Presentation on theme: "Don’t Know Much About Qualia… Or Do We? Justin C. Fisher University of Arizona – Dept of Philosophy March 10, 2004."— Presentation transcript:
Don’t Know Much About Qualia… Or Do We? Justin C. Fisher University of Arizona – Dept of Philosophy March 10, 2004
Overview Introduction Anti-Physicalist Arguments A Parody: The Confoundment of Man (The End) Objections and Replies
a priori vs a posteriori knowledge Water is the predominant local stuff that rains from sky, flows in rivers, etc… If the local stuff that actually does all those things is H 2 O, then water is H 2 O. Ah yes… H 2 O is the local stuff that actually does all those things.
Various Formulations of Physicalism There is nothing more to the world than the sorts of things and properties that physicists study. Insofar as contingent arrangements of objects and properties serve to make our claims true, these arrangements are of physical objects and properties. (All information is physical information.) (The physical truths a priori entail all the truths.) (A minimal physical duplicate of our world would be a complete duplicate…)
What are Qualia? Qualia are supposed to be the properties that constitute the ‘phenomenal character’ or the ‘what it’s like’ of conscious experience. We are supposed to have direct knowledge of our (current) qualia. Louis Armstrong: “When you got to ask what it is, you’ll never get to know.”
The Explanatory Gap (Joe Levine) No amount of physical findings could explain the things we know about qualia. (For we should know a priori how any plausible explanations might go, and we have no such knowledge…) ??
The Knowledge Argument Mary spends her entire life in a black and white room, and there learns all the physical info relevant to color vision. When she finally sees color, she gains new info. So not all info is physical info. Frank Jackson
Rene Descartes Conceivability Arguments (1) I can conceive of my mind existing without any body, so my mind must be distinct from my body.
Zombies & Spectral Inverts It’s conceivable that physically indistinguishable beings might have different qualia… so qualia must be non-physical. == Dave Chalmers
Common Structure P1. We have qualia. P2. We will forever lack a priori knowledge of the relations between qualia and ordinary physical properties. P3. Such a priori ignorance about a property we have would pose problems for physicalism. –Physicalism can’t hope to explain qualia. –Physical knowledge won’t yield qualia knowledge. –Zombies must be conceivable, hence possible. C. Qualia are distinct from physical properties.
My Strategy I will describe a case mirroring the case of qualia, but in which it is stipulated that the properties in question are physical ones. I will then show that the anti-physicalist style of argument runs into problems in this case. Delving into why these arguments would fail in my imagined case will at least help us to understand how these arguments are supposed to work in the case of qualia, and perhaps it will also reveal that they fail in that case as well.
The Confoundment of Man I’LL ENDOW THAT MORTAL FOOL WITH AN EXTRA WAY OF KNOWING THE CURRENT STATE OF HIS VISUAL CORTEX. THAT WILL SURELY CONFOUND HIM!
I now know, beyond a doubt, that I have certain properties. I’ll call them ‘schmalia’… I know some things about how different schmalia are related to one another… But I know absolutely nothing about how my schmalia might be related to the properties that I know about in more ordinary ways….
What are these Schmalia? Are my schmalia familiar properties like mass, or wealth, or being third in line at the marketplace? Or are they new and mysterious properties, of a kind never before encountered? I must seek the advice of wise men…
Joseph Schlevine “Given your ignorance of how your schmalia might possibly be related to other things, no amount of physical information can gain any explanatory foothold with respect to your schmalia. “Even if you found perfect correlates of schmalia you still wouldn’t be able to explain why schmalia are correlated with those properties rather than other ones.”
Frank Schmackson “Imagine that prior to your gift from the gods, you had learned all the physical info. “You’re sure that all this physical knowledge wouldn’t have enabled you to infer the things that you now know about schmalia. “So your schmalia must be non-physical.”
David Schalmers “Given your ignorance about the relations between schmalia and other properties, you can coherently conceive of schombies and schmalia inverts. “So schmalia must not be physical properties.”
The Upshot The gods endowed the man with special knowledge of certain physical properties – ‘schmalia’. Close analogs of the three popular anti-physicalist arguments would lead the man to conclude that his schmalia are not, in fact, physical properties. Since that style of argument would lead the man from true premises to a false conclusion, there must be something wrong with that style of argument.
Possible Responses (1)To deny that the described case is possible. (2)To point out some important disanalogy between schmalia and qualia. –The natural counter would then be to try to remedy the disanalogy. Ultimately, both responses amount to the same thing: denying that the schmalia case can be fixed up in such a way that it is both (1) possible and (2) strongly analogous to the case of qualia.
#1. Deny that the man could have this sort of direct knowledge of physical properties. But most anti-physicalists say that we can have such direct knowledge, at least of qualia. What principled reason do we have for thinking that one couldn’t have such direct knowledge of physical properties?
#2. Demand a story of the mechanism by which the man knows schmalia, while being quite ignorant of their nature. Several physicalists have offered potential stories (e.g., Loar, Millikan, Papineau). (Anti-physicalists have no better story of the mechanism by which we know qualia.)
#3. Insist that direct knowledge of physical properties would reveal them as such. But this is hard to motivate… It also gives the anti-physicalist a suspiciously easy argument: –If my qualia were physical properties I’d know it. –I don’t know any such thing. –Hence, my qualia aren’t physical properties.
#4. Deny that the man can ‘positively conceive’ of schmalia in the way that would be needed to entail possibility. No one has a clear account of ‘positive conceivability’! It’s not clear that we can ‘positively conceive’ of qualia. Supposing we can positively conceive of qualia in the relevant sense, it’s not clear what principled reason we could have for saying that the man couldn’t possibly positively conceive of schmalia in the relevant sense.
#5. Deny that the man could be truly a priori ignorant of the relations between schmalia and ordinary physical properties? (1) What else might the man know a priori ? –That schmalia play a causal role in generating his confident beliefs and reports about schmalia? –That, if the most parsimonious theory of everything identifies schmalia with certain physical properties, then (probably) schmalia are identical with those physical properties? –That schmalia are properties that are related to his beliefs about schmalia in accordance with some good naturalized theory of representation?
#5. Deny that the man could be truly a priori ignorant of the relations between schmalia and ordinary physical properties? (2) Extra a priori knowledge might help block the anti-physicalist arguments in either case. It’s more plausible that we do have such a priori knowledge in the single case of qualia, than that one would have to have such knowledge in any possible case of knowing schmalia. Hence, this response invites more problems than it solves for the anti-physicalist.
#6. What about Chalmers’ 2D-argument? 1.Zombies are conceivable. 2.So, there is an epistemically possible way that the world might turn out actually to be, such that there are zombies in it. 3.For each epistemic possibility, there is a corresponding genuine metaphysical possibility. 4.Whenever a Qualia-claim is conceived as being true of an epistemic possibility, the corresponding Qualia-claim would be true of the corresponding genuine metaphysical possibility. 5.So, zombies are metaphysically possible. 6.So, physicalism is false.
(4Q) Whenever a Qualia-claim is conceived as being true of an epistemic possibility, the corresponding Qualia-claim would be true of the corresponding genuine metaphysical possibility. This substantive premise is not entailed by (and may not even be compatible with) the claim that we are quite a priori ignorant about our qualia. Hence, one might hold that such a premise holds in the case of qualia, but not schmalia; thereby yielding a disanalogy between the two cases. But what exactly does this premise mean?
Conceivably, (4W) Whenever a Water-claim is conceived as being true of an epistemic possibility, the corresponding Water- claim would be true of the corresponding genuine metaphysical possibility. The ‘water’-version of premise 4 can be shown to be false… Actually, H2OH2OXYZ Possibly, XYZ H2OH2O H2OH2O
(4H). Whenever a Healer-claim is conceived as being true of an epistemic possibility, the corresponding Healer-claim would be true of the corresponding genuine metaphysical possibility. The ‘healer’-version of premise 4 is plausibly true… Actually, Possibly, Conceivably,
Two Models Water: for a possible substance to be water it must be the same substance as whatever local substance actually plays the watery role. We can conceive that water might be some other substance, but this isn’t genuinely possible. Healer: for a possible being to be a healer, it need only play an appropriate role; and it doesn’t matter at all what our local healers turn out to be like. Whenever we (positively) conceive of an alien healer, there is a corresponding genuinely possible healer.
Which model best fits qualia? Unlike ‘water’, we (seemingly) can’t say very much a priori about the qualia-y role that local qualia must play. –At best, we can say, whatever Q 23 is, it’s that property, the one I’m having now. (Is this enough?) Unlike ‘healer’, there seems to be no hope of giving a general a priori specification of the role that any possible property would need to play in order to count as an instance of a given quale. –At best we can say that a given quale must play the ‘role’ of feeling as it does. (But why think a given metaphysical possibility genuinely would feel the way the corresponding epistemic possibility is conceived as feeling?)
(4Q) Whenever a Qualia-claim is conceived as being true of an epistemic possibility, the corresponding Qualia-claim would be true of the corresponding genuine metaphysical possibility. The (Type B) physicalist holds… Actually, Conceivably, Possibly,
(4Q) Whenever a Qualia-claim is conceived as being true of an epistemic possibility, the corresponding Qualia-claim would be true of the corresponding genuine metaphysical possibility. The (Type B) physicalist holds that a)As a matter of empirical fact, the property I know as quale Q 23 actually is some physical property, say P 45. b)But still it is conceivable that my quale Q 23 might turn out to be ectoplasmic property E 67, and hence that I may have a zombie twin who lacks Q 23. c)Corresponding to this epistemic possibility, there is a metaphysically possible world, with a smattering of E 67. d)But, this metaphysically possible world is not a world in which quale Q 23 (i.e., physical property P 45 ) is E 67. e)So premise 4 is false.
Upshot Regarding 2D-Argument Chalmers’ 2D-argument requires premise 4. It may be hard to make a plausible version of premise 4 in the case of schmalia; hence, the 2D-argument may evade my parody. But still, premise 4 is not obviously true, and the physicalist might plausibly deny it. Hence, even if the 2D-argument may evade my parody, it does so by taking on a premise that is more difficult to sustain than any in the arguments I parodied.