physical terms.
- Jackson points out an important difference between this argument and the Knowledge argument. The crux of the latter is not that we don’t know what it’s like to be Fred, but only that there’s something about his experience – a property of it – that we were ignorant of. Even were we to be able to distinguish between red1 and red2, we still wouldn’t know what it’s like to be Fred. We are not Fred, and no amount of knowledge, physical or otherwise, about Fred will help us to know Fred from the inside.
- When Fred sees red1 he knows two things; firstly, that he sees it as distinct from red2 ; secondly that he himself is seeing it. Physicalists no more than qualia freaks would suppose that knowledge of any sort that others have about Fred supplies knowledge of the second kind. Jackson’s argument is based on the first form of absent knowledge.
- According to Nagel, while we might be able to extrapolate for human beings from one shade of blue to another, the gulf between humans and bats is too great. However, Jackson sees no problem for physicalism here, which need make no claims about the imaginative powers of human beings.
- The reason the Knowledge argument goes through, according to Jackson, is that it makes no assumptions about our imaginative powers, which would be unnecessary if physicalism gave us all the knowledge we need.
- The Bogey of Epiphenomenalism
- Frank Jackson argues that there are no good reasons for rejecting the causal impotence of qualia. However, he does not address two other typical epiphenominalist views.
- That mental states have no causal effects. All he wants to argue is that some properties of some mental states make no difference to the physical world.
- That the mental is totally causally inefficacious. He thinks that qualia may affect other mental states even though they affect nothing physical, and that our awareness of qualia demands this.
- There are three standard reasons put forward for why qualia like the hurtfulness of a pain must sometimes make a difference to the physical brain or have other causal effects on the physical world.
- Obvious Consequences: It is taken as obvious that it is the hurtfulness of pain that is at least partly responsible for us avoiding it, or complaining that it hurts. Response: the constant conjunction of A and B may not be that A causes B, but that both A and B have a common cause. Certain happenings in the brain cause both behaviour and the feeling of hurt, just as the film director’s skilful use of film in a fight scene gives the illusion that a flying fist causes a head to shoot back, when it’s the case that his direction is the common cause of both.
- Evolutionary Origins: Qualia could only have evolved if they were useful for survival, which would not be the case if they have no impact on the physical world. Response: evolved characteristics have either to be conducive for survival or a by-product of such a quality. Polar bears evolved heavy coats that slow them down as a by-product of them evolving warm coats. Qualia are by-products of brain processes that are conducive to survival.
- Knowledge of Other Minds: how we know about other minds is controversial, but what is agreed on is that it depends at least in part on inference from behaviour. So, how can observation give reason to believe that other people have qualia unless, contra the epiphenominalist, their behaviour is thought of as the outcome of the qualia? How can I infer Man Friday’s existence from a footprint if I deny that footprints arise from feet? Response: similar to (i). Reading the result of a football match in paper A is good reason for me to expect to read about it in paper B, not because paper B gets its information from paper A, but because they both get their information directly by sending reporters to the match. So, A & B have a common cause, rather than A causing B. The epiphenominalist can similarly argue that qualia, though they have no physical effects, are caused by the same physical thing, namely brain workings, as behaviour. So he can argue back from others’ behaviour to others’ brain workings and out again to others’ qualia. While there may be problems with this analogy, things are no worse for epiphenominalism that for other theories of mind such as Interactionism. The problem of other minds is a major philosophical problem.
- There is a natural response to these responses that, while there is no knock-down response to epiphenominalism, it still leaves qualia as an excrescence that do and explain nothing and whose place in the worldview of science is a mystery.
- Jackson’s response to this view is that, while true, it rests on an over-optimistic expectation of the capacities of the human intellect. The understanding is formed by evolution, and since qualia have no physical consequences they can have no survival value. Consequently, there has been no way for evolution to get a purchase on qualia and give a selective advantage to those who can understand them over those who can’t. Hence, minds capable of understanding qualia have not evolved.
- Evolution is a matter of chance constrained by preservation or increase of survival value. It is not surprising that there are some things outside our comprehension – maybe qualia being such. Rather, it is surprising that we can understand as much as we can.
- Jackson ends with an analogy. There might be supposed to be beings that have evolved in more restricted or more expansive environments than us, the former denying the existence of things known to us and the latter knowing more. The tough-minded “intelligent sea-slugs” may deny the existence of some things known to us (as tough-minded philosophers of mind deny qualia) on the grounds that no sea-slug can explain how these things fit into the successful sea-slug science. From our perspective, we can see what the sea-slugs can’t and we can suppose super-beings whose perspective may allow them to understand things we can’t.
- This is the write-up as it was when this Abstract was last output, with text as at the timestamp indicated (10/04/2017 23:38:24).
- Link to Latest Write-Up Note.
- Originally, this write-up was only available as a PDF, see File Note (PDF).
- It has now been converted to Note format.
- I’m not sure when I wrote the original version – here reproduced; presumably in 2002 or thereabouts.
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