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In
philosophy and certain models of
psychology,
qualia (
or
; singular form:
quale) are defined to be individual instances of
subjective,
conscious experience. The term
qualia derives from the
Latin neuter plural form (
qualia) of the Latin adjective
quālis (
Latin pronunciation: [ˈkʷaːlɪs])
meaning "of what sort" or "of what kind" in a specific instance like
"what it is like to taste a specific orange, this particular orange
now".
Examples of qualia include the perceived sensation of
pain of a headache, the
taste of wine, as well as the
redness of an evening sky. As qualitative characters of sensation, qualia stand in contrast to "
propositional attitudes",
[1] where the focus is on beliefs about experience rather than what it is directly like to be experiencing.
Philosopher and
cognitive scientist Daniel Dennett once suggested that
qualia was "an unfamiliar term for something that could not be more familiar to each of us: the ways things seem to us".
[2]
Much of the debate over their importance hinges on the definition of
the term, and various philosophers emphasize or deny the existence of
certain features of qualia. Consequently, the nature and existence of
various definitions of qualia remains controversial due to qualia not
being a pragmatically verifiable matter.
Definitions
Saturated colors are a commonly used example of a quale.
There are many definitions of qualia, which have changed over time.
One of the simpler, broader definitions is: "The 'what it is like'
character of mental states. The way it feels to have mental states such
as pain, seeing red, smelling a rose, etc."
[3]
Clarence Irving Lewis, in his book
Mind and the World Order (1929), was the first to use the term "qualia" in its generally agreed upon modern sense.
There are recognizable qualitative characters of the given, which may
be repeated in different experiences, and are thus a sort of
universals; I call these "qualia." But although such qualia are
universals, in the sense of being recognized from one to another
experience, they must be distinguished from the properties of objects.
Confusion of these two is characteristic of many historical conceptions,
as well as of current essence-theories. The quale is directly intuited,
given, and is not the subject of any possible error because it is
purely subjective.[citation needed]
Frank Jackson
(1982) later defined qualia as "...certain features of the bodily
sensations especially, but also of certain perceptual experiences, which
no amount of purely physical information includes" (p. 273).
[page needed]
Daniel Dennett identifies four properties that are commonly ascribed to qualia.
[4] According to these, qualia are:
- ineffable; that is, they cannot be communicated, or apprehended by any other means than direct experience.
- intrinsic; that is, they are non-relational properties, which do not change depending on the experience's relation to other things.
- private; that is, all interpersonal comparisons of qualia are systematically impossible.
- directly or immediately apprehensible in consciousness; that is, to experience a quale is to know one experiences a quale, and to know all there is to know about that quale.
If qualia of this sort exist, then a normally sighted person who sees red would be unable to describe the experience of this
perception
in such a way that a listener who has never experienced color will be
able to know everything there is to know about that experience. Though
it is possible to make an
analogy,
such as "red looks hot", or to provide a description of the conditions
under which the experience occurs, such as "it's the color you see when
light of 700-
nm
wavelength is directed at you", supporters of this kind of qualia
contend that such a description is incapable of providing a complete
description of the experience.
[citation needed]
Another way of defining qualia is as "raw feels". A
raw feel
is a perception in and of itself, considered entirely in isolation from
any effect it might have on behavior and behavioral disposition. In
contrast, a
cooked feel is that perception seen as existing in
terms of its effects. For example, the perception of the taste of wine
is an ineffable, raw feel, while the experience of warmth or bitterness
caused by that taste of wine would be a cooked feel. Cooked feels are
not qualia.
[citation needed]
According to an
argument put forth by
Saul Kripke
in his paper "Identity and Necessity" (1971), one key consequence of
the claim that such things as raw feels can be meaningfully
discussed—that qualia exist—is that it leads to the logical possibility
of two entities exhibiting identical behavior in all ways despite one of
them entirely lacking qualia. While very few ever claim that such an
entity, called a
philosophical zombie, actually exists, the mere possibility is claimed to be sufficient to refute
physicalism.
[citation needed]
Arguments for the existence
Since it is by definition impossible to convey qualia verbally, it is
also impossible to demonstrate them directly in an argument; so a more
tangential approach is needed. Arguments for qualia generally come in
the form of
thought experiments designed to lead one to the conclusion that qualia exist.
[citation needed]
"What's it like to be?" argument
Although it does not actually mention the word "qualia",
Thomas Nagel's paper "
What Is it Like to Be a Bat?"
[5]
is often cited in debates over qualia. Nagel argues that consciousness
has an essentially subjective character, a what-it-is-like aspect. He
states that "an organism has conscious mental states if and only if
there is something that it is like to
be that organism—something it is like
for the organism."
[6] Nagel also suggests that the subjective aspect of the mind may not ever be sufficiently accounted for by the
objective methods of
reductionistic
science. He claims that "if we acknowledge that a physical theory of
mind must account for the subjective character of experience, we must
admit that no presently available conception gives us a clue about how
this could be done."
[7]
Furthermore, he states that "it seems unlikely that any physical theory
of mind can be contemplated until more thought has been given to the
general problem of subjective and objective."
[7]
Inverted spectrum argument
The inverted spectrum thought experiment, originally developed by
John Locke,
[8]
invites us to imagine that we wake up one morning and find that for
some unknown reason all the colors in the world have been inverted.
Furthermore, we discover that no physical changes have occurred in our
brains or bodies that would explain this phenomenon. Supporters of the
existence of qualia argue that since we can imagine this happening
without contradiction, it follows that we are imagining a change in a
property that determines the way things look to us, but that has no
physical basis.
[9][10] In more detail:
- Metaphysical identity holds of necessity.
- If something is possibly false, it is not necessary.
- It is conceivable that qualia could have a different relationship to physical brain-states.
- If it is conceivable, then it is possible.
- Since it is possible for qualia to have a different relationship
with physical brain-states, they cannot be identical to brain states (by
1).
- Therefore, qualia are non-physical.
The argument thus claims that if we find the inverted spectrum
plausible, we must admit that qualia exist (and are non-physical). Some
philosophers find it absurd that an armchair argument can prove
something to exist, and the detailed argument does involve a lot of
assumptions about conceivability and possibility, which are open to
criticism. Perhaps it is not possible for a given brain state to produce
anything other than a given quale in our universe, and that is all that
matters.
The idea that an inverted spectrum would be undetectable in practice
is also open to criticism on more scientific grounds (see main article).
[9][10] There is an actual experiment—albeit somewhat obscure—that parallels the inverted spectrum argument.
George M. Stratton, professor of
psychology
at the University of California, Berkeley, performed an experiment in
which he wore special prism glasses that caused the external world to
appear upside down.
[11][12]
After a few days of continually wearing the glasses, an adaptation
occurred and the external world appeared righted. When the glasses were
removed, the external world again appeared inverted. After a similar
period, perception of the external world returned to the "normal"
perceptual state. If this argument provides indicia that qualia exist,
it does not necessarily follow that they must be non-physical, because
that distinction should be considered a separate epistemological issue.
Zombie argument
A similar argument holds that it is conceivable (or not
inconceivable) that there could be physical duplicates of people, called
"
philosophical zombies",
without any qualia at all. These "zombies" would demonstrate outward
behavior precisely similar to that of a normal human, but would not have
a subjective phenomenology. It is worth noting that a necessary
condition for the possibility of philosophical zombies is that there be
no specific part or parts of the brain that directly give rise to
qualia—the zombie can only exist if subjective consciousness is causally
separate from the physical brain.
[citation needed]
Explanatory gap argument
Joseph Levine's paper
Conceivability, Identity, and the Explanatory Gap
takes up where the criticisms of conceivability arguments, such as the
inverted spectrum argument and the zombie argument, leave off. Levine
agrees that conceivability is flawed as a means of establishing
metaphysical realities, but points out that even if we come to the
metaphysical conclusion that qualia are physical, there is still an
explanatory problem.
While I think this materialist response is right in the end, it does
not suffice to put the mind-body problem to rest. Even if conceivability
considerations do not establish that the mind is in fact distinct from
the body, or that mental properties are metaphysically irreducible to
physical properties, still they do demonstrate that we lack an
explanation of the mental in terms of the physical.
However, such an
epistemological
or explanatory problem might indicate an underlying metaphysical
issue—the non-physicality of qualia, even if not proven by
conceivability arguments is far from ruled out.
In the end, we are right back where we started. The explanatory gap
argument doesn't demonstrate a gap in nature, but a gap in our
understanding of nature. Of course a plausible explanation for there
being a gap in our understanding of nature is that there is a genuine
gap in nature. But so long as we have countervailing reasons for
doubting the latter, we have to look elsewhere for an explanation of the
former.[13]
Knowledge argument
In the article "Epiphenomenal Qualia" (1982),
[14] Frank Jackson offers what he calls the "knowledge argument" for qualia. One example runs as follows:
Mary the color scientist knows all the physical facts about color, including every physical fact about the experience of color in other people, from the behavior a particular color is likely to elicit to the specific sequence of neurological
firings that register that a color has been seen. However, she has been
confined from birth to a room that is black and white, and is only
allowed to observe the outside world through a black and white monitor.
When she is allowed to leave the room, it must be admitted that she
learns something about the color red the first time she sees it —
specifically, she learns what it is like to see that color.
This
thought experiment
has two purposes. First, it is intended to show that qualia exist. If
one agrees with the thought experiment, we believe that Mary gains
something after she leaves the room—that she acquires knowledge of a
particular thing that she did not possess before. That knowledge,
Jackson argues, is knowledge of the quale that corresponds to the
experience of seeing red, and it must thus be conceded that qualia are
real properties, since there is a difference between a person who has
access to a particular quale and one who does not.
The second purpose of this argument is to refute the physicalist
account of the mind. Specifically, the knowledge argument is an attack
on the physicalist claim about the completeness of physical truths. The
challenge posed to
physicalism by the knowledge argument runs as follows:
- Before her release, Mary was in possession of all the physical information about color experiences of other people.
- After her release, Mary learns something about the color experiences of other people.
Therefore,
- Before her release, Mary was not in possession of all the
information about other people's color experiences, even though she was
in possession of all the physical information.
Therefore,
- There are truths about other people's color experience that are not physical.
Therefore,
- Physicalism is false.
First Jackson argued that qualia are
epiphenomenal: not
causally
efficacious with respect to the physical world. Jackson does not give a
positive justification for this claim—rather, he seems to assert it
simply because it defends qualia against the classic problem of
dualism. Our
[who?] natural assumption would be that qualia must be causally efficacious in the physical world, but some would ask how we
[who?]
could argue for their existence if they did not affect our brains. If
qualia are to be non-physical properties (which they must be in order to
constitute an argument against physicalism), some argue that it is
almost impossible to imagine how they could have a causal effect on the
physical world. By redefining qualia as epiphenomenal, Jackson attempts
to protect them from the demand of playing a causal role.
Later, however, he rejected epiphenomenalism. This, he argues, is
because when Mary first sees red, she says "wow", so it must be Mary's
qualia that cause her to say "wow". This contradicts epiphenomenalism.
Since the Mary's room thought experiment seems to create this
contradiction, there must be something wrong with it. This is often
referred to as the "there must be a reply" reply.
Critics of qualia
Daniel Dennett
In
Consciousness Explained (1991) and "Quining Qualia" (1988),
[15] Daniel Dennett
offers an argument against qualia that demonstrates that the above
definition breaks down when one tries to make a practical application of
it. In a series of
thought experiments, which he calls "
intuition pumps", he brings qualia into the world of
neurosurgery,
clinical psychology,
and psychological experimentation. His argument shows that, once the
concept of qualia is so imported, it turns out that we can either make
no use of it in the situation in question, or that the questions posed
by the introduction of qualia are unanswerable precisely because of the
special properties defined for qualia.
In Dennett's updated version of the inverted spectrum thought
experiment, "alternative neurosurgery", you again awake to find that
your qualia have been inverted—grass appears red, the sky appears
orange, etc. According to the original account, you should be
immediately aware that something has gone horribly wrong. Dennett
argues, however, that it is impossible to know whether the diabolical
neurosurgeons have indeed inverted your qualia (by tampering with your
optic nerve, say), or have simply inverted your connection to memories
of past qualia. Since both operations would produce the same result, you
would have no means on your own to tell which operation has actually
been conducted, and you are thus in the odd position of not knowing
whether there has been a change in your "immediately apprehensible"
qualia.
Dennett's argument revolves around the central objection that, for
qualia to be taken seriously as a component of experience—for them to
even make sense as a discrete concept—it must be possible to show that
- a) it is possible to know that a change in qualia has occurred, as opposed to a change in something else; or that
- b) there is a difference between having a change in qualia and not having one.
Dennett attempts to show that we cannot satisfy (a) either through
introspection or through observation, and that qualia's very definition
undermines its chances of satisfying (b).
Supporters of qualia could point out that in order for you to notice a
change in qualia, you must compare your current qualia with your
memories of past qualia. Arguably, such a comparison would involve
immediate apprehension of your current qualia
and your memories of past qualia, but not the past qualia
themselves.
Furthermore, modern functional brain imaging has increasingly suggested
that the memory of an experience is processed in similar ways and in
similar zones of the brain as those originally involved in the original
perception. This may mean that there would be asymmetry in outcomes
between altering the mechanism of perception of qualia and altering
their memories. If the diabolical neurosurgery altered the immediate
perception of qualia, you might not even notice the inversion directly,
since the brain zones which re-process the memories would themselves
invert the qualia remembered. On the other hand, alteration of the
qualia memories themselves would be processed without inversion, and
thus you would perceive them as an inversion. Thus, you might know
immediately if memory of your qualia had been altered, but might not
know if immediate qualia were inverted or whether the diabolical
neurosurgeons had done a sham procedure
(Ungerleider, 1995).
Dennett also has a response to the
"Mary the color scientist"
thought experiment. He argues that Mary would not, in fact, learn
something new if she stepped out of her black and white room to see the
color red. Dennett asserts that if she already truly knew "everything
about color", that knowledge would include a deep understanding of why
and how human neurology causes us to sense the "quale" of color. Mary
would therefore already know exactly what to expect of seeing red,
before ever leaving the room. Dennett argues that the misleading aspect
of the story is that Mary is supposed to not merely be knowledgeable
about color but to actually know
all the physical facts about it,
which would be a knowledge so deep that it exceeds what can be
imagined, and twists our intuitions.
If Mary really does know everything physical there is to know about
the experience of color, then this effectively grants her almost
omniscient powers of knowledge. Using this, she will be able to deduce
her own reaction, and figure out exactly what the experience of seeing
red will feel like.
Dennett finds that many people find it difficult to see this, so he
uses the case of RoboMary to further illustrate what it would be like
for Mary to possess such a vast knowledge of the physical workings of
the human brain and color vision. RoboMary is an intelligent robot who,
instead of the ordinary color camera-eyes, has a software lock such that
she is only able to perceive black and white and shades in-between.
RoboMary can examine the computer brain of similar non-color-locked
robots when they look at a red tomato, and see exactly how they react
and what kinds of impulses occur. RoboMary can also construct a
simulation of her own brain, unlock the simulation's color-lock and,
with reference to the other robots, simulate exactly how this simulation
of herself reacts to seeing a red tomato. RoboMary naturally has
control over all of her internal states except for the color-lock. With
the knowledge of her simulation's internal states upon seeing a red
tomato, RoboMary can put her own internal states directly into the
states they would be in upon seeing a red tomato. In this way, without
ever seeing a red tomato through her cameras, she will know exactly what
it is like to see a red tomato.
Dennett uses this example to show us that Mary's all-encompassing
physical knowledge makes her own internal states as transparent as those
of a robot or computer, and it is almost straightforward for her to
figure out exactly how it feels to see red.
Perhaps Mary's failure to learn exactly what seeing red feels like is
simply a failure of language, or a failure of our ability to describe
experiences. An alien race with a different method of communication or
description might be perfectly able to teach their version of Mary
exactly how seeing the color red would feel. Perhaps it is simply a
uniquely human failing to communicate first-person experiences from a
third-person perspective. Dennett suggests that the description might
even be possible using English. He uses a simpler version of the Mary
thought experiment to show how this might work. What if Mary was in a
room without triangles and was prevented from seeing or making any
triangles? An English-language description of just a few words would be
sufficient for her to imagine what it is like to see a triangle—she can
simply and directly visualize a triangle in her mind. Similarly, Dennett
proposes, it is perfectly, logically possible that the quale of what it
is like to see red could eventually be described in an English-language
description of millions or billions of words.
In "Are we explaining consciousness yet?" (2001), Dennett approves of
an account of qualia defined as the deep, rich collection of individual
neural responses that are too fine-grained for language to capture. For
instance, a person might have an alarming reaction to yellow because of
a yellow car that hit her previously, and someone else might have a
nostalgic reaction to a comfort food. These effects are too
individual-specific to be captured by English words. "If one dubs this
inevitable residue
qualia, then qualia are guaranteed to exist,
but they are just more of the same, dispositional properties that have
not yet been entered in the catalog [...]."
[16]
Paul Churchland
According to
Paul Churchland, Mary might be considered to be like a
feral child.
Feral children have suffered extreme isolation during childhood.
Technically when Mary leaves the room, she would not have the ability to
see or know what the color red is. A brain has to learn and develop how
to see colors. Patterns need to form in the V4 section of the
visual cortex. These patterns are formed from exposure to wavelengths of light. This exposure is needed during the early stages of
brain development. In Mary's case, the identifications and categorizations of
color will only be in respect to representations of black and white.
[17]
Gary Drescher
In his book
Good and Real (2006),
Gary Drescher compares qualia with "
gensyms" (generated symbols) in
Common Lisp.
These are objects that Lisp treats as having no properties or
components and which can only be identified as equal or not equal to
other objects. Drescher explains, "we have no introspective access to
whatever internal properties make the
red gensym recognizably distinct from the
green [...] even though we know the sensation when we experience it."
[18]
Under this interpretation of qualia, Drescher responds to the Mary
thought experiment by noting that "knowing about red-related cognitive
structures and the dispositions they
engender—even
if that knowledge were implausibly detailed and exhaustive—would not
necessarily give someone who lacks prior color-experience the slightest
clue whether the card now being shown is of the color called red." This
does not, however, imply that our experience of red is non-mechanical;
"on the contrary, gensyms are a routine feature of computer-programming
languages".
[19]
David Lewis
David Lewis
has an argument that introduces a new hypothesis about types of
knowledge and their transmission in qualia cases. Lewis agrees that Mary
cannot learn what red looks like through her monochrome physicalist
studies. But he proposes that this doesn't matter. Learning transmits
information, but experiencing qualia doesn't transmit information;
instead it communicates abilities. When Mary sees red, she doesn't get
any new information. She gains new abilities—now she can remember what
red looks like, imagine what other red things might look like and
recognize further instances of redness. Lewis states that Jackson's
thought experiment uses the "Phenomenal Information Hypothesis"—that is,
the new knowledge that Mary gains upon seeing red is phenomenal
information. Lewis then proposes a different "Ability Hypothesis" that
differentiates between two types of knowledge: knowledge that
(information) and knowledge how (abilities). Normally the two are
entangled; ordinary learning is also an experience of the subject
concerned, and people both learn information (for instance, that Freud
was a psychologist) and gain ability (to recognize images of Freud).
However, in the thought experiment, Mary can only use ordinary learning
to gain know-that knowledge. She is prevented from using experience to
gain the know-how knowledge that would allow her to remember, imagine
and recognize the color red.
We have the intuition that Mary has been deprived of some vital data
to do with the experience of redness. It is also uncontroversial that
some things cannot be learned inside the room; for example, we do not
expect Mary to learn how to ski within the room. Lewis has articulated
that information and ability are potentially different things. In this
way, physicalism is still compatible with the conclusion that Mary gains
new knowledge. It is also useful for considering other instances of
qualia; "being a bat" is an ability, so it is know-how knowledge.
[20]
Marvin Minsky
The
artificial intelligence researcher
Marvin Minsky thinks the problems posed by qualia are essentially issues of complexity, or rather of mistaking complexity for simplicity.
Now, a philosophical dualist might then complain: "You've described
how hurting affects your mind—but you still can't express how hurting
feels." This, I maintain, is a huge mistake—that attempt to reify
"feeling" as an independent entity, with an essence that's
indescribable. As I see it, feelings are not strange alien things. It is
precisely those cognitive changes themselves that constitute what
"hurting" is—and this also includes all those clumsy attempts to
represent and summarize those changes. The big mistake comes from
looking for some single, simple, "essence" of hurting, rather than
recognizing that this is the word we use for complex rearrangement of
our disposition of resources.[21]
Michael Tye
Michael Tye
holds the opinion there are no qualia, no "veils of perception" between
us and the referents of our thought. He describes our experience of an
object in the world as "transparent". By this he means that no matter
what private understandings and/or misunderstandings we may have of some
public entity, it is still there before us in reality. The idea that
qualia intervene between ourselves and their origins he regards as "a
massive error"; as he says, "it is just not credible that visual
experiences are systematically misleading in this way";
[22] "the only objects of which you are aware are the external ones making up the scene before your eyes";
[23]
there are "no such things as the qualities of experiences" for "they
are qualities of external surfaces (and volumes and films) if they are
qualities of anything."
[24]
This insistence permits him to take our experience as having a reliable
base since there is no fear of losing contact with the realness of
public objects.
In Tye's thought there is no question of qualia without information
being contained within them; it is always "an awareness that", always
"representational". He characterizes the perception of children as a
misperception of referents that are undoubtedly as present for them as
they are for grown-ups. As he puts it, they may not know that "the house
is dilapidated", but there is no doubt about their seeing the house.
After-images are dismissed as presenting no problem for the Transparency
Theory because, as he puts it, after-images being illusory, there is
nothing that one sees.
Tye proposes that phenomenal experience has five basic elements, for
which he has coined the acronym PANIC—Poised, Abstract, Nonconceptual,
Intentional Content.
[25]
It is "Poised" in the sense that the phenomenal experience is always
presented to the understanding, whether or not the agent is able to
apply a concept to it. Tye adds that the experience is "maplike" in
that, in most cases, it reaches through to the distribution of shapes,
edges, volumes, etc. in the world—you may not be reading the "map" but,
as with an actual map there is a reliable match with what it is mapping.
It is "Abstract" because it is still an open question in a particular
case whether you are in touch with a concrete object (someone may feel a
pain in a "left leg" when that leg has actually been amputated). It is
"Nonconceptual" because a phenomenon can exist although one does not
have the concept by which to recognize it. Nevertheless, it is
"Intentional" in the sense that it represents something, again whether
or not the particular observer is taking advantage of that fact; this is
why Tye calls his theory "representationalism". This last makes it
plain that Tye believes that he has retained a direct contact with what
produces the phenomena and is therefore not hampered by any trace of a
"veil of perception".
[26]
Proponents of qualia
David Chalmers
David Chalmers formulated the
hard problem of consciousness, raising the issue of qualia to a new level of importance and acceptance in the field.
[citation needed] In his paper
"Absent Qualia, Fading Qualia, Dancing Qualia",
he also argued for what he called "the principle of organizational
invariance". In this paper, he argues that if a system such as one of
appropriately configured computer chips reproduces the functional
organization of the brain, it will also reproduce the qualia associated
with the brain.
E. J. Lowe
E. J. Lowe,
of Durham University, denies that holding to indirect realism (in which
we have access only to sensory features internal to the brain)
necessarily implies a Cartesian dualism. He agrees with
Bertrand Russell
that our "retinal images"—that is, the distributions across our
retinas—are connected to "patterns of neural activity in the cortex"
(Lowe 1986). He defends a version of the Causal Theory of Perception in
which a causal path can be traced between the external object and the
perception of it. He is careful to deny that we do any inferring from
the sensory field, a view which he believes allows us to found an access
to knowledge on that causal connection. In a later work he moves closer
to the non-epistemic theory in that he postulates "a wholly
non-conceptual component of perceptual experience",
[27]
but he refrains from analyzing the relation between the perceptual and
the "non-conceptual". Most recently he has drawn attention to the
problems that hallucination raises for the direct realist and to their
disinclination to enter the discussion on the topic.
[28]
J. B. Maund
John Barry Maund, an Australian philosopher of perception at the
University of Western Australia, draws attention to a key distinction of
qualia. Qualia are open to being described on two levels, a fact that
he refers to as "dual coding". Using the Television Analogy (which, as
the
non-epistemic argument
shows, can be shorn of its objectionable aspects), he points out that,
if asked what we see on a television screen there are two answers that
we might give:
The states of the screen during a football match are unquestionably
different from those of the screen during a chess game, but there is no
way available to us of describing the ways in which they are different
except by reference to the play, moves and pieces in each game.
[29]
He has refined the explanation by shifting to the example of a "
Movitype"
screen, often used for advertisements and announcements in public
places. A Movitype screen consists of a matrix—or "raster" as the
neuroscientists prefer to call it (from the Latin
rastrum, a
"rake"; think of the lines on a TV screen as "raked" across)—that is
made up of an array of tiny light-sources. A computer-led input can
excite these lights so as to give the impression of letters passing from
right to left, or even, on the more advanced forms now commonly used in
advertisements, to show moving pictures. Maund's point is as follows.
It is obvious that there are two ways of describing what you are seeing.
We could either adopt the everyday public language and say "I saw some
sentences, followed by a picture of a 7-Up can." Although that is a
perfectly adequate way of describing the sight, nevertheless, there is a
scientific way of describing it which bears no relation whatsoever to
this commonsense description. One could ask the electronics engineer to
provide us with a computer print-out staged across the seconds that you
were watching it of the point-states of the raster of lights. This would
no doubt be a long and complex document, with the state of each tiny
light-source given its place in the sequence. The interesting aspect of
this list is that, although it would give a comprehensive and
point-by-point-detailed description of the state of the screen, nowhere
in that list would there be a mention of "English sentences" or "a 7-Up
can".
What this makes clear is that there are two ways to describe such a
screen, (1) the "commonsense" one, in which publicly recognizable
objects are mentioned, and (2) an accurate point-by-point account of the
actual state of the field, but makes no mention of what any passer-by
would or would not make of it. This second description would be
non-epistemic from the common sense point of view, since no objects are
mentioned in the print-out, but perfectly acceptable from the engineer's
point of view. Note that, if one carries this analysis across to human
sensing and perceiving, this rules out Daniel Dennett's claim that all
qualiaphiles must regard qualia as "ineffable", for at this second level
they are in principle quite "effable"—indeed, it is not ruled out that
some neurophysiologist of the future might be able to describe the
neural detail of qualia at this level.
Maund has also extended his argument particularly with reference of color.
[30]
Color he sees as a dispositional property, not an objective one, an
approach which allows for the facts of difference between person and
person, and also leaves aside the claim that external objects are
colored. Colors are therefore "virtual properties", in that it is as if
things possessed them; although the naïve view attributes them to
objects, they are intrinsic, non-relational inner experiences.
Moreland Perkins
In his book
Sensing the World,
[31]
Moreland Perkins argues that qualia need not be identified with their
objective sources: a smell, for instance, bears no direct resemblance to
the molecular shape that gives rise to it, nor is a toothache actually
in the tooth. He is also like Hobbes in being able to view the process
of sensing as being something complete in itself; as he puts it, it is
not like "kicking a football" where an external object is required—it is
more like "kicking a kick", an explanation which entirely avoids the
familiar Homunculus Objection, as adhered to, for example, by
Gilbert Ryle.
Ryle was quite unable even to entertain this possibility, protesting
that "in effect it explained the having of sensations as the not having
of sensations."
[32] However,
A.J. Ayer
in a rejoinder identified this objection as "very weak" as it betrayed
an inability to detach the notion of eyes, indeed any sensory organ,
from the neural sensory experience.
[33]
Ramachandran and Hirstein
Vilayanur S. Ramachandran
Vilayanur S. Ramachandran and
William Hirstein[34]
proposed three laws of qualia (with a fourth later added), which are
"functional criteria that need to be fulfilled in order for certain
neural events to be associated with qualia" by philosophers of the mind:
- Qualia are irrevocable and indubitable. You don't say 'maybe it is
red but I can visualize it as green if I want to'. An explicit neural
representation of red is created that invariably and automatically
'reports' this to higher brain centres.
- Once the representation is created, what can be done with it is
open-ended. You have the luxury of choice, e.g., if you have the percept
of an apple you can use it to tempt Adam, to keep the doctor away, bake
a pie, or just to eat. Even though the representation at the input
level is immutable and automatic, the output is potentially infinite.
This isn't true for, say, a spinal reflex arc where the output is also
inevitable and automatic. Indeed, a paraplegic can even have an erection
and ejaculate without an orgasm.
- Short-term memory. The input invariably creates a representation
that persists in short-term memory—long enough to allow time for choice
of output. Without this component, again, you get just a reflex arc.
- Attention. Qualia and attention are closely linked. You need
attention to fulfill criterion number two; to choose. A study of
circuits involved in attention, therefore, will shed much light on the
riddle of qualia.[35]
They proposed that the phenomenal nature of qualia could be communicated (as in "oh
that is what salt tastes like") if brains could be appropriately connected with a "cable of neurons".
[34]
If this turned out to be possible this would scientifically prove or
objectively demonstrate the existence and the nature of qualia.
Howard Robinson and William Robinson
Howard Robinson is a philosopher who has concentrated his research within the
philosophy of mind. Taking what has been through the latter part of the last century an
unfashionable stance, he has consistently argued against those
explanations of sensory experience that would reduce them to physical
origins. He has never regarded the theory of sense-data as refuted, but
has set out to refute in turn the objections which so many have
considered to be conclusive. The version of the theory of
sense-data
he defends takes what is before consciousness in perception to be
qualia as mental presentations that are causally linked to external
entities, but which are not physical in themselves. Unlike the
philosophers so far mentioned, he is therefore a dualist, one who takes
both matter and mind to have real and metaphysically distinct natures.
His books (particularly
Matter and Sense and
Perception[36])
are characterized by the thoroughness with which he deals with the
arguments of opposing philosophers, thus setting a professional example
that it would be well for his opponents to follow (for there has been a
tendency to take for granted that the theory of sense-data is wholly
obsolescent). In one of his most recent articles he takes the
physicalist
to task for ignoring the fact that sensory experience can be entirely
free of representational character. He cites phosphenes as a stubborn
example (
phosphenes
are flashes of neural light that result either from sudden pressure in
the brain—as induced, for example, by intense coughing, or through
direct physical pressure on the retina), and points out that it is
grossly counter-intuitive to argue that these are not visual experiences
on a par with open-eye seeing.
William Robinson (no relation) takes a very similar view to that of his namesake. In his most recent book,
Understanding Phenomenal Consciousness,
[37]
he is unusual as a dualist in calling for research programs that
investigate the relation of qualia to the brain. The problem is so
stubborn, he says, that too many philosophers would prefer "to explain
it away", but he would rather have it explained and does not see why the
effort should not be made. However, he does not expect there to be a
straightforward scientific reduction of phenomenal experience to neural
architecture; on the contrary he regards this as a forlorn hope. The
"Qualitative Event Realism" that Robinson espouses sees phenomenal
consciousness as caused by brain events but not identical with them,
being non-material events.
It is noteworthy that he refuses to set aside the vividness—and
commonness—of mental images, both visual and aural, standing here in
direct opposition to Daniel Dennett, who has difficulty in crediting the
experience in others. He is similar to Moreland Perkins in keeping his
investigation wide enough to apply to all the senses.
Edmond Wright
Edmond Wright is a philosopher who considers the intersubjective aspect of perception.
[38][39]
From Locke onwards it had been normal to frame perception problems in
terms of a single subject S looking at a single entity E with a property
p. However, if we begin with the facts of the differences in sensory
registration from person to person, coupled with the differences in the
criteria we have learned for distinguishing what we together call "the
same" things, then a problem arises of how two persons align their
differences on these two levels so that they can still get a practical
overlap on parts of the real about them—and, in particular, update each
other about them.
Wright mentions being struck with the hearing difference between
himself and his son, discovering that his son could hear sounds up to
nearly 20 kilohertz while his range only reached to 14 kHz or so. This
implies that a difference in qualia could emerge in human action (for
example, the son could warn the father of a high-pitched escape of a
dangerous gas kept under pressure, the sound-waves of which would be
producing no qualia evidence at all for the father). The relevance for
language thus becomes critical, for an informative statement can best be
understood as an updating of a perception—and this may involve a
radical re-selection from the qualia fields viewed as non-epistemic,
even perhaps of the presumed singularity of "the" referent, a fortiori
if that "referent" is the self. Here he distinguishes his view from that
of Revonsuo, who too readily makes his "virtual space" "egocentric".
Wright's particular emphasis has been on what he asserts is a core
feature of communication, that, in order for an updating to be set up
and made possible, both speaker and hearer have to behave as if they
have identified "the same singular thing", which, he notes, partakes of
the structure of a joke or a story.
[38]
Wright says that this systematic ambiguity seems to opponents of qualia
to be a sign of fallacy in the argument (as ambiguity is in pure logic)
whereas, on the contrary, it is sign—in talk about "what" is
perceived—of something those speaking to each other have to learn to
take advantage of. In extending this analysis, he has been led to argue
for an important feature of human communication being the degree and
character of the faith maintained by the participants in the dialogue, a
faith that has priority over what has before been taken to be the key
virtues of language, such as "sincerity", "truth", and "objectivity".
Indeed, he considers that to prioritize them over faith is to move into
superstition.
Erwin Schrödinger
Erwin Schrödinger,
a theoretical physicist and one of the leading pioneers of quantum
mechanics, also published in the areas of colorimetry and color
perception. In several of his philosophical writings, he defends the
notion that qualia are not physical.
The sensation of colour cannot be accounted for by the physicist's
objective picture of light-waves. Could the physiologist account for it,
if he had fuller knowledge than he has of the processes in the retina
and the nervous processes set up by them in the optical nerve bundles
and in the brain? I do not think so.[40]:154
He continues on to remark that subjective experiences do not form a
one-to-one correspondence with stimuli. For example, light of wavelength
in the neighborhood of 590 nm produces the sensation of yellow, whereas
exactly the same sensation is produced by mixing red light, with
wavelength 760 nm, with green light, at 535 nm. From this he concludes
that there is no "numerical connection with these physical, objective
characteristics of the waves" and the sensations they produce.
Schrödinger concludes with a proposal of how it is that we might
arrive at the mistaken belief that a satisfactory theoretical account of
qualitative experience has—or might ever—be achieved:
Scientific theories serve to facilitate the survey of our
observations and experimental findings. Every scientist knows how
difficult it is to remember a moderately extended group of facts, before
at least some primitive theoretical picture about them has been shaped.
It is therefore small wonder, and by no means to be blamed on the
authors of original papers or of text-books, that after a reasonably
coherent theory has been formed, they do not describe the bare facts
they have found or wish to convey to the reader, but clothe them in the
terminology of that theory or theories. This procedure, while very
useful for our remembering the fact in a well-ordered pattern, tends to
obliterate the distinction between the actual observations and the
theory arisen from them. And since the former always are of some sensual
quality, theories are easily thought to account for sensual qualities;
which, of course, they never do.[40]:163–164
Neurobiological blending of perspectives
Rodolfo Llinás
When
looked at philosophically, qualia become a tipping point between
physicality and the metaphysical, which polarizes the discussion, as
we've seen above, into "Do they or do they not exist?" and "Are they
physical or beyond the physical?" However, from a strictly neurological
perspective, they can both exist, and be very important to the
organism's survival, and be the result of strict neuronal oscillation,
and still not rule out the metaphysical. A good example of this pro/con
blending is in
Rodolfo Llinás's
I of the Vortex (MIT Press, 2002, pp. 202–207). Llinás argues that qualia are ancient and necessary for an organism's survival
and
a product of neuronal oscillation. Llinás gives the evidence of
anesthesia of the brain and subsequent stimulation of limbs to
demonstrate that qualia can be "turned off" with changing only the
variable of neuronal oscillation (local brain electrical activity),
while all other connections remain intact, arguing strongly for an
oscillatory—electrical origin of qualia, or important aspects of them.
Roger Orpwood
Roger
Orpwood, an engineer with a strong background in studying neural
mechanisms, proposed a neurobiological model that gives rise to qualia
and ultimately, consciousness. As advancements in cognitive and
computational neuroscience continue to grow, the need to study the mind,
and qualia, from a scientific perspective follows. Orpwood does not
deny the existence of qualia, nor does he intend to debate its physical
or non-physical existence. Rather, he suggests that qualia are created
through the neurobiological mechanism of
re-entrant feedback in cortical systems
[41][42][43]
Orpwood develops his mechanism by first addressing the issue of
information. One unsolved aspect of qualia is the concept of the
fundamental information involved in creating the experience. He does not
address a position on the metaphysics of the information underlying the
experience of qualia, nor does he state what information actually is.
However, Orpwood does suggest that information in general is of two
types: the information structure and information message. Information
structures are defined by the physical vehicles and structural,
biological patterns encoding information. That encoded information is
the information message; a source describing
what that
information is. The neural mechanism or network receives input
information structures, completes a designated instructional task
(firing of the neuron or network), and outputs a modified information
structure to downstream regions. The information message is the purpose
and meaning of the information structure and causally exists as a result
of that particular information structure. Modification of the
information structure changes the meaning of the information message,
but the message itself cannot be directly altered.
Local cortical networks have the capacity to receive feedback from
their own output information structures. This form of local feedback
continuously cycles part of the networks output structures as its next
input information structure. Since the output structure must represent
the information message derived from the input structure, each
consecutive cycle that is fed-back will represent the output structure
the network just generated. As the network of mechanisms cannot
recognize the information message, but only the input information
structure, the network is unaware that it is representing its own
previous outputs. The neural mechanisms are merely completing their
instructional tasks and outputting any recognizable information
structures. Orpwood proposes that these local networks come into an
attractor state that consistently outputs exactly the same information
structure as the input structure. Instead of only representing the
information message derived from the input structure, the network will
now represent its own output and thereby its own information message. As
the input structures are fed-back, the network identifies the previous
information structure as being a previous representation of the
information message. As Orpwood states,
Once an attractor state has been established, the output [of a network] is a representation of its own identity to the network.[43]:4
Representation of the networks own output structures, by which
represents its own information message, is Orpwood's explanation that
grounds the manifestation of qualia via neurobiological mechanisms.
These mechanisms are particular to networks of pyramidal neurons.
Although computational neuroscience still has much to investigate
regarding pyramidal neurons, their complex circuitry is relatively
unique. Research shows that the complexity of pyramidal neuron networks
is directly related to the increase in the functional capabilities of a
species.
[44]
When human pyramidal networks are compared with other primate species
and species with less intricate behavioral and social interactions, the
complexity of these neural networks drastically decline. The complexity
of these networks are also increased in frontal brain regions. These
regions are often associated with conscious assessment and modification
of one's immediate environment; often referred to as
executive functions.
Sensory input is necessary to gain information from the environment,
and perception of that input is necessary for navigating and modifying
interactions with the environment. This suggests that frontal regions
containing more complex pyramidal networks are associated with an
increased perceptive capacity. As perception is necessary for conscious
thought to occur, and since the experience of qualia is derived from
consciously recognizing some perception, qualia may indeed be specific
to the functional capacity of pyramidal networks. This derives Orpwood's
notion that the mechanisms of re-entrant feedback may not only create
qualia, but also be the foundation to consciousness.
Other issues
Indeterminacy
It is possible to apply a criticism similar to
Nietzsche's criticism of
Kant's "
thing in itself"
to qualia: Qualia are unobservable in others and unquantifiable in us.
We cannot possibly be sure, when discussing individual qualia, that we
are even discussing the same phenomena. Thus, any discussion of them is
of indeterminate value, as descriptions of qualia are necessarily of
indeterminate accuracy.
[citation needed]
Qualia can be compared to "things in themselves" in that they have no
publicly demonstrable properties; this, along with the impossibility of
being sure that we are communicating about the same qualia, makes them
of
indeterminate value and definition in any philosophy in which proof relies upon precise definition.
[citation needed] On the other hand, qualia could be considered akin to
Kantian phenomena
since they are held to be seemings of appearances. Revonsuo, however,
considers that, within neurophysiological inquiry, a definition at the
level of the fields may become possible (just as we can define a
television picture at the level of liquid crystal pixels).
Causal efficacy
Whether or not qualia or consciousness can play any causal role in the physical world remains an open question, with
epiphenomenalism
acknowledging the existence of qualia while denying it any causal
power. The position has been criticized by a number of philosophers,
[45]
if only because our own consciousness seem to be causally active. In
order to avoid epiphenomenalism, one who believes that qualia are
nonphysical would need to embrace something like
interactionist dualism; or perhaps
emergentism,
the claim that there are as yet unknown causal relations between the
mental and physical. This in turn would imply that qualia can be
detected by an external agency through their causal powers.
Epistemological issues
To
illustrate: one might be tempted to give as examples of qualia "the
pain of a headache, the taste of wine, or the redness of an evening
sky". But this list of examples already prejudges a central issue in the
current debate on qualia.
[citation needed]
An analogy might make this clearer. Suppose someone wants to know the
nature of the liquid crystal pixels on a television screen, those tiny
elements that provide all the distributions of color that go to make up
the picture. It would not suffice as an answer to say that they are the
"redness of an evening sky" as it appears on the screen. We would
protest that their real character was being ignored. One can see that
relying on the list above assumes that we must tie sensations not only
to the notion of given objects in the world (the "head", "wine", "an
evening sky"), but also to the properties with which we characterize the
experiences themselves ("redness", for example).
Nor is it satisfactory to print a little red square as at the top of
the article, for, since each person has a slightly different
registration of the light-rays,
[46]
it confusingly suggests that we all have the same response. Imagine in a
television shop seeing "a red square" on twenty screens at once, each
slightly different—something of vital importance would be overlooked if a
single example were to be taken as defining them all.
Yet it has been argued whether or not identification with the
external object should still be the core of a correct approach to
sensation, for there are many who state the definition thus because they
regard the link with external reality as crucial. If sensations are
defined as "raw feels", there arises a palpable threat to the
reliability of knowledge. The reason has been given that, if one sees
them as neurophysiological happenings in the brain, it is difficult to
understand how they could have any connection to entities, whether in
the body or the external world. It has been declared, by
John McDowell for example, that to countenance qualia as a "bare presence" prevents us ever gaining a certain ground for our knowledge.
[47] The issue is thus fundamentally an
epistemological
one: it would appear that access to knowledge is blocked if one allows
the existence of qualia as fields in which only virtual constructs are
before the mind.
His reason is that it puts the entities about which we require knowledge behind a "
veil of perception",
an occult field of "appearance" which leaves us ignorant of the reality
presumed to be beyond it. He is convinced that such uncertainty propels
into the dangerous regions of
relativism and
solipsism:
relativism sees all truth as determined by the single observer;
solipsism, in which the single observer is the only creator of and
legislator for his or her own universe, carries the assumption that no
one else exists. These accusations constitute a powerful ethical
argument against qualia being something going on in the brain, and these
implications are probably largely responsible for the fact that in the
20th century it was regarded as not only freakish, but also dangerously
misguided to uphold the notion of sensations as going on inside the
head. The argument was usually strengthened with mockery at the very
idea of "redness" being in the brain: the question was—and still is
[48]—"How can there be red neurons in the brain?" which strikes one as a justifiable appeal to common sense.
To maintain a philosophical balance, the argument for "raw feels"
needs to be set side by side with the claim above. Viewing sensations as
"raw feels" implies that initially they have not yet—to carry on the
metaphor—been "cooked", that is, unified into "things" and "persons",
which is something the mind does after the sensation has responded to
the blank input, that response driven by motivation, that is, initially
by pain and pleasure, and subsequently, when memories have been
implanted, by desire and fear. Such a "raw-feel" state has been more
formally identified as "non-
epistemic".
In support of this view, the theorists cite a range of empirical facts.
The following can be taken as representative. There are brain-damaged
persons, known as "agnosics" (literally "not-knowing") who still have
vivid visual sensations but are quite unable to identify any entity
before them, including parts of their own body. There is also the
similar predicament of persons, formerly blind, who are given sight for
the first time—and consider what it is a newborn baby must experience. A
German psychologist of the 19th century,
Hermann von Helmholtz,
proposed a simple experiment to demonstrate the non-epistemic nature of
qualia: his instructions were to stand in front of a familiar
landscape, turn your back on it, bend down and look at the landscape
between your legs—you will find it difficult in the upside-down view to
recognize what you found familiar before.
[49]
These examples suggest that a "bare presence"—that is, knowledgeless
sensation that is no more than evidence—may really occur. Present
supporters of the non-epistemic theory thus regard sensations as only
data in the sense that they are "given" (Latin
datum, "given")
and fundamentally involuntary, which is a good reason for not regarding
them as basically mental. In the last century they were called
"sense-data" by the proponents of qualia, but this led to the confusion
that they carried with them reliable proofs of objective causal origins.
For instance, one supporter of qualia was happy to speak of the redness
and bulginess of a cricket ball as a typical "sense-datum",
[50] though not all of them were happy to define qualia by their relation to external entities (see Roy Wood Sellars
[51]).
The modern argument, following Sellars' lead, centers on how we learn
under the regime of motivation to interpret the sensory evidence in
terms of "things", "persons", and "selves" through a continuing process
of feedback.
The definition of qualia thus is governed by one's point of view, and
that inevitably brings with it philosophical and neurophysiological
presuppositions. The question, therefore, of what qualia can be raises
profound issues in the
philosophy of mind, since some
materialists
want to deny their existence altogether: on the other hand, if they are
accepted, they cannot be easily accounted for as they raise the
difficult problem of consciousness. There are committed
dualists such as Richard L. Amoroso or
John Hagelin
who believe that the mental and the material are two distinct aspects
of physical reality like the distinction between the classical and
quantum regimes.
[52] In contrast, there are
direct realists
for whom the thought of qualia is unscientific as there appears to be
no way of making them fit within the modern scientific picture; and
there are committed proselytizers for a final truth who reject them as
forcing knowledge out of reach.
