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American Philosophical Association Eastern Division Colloquium: Philosophy of Mind, December 29, 1995.{1}

Revenge of the Zombies

Larry Hauser (lshauser@aol.com)

ABSTRACT

 Zombies recently conjured by Searle and others threaten civilized (i.e., materialistic) philosophy of mind and scientific psychology as we know it. Humanoid beings that behave like us and may share our functional organizations and even, perhaps, our neurophysiological makeups without qualetative conscious experiences, zombies seem to meet every materialist condition for thought on offer and yet -- the wonted intuitions go -- are still disqualefied (disqualified for lack of qualia) from being thinking things. I have a plan. Other zombies -- good (qualia eating) zombies -- can battle their evil (behavior eating) cousins to a standoff. Perhaps even defeat them. Familiar zombies and supersmart zombies resist disqualefication, making the world safe, again, for materialism. Behavioristic materialism. Alas for functionalism, good zombies still eat programs. Alas for identity theory, all zombies -- every B movie fan knows -- eat brains.

HORROR OF THE ZOMBIES

 The philosophy of mind has been invaded by zombies. These humanoid beings look like they see, harken like they hear, and act like they want. They even talk like they understand our language and know things; but it's all without conscious experiences. Not a quale to call their own.{2To imagine what this would (or, rather, wouldn't) be like for you if you were them, recent zombie experiments have it, is to realize you'd be utterly mindless. You'd have no mental properties whatever! Worse, it seems every physical correlate of the mental qualities that zombies act like they have can be cogently stipulated or imagined to obtain minus conscious experiences. Whatever their behavior, physical constitution, and functional organization are supposed to be -- the wonted intuitions go -- zombies are still disqualefied from being thinking things. Hereon hangs the horror of the tale. If they eat behavior, brains, and programs, zombies seem to devour everythingphysical that minds have plausibly been thought to be.{3}Zombies threaten to return us to the failed policies of the past: to dualism.

These zombies must be stopped before they destroy civilized philosophy of mind and scientific psychology as we know it. I have a plan. Enlist good zombies to battle their evil cousins.{4}Supersmart zombies, and familiar zombies, I have discovered, resist disqualefication. Their imagined or stipulated lack of qualia seems not to impugn the genuineness of their apparent cognitive or intentionalmental endowments. These zombies can battle their evil cousins to a standoff, at least. Perhaps even defeat them. Good zombies eat dualistic stuff: qualia for breakfast. Woe to functionalism, though: for lunch they still eat programs. And woe to identity theory: they still dine on brains. But they don't eat behavior. Familiar zombies and supersmart ones preach behaviorism.

ISLAND OF DR. SEARLEAU

To evoke zombies, Searle instructs, "always think of [the thought experiment] from the first person point of view" (Searle 1992: 67). Searle's 1992 evocation illustrates the procedure. As stage setting, suppose that doctors gradually replace your brain with silicon chips, perhaps to remedy its progressive deterioration. From here, conjure yourself a zombie by imagining as follows:

as the silicon is progressively implanted into your dwindling brain, you find that the area of your conscious experience is shrinking, but that this shows no effect on your external behavior. You find, to your total amazement, that you are indeed losing control of your external behavior. . . . [You've gone blind but] you hear your voice saying in a way that is completely out of your control, "I see a red object in front of me." . . . [I]magine that your conscious experience slowly shrinks to nothing while your externally observable behavior remains the same. ( 66-67)
No sooner are such zombies conjured, of course, than they're off on their destructive rampage against behaviorism: "we imagined . . . the behavior was unaffected, but the mental states disappeared" (Searle 1992: 69). And again, there seems no way to stop them before they transmogrify. Suppose -- besides maintaining behavior -- the replacement chips implement the same programs, maintaining the all same functional relations as the neurons replaced. There goes functionalism. As for identity theory . . . suppose the medical doctors are powerless. You are desperate. You have heard of a certain witch doctor. You fly to a remote isle, voodoo rites are enacted, and voila. The deterioration of your brain is magically reversed. It functions physically (chemically, electrically, etc.) just as before. To the amazed medical doctors back at the clinic, your brain is indistinguishable from your very own predeteriorated brain. But wait! As your brain is being magically restored . . . it's just as before. Your conscious experience slowly shrinks to nothing.{5}There goes identity theory. Zombies ate its brain.

Against Searle's zombie, Daniel Dennett proposes a line of defense -- or rather prophylaxis. Searle's evocation, Dennett complains, is "only one of the logically possible interpretations" of the experiment. "The other," Dennett asserts, "is the crucial one: while you . . . are dying, another consciousness is taking over your body. The speech acts you faintly hear your body uttering are not yours, but they are not nobody's!" (Dennett 1993: 198-9){6}Where Searle conjures zombies, Dennett imagines multiple personalities. While yours fades out, an alien one (not a zombie) fades in. Unfortunately, this won't do. Zombies (as Bringsjord 1994 points out) easily breech this Dennettian line. To be "one of the logically possible interpretations" is still to be a logically possible interpretation: just Searle's point. As logical possibilities, it seems zombies can't be prevented. Once loosed, they can't be stopped before they transmogrify. Good zombies to the rescue.

LOGIC CHOPPER CHICKS IN ZOMBIETOWN

To premise that lack of consciousness or subjective experiences disqualefies a body from having any mental properties whatever -- to make this the basis of your thought experiment -- is question-begging. Thought experiments, like other experiments, are supposed to adjudicate between competing hypotheses; but only dualistic hypotheses privilege evidence of subjective experiences, accessible only privately or introspectively, from the subject's "first-person point of view," to override all public evidence of performance and physiology accessible to third-persons.{7}Competing materialistic hypotheses (behaviorism, functionalism, identity theory) do not so privilege the first-person. So, the epistemic priority of the first-person point of view cannot be assumed here. It has to be supported . . . and, perhaps, it is . . . by the zombie spawning thought experiment itself. The intuition by which Searle conjures zombies -- despite Searle's strict decoupling of epistemology from ontology elsewhere -- must be at least partly epistemic. Though the first-person point of view is, ultimately, supposed to be epistemically privileged because "the ontology of the mental is essentially a first-person ontology" (Searle 1990: 70), what evidences this first-person ontology in Searle's thought experiment seems to be the epistemic intuition that "from a third-person point of view, somebody [else] might not be able to tell whether I had any mental states at all" but for me, "[f]rom the first-person point of view, there is no question" (Searle 1992: 70).

Let us concede that Searle's and like zombie experiments do pump such epistemic and, perhaps, concurrently ontological intuitions. Searle and like-minded zombiephiles seem to think end of story. This is due to their "one-sided diet" of philosophical examples (Wittgenstein 1958, 593). Though zombiephobes like me are no more entitled to assume the first-person point of view to be nonprivileged than zombiephiles like Searle are entitled to assume "the first-person point of view is primary" (Searle 1992: 20), we are entitled -- thank you very much -- to conduct our own thought experiments, imagining different zombies from other points of view. To "always think of [zombies] from the first person point of view" (Searle 1992: 70: my emphasis) -- as Searle recommends -- biases our imagining several ways. Counterpoising an intimate, engaged, first-person perspective to a detached, impersonal third-person one, for instance, works strongly to the latter's intuitive disadvantage in such cases as zombiephiles consider. Works illicitly, I submit; for herein it neglects a crucial third alternative. The second-person point of view: engaged, though external. From this perspective, there's I and thou . . . and thou art zombies. Searle says, "we need to rediscover the social character of the mind" (Searle 1992: 248). Familiar zombies inhabit this neglected territory. Zombiephile scenarios also gratuitously tend to constrain how smart we imagine our zombies to be(have), tending to limit us to imagining them to be(have) no smarter than us. Supersmart zombies throw off this constraint. Then again, to imagine oneself a zombie is to imagine just one. The first-person point of view inclines you to imagine your zombiehood to be exceptional. Unless we control for this, the possibility remains that the intuition that zombification is tantamount to complete dementalization is (partly or entirely) not an intuition that you're disqualefied but that you're excepted. Indeed, imagining oneself the zombie doubly eases the exclusion of zombies from the club of thinkers: in the first place because it's just one; and in the second because it's oneself (you needn't blackball someone else, just resign your own membership.)

Familiar zombies and supersmart zombies pump intuitions contrary to and at least as compelling as those pumped by dualists' zombie familiars. I think more compelling -- but let the reader decide. Given their weighty theoretical and methodological baggage, a push is enough to sink the dualistic alternatives. Little else, besides zombiephile intuitions, I submit, commends them.

I WALKED WITH A ZOMBIE

 If cognitive science is deformed by the neglect of any point of view, perhaps it's the second-person, not the first. Imagine, then, for starters, that your mother's a zombie. How you might discover this is, strictly, beside the point; but, as an aid to imagination, add some cheesy special effects. It's discovered during would-have-been routine brain surgery that Mother, in place of a brain (like you) has a head full of sawdust (like some antique dolls): a head full of something that's (1) not like our neurophysiological stuff, (2) not apt to be giving off qualia,{8}and (3) insufficiently differentiated to support much functional organization. Of course, nothing turns essentially on sawdust. Substitute whatever you like. Or nothing at all: a vacuum: her brainpan's hermetically sealed, and the air rushes in with a whoosh when her skull is opened for surgery. Or just take your stipulation neat. Sawdust heads are just a graphic way of imagining various candidate thinkers who fail to meet dualistic and functionalist and identity theoretic conditions for thought. Stipulate (or imagine), then, that Mother hasn't a quale to call her own; nor has she suitable neurophysiological stuff; nor appropriate functional organization. Her behavior, as ever, is unchanged. I submit, you should not deny her mental abilities and attainments. She still wants you to succeed, still knows where her children are, prefers scotch to bourbon, etc. To strengthen the intuition, extend the fantasy to your father, your spouse, your children, all your friends, siblings, colleagues, teachers, your thesis advisor, all the members of your guidance committee, most everyone you know. They're all zombies! Sawdust for brains every one. Should you conclude Mother and the rest think not: that they know nothing at all and don't understand English? How could you? It was from them, after all, that you got your English. It was from Mother et al., in particular, that you got such words as "think," "know," and "understand". I think you should conclude, "How odd! I alone have these peculiar twinges, images, etc. besides the wants, beliefs, etc. others have." And had you previously thought qualia to be the very "stuff" of thinking -- laboring under the impression that what Mother et al. had sought to do in teaching you the vocabulary of "belief," "desire," etc. was, by a kind of "inner" ostension, to get you to refer by "belief," "desire," etc. to such qualia as you alone (you now discover) so strikingly experience -- you should, I think, under the envisaged circumstances, conclude, you were mistaken. The thought of mental life without qualia may be horrible; but it's possible. Familiar zombies show this.{9}

THE ASTRO-ZOMBIES

They come from outer space: humanoid in form except . . . you guessed it. Vacuum heads. These extraterrestrials haven't qualia and lack appropriate functional organizations and neurophysiological stuff. Yet they behave intelligently. Very intelligently. They show us how to make our microwaves synthesize food out of thin air and how to turn our Ford Tempos into time machines, revolutionizing our physics as they explain how. Let them show us how to achieve peace on earth, with liberty and justice for all, before they depart. What should we say? That our ET benefactors didn't really know how to turn Tempos into time machines? That they didn't really understand the revolutionary physical principles involved but now we do? Even in our present unregenerate state, I think we're not so ungrateful and conceited as that. We'd say our qualia bereft benefactors knew how to turn Tempos into time machines.

Or if the carrot doesn't persuade . . . suppose the Astro-zombies act just as smart, but unfriendly.{10}They come to conquer. Let the conquest be achieved by wile, rather than by superior force of arms. They do it this way to rub it in how superior they are . . . and so as not to waste food. Most of us amply qualefied folk, you see, they fatten up to eat. A few they keep, after the conquest, as hewers of dilithium crystals and drawers of XYZ. Suppose the role of our hewing and drawing in the Astro-zombie form of "life" to be as far beyond our pathetic qualia addled brains' comprehension as the principles of agricultural economy are beyond the ox.{11}I don't imagine us hewers of dilithium crystals and soon-to-be humanburgers being much inclined to console ourselves with thoughts of our intellectual superiority and their intellectual nullity.

ZOMBIES ON BROADWAY (IN THE LOUVRE, AT CAMBRIDGE . . .)

These zombies are both smart and familiar ( or, rather, venerated). It's discovered, imagine, that many, most, or even all the leading contributors to our human intellectual heritage(s) were zombies. Again -- talking metaphysics -- it's irrelevant how this might be discovered. Perhaps they're exhumed, autopsied, and -- surprise! -- heads full of sawdust. Nevertheless, I submit, we should not deny their mental attainments. We should not infer as follows: deriving, being a mental activity, necessarily involves qualia; Newton, we now know, had no qualia; so, Newton never derived "Kepler's" laws of planetary motion and "Galileo's" laws of free fall from "his" laws of motion and universal gravitation. Should we revise our accounts of intellectual history, under the circumstances, to say the first bebrained qualefied plodder to read and passably understand Newton's Principia was really the first to derive "Kepler's" and "Galileo's" laws from "Newton's"? I think not. Their neurophysiological and functional deficits seem similarly powerless to nullify these zombies' intellectual attainments. Despite not meeting any would-be essential condition for thought on offer, these famously smart zombies remain not just candidate thinkers but paradigm thinkers, solely on the strength of their deeds. On the strength of behavior.{12}

SOLE SURVIVOR

If bad zombies eat behavior, and good zombies eat qualia, and all zombies eat brains and programs, it seems, at first glance, that zombies destroy all. No credible theory of mind survives. It seems the materialism that zombies make the world safe for is just the eliminative sort. A closer look, though, discovers behaviorism, and it seems dualism too, sheltered in a gap the battle of good and bad zombies reinforces. Our differing intuitions about intentional mental states and qualetative states under the different zombie-thought-experimental conditions imagined gives further "reason to firmly distinguish between qualitative and nonqualitative mental states" (Block 1978: 288). Imagining Searle's zombie from the first-person point of view, while seeming to undermine behavioristic accounts of qualetative states, still leaves scope for behaviorism about the intentional. Conversely, imagining familiar zombies and supersmart zombies from second-person and third-person points of view, while undermining dualistic accounts of intentional states, seems still to leave scope for dualistic accounts of the qualetative.

Is it a standoff, then? Does dualism rule the qualetative night, and behaviorism the cognitive day? This seems an unstable situation: behaviorism and dualism are mortal enemies. One should like a more unified account of the mental -- qualetative and cognitive -- than the division of the territory we now contemplate seems to allow. Even if one sympathizes with Block's observation that "qualia may well not be in the domain of psychology" (Block 1978: 288), the tension is not well resolved: these are at least adjoining territories, wanting perhaps different accounts, but not warring accounts. Dualism must die! With one foot in the grave already -- if dualism isn't the only conceivable account of the qualetative -- good zombies may yet provide the banana peel. I think they do.

By dualism's "foot in the grave" I mean its longstanding, intractable, other minds problems, introspection troubles, and mind-body interaction puzzles. The banana peel? A dualistic account of just the qualetative states -- that wallowed in "raw feels" to the exclusion of proper cognition -- would not be leaner and meaner but a travesty. Enough to make Descartes rise from his grave. The "real gap" Searle acknowledges "in [his own] account . . . that [it] do[es] not explain the details of the relation between intentionality and consciousness" (Searle 1991: 181) looks irreparable (see Wittgenstein 1958; c.f. Kripke 1982) and fatal. Behaviorism about just the intentional states, on the other hand, might wellbe leaner and meaner.{13}

 But what of the qualetative? A zombieproof account of the qualetative crucially incorporating behavioristic elements may be at hand (see especially Lewis 1995): a "mixed theory," such as David Lewis proposes, " that joins claims of type-type psychophysical identity with a behaviorist[ic] . . . way of characterizing mental states," (Lewis1980: 217){14}short-circuits intuitions animating voodoo zombies.{15}It does so by insisting, behavioristically, that pain (e.g.) is not a natural kind, that "the concept of pain . . . is a nonrigid concept," and "the word 'pain' is a nonrigid designator" (Lewis 1980: 218) Thanks to this behavioristic admixture, the mere logical possibility of voodoo zombies holds no terror for this sort of identity theory.{16}Intentional states, however, require no identity theoretic admixture. Good zombie experiments seem to show that, besides requiring no identity theoretic admixture to their accounts, intentional states admit none.{17}{18}

"But isn't behaviorism a carcass"{19}itself? Though I am firmly persuaded that reports of metaphysical behaviorism's demise have been exaggerated, I only pause, here, to note that good zombie cases, themselves, have palliative virtues for behaviorism that are not inconsiderable.  If metaphysical behaviorism really were defunct -- zombies being notoriously persistent and hard to ignore -- there would seem to be no alternative but eliminativism: the nonalternative. Surely prospects for behaviorism are not so desperate as that.{20}

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NOTES

1. Thanks to the members of the Michigan State University Philosophy of Language Discussion Group -- Barbara Abbott, Gene Cline, Rich Hall, Herb Hendry, Miles McNally, Stan Mortel, and Carol Slater -- for their many helpful comments on this paper, and for discussions of related issues over the past several years. I am also grateful to Selmer Bringsjord for alerting me to the seriousness of the zombie menace to materialism (which he is more inclined to see as deliverance from materialism) and for several provocative discussions which helped inspire this paper. A videotape of me presenting this paper at the Eastern APA is available from Milk Bottle Productions.^

2. Besides Searle's recent (1992) brain-implant zombies (considered below), zombiekind includes Searle's (1980a) Chinese room and its variants (see, e.g., Bringsjord 1992, chapt.5); Gunderson's (1993) MUSAIs (robots that mimic but don't really have qualetative mental states like ours); Block's (1978, sect. 1.2) homunculi heads and variants (cf. Searle 1990a's Chinese gymnasium; Bringsjord 1992, chap.6); and various other "arbitrary instantiation" scenarios such as Searle's (1984: 28-9; 1990a) wind-powered beer cans, Block's (1990) mice and cheese logic gates (i.e., computers made therefrom), etc. Block's (1981) conversational "jukebox" is also zombielike but -- being imagined or intuited to be disfunctional rather than disqualefied -- not a proper zombie according to the characterization of zombies adopted here.

3. "Zombies eat X" should be understood to abbreviate something like "Zombies counterinstance the theory that minds are analyzable in terms of or essentially identifiable with X."^

4. Much as it took the combined might of Mothra, Rodan, and Godzilla to save the world from Ghidrah (Hondo 1965): "Tokyo once again gets trampled" (Connors & Furtaw 1995: 425), though.^

 5. If "mental states only exist as subjective, first-person phenomena" then, as Searle asserts, "it seems easy to imagine that some sort of being could have brain states like [mine when I have pain] without having the pain" and even "in which I had this very brain state [I'm in when in pain] without having a pain" (Searle 1992: 39: my emphasis). Searle, here, follows Kripke: "it seems clearly possible that X [a pain] should have existed without the corresponding brain state; or that the brain state should have existed without the pain" (Kripke 1971: 99n17). Though Searle says these things explicitly with regard to pain, if intentional mental states such as propositional attitudes (with which I am mainly concerned here) are essentially qualetative themselves, as zombiephiles generally maintain, then the preceding remarks apply equally to these. (According to Searle, e.g., beliefs and desires are "experienced as such" (Searle 1992: 61) no less than pains and itches: "the mind consists of qualia, so to speak, right down to the ground" (Searle 1992: 20).) Again, if it's "simply an empirical fact about the way the world works" that "intentional mental states are caused by and realized in the structure of the brain" (Searle 1982: 345), to imagine mental states to be sometimes caused (and sometimes not) by these same structures is just, permissibly, imagining another way the world might work. Even more strikingly, according to Searle there are but "few cases where there is a lawlike connection between facts specified in neural terms and facts specified in intentional terms" (Searle 1992: 159; c.f. Searle 1990b: 587).^

6. Cole 1991 advances a similar "multiple personality" reply to Searle's Chinese room experiment.^

7. Though Searle vehemently protests that he is no dualist, he protests too much. His views are at least dualistic -- "as-if dualism", I call it. Searle claims to "give a coherent account of the facts about the mind without endorsing any of the discredited Cartesian apparatus" (1992: 14) then deploys-- by my count -- at least seven Cartesian devices in the account immediately following (14ff). That account affirms (1) the essential subjectivity of mental phenomena; (2) the ontological character of the subjectivity; (3) a distinction between "as-if" and true conscious mentality (which Descartes deploys to deny "the brutes" any mentality -- which Searle redeploys against computers); (4) the "Connection Principle" that "[b]eliefs, desires, etc. . . . are always potentially conscious"; (5) a methodological principle of privileged access -- "that the first-person point of view is primary"; (6) a Cartesian ego, i.e., "a `first person' an `I,' that has these mental states" (n.b., this I <> my brain or body!); (7) a distinction between primary ("intrinsic") and secondary ("observer relative") properties. Perhaps Searle thinks all this Cartesian apparatus creditable -- but then, one wonders what Cartesian paraphernalia he thinks discredited. (C.f. Searle 1987:146.) (Hauser 1993a, chapt.6, shows how Searlean as-if dualism inherits all the most pressing difficulties -- about introspection, knowledge of other minds, and mind-body interaction -- of plain old dualism. See also Hauser 1993b; 1994.)^

8. In the best, "damn the epistemology, metaphysics ahead full" spirit, glossing over real difficulties about how we could ever know this.^

9. Perhaps this zombie fantasy is even more horrible than Searle's. There only I was tragically bereft of qualia. Now, it's Mom and Dad, and everyone dear to me. Sad, no doubt. But at issue is not whether we would or should be saddened, whether it's tragic. At issue is whether, in the envisaged circumstances, we should judge our mothers, fathers, et al. to be mindless -- missing not only itches, tingles, heartburn, afterimages, and the like, but every mental attribute besides.^

10. I am indebted to Herb Hendry (personal communication) for this version of the scenario.^

11. An irony of the recent philosophical quest for the holy quale (pursuit of the hypothesis that qualia are very "stuff" and essence of thought ) is that qualia ( pains, itches, visual imagery, etc.) -- or at least surfeit of qualia -- seem common-sensically to be more of a bane to cognition than a boon. Ample philosophical tradition concurs in this judgment. Common sense has it that no one ever thought up a mathematical theorem or devised a proof while in the throes of orgasm. Traditionally, "active thought" processes such as those involved in philosophical contemplation and mathematical conception have been held (especially by Aristotelians and Cartesians) to be abstract and essentially imageless, i.e., nonqualetative.^

12. My sawdust headed zombies may have been inspired by Thomas Edelson's "autopsy" variation on Searle's Chinese room experiment (Searle 1980a). In opposition to Searle's claims about his Chinese room example Edelson 1982 observes:

The only sure way to demonstrate [Searle's thesis that attribution of intentionality to something depends crucially on the concrete biological nature of what is going on inside] would be to remove from the example all the external differences between it and paradigm cases of intentionality, that is, real people, going about their mental lives in the ordinary way.
 Edelson then proposes what he takes to be such a thought experiment, imagining
A person learns and uses language normally (or appears to) over the entire course of his life. An autopsy reveals that he entirely lacked the brain structures that carry out language functions in everyone else. His normal-seeming behavior was produced by an adaptation that used quite different biological mechanisms.
He then asks: Could the conclusion that "contrary to appearances, this individual never actually understood a language at all . . . ever be justified by any imaginable autopsy results?" He answers,
I think not; having postulated normality in the person's relationships with his environment, we have said everything that is relevant to the claim that he had understanding, and in general a complete mental life. The question of how the black box works, though we may find it interesting, has no bearing on this issue.
Edelson remarks,
This becomes clear once we have the right example, namely, the one that differs from ordinary people in exactly the way that Searle (in what I have called his strong thesis) claims to be relevant. Therefore, assuming that I have correctly identified what Searle's thesis is, I conclude that his argument fails to support it.
My zombie variations offer stronger paradigm cases of intentionality counterinstancing Searle's dualistic intuitions about zombies besides the identity theoretic intuitions Edelson targets (and, perhaps understandably, mistakes for Searle's). They offer stronger paradigm cases by upping the intimacy coefficient (familiar zombies), increasing the intelligence quotient (supersmart zombies), and multiplying the zombie population.

Searle 1982 replies that Edelson has misunderstood -- he (Searle) is not denying "that eccentric biological systems might produce intentionality." Professing to find it "puzzling . . . why Edelson would suppose this [autopsy variation] is an objection to me, since it is precisely a consequence of my argument and, indeed, is a simple application of my principle of always considering the first person case" (Searle 1982: 346), Searle protests that Edelson mistakes him for a mind-brain identity theorist, when he's not. He's more like a dualist. Of course Searle also protests that he is no dualist. He protests too much. Whatever he calls it, the thesis Searle avows in disavowing identity theory to sidestep Edelson is that attribution of intentionality depends crucially just on the qualetative nature of what is going on "inside." My voodoo zombie variation advances Edelson's case by further removing all internal physical differences between zombies and paradigm cases of intentionality, so only qualetative differences remain. We might have even stipulated all our zombies to be voodoo-type (hexed headed) instead of sawdust headed had we only been concerned to counterinstance dualism (and not functionalism and identity theory as well). Notice, though, that (what I'll call) the weak Searlean principle of "always considering the first person case" besides the third cuts no ice against qualia eating zombies regardless of whether they've brains like us or sawdust: in imagining them, we do consider the first-person case -- as lacking. To counter these examples requires (what I'll call) the strong Searlean principle of only considering the first-person case. Alternately, it requires considering the first-person case not just "as in some sense epistemically different" (Searle 1992: 145: my emphasis) but as in an all too familiar sense epistemically privileged. Alternately, again all too familiarly, it requires refusing to countenance any thinker other than oneself, or any thoughts besides one's own conscious experiences, as paradigmatic. Such strong Searlean principles, by any reckoning (except perhaps Searle's), are Cartesian apparatus.

I note, in passing -- with regard to Edelson's "misunderstanding" -- that Searle's new and deproved version of the argument from analogy for other minds (Searle 1992: 71-7) clearly does premise that, as Edelson puts it, "[a]ttribution of intentionality to something depends crucially on the concrete biological nature of what is going on inside."^

13. "Rylean behaviorism," Searle notes, though "always troubled by the analysis of sensations, such as pains" seems "much more satisfactory for beliefs and desires" (Searle 1980b: 406).^

14. What Lewis says, without my elision, is that his theory "joins claims of type-type psychophysical identity with a behaviorist or functionalist way of characterizing mental states." Whether Lewis is a functionalist or behaviorist turns on how you distinguish them. If Lewis counts as a functionalist on your preferred demarcation . . . still this brand of "functionalism" is behavioristic. (See note 21, below, for further discussion.) As Block points out, Lewis/Armstrong style "a priori functionalists . . . are the heirs of the logical behaviorists" (Block 1978: 271); and it's the behavioristic element of inessentialism that shortcircuits Kripkesque intuitions. The zombieproofing gets done, precisely, by what seems from the point of view of mainstream (e.g., Fodorian) "psychofunctionalism" (Block 1978) to be Lewis-style "functionalism"'s remaining taint of behaviorism. I take the liberty, therefore, of styling Lewis' view "behavioristic".^

15. On Lewis' (1980) account,

We may say that X is in pain simpliciter if and only if X is in the state that occupies the causal role of pain for the appropriate population. But what is the appropriate population. Perhaps (1) it should be us; after all, it's our concept and our word. On the other hand, if it's X we're talking about, perhaps (2) it should be a population that X himself belongs to, and (3) it should preferably be one in which X is not exceptional. Either way, (4) an appropriate population should be a natural kind -- a species, perhaps. (219-20)
 Lewis continues,
Since the four criteria agree in the case of the common man, which is the case we usually have in mind, there is no reason why we should have made up our minds about their relative importance in case of conflict. It should be no surprise if ambiguity and uncertainty arise in such cases. Still some cases do seem reasonably clear. (1980: 220)
Lewis' notion is that a population might qualify as appropriate without satisfying all these criteria -- if it satisfies them on balance or for the most part. It's the way this on balance hedge interacts with the nonessentialist take on pain that short-circuits Kripkesque intuitions about voodoo zombies.^

16. Lewis notes in this connection that "the sort of identity theory Kripke opposes by argument [c.f. Kripke 1971: 99n18] rather than by appeal to self-evidence [c.f. Kripke 1971: 98n17] is not the sort Armstrong [1968] and I propose" (Lewis 1980: 217n2). Kripke's "brief restatement of the argument" begins "If `pain' and 'C-fiber stimulation' are rigid designators of phenomena, one who identifies them must regard the identity as necessary" (Kripke 1971: 99n18). Since Lewis denies that "pain" is rigid he is free to maintain the contingency of the identity. Abbott 1989 makes an interesting case that "an argument that [the word] pain is descriptive [hence, presumably, nonrigid] may be taken from Kripke's own remarks on the mind-body problem": "[r]ecall that a term is nondescriptional if the reference determining property associated with it is nevertheless not semantically associated with it"; i.e., "we could discover that we were wrong about this property"; but "that is not the case with pain" since (as Abbott agrees with Kripke) "[w]e could hardly discover that what we had felt as pain actually was not"; i.e., "it would be contradictory to say something felt painful but actually wasn't" (Abbott 1989: 279) Compare Lewis: "It would indeed be a mistake to consider whether a state is pain while ignoring what it [feels] like to have it"; but "it is an impossible mistake to make"; "like the impossible mistake of considering whether a number is composite while ignoring the question of what factors it has" (Lewis 1980: 221-222).^

17. Mad pain, associated with none of the behavior (or dispositions) usually associated (under given psychological background conditions) with pain -- even associated with contrary behavior (or dispositions) -- is conceivable (see Lewis 1980). Mad knowledge, I submit, is not. What further distinguishes my views from Lewis' -- besides denial of the appropriateness of identity theoretic admixture in accounts of intentional states-- is my (I take it connected) denial of the causal character of the most central "generalizations [pertaining to these states] set forth in commonsense psychology" (Lewis 1980: 218). See especially Hauser 1992.^

18. Perhaps (pace Block 1981), accounts of cognitive states could stand some functionalistic admixture. Good zombies argue, not much. Ironically, though Block 1981 purports to show how "behaviorism can be refuted" (n.8), the leaven of "psychologism" required to accommodate intuitions about his disfunctional zomboid (a sort of conversational jukebox) is slight: the doctrine that results retains its "behavioristic flavor" (n. 18). Furthermore, pace Block's (1981) Martians (like my Astro-zombies) at most a dash of "psychologistic" leaven is allowed. Block concludes, "there is no single natural kind of information processing underlying all intelligent behavior." There can be no "positive characterization of the type of information processing underlying all intelligent behavior" nor even of "a kind of processing common to all unintelligent entities that nonetheless pass the Turing Test" (p. 43).^

19. Bringsjord, personal communication.^

20. Behaviorism, like eliminativism, (unlike dualism, functionalism, and identity theory) denies there is any hidden (qualetative, procedural, or neurophysiological) essence of thought to be discovered. Yet behaviorism, unlike eliminativism, does not take the reality of thought to be thereby impugned. (C.f. Hauser 1993a, chapt.1; 1994) Behaviorism, you might say, is eliminativism lite. Though differentiation of behaviorism from functionalism in terms of their essentialist commitments (functionalism) or lack of same (behaviorism) -- as I differentiate them -- accords, roughly, with Block1978's initial characterization of functionalism as holding "that pain [e.g.] is a functional state, just as identity theory formulations of physicalism hold that pain [e.g.] is a physical state" ( Block 1978: 268), Block's further characterization of functionalism as the view that "each type of mental state is a state consisting of a disposition to act in certain ways and to have certain mental states" (Block 1978: 268) is inadequate, I think, as stated and, even when clarified, undeserving of the canonical status it is commonly accorded.

According to Block's widely credited differentiation of functionalism from behaviorism, "[f]unctionalism replaces behaviorism's `sensory inputs' with `sensory inputs and mental states' and functionalism replaces behaviorism's `disposition to act' with `disposition to act and have certain mental states'" (Block 1978: 269). This, while it may be "vague enough to be accepted by most functionalists" (Block 1978: 268) is also vague enough to be accepted by many behaviorists! On this point Searle is commendable: "Rylean behaviorism," he notes, typically holds that "having beliefs and desires, especially in the right combination [my emphasis], is just being disposed to behave in certain ways" (Searle 1980b: 406). (C.f. Ryle 1949; Anscombe 1963; Taylor 1964; Melden 1961; Hauser 1992.) It may be objected that Block's differentiation as stated, rather than being vague enough to be accepted by behaviorists is ambiguous between "disposition to act in consort with other mental states" (which a behaviorist can accept) and "disposition to act and go into other mental states" (which is properly functionalistic, and not behavioristically acceptable). Several things ought still to temper enthusiasm for this last as a canonical differentiation. In the first place -- even allowing for the inevitably ex post facto nature of the differentiation -- it is troubling that Ryle still seems to come out a functionalist on this account. (Ryle's characterization of vanity, for instance, besides dispositions "to talk a lot about himself, to cleave to the society of the eminent, to reject criticisms, to seek the footlights and disengage himself from conversations about the merits of others," also invokes dispositions "to indulge in roseate daydreams about his own successes, to avoid recalling past failures and to plan for his own advancement"; it even includes dispositions "to feel certain pangs and flutters in certain situations . . . to have an acute sinking feeling, when an eminent person forgets his name, and to feel buoyant of heart and light of toe on hearing of the misfortunes of his rivals," though Ryle deems these "less directly indicative" (Ryle 1949: 86).) Enthusiasm for differentiation along the lines in question ought further to be tempered by the consideration that "given an explicit definition of behaviorism" (Block 1980: 176) and functionalism along these lines, such as Bealer 1978 and Thomas 1978 offer, provably, "functional definitions exist only if ordinary explicit definitions [which appeal solely to behavioral properties] exist as well (Bealer 1978: 337); "functional state descriptions are equivalently expressible by indexed input-output dispositional descriptions, and hence if functionalism is correct it is possible in principle to express logically sufficient conditions for the truth of any pure mental predicate entirely in behavioristic terminology (Thomas 1978: 262).

Yet a third characterization by Block, according to which "[f]unctionalists want to individuate mental states causally" (Block 1978: 268: my emphasis) is, perhaps, closer to (though not identical with) his first. On this last account Armstrong (1968) and Lewis (1966, 1980), perhaps, get classed as functionalists (as Block deems them), while Ryle, Anscombe, Taylor, Melden, and I, perhaps, do not. As already noted, Lewis himself styles his proposed "way of characterizing mental states" as "behaviorist or functionalist [my emphasis]" (Lewis 1980: 217). According Block's first characterization -- at least on my preferred essentialist/nonessentialist take on it -- Lewis' views are more behaviorist than functionalist, though, I suppose, the causal character of Lewis' "causal descriptivism" makes his a functionalistic sort of behaviorist.^

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