Tuesday, October 1, 2013

Epiphenomenal Qualia, The Knowledge Argument (Aka Mary's Room): Frank Jackson

Introduction and Context
Frank Jackson (no relation to the late Michael Jackson) argues that even if you knew all the physical facts about a conscious experience and what brings it about, you would still be missing information.   That is, supposing you knew everything that happens in the brain--down to the neuron--when sees the color red and you knew all the different surface properties that can produce "red" experiences, a physicalist theory of mind would not be able to account for all the facts about seeing red.  You would still not know every fact about seeing red.  The account would leave out the facts about the subjective experience of seeing red.  The conclusion is that a purely physical theory of mind will always be incomplete.

Lets take a step back and look at how we got to this point in our discussion of mind so far.  We started with dualism and saw how it has some major problems, among them the inability to explain immaterial soul-material body interaction and to account for the observed decrease in mental capacities of people with some types of brain damage (since the immaterial mind is supposed to persist independent of a physical body/brain).

Then we looked at the other extreme, eliminative materialism--the idea that we when talk about the mind, we should only talk about brain states and their underlying neurological and physical structures. We should even reject folk psychological terms like "belief" and "desire" because they don't refer to anything that is reducible to a common physical structure that can be studied by the hard sciences.  Folk psychological concepts are outdated pre-scientific concepts that shouldn't be forced onto modern brain science.  Modern brain science should be free to come up with its own concepts that best fit the observational data. 

Fodor was all, "why you talking smack about folk psychology?".   At the organism-level of analysis, we should use concepts like "belief" and "desire" because they are part of a theory of mind that has tremendous explanatory and predictive power.  And, just as we do with other scientific concepts, if they have strong predictive and explanatory power, we accord them ontological status (i.e., we say the things they refer to exist).

Furthermore, we should give a functionalist account of beliefs and desires.  Thus, the concepts we employ in theories of mind need not be reducible to particular physical structures.  It's ok, nay! it is necessary to have higher levels of analysis that function independently from what's happening in the brain at the neurological and physical level. 

So, now where we at?  We're going to continue scrutinizing purely physicalist theories of mind with the help of Jackson's knowledge argument.  Lets begin with a quick overview of what physicalist positions share...

Physicalist Theories of Mind
Mental states are brain states.  The End.  

Ok...I kid! I kid!  There's a bit more to it...

Lets frame the issue:  Both dualists (not necessarily substance dualists, but all types including property dualists like Fodor) need to explain how the mental affects the physical (i.e., how my thoughts can affect my body's actions) and how the physical affects the mental (i.e., how what happens to my body affects what I experience mentally).  

The physicalist says mental states "just are" brain states.  The problem for the physicalist arises when he tries to give an account of subjective experience (like feeling pain, seeing red, smelling a rose, tasting chocolate, etc...).  In short, the physicalist account seems to leave something out (i.e., subjective conscious experience).

Epiphenominalism: General
Before getting into Jackson's specific epiphenominalim, lets figure out what this big fancy word means in the context of philosophy of mind.  First, lets break down the word:  "epi" is latin for "above" and "phenomenon" is latin for Ami, although some have alternatively translated it as "appearance" or "appear".  Epiphenominalism is the view that mental properties emerge as a consequence of certain complex arrangements of matter/complex physical processes.   Lets consider some other examples:  the property of solidity or hardness emerges out of a particular arrangement of matter; "life" also arises out of a certain arrangement of matter (a cell).  So, the epiphenominalist says the same about mental properties--they are an emergent property that are the consequence of certain complex physical processes and arrangements of matter.

Traditional epiphenominalism says that the causal relationship between the brain process and mental experiences (consciousness) runs only one way--from physical to mental.  That is, stuff happens in our brain which causes the brain to have mental properties (like feeling pain, seeing blue, smelling a rose, etc...).  Mental awareness "piggy-backs" on the automatic workings of the body and brain.  It has no causal power the other way.  The perception that our conscious experiences of volition, pain, etc... cause us to act in certain ways is only an illusion.  Our bodies and brains have already acted.

Qualia Epiphenominalism:  Jackson
Qualia is a fancy word to describe the subjective nature of experience; for example, what it's like to have the experience of seeing red, of tasting ice cream, of feeling pain...  Remember that your brain reconstructs an image of reality--we don't perceive reality directly.  The redness of a rose doesn't fly into your eye an enter your brain.  The rose absorbs some parts of the light spectrum and reflects others.  The wavelengths that reach your retina are converted, via the cones, into electro-chemical signals which travel down the optical nerve, which then do a bunch of crazy stuff in the brain, and somehow you end up with the experience of seeing red.  These reconstructions are the qualia. 

Contrary to general epiphenominalism which argues that all mental experiences are causally inert, Jackson argues that only qualia are causally inert.  So, maybe mental experiences of volition and desire are not.

The Knowledge Argument
Jackson defines physical information as all information that is dealt with in physics, chemistry, biology, and everything in between like neuroscience and bio-chemistry, etc...  Essentially, this is the type of information that can be used to understand and predict relationships between an individual's environment and their neurological states.  Also included in physical information are explanations and predictions about the relationships between Fodor's functionally defined mental states (e.g., beliefs and desires), agent behaviors, and the environment.

The core of Jackson's argument against a purely physicalist account of mind is that there are features of bodily sensations and perceptual experiences that can't be captured by purely physical information. These feature, as you should have picked up by now, are called "qualia".   The physicalist has to argue that given full development of the physical sciences, we will be able to give a complete explanation of all aspects of the mind but Jackson's going to show why this isn't true.  Because no amount of information about brain states can capture the subjective experience of seeing red, tasting coffee, etc... we need to extend out ontology to include non-physical properties; i.e., qualia.

Argument 1:  Fred and Red 1 and Red 2
Suppose that Fred distinguishes what we see as "red" as two distinct colors.  He doesn't just perceive them as different shades of the same color but he perceives them as distinctly as we perceive yellow and blue.  Fred calls them Red 1 and Red 2 to avoid communication problems with the rest of the world.

As it turns out, Fred makes this distinction because of a certain mutation in the physiology of his cones (this actually happens, some women have a 4th cone--check out the link at the end of the post).  Fred's cones respond differently to certain light waves in the red section of the spectrum that make no difference to ours.  This different response leads to different brain states from what we'd normally experience if our cones where hit by that same red light.

Suppose, we wanted to know what Fred's experience of Red 2 was like.  This is information we don't have.  If we had complete physical information--from his unique physiology down to the electron activity in his neurons when he sees Red 2-- would this tell us anything about what the experience of seeing Red 2 is like?  Jackson says, no.  The point is that despite all the physical information, something is left out.

Now, suppose that scientists in lab coats, using breakers and bunsen burners are able to use stem cells to recreate Fred's optical physiology in anyone who so chooses.  By undergoing this process and being able to perceive the formerly unperceived color Red 2, would these people have acquired new information?  Jackson says yes, they'd now know what Red 2 looks like (and what it's like to perceive it).   This additionally reinforces his hypothesis that the purely physicalist account of mind is incomplete:  it leaves something out--knowledge of what it's like to have certain experiences.

Argument 2: Mary the Color Scientist
Suppose Mary is a brilliant color scientist (yay!).  Though a series of unfortunate circumstances, since the day she was born, she was never able to leave her bunker in which everything is either black or white (boo!).  She does have a TV (yay!), but it's black and white too (boo!).

Despite her regrettable circumstances, Mary has studied everything there is to know about color.  She can look at any brain scan of a person looking at a color, and based on the neurological activity, she can tell you what color the person is looking at.  She can tell you what's happening in each brain cell as someone perceives red.  She also knows the relationship between every surface property and every color.  All this, and she's never left her room to see the actual colors.

Here's the million dollar question:  If Mary walked out of her room into our world, will she learn anything new about color?  Jackson says, "duh! of course she will!"  The conclusion is that despite her complete knowledge of every physical fact about color and color perception, her knowledge was incomplete, and therefore physicalism doesn't account for all facts.

The same types of arguments could be used for taste, hearing, and bodily sensations, and any mental state with phenomenal features.

Replies To Possible Objections to Epiphenominalism

Causal Impotence of Qualia

The standard objection to classical epiphenominalism is that to say that mental states are causally impotent seems to run counter to our experience.  However, Jacksons claim isn't that all mental states are causally impotent, only that qualia are.  Nevertheless, he is still going to be subject to many of the same objections directed at general epiphenominalism. 

Defense 1 For the Causal Impotence of Qualia:  The Underlying Cause
It is supposed that the (unpleasant) experience of pain is partly responsible for our avoiding it.  But this is to suppose causation with there may be non.  For instance, simply because B always follows A it doesn't necessarily mean the A causes B.  There may be an underlying cause of both A and B.  In other words, there may be some event C which, every time it occurs, causes both A and B to happen.  In the case of explaining qualia, there may be a brain even causes both our reaction to the pain and the sensation of pain, but the sensation doesn't cause the reaction.

Consider another example to illustrate the principle.  It has been noted that the bigger a child's shoe size, the better their hand-writing.  Does this mean that larger feet causes better hand-writing?  No, there is a third event that's causing both the shoe size increase and the better hand-writing: that is, general growth over time.  As children get older, they get bigger but their brains also become more developed and adept at complex tasks.  

Another example from a recent study (that was misreported by the popular media):  men with small testicles are better fathers:  The headlines make it seem like having small testicles make men better fathers.  But this is just silly--there's a further underlying cause of both.  Men who are good fathers generally get up at night to tend to crying children and so they get less sleep.  Less sleep translates to lower testosterone levels, which in turn leads to otherwise smaller testicles.  So, let that be a warning to you ladies.  Just because a man has small testicles, it doesn't automatically mean he's a keeper.  Maybe he just doesn't get much sleep for a variety of reasons.  (See! philosophy is useful!)

Defense 2 For the Causal Impotence of Qualia:  Vs Argument from Evolution
Assuming that evolution only keeps and perpetuates adaptations that are efficacious (give us a survival edge), why did we evolve the capacity for qualia?  It seems like a perfectly useless adaptation if it doesn't help our survival.

Consider the polar bears' coat (the one's that drink Coke).  The theory of evolution tells us that having a thick warm coat is conducive to survival in the Antarctic.  But having a thick warm coat also means having a heavy coat--which is not conducive to survival.   The fact that polar bears have heavy coats (i.e., a trait not conducive to survival) isn't a refutation of evolutionary theory, rather, the heaviness of the coat is an unintended byproduct of having a thick warm coat.

We can draw an analogy with qualia.  Qualia are an unintended byproduct of having a certain level of complexity in the brain--they are not an adaptation for survival just as the heaviness of the polar bear's coat is not.

Master Defense:  Vs The Kitchen SinkOne could reply that despite all these counter-replies to anti-epiphenominalism the fact remains that qualia do nothing, explain nothing, serve only to soothe dualist intuitions, and still leave it a mystery as to how they fit into the world.

Jackson concedes this but replies that our failure to understand still is no objection to qualia.  We shouldn't suppose that we will be able to understand the role of qualia because evolution doesn't favor those who "make sense of how [qualia] are caused and the laws governing them, or in fact why they exist at all."  In short, we can't understand qualia because there is no evolutionary advantage to understanding them. And the same argument can apply to many things in the universe.  We shouldn't be surprised that some matters with fall outside of our explanatory capabilities...humans should show a little humility and not assume that we will one day be able to explain everything!

Check out these podcast episodes on real people and other species with cone mutations and how they perceive: (if you're going to listen to only one, definitely listen to the first one--your head will explode). 

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