On Paul Churchland's 'Refutation' of the Knowledge Argument

If this post needs theme music, I suggest Party Lights (1962) by the one-hit wonder, Claudine Clark:  "I see the lights/I see the party lights/They're red and blue and green/Everybody in the crowd is there/But you won't let me make the scene!"  (Because, mama dear, you've kept me cooped up in a black-and-white room studying neuroscience.)

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The 'Knowledge Argument' as it is known in the trade has convinced many of the untenability of functionalism in the philosophy of mind.  Here is Paul M. Churchland's presentation of Frank Jackson's version of the argument:

1. Mary knows everything there is to know about brain states and their properties.
2. It is not the case that Mary knows everything there is to know about sensations and their properties.
Therefore, by Leibniz's law [i.e., the Indiscernibility of Identicals; see my post 'Leibniz's Law': A Useless Expression],
3. Sensations and their properties are not identical to brain states and their properties.

("Reduction, Qualia, and the Direct Introspection of the Brain," Journal of Philosophy, vol. 82, no. 1, January 1985, pp. 8-28, sec. IV, "Jackson's Knowledge Argument.")

Mary is a brilliant neuroscientist who has spent her entire life in a visually impoverished state.  Pent up in a room from birth and sheltered from colors, her visual experience is restricted to black and white and shades of gray.  You are to imagine that she has come to know everything there is to know about the brain and its visual system.  Her access to the outer world is via black-and-white TV.  The neuroscience texts over which she so assiduously pores have beeen expurgated by the dreaded Color Censor.

Churchland finds two "shortcomings" with the above argument. I will discuss only the first in this post.

Churchland smells a fallacy of equivocation.  'Knows about,' he claims, is being used in different senses in (1) and (2):

Knowledge in (1) seems to be a matter of having mastered a set of sentences or propositions, the kind one finds written in neuroscience texts, whereas knowledge in (2) seems to be a matter of having a representation of redness in some prelingusitic or sublinguistic medium of representation for sensory variables, or to be a matter of being able to make certain sensory discriminations, or something along these lines. (Emphasis in original)

Rather than argue that that there is no equivocation in the argument as Churchland formulates it, I think it is best to concede the point, urging instead that Chuchland has not presented the Knowledge Argument fairly.  He finds an equivocation only because he has set up a straw man.  Consider the following version:

4. Mary knows all of the of the physical facts about color vision.
5. Venturing outside her black-and-white domain for the first time, she comes to know a new fact: what it is like to see red.
Therefore
6. This new fact is not a physical fact.

There is no equivocation on 'knows' in this argument.  Mary knows all of the physical facts about the brain and the visual system.  If the physical facts are all the facts, then, when she emerges from the room and views a red sunset, she learns nothing new.  But this is not the case.  She does learn something new, something she might express by exclaiming, "So this is what it is like to see red!"  That is a new fact that she comes to know.

The best counter to this argument is to deny (2) by arguing that that no new fact is learned when Mary steps outside.  Mary simply acquires a new concept, a new way of gaining epistemic access to the same old physical facts, namely, the physical and functional facts involved in seeing a red thing.  As Churchland puts it,

. . . the difference between a person who knows all about the visual cortex but has never enjoyed a sensation of red, and a person who knows no neuroscience but knows well the sensation of red, may reside not in what is respectively known by each (brain states by the former, qualia by the latter), but rather in the different type of knowledge each has of exactly the same thing.  The difference is in the manner of the knowing, not in the nature(s) of the thing known. (Emphases in original)

Churchland's suggestion is that one and the same  physical reality appears, or can appear, in two different ways, a third-person way and a first-person way, and that this first-person way of access is no evidence of a first-person way of being.  The sensory quale is not an item distinct from the underlying state of the brain, an item that escapes the physicalist's net; the quale is a mode of presentation of the brain state.   The quale is an appearance of the brain state.  And so Churchland thinks that one can have knowledge of one's sensations via their qualitative features without knowing any neuroscience without it being the case that "sensations are beyond the reach of physical science."

In sum, sensations are identical to brain states.  But they can be accessed in two ways, via qualia, and via neuroscience.  That there are two different modes of epistemic access does not entail that qualia are distinct in reality from brain states.  One and the same btrain "uses more modes and media or representation than the simple stoarge of sentences." 

Critique

Unfortunately, there is no clear sense in which a quale is an appearance of a brain state. The former may be caused by the latter. But that is not to say that the  quale is of or about the brain state. Phenomenal redness does not present a brain state to me. It does not present anything (distinct from itself) to me. After all, qualia are non-intentional: they lack aboutness.   No doubt a quale has a certain content, but not an intentional or representational content. One can describe it without describing what it is of, for the simple reason that there is nothing it is of. An intentional state, however, cannot be described without describing what it is of.  I can't desire without desiring something, a cold beer, say.  So 'cold beer' enters, and enters necessarily, into the description of the mental state I am in when I desire a cold beer.  But no words referring to neural items need enter into the description of what I experience when I experience a yellowish-orange afterimage, or feel anxious.

Qualia do not play a merely epistemic role as Churchland thinks.  They are items in their own right.  They are not mere appearances of an underlying reality; they are items with their own mode of being.  For a quale, to be is to be perceived.  Its reality consists in its appearing.  For this reason it makes no sense to say that the reality of a quale is something distinct from it, something physical to which the quale refers.

Suppose someone, armed with the Indiscernibility of Identicals,  were to argue that the Morning Star and the Evening Star are numerically distinct because they differ property-wise, the one, but not the other, being the brightest celestial object in the morning sky.    Such an argument could be easily rebutted by pointing  out that the two 'stars'  are merely different modes of presentation of one and the same physical thing, the planet Venus.  Difference in epistemic access does not argue difference in being!  Churchland  thinks he can similarly rebut the person who argues that qualia are distinct from brain states by claiming that qualia and sentences of neuroscience are different modes of presentation or "media of representation" of one and the same thing, which is wholly physical.

But here is precisely where the mistake is made.  Qualia do not present or represent anything. In particular, they do not represent their causes.  They are items in their own right with their own mode of being, a mode of being distinct from the mode of being of physical items.  For a quale, to be is to be perceived.  For a physical item, this is not the case.  One cannot drive a wedge between the appearance and the reality of a quale; but one can and must drive such a wedge between the appearance and the reality of physical items. 

Even if one were to insist that qualia present or represent their underlying brain states, the materialist position would still be absurd.  For if x represents y, then x is distinct from y -- in reality and not merely for us.  So if phenomenal redness is an appearance of a complex brain state, the two items are distinct.  Churchland thinks he can place qualia on the side of representation and then forget about them.  But that is an obvious mistake.

Underlying this obvious mistake is the fundamental absurdity of materialism, which is the attempt to understand mind in wholly non-mental terms.  It cannot be done since the very investigation of physical reality presupposes mind.

Comments

[Spencer]

Hi Bill,

Nice Post! You write: "For a quale, to be is to be perceived. Its reality consists in its appearing." I think you may be able to make an additional argument against Churchland. You might push the point that nothing just plain "appears"; everything appears to some subject. I know Buddhists disagree, but to me it seems that the presence of an appearance entails a subject to whom that appearance appears. If that's right, then the materialist faces the additional challenge of explaining (or explaining away) the subject.

You write: "The former may be caused by the latter. But that is not to say that the quale is of or about the brain state."

I think Churchland may have an extremely deflationary account of "representation" such that to represent X just is to be in some causal relationship with X. My professor, Michael Tooley, endorses something similar. I'd be inclined to say, and I think you'd agree, that this is an error theory of, rather than an account of, representation. But that seems to me to be what Churchland is committed to.

Finally, the eliminitivist interlocutor is going to insist that you've begged the question by asserting that there are "what it's like" facts in the second premise of your version of the argument. "Our very position is the denial of that claim! All you're doing is asserting that our claim is false and that does not constitute an argument!"

Take care,

[Spencer]

Oh yeah, and "refute" is a success term. Your title suggests Churchland was successful.

[Matt Hart]

Bill,

You say, "Churchland thinks he can similarly rebut the person who argues that qualia are distinct from brain states by claiming that qualia and sentences of neuroscience are different modes of presentation or "media of representation" of one and the same thing, which is wholly physical."

Is this really Churchland's position? I would read him as claiming that qualia-awareness and sentences of neuroscience-awareness are both awarenesses of something wholly physical. So we should distinguish between the type of awareness and the object of awareness, such that when Churchland talks about awareness of qualia he doesn't intend to refer to the object of that awareness, but to that type of awareness state.

But if that is true, then your complaint that qualia "do not present or represent anything" is neither here nor there – the debate concerns the object of certain awareness states, and 'qualia' merely functions to denote a type of awareness state.

And if you claim that it is obvious that qualia are the object of qualia-awareness states, then he will presumably play the adverbial card: you aren't seeing red, you're seeing redly. The upshot being that he isn't committed to the claim that qualia (qua object of awareness states) are the entities doing the representing.

[Bill Vallicella]

Spencer,

Thanks for the comments. You are absolutely right, 'refute' is a verb of success. (I have made this point myself more than once.) I have made a correction in the title by the addition of 'sneer' quotes.

I also agree with you that to appear is to appear to something. One could give that the fancy name, 'dative of manifestation.' Presumably a materialist has to say that qualia appear to the brain, that the brain is the subject of experience -- which I find absurd. The brain is no more the subject of experience than my eyeglasses are the subject of vision. I didn't go into this because I thought it best reserved for a separate post.

The Buddhists and Humeans who deny the subject are in a better position than those who identify it with the brain.

[Bill Vallicella]

Spencer,

As for analyzing representation in causal terms, I think that is quite hopeless. See this post on representation and causation: http://maverickphilosopher.typepad.com/maverick_philosopher/2011/01/representation-and-causation-with-some-help-from-putnam.html

Anyone who denies that there are qualia is a sophist, and as a general rule: Never debate with sophists! Perhaps the best way to deal wth a qualia-denier is to kick him in the balls and then ask him whether he feels anything. When he agrees in expletive-loaded sentences, you say, "Now you know what qualia are!"

That there are qualia is a self-evident phenomenological given. But that leaves us with the question whether they can be reduced to something physicalistically respectable. (Prima facie, elimination is not the same as reduction.) The way I read Churchland in that section of his paper on which I am commenting, is that he reduces qualia to modes of presentation of brain states. Qualia are the brain's presentation to itself of certain of its states. But then I argue that qualia cannot be merely epistemic, but are items in their own right. (Here I agree with Searle.)

So I am not begging the question.

If I am told that I beg the question by affirming the existence of qualia, then I say that I am merely pointing out what is obvious to all who are not in the grip of physicalist/eliminativist ideology. Pointing out plain data cannot be a fallacious procedure. (All philosophy begins with data.) If I say that there are rattle snakes in Arizona and you are an eliminativist about Arizona rattlesnakes, I haven't 'begged the question.' There simply is no legitimate question whether there are Arizona rattlesnakes.

It is worth noting that the existence of qualia is more certain than is the existence of Arizona rattlesnakes -- for Cartesian reasons.

What is truly bizarre is that intelligent people can be tempted to take seriously this eliminativist nonsense.

[Bill Vallicella]

Matt,

Your comment reminds me of our earlier discussion of property dualism. You seemed to be disagreeing with me, but it turned out we were 'on the same page.' Ditto here.

For C. the only reality is physical reality. So there is nothing more to mind than brain and its states. But then what do you do with phenomenal redness? C's move is to say that phenomenal redness is just a way certain brain states appear. Therefore it has no ontic status. In reality there are just brain states. Therefore the physicalist net snags everything in reality there is to snag. Therefore, physicalism leaves nothing out. Therefore qualia constitute no argument against (functionalist) physicalism. Therefore, Mary, upon emerging from her B & W room, learns no new fact about the world; she merely acquires a new way of conceptualizing, of accessing, physical facts that before she accessed merely via the sentences of neuroscience.

[Matt Hart]

Bill,

Yes, but you say, "C's move is to say that phenomenal redness is just a way certain brain states appear. Therefore it has no ontic status."

My point is just that I don't think C. would say that "phenomenal redness" is what is doing the representing, but the mental event/state which we term 'being aware of phenomenal redness'.

[Eric Thomson]

Interesting arguments I will have to think about more, but here's a first pass at how Churchland might rephrase things.

For Churchland, appearings (in the phenomenological sense) are states of nervous systems. Every animal with the right kind of brain can undergo such events. My dog has Buddy a phenomenology, for instance.

In addition to this capacity, a few lucky nervous systems can actually describe experiences and form concepts about qualia. This is relevant because Mary arguments trade on knowledge of experiences, not merely having experiences. To be able to talk about qualia is a sophisticated skill that comes with people thinking about perception. Unfortunately, my dog Buddy cannot form concepts about experiences qua experiences. He has no theory of perceptual contents. He has perceptual contents but doesn't know it.

For the species lucky enough to be able to think about qualia, according to Churchland, there are two routes to gain knowledge of these states. Note I am not saying there are two ways these brain states "appear" (phenomenologically) as that would invite confusion, and is most likely false. It is about two routes to gain knowledge of qualia. For Churchland the claim to have knowledge is not a directly phenomenological claim, so to frame his argument as about two ways the brain state can 'appear' would be inaccurate.

One route to learn about qualia, the "scientific" route, Mary can take. She can study these experiential states from the outside, as a scientist. Even though her brain will never be in that experiential state, she knows the hell out of them.

The other, "direct" route is only open to those who are able to be in that brain state, that state of having color experiences. In addition to being able to experience color (as my dog can), they can learn to describe color experiences as such, and they can do this 'directly' in response to having that experience (my dog cannot).

Normals learn to recognize they are experiencing redness and say 'I am experiencing redness right now,' while poor Mary would have to look at their fMRI and say 'Oh look she is experiencing redness right now!' But both have the knowledge that subject X is experiencing redness. One just isn't in that brain state herself, so is not having that experience (and this would trivially flow from Mary's theory: she would predict this).

In both cases, the target phenomenon is the same experience (the neural state) but the route to activation of the relevant concepts that constitute knowledge of said experience is quite different.

[Bill Vallicella]

Matt,

I didn't say that phenomenal redness does the representing, but that phen. redness is just a way certain brain states appear.

C speaks of two different "manners of knowing" one and the same thing. The move C is making is to say that, since qualia are merely a manner of knowing, they have no ontic status; therefore, physicalism does not leave them out.

Consider lightning. It is true to say that lightning is just an atmospheric electrical discharge. There is nothing spooky or occult about it. The reduction goes through. We can ignore, for the sake of that scientific reduction, the appearing of lightning to us.

C thinks the same move can be made with respect to the sensations associated with the seeing of lighning: we can prise apart the appearance and the reality. The reality is the brain state. The appearance is simply a manner of knowing that brain state which we can safely ignore for the sake of the scientific reduction.

This doesn't work, however. One cannot prise apart the appearance and the reality of the appearing of the lightning. That appearing is an item on its own account and it does elude the physicalist net.

[Bill Vallicella]

Eric,

Thanks for the comments.

>>To be able to talk about qualia is a sophisticated skill that comes with people thinking about perception.<< I agree, but one cannot talk about them, or describe them unless they appear. I stare at a bright light, then close my eyes. An afterimage appears. That is an example of a quale. I can talk about it and describe it as oval in shape, orangeish in color, etc, but only if it appears to me.

>>One route to learn about qualia, the "scientific" route, Mary can take. She can study these experiential states from the outside, as a scientist. Even though her brain will never be in that experiential state, she knows the hell out of them.<<

I think this misrepresents the situation. Mary while in the B & W room has no acquintance with color qualia at all (though she is acquainted with other qualia). So she cannot learn about color qualia while in the room. What she learns about are patterns of neuron firings, etc. She reads in her black and white book something like, "When a normal human is presented with a red rose, such-and-such a pattern of neruon firings occurs in such-and-such a region of the visual cortex." Mary is in no position to correlate the sensory quale, phenomenal redness, with the brain states mentioned in the text because she has no acquintance with phenomenal redness whatsoever while she is in the room.

So, contrary to what you say, Mary in the room learns nothing about color qualia; she learns about the underlying brain states that would occur in her were she to go outside and look at a red rose, say.

I think you are just assuming that the quale is identical to the brain state. And then the difference between Mary in the room and Mary outside the room is the difference between Mary having only book knowledge about the brain state and Mary having book knowledge and actually being in the brain state in question.

But this simply begs the question by assuming that quale = brain state. But I say they cannot be identical since the quale has phen. features that a brain state cannot have.

Or are we playing a game of mutual question-begging?

[Eric Thomson]

I think the question-begging isn't mutual. Since the point of the Mary scenario is to compel us to reject materialism, it seems a perfectly legitimate strategy to show how the Mary scenario could obtain, but materialism still be true. Sort of like responding to the argument from Evil by saying that God has motive X, even though the point of the argument is to compel us to reject God.

The response to Mary doesn't show that materialism is true, but only that the Mary argument doesn't kill it.

Incidentally, Frank Jackson discusses why he now rejects his Mary argument, and his representationalism about consciousness in this piece.

[S01]

Ed Feser also has some interesting things to say about Jackson's turnabout. Kim's turnabout in the other direction is worth noting too.

[Bill]

I am not a reductive physicalist, but have always been puzzled by an implicit assumption about knowledge and thought made by both Jackson and Churchland.

There appears to be an assumption that thinking about verbally expressible concepts, no matter how abstract, is somehow without paradox for a reductive physicalist, but the non-verbal conceptual knowledge of a phenomenon like a raw sensory experience, even though gotten via ordinary experience of the physical world, is somehow a problem for the reductive physicalist.

For example:

Mary thinks about a new sensation created by concretely red in wavelength light striking her retina, and this nonverbal experiential knowledge is somehow not physical knowledge, apparently? (What is "physical knowledge" then?)

Mary thinks about quantum membrane potentials, or the mathematics of probability theory, and this is somehow fine for the physicalist, even though the abstract concepts in her thought are not concrete?

This is confusing. Why should abstract semantic thought be acceptable to the reductive physicalist and nonverbal sensory experience somehow be problematic to him? It should be both or neither.

[Bill Vallicella]

Bill H writes, >>There appears to be an assumption that thinking about verbally expressible concepts, no matter how abstract, is somehow without paradox for a reductive physicalist, but the non-verbal conceptual knowledge of a phenomenon like a raw sensory experience, even though gotten via ordinary experience of the physical world, is somehow a problem for the reductive physicalist.<<

That's basically right, except that you should strike 'conceptual.' I wouldn't call a "raw feel," to use Herbert Feigl's old expression, 'conceptual.' Most physicalists distinguish the problem of intentionality from the problem of qualia, and refer to the latter as the 'hard problem.' This implies that intentionality, if not exactly 'easy,' is at least tractable. I would say that the distinction is crude and superficial and that both problems spell the doom of physicalism.

>>Why should abstract semantic thought be acceptable to the reductive physicalist and nonverbal sensory experience somehow be problematic to him? It should be both or neither.<<

Your question is a reasonable one. The answer is that qualia have an intrinsic character that resists functional analysis. This is hard to explain in a few words, so I'll refer you to my other posts.

[Bill]

>>qualia have an intrinsic character that resists functional analysis

So by "reductive" or "functional" analysis we mean, put into mathematical and abstract, verbally communicable form in the language of physics?

This is not a "knowledge" argument, it is a communicability argument.

Both Jackson and Churchland have a false analogy in mind about mental representation. It is as if they think that reductive physicalism means that everything we think or feel must be "written" and readable in symbols in the brain, as if all of our thought and feelings were somehow written down somewhere like instant messages.

Yes, "qualia" or nonverbal knowledge is not expressible or communicable fully in that way, but how does the communicability of a thought in semantic terms mean anything about whether knowledge, feeling, or thought themselves are physical?

[Bill Vallicella]

Not quite. Maybe tomorrow I can explain it more fully.

[Eric Thomson]

Disagree with: "After all, qualia are non-intentional: they lack aboutness. No doubt a quale has a certain content, but not an intentional or representational content."

and agree with:
"one is superficial and thoughtless if one imagines that a clean separation can be made between qualia and intentional phenomena."