AnAn EndEnd totoQualia? ? Dennett'sDennett's DefenseDefense ofof HeterophenomenologyHeterophenomenology

SweetSweet Dreams:Dreams: PhilosophicalPhilosophical ObstaclesObstacles toto aa ScienceScience ofof ConsciousnessConsciousness ByBy DanielDaniel C.C. Dennett.Dennett. Cambridge,Cambridge, MA:MA: MITMIT Press,Press, 2005.2005.199 199 pp.pp. Cloth,Cloth, $28.00.$28.00. ForgoingForgoing recentrecent excursionsexcursions intointo thethe philosophicalphilosophical implicationsimplications ofof neo-Darwinismneo-Darwinism andand freefreewill, will,Dennett Dennett returnsreturns toto hishis roots,roots,defending defending bothboth hishis theorytheoryof of consciousconscious­ nessness (the(the multiple-draftsmultiple-draftsmodel) model) andand hishis methodologicalmethodological approachapproach (heterophe(heterophe­ nomenology)nomenology) fromfrom recentrecent critics.critics.For For thosethose unfamiliarunfamiliar withwith Dennett'sDennett's philosophyphilosophy ofofmind, mind, bebe preparedprepared toto incrementallyincrementallyagree agree withwith aa persuasive,persuasive, clear,clear, andand creativecreative writerwriter untiluntil reachingreaching perhapsperhaps thethemost most nonintuitivenonintuitive conclusionconclusion possible:possible: ThereThere isis nono consciousconscious entityentity thatthat requiresrequires explanation.explanation. InIn SweetSweetDreams, Dreams, DennettDennett goesgoes onon thethe offensiveoffensive againstagainst thethe "new"newmysterians," mysterians," thosethosewho who argueargue thatthat thethe problemproblem ofof consciousnessconsciousness isis fundamentallyfundamentally unsolvableunsolvable oror requiresrequires anan explanatoryexplanatory frameframe­ workwork outsideoutside thatthat usedused byby observationalobservational science.science. AlongAlong thetheway, way,we we encounterencounter aa gallerygallery ofof philosophicalphilosophical troublemakers,troublemakers, circuscircus performersperformers whowho wouldwould makemake eveneven BarnumBarnum hesitant,hesitant, includingincluding aa plethoraplethora ofof possiblepossible zombies,zombies, MartianMartian scientists,scientists, cunningcunning magicians,magicians, replicantreplicant impostors,impostors, emotionallyemotionally invertedinverted colorcolor perceivers,perceivers, andand aa triotrioof of imprisonedimprisoned colorcolor scientists:scientists: thethe originaloriginal Mary,Mary, thethe struck-by-lightningstruck-by-lightning brain-reorganizedbrain-reorganized Swamp-Mary,Swamp-Mary, andand thethe color-challengedcolor-ehallenged RoboticRobotic Mark-19Mark-19 Mary.Mary. AlthoughAlthough DennettDennett isisunmatched unmatched (save(save perhapsperhaps DawkinsDawkins inin biology)biology) inin communicommuni­ catingcating complexcomplex ideasideas ininways ways thatthat resonateresonate withwith readers,readers, thethe currentcurrent workwork isis lessless unifiedunified thanthanmost most recentrecen tefforts,efforts,consisting consisting ofof aa seriesseries ofof reworkedreworked paperspapers andand adad­ dressesdresses givengiven overover thethe pastpast 77 years,years, focusedfocused onon specificspecific criticismscriticismsand and elaborationselaborations ofof hishis approach.approach. EachEach ofof thethe firstfirstfive fivechapters chapters isisautonomous, autonomous, andand commentscomments areare presentedpresented sequentially.sequentially. TheThe remainingremaining threethree chapterschapters areare re-presentationsre-presentations ofof thisthis initialinitialmaterial, material, addingadding newnew slantsslants toto thethe discussiondiscussion butbut littlelittlenew new content.content.

ChapterChapter 1:1: TheThe ZombicZombie hunchhuneh DennettDennett beginsbegins hishis assaultassault onon thethenew newmysterians mysterians (e.g.,(e.g., Chomsky,Chomsky,Chalmers, Chalmers, SearSear­ le)le) byby addressingaddressing oneone ofof thethe oldest:oldest: Leibniz.Leibniz. InInMonadology, Monadology, LeibnizLeibniz (1714/1898)(1714/1898) statesstates thatthatperception perception isis inexplicableinexplicable onon mechanicalmechanical grounds,grounds, claimingclaiming thatthat ififone one builtbuilt aa machinemachine thatthatwas was ableable toto perceive,perceive, anan inspectioninspection ofof itsitsgears gears wouldwould nevernever lendlend anan explanationexplanation ofof unitaryunitary perception.perception. DennettDennett believesbelieves thatthat anan essentialessential misconceptionmisconception presentpresent inin thisthisargument argument underliesunderlies similarsimilar argumentsarguments today.today. LeibnizLeibniz nevernever arguesargues thatthat perceptionperception isis nondecomposable;nondecomposable; hehe simplysimply assertsasserts thethe fact,fact, andand DennettDennett claimsclaims thatthat thethe newnew mysteriansmysterians performperform thethe samesame movemove withwith regardregard toto .consciousness. AssertionAssertion isisnot not argument,argument, andand soso "surely"surely ititmust must bebe thethe casecase that"that" thoughtthought experimentsexperiments useuse whatwhat DennettDennett callscalls anan ""intuition pump,"pump," oftenoften containingcontaining concealedconcealed premisespremises andand biases.biases. Ultimately,Ultimately, intuitionsintuitions areare aa thinthin basisbasis forfor theory:theory:Our Our intuitionsintuitionsmay may differdiffer fromfrom eacheach otherother oror simplysimply bebe wrong.wrong. Also,Also, ourour conceptualconceptual toolstools forfor addressingaddressing complexcomplex questionsquestions maymay developdevelop overover time,time,altering alteringwhat what anan explanationexplanation mightmight looklook likelike andand changingchanging ourour intuitionsintuitionsof of whatwhat isis possible.possible. ForFor example,example, computerscomputers andand thethe adventadvent ofof thethe algorithmalgorithm allowallow usus toto understandunderstand evolutionevolution inin aa newnew wayway (e.g.,(e.g., seesee Dennett,Dennett, 1995);1995); whywhy shouldshould wewe simplysimplygive give upup onceonce andand forfor allall onon anan empiricallyempirically basedbased theorytheoryof of consciousness?consciousness? AA properlyproperly developeddeveloped computationalcomputational approach,approach, withwith levelslevelsof of processingprocessing interactinteract­ inging onon manymany levels,levels,may may ultimatelyultimately dodo thethe trick.trick.Among Among thethe newnew mysteriansmysterians whowho walkwalk thisthis intuitionistintuitionistroad, road,Dennett Dennett citescitesNagel, Nagel, Chomsky,Chomsky, Strawson,Strawson, Penrose,Penrose, andand mostmost notablynotably ChalmersChalmers (a(a self-avowedself-avoweddualist dualist whowho simplysimplybelieves believes thatthatconscious conscious­ nessness isis aa nonreduciblenonreducible fundamentalfundamental propertyproperty ofof thethe universe,universe, muchmuch likelike quarksquarks oror electrons;electrons; Chalmers,Chalmers, 1996).1996). InIn addition,addition, DennettDennett faultsfaultsmany many newnew mysteriansmysterians forforbelieving believing thatthatdiscoveries discoveries inin nondeterministicnondeterministic physicsphysicswill will eventuallyeventuallywin win thethe dayday byby somehowsomehow introducingintroducing somesome mentalmental causationcausation wigglewiggle roomroom intointo thethe equation.equation. InIn FreedomFreedomEvolves Evolves (2003)(2003) DennettDennett pointspoints outout thatthat truetrue randomnessrandomness buysbuys oneone nothingnothing withwith regardregard totomental mental causation,causation, andand DennettDennett makesmakes aa similarsimilar argumentargument here.here. AssumeAssume thatthat quantumquantum effectseffectsallow allow forfor qualia,qualia, thethewhat-it-is-like-to-be-something what-it-is-like-to-be-somethingphenomenon.phenomenon. WeWe areare stillstill stuckstuck withwith thethe problemproblem ofof whywhy organizedorganized collectionscollections ofof neurons,neurons, likelike ourour ownown brainsbrains (unlike(unlike aa collectioncollection ofof neuronsneurons inin aa petripetri dish),dish), areare capablecapable ofof comcom­ plexplex computationalcomputational states,states, suchsuch asas representation.representation. BecauseBecause quantumquantum effectseffectsexist exist inin bothboth cases,cases, anan explanationexplanation mustmust occuroccur atat aa higherhigher level:level: thethe communicationcommunication andand relationshiprelationship betweenbetween cells.cells. BecauseBecause oneone needsneeds aa computationalcomputational accountaccount ofof complexcomplex informationinformationprocessing processing toto accountaccount forfor thisthisdistinction, distinction, itit isisunclear unclear whatwhat quantum-levelquantum-level interventionsinterventions contributecontribute toto overalloverall explanations.explanations. DennettDennett arguesargues thatthat suchsuch radicalradical interventionsinterventions areare necessarynecessary onlyonly ififone one buysbuys intointo thethe ZombicZombic hunch:hunch: thethe beliefbelief thatthat aa perfectperfect computationalcomputational duplicateduplicate ofof aa personperson lackinglacking qualiaqualia (a(a zombie)zombie) isis fundamentallyfundamentallydifferent differentfrom froma a normalnormal personperson possessingpossessing qualia.qualia. AccordingAccording toto thethedoctrine doctrine ofof "Zombism,""Zombism," becausebecause computationalcomputational explanationsexplanations failfail toto accountaccount forfor thisthisdifference, difference, theytheyare are explanatorilyexplanatorily insufficient.insufficient. DennettDennett respondsresponds thatthat aa theorytheoryneed need makemake suchsuch aa distinctiondistinction onlyonly ififone one believesbelieves inin aa dichotomydichotomy betweenbetween thethe thingsthings thatthat possesspossess consciousnessconsciousness andand thosethose thatthatdo do not.not. IfIf oneone deniesdenies thisthisdifference, difference, nono suchsuch demarcationdemarcation criterioncriterion isis necessarynecessary oror eveneven makesmakes sense.sense. TheThe burdenburden ofof proofproof isison on thethemysterians, mysterians, andand DennettDennett claimsclaims thatthat thethe "Zombic"Zombic hunch"hunch" isis anan intuitionintuition thatthatwill will fadefade inin time,time, alongsidealongside otherother seeminglyseemingly erroneouserroneous beliefs.beliefs.

ChapterChapter 2:2: AA third-personthird-person approachapproach toto consciousnessconsciousness InIn chapterchapter 2,2, DennettDennett turnsturns toto aa defensedefense ofof hishis explanatoryexplanatory framework:framework: hethet­ erophenomenologyerophenomenology (HP),(HP), aa projectproject moremore extensivelyextensively introducedintroduced inin ConsciousConscious­ nessnessExplained Explained (199(1991). 1). HeHe beginsbegins byby suggestingsuggesting thatthatwe we useuse standardstandard third-personthird-person observationalobservational techniquestechniques inin examiningexamining consciousnessconsciousness andand seesee howhow farfar suchsuch anan investigationinvestigation takestakes us.us. ToTo preventprevent usus fromfrom sneakingsneaking sharedshared introspectionintrospection intointo ourour account,account, wewe areare joinedjoined inin thisthisendeavor endeavor byby alienalien anthropologists,anthropologists, capablecapable ofof datadata collectioncollection andand inferenceinference butbut unableunable (at(at leastleast beforebefore collectingcollecting data)data) toto knowknowwhat what itit isis likelike toto bebe us.us. ForFor thethe newnew mysterians,mysterians, thethe situationsituation isis aa nonstarter.nonstarter. ButBut forforHP, HP, thethe factfact thatthatpeople people reportreport havinghaving aa qualitativequalitative experienceexperience isis simplysimplyanother another piecepiece ofof behaviorbehavior thatthatneeds needs toto bebe explained,explained, alongsidealongside otherother piecespieces ofof evidenceevidence (e.g.,(e.g., moviemovie voiceovers,voiceovers, philosophicalphilosophical treatisestreatiseson on consciousness)consciousness) thatthat indicateindicate peoplepeople believebelieve theytheypossess possess aa uniqueunique subjectivesubjective pointpoint ofof view.view. (This(This viewview isiswhat what separatesseparates DennettDennett fromfromepiphenomenalism: epiphenomenalism: IfIfqualia qualia werewere trulytrulynoncausal, noncausal, wewe wouldwould notnot bebe ableable toto speakspeak ofof it.it.The The factfact thatthatwe we cancan meansmeans somethingsomething isisgoing going onon thatthat needsneeds toto bebe explained.)explained.) DennettDennett arguesargues thatthat allall third-personthird-person investigationsinvestigations areare limited;limited; whateverwhatever wewe study,study, therethere willwill always always bebe somesome residualresidual uncertaintyuncertainty (e.g.,(e.g., thethe nextnext significantsignificant digit,digit, probabilisticprobabilistic assumptionsassumptions ofof priorprior locationslocations oror environmentalenvironmental conditions).conditions). TheThe samesame appliesapplies toto consciousness.consciousness. ThereThere willwill always always bebe somesome knowledgeknowledge thatthat remainsremains incompleteincomplete oror uncertain,uncertain, butbut thisthis isis truetrue inin everyevery third-personthird-person inquiry.inquiry.A A failurefailure toto arrivearrive atat completecomplete knowledgeknowledge ofof consciousnessconsciousness viavia aa standardstandard scientificscientific approachapproach isis philosophicallyphilosophically problematicproblematic onlyonly ififone one believesbelieves oneone hashas completecomplete andand infallibleinfallibleknowledge knowledge ofof consciousnessconsciousness fromfrom aa first-personfirst-personapproach. approach. However,However, DennettDennett showsshows thatthat thisthis isisnot not thethe case:case: OurOur intuitionsintuitions aboutabout ourour ownown experienceexperience areare falliblefallible (e.g.,(e.g., withwith regardregard toto thethe capacitycapacity ofof nonfovealnonfoveal visualvisual perception),perception), andand manymany third-personthird-person descriptionsdescriptions actuallyactually areare richerricher thanthan aa first-personfirst-personaccount account (e.g.,(e.g., withwith regardregard totomasked masked primingpriming oror blindsight,blindsight, wherewhere wewe havehave nono consciousconscious experienceexperience thatthatwe we havehave beenbeen affectedaffected byby stimuli).stimuli). InIn mostmost areasareas ofof inquiry,inquiry,counterintuitive counterintuitive findingsfindings oftenoften areare seenseen asas greatgreat adad­ vances,vances, butbut withwith regardregard toto consciousness,consciousness, suchsuch conclusionsconclusions inexplicablyinexplicably indicateindicate thatthatone's one's theorytheorymust must bebe wrong.wrong. ThisThis isisparticularly particularly strangestrange becausebecause ourour intuitionsintuitions regardingregarding thethe naturenature ofof ourour experienceexperience oftenoften havehave beenbeen shownshown toto bebe misguided.misguided. ReturningReturning toto thethe exampleexample ofof ourour visualvisual perception,perception, simplesimple psychophysicalpsychophysical teststests revealreveal visualvisual acuityacuity andand colorcolor perceptionperception onlyonly inin centralcentral vision,vision, aa factfact contrarycontrary toto ourour experience.experience. DoDo wewe thenthen ask,ask,

"Why,"Why, sincesince people'speople's visualvisual fieldsfields areare detaileddetailed andand coloredcolored allall thethe wayway outout (that's(that's whatwhat theythey telltell us),us), can'tcan't theythey identifyidentify thingsthings theythey seesee movingmoving inin thethe parafovealparafoveal partsparts ofof theirtheir visualvisual fields?"fields?" (p.(p. 41)41)

or,or,more more properly,properly,

"Why"Why dodo peoplepeople thinkthink thatthat theirtheir visualvisual fieldsfields areare detaileddetailed allall thethe wayway out?"out?" (p.(p. 41)41)

TheThe HPHP approachapproach involvesinvolvesgathering gathering aa corpuscorpus ofofmaterial material thatthat isis thenthen subjectsubject toto analysis.analysis. ThisThis consistsconsists ofof allall ofof aa person'sperson's physicallyphysically observableobservable behaviorbehavior (e.g.,(e.g., globalglobal actionsactions ofof thethe individual,individual, neuralneural andand biochemicalbiochemical states),states), andand includesincludes speechspeech behaviorsbehaviors referringreferring toto thethe beliefbelief thatthatwe we havehave qualia,qualia, andand zombieszombies dodo notnot havehave qualia,qualia, thatthatwe we havehave experiencesexperiences thatthat areare uniquelyuniquely ourour own,own, andand soso on.on. CommunicativeCommunicative actionsactions areare thenthen interpretedinterpreted inin thethe contextcontext ofof brainbrain states,states, environmentalenvironmental conditions,conditions, andand soso on,on, toto determinedetermine anthropologicallyanthropologically ourour beliefbelief systemssystemsabout about consciousness,consciousness, andand thesethese beliefsbeliefs becomebecome partpart ofof whatwhat needsneeds toto bebe explained.explained. WheneverWhenever beliefbelief ascriptionascription occurs,occurs, DennettDennett claimsclaims wewe areare simplysimply adoptingadopting anan explanatoryexplanatory framework:framework: thethe intentionalintentional stance.stance. ForFor Dennett,Dennett, teleologicalteleological beliefbelief­ desiredesire talktalk isisneutral neutral withwith regardregard totowhether whether entitiesentitiesmetaphysically metaphysically possesspossess thesethese propositionalpropositional attitudesattitudes andand isisapplicable applicable toto thermostatsthermostatsas as easilyeasily asas humanshumans (Den(Den­ nett,nett, 1978).1978). BecauseBecause thethe intentionalintentional stancestance isisneutral neutral regardingregarding qualia,qualia, aa zombiezombie willwill havehave exactlyexactly thethe samesame ascriptionsascriptions assignedassigned toto itit asas aa nonzombienonzombie (including(including thethe assertionassertion thatthat itit hashas qualia,qualia, too).too). Therefore,Therefore, whetherwhether aa zombiezombie actuallyactually hashas qualiaqualia (or,(or,more more toto thethe point,point, whetherwhether wewe actuallyactually havehave qualia)qualia) makesmakes absolutelyabsolutely nono differencedifference toto thethe analysisanalysis andand becomesbecomes moot.moot. InIn thethe end,end, therethere isisnothing nothing toto bebe explained:explained: AA completecomplete explanationexplanation ofof thethe zombiezombie isis identicalidentical toto aa completecomplete explanationexplanation ofof aa nonzombie.nonzombie. OneOne isis remindedreminded ofof James'sJames's famousfamous verificationistverificationist motto,motto, "A"A differencedifference thatthatmakes makes nono difference,difference, isis nono difference."difference."

ChapterChapter 3:3: ExplainingExplaining thethe "magic""magic" ofof consciousnessconsciousness InIn thethe briefbrief chapterchapter 3,3, DennettDennett presentspresents twotwo incompatibleincompatible viewsviews ofof whatwhat anan explanationexplanation ofof consciousnessconsciousness isis shouldshould looklook like.like.For For Dennett,Dennett, anan exorcismexorcism ofof thethe homunculushomunculus inin thethe explanansexplanans (e.g.,(e.g., asjustasjust performedperformed inin thethe previousprevious discussion)discussion) isisa a necessarynecessary componentcomponent forfora a noncircularnoncircular account.account. However,However, thethe newnew mysteriansmysterians argueargue thatthatany any suchsuch approachapproach cannotcannot reallyreallybe be anan explanationexplanation becausebecause qualiaqualia areare nowherenowhere toto bebe seen.seen. Conversely,Conversely,Dennett Dennett arguesargues thatthat anyany explanationexplanation thatthat leavesleaves thethe homunculushomunculus inin hashas notnot reallyreally explainedexplained anythinganything atat all.all. TheThe conflictconflict seemsseems intractable,intractable, butbut DennettDennett suggestssuggests thatthat perhapsperhaps thethe issueissue wouldwould gogo awayaway withwith aa properproper understandingunderstanding ofof "the"the hardhard problem"problem" (a(a termtermcoined coined bybyChalmers Chalmers referringreferring toto thethe qualia-relatedqualia-related puzzlespuzzles thatthat seemseem resistantresistant toto computationalcomputational explanation).explanation). ToTo thisthisend, end, DennettDennett discussesdiscusses aa famousfamous tricktrickby bymagician magician RalphRalph Hull:Hull: thethe tunedtuned deck.deck. UponUpon performingperforming aa standardstandard find-the-cardfind-the-cardtrick, trick,Hull Hull challengedchallenged anyoneanyone toto figurefigureout out howhow hehe performedperformed it.it.He He thenthen performedperformed thethe samesame tricktrickwith with aa secondsecond techniquetechnique differentdifferent fromfrom thethe first,first,and and subsequentlysubsequently aa thirdthird technique,technique, andand soso on.on. AnyAny hypothesishypothesis waswas pursuingpursuing aa movingmoving target,target,and and thethe tricktrickwas was simplysimply inin thethe title:title: "the"the tunedtuned deck."deck." DennettDennett hypothesizeshypothesizes thatthat thethehard hard problemproblem representsrepresents aa similarsimilar situation,situation, aa collectioncollection ofof problemsproblems thatthat seemseem unifiedunified butbut maymay bebe amenableamenable toto divide-and-conquerdivide-and-conquer strategiesstrategies ofof computationalcomputational analysis.analysis.

ChapterChapter 4:4: AreAre qualiaqualia whatwhat makemake lifelifeworth worth living?living? BackBack onon thethe offensive,offensive,Dennett Dennett putsputs thethe burdenburden ofof proofproof onon thethe oppositionopposition andand challengeschallenges thethe newnewmysterians mysterians toto definedefine theirtheirkey key term:term:What What exactlyexactly isis aa quale?quale? AA negativenegative definitiondefinition willwill notnot dodo (it(it isiswhat what zombieszombies dodo notnot have),have), nornor willwill definingdefining ititas as thethe phenomenalphenomenal aspectsaspects ofof ourour mentalmental lives.lives.Dennett Dennett asks,asks, "Which"Which aspectsaspects ofof ourour experienceexperience areare phenomenalphenomenal andand whichwhich areare not?"not?" (p.(p. 79).79). ConsiderConsider changechange blindness:blindness: BeforeBefore oneone noticesnotices thethe change,change, areare therethere differencesdifferences inin qualiaqualia whenwhen oneone viewsviews thethe twotwovisual visual scenes?scenes? CertainlyCertainly theretherewere were physiologicphysiologic differencesdifferences (e.g.,(e.g., inin thethe retina).retina). IfIfone one claimsclaims therethere areare differencesdifferences inin qualiaqualia withoutwithout oneone perceivingperceiving them,them,one one beginsbegins totoquestion question thethe basisbasis ofof thethewhole whole enterpriseenterprise (i.e.,(Le., thatthatone one isisan an absoluteabsolute authorityauthority aboutabout one'sone's ownown qualia).qualia). IfIfone one doesdoes notnot havehave accessaccess toto one'sone's ownown qualia,qualia, whowho does?does? OnOn thethe otherother hand,hand, ififone one deniesdenies therethere areare differencesdifferences inin qualiaqualia beforebefore andand afterafter detection,detection, nownow qualiaqualia occuroccur onlyonlywhen when youyou claimclaim theythey do.do. BecauseBecause zombieszombies insistinsist theytheyhave have qualiaqualia too,too, thisthisshould should bebe sufficientsufficientto to givegive itit toto them!them!Dennett Dennett finishesfinishes thethe chapterchapter byby proposingproposing aa versionversion ofof thethe classicclassic colorcolor inversioninversion situation,situation, ininwhich which oneone wakeswakes upup oneone morningmorning withwith one'sone's emotionalemotional reactionreaction toto colorscolors invertedinverted (e.g.,(e.g., mymy favoritefavoritecolor color usedused toto bebe blue,blue, nownow itit isis yelyel- low).low). AreAre qualiaqualia invertedinverted inin thisthis case?case? TheThe answeranswer isisunclear, unclear, andand DennettDennett arguesargues thatthatqualia qualia areare simplysimply ill-conceivedill-conceived constructs.constructs.

ChapterChapter 5:5:What What RoboMaryRoboMary knowsknows InIn chapterchapter 5,5, wewe encounterencounter permutationspermutations ofof FrankJackson'sFrankJackson's classicclassic "Mary"Mary thethe colorcolor scientist"scientist" scenario.scenario. InIn thethe original,original,Mary Mary isis imprisonedimprisoned inin aa monochromaticmonochromatic environmentenvironment andand askedasked toto researchresearch colorcolor vision.vision. SheShe ultimatelyultimately learnslearns allall therethere isis toto knowknow aboutabout colorcolor fromfrom aa third-personthird-personperspective. perspective. TheThe newnew mysteriansmysterians argueargue thatthat therethere isis stillstillsomething something sheshe doesdoes notnot knowknow aboutabout color:color: qualia,qualia, whatwhat itit isis likelike toto experientiallyexperientially seesee thatthatcolor. color. ShowShow herher aa blueblue banana,banana, andand sheshe willwill say,say,"Oh, "Oh, that'sthat's whatwhat yellowyellow lookslooks like."like."Dennett Dennett beginsbegins byby challengingchallenging thatthatMary Mary reallyreallywould would bebe surprised:surprised:What What wouldwould knowingknowing allall aboutabout colorcolor visionvision reallyreally entail?entail?Might Might ititnot not resultresult inin herher recognizingrecognizing thethe blueblue banana?banana? HeHe arguesargues thatthat ourour intuitionsintuitions aboutabout knowingknowing everythingeverythingtherethere isis toto knowknow aboutabout colorcolor areare somewhatsomewhat murkymurky andand pointpoint towardtoward aa thoughtthought experimentexperiment withwith hiddenhidden biases.biases. MoreMore directly,directly, ifif thethe argumentargument mademade byby thethe newnew mysteriansmysterians isis thatthat qualiaqualia areare ineffableineffableand and thusthusnoninferential noninferential fromfrom third-personthird-persondata data (Lycan),(Lycan), whatwhat evidenceevidence isis therethere forfor suchsuch ineffability?ineffability?MightMight notnot someonesomeone whowho knewknew everythingabouteverythingaboutcolor color bebe ableable toto "eff'"eff' it?it?Again, Again, thethemysterians mysterians simplysimply assert,assert, notnot argue.argue. ClosingClosing thethe chapter,chapter,Dennett Dennett introducesintroduces RoboMary,RoboMary, thethemechanical mechanical versionversion ofofMary, Mary, whowho hashas black-and-whiteblack-and-white moviemovie camerascameras mountedmounted onon aa visualvisual systemsystem otherwiseotherwise enabledenabled forfor colorcolor vision.vision. DennettDennett arguesargues thatthat becausebecause colorizationcolorization cancan bebe accomplishedaccomplished computationally,computationally, therethere isisnothing nothing RoboMaryRoboMary wouldwould gaingain fromfrom thethe introductionintroduction ofof actualactual colorcolor camerascameras (I(I suspectsuspect thisthis latterlatterargument argument isispreaching preaching toto thethe converted,converted, sittingsitting nicelynicely withwith thosethose whowho agreeagree withwith DennettDennett butbut havinghaving nono effecteffect onon thosethose denyingdenying strongstrong artificialartificial intelligence).intelligence).

ChaptersChapters 6,6, 7,7, andand 88 TheThe finalfinal threethree chapterschapters representrepresent autonomousautonomous presentationspresentations ofofmuch much ofof thethe materialmaterial discusseddiscussed thusthus farfar (one(one wonderswonders whywhy theytheywere were notnot presentedpresented asas initialinitial discussionsdiscussions ratherrather thanthan asas thethe closingclosing chapters).chapters). DiscussedDiscussed areare distributeddistributed processprocess­ ing,ing,consciousness consciousness asas thethe "winner""winner" inin globalglobal communication,communication, whetherwhether anan explanaexplana­ tiontion ofof consciousnessconsciousness needsneeds toto leaveleave thethe subjectsubject out,out, andand thethe coherencecoherence ofof thethe qualiaqualia concept.concept. TheThe finalfinalchapter chapter providesprovides aa hypotheticalhypothetical informalinformaldiscussion discussion thatthat illustratesillustrates thethe problemsproblems withwith thethe coherencecoherence ofof qualiaqualia discusseddiscussed previously.previously.Many Many ofof Dennett'sDennett's argumentsarguments inin thesethese sectionssections reiteratereiteratewho who hashas thethe burdenburden ofof proof:proof: II havehave argument,argument, hehe claims,claims, andand thethemysterians mysterians havehave onlyonly intuition.intuition.

CommentsComments ThoseThose familiarfamiliarwith with Dennett'sDennett's writingswritings areare inin forfor thethe usualusual treat;treat; hishis talenttalent forfor producingproducing enjoyable,enjoyable, thought-provokingthought-provoking expositionsexpositions againagain isis inin fullfull force.force. HowHow­ ever,ever, forfor thosethose unfamiliarunfamiliar withwith hishis work,work, II recommendrecommend readingreading aa moremore completecomplete treatmenttreatment ofof thethe subjectsubject inin ConsciousnessConsciousnessExplained Explained beforebefore tacklingtacklingmany many ofof thethe adad hochoc argumentsarguments hehe presentspresents inin thethe currentcurrent work.work. TheThe layoutlayout ofof thethe chapterschapters isis somewhatsomewhat awkward,awkward, andand II recommendrecommend readingreading thethe lastlast threethree chapterschapters firstfirst(which (which givegive aa moremore coherentcoherent structure),structure), followedfollowed byby thethe firstfirstfive fivechapters, chapters, whichwhich gogo intointo moremore detaildetail onon thethe variousvarious issues.issues. DennettDennett centralcentral complaintcomplaint inin SweetSweetDreams Dreams isis thatthat criticismscriticismsof of hishis positionposition restrest onon unanalyzedunanalyzed intuition:intuition: "Surely"Surely thatthatcannot cannot bebe right."right." ItIt isishard hard toto findfind faultfaultwith with thisthis claim.claim. InIn fact,fact, ififone one cancan getget overover one'sone's initialinitial incredulity,incredulity,one one justjust maymay findfind one'sone's intuitionsintuitions changingchanging overover time.time.Reflections Reflections ofof one'sone's ownown unityunity ofof consciousconscious­ ness,ness, possessionpossession ofof qualia,qualia, andand soso on,on, cancan changechange basedbased onon one'sone's philosophicalphilosophical perspective.perspective. DennettDennett arguesargues thatthat ourour intuitionsintuitions ofof whetherwhether anan explanationexplanation ofof consciousnessconsciousness isis possiblepossible maymay changechange withwith thethe developmentdevelopment ofof newnew conceptualconceptual tools.tools. OverOver thethe years,years,Dennett's Dennett's workwork hashas changedchanged mymy ownown intuitionsintuitions regardingregarding thethe naturenature ofof mymy personalpersonal consciousnessconsciousness andand hashas servedserved asas preciselyprecisely thethe kindkind ofof conceptualconceptual bootstrappingbootstrapping necessarynecessary toto rethinkrethinkwhat what consciousnessconsciousness is.is.Though Though notnot hishis mostmost unifiedunified work,work, SweetSweetDreams Dreams isis purepure DennettDennett andand worthwhileworthwhile readingreading forfor anyoneanyone inin thethe cognitivecognitive sciencescience community.community. JasonJason A.A. WilliamsWilliams DepartmentDepartmentof ofPsycholoy Psychology GonzagaGonzaga UniversityUniversity 501501 E.E. BooneBoone Avenue,Avenue,AD54 AD54 Spokane,Spokane,WA WA 9925899258 E-mail:E-mail: [email protected]@gonzaga.edu

ReferencesReferences Chalmers,Chalmers, D.D. (1996).(1996). TheThe consciousconscious mind.mind. NewNew York:York: OxfordOxford UniversityUniversity Press.Press. Dennett,Dennett, D.D. C.C. (1978).(1978). .Brainstorms.Montgomery,Montgomery, VT: Vf: Bradford.Bradford. Dennett,Dennett, D.D. C.C. (1991).(1991). ConsciousnessConsciousnessexplained.explained. Boston:Boston: Little,Little,Brown. Brown. Dennett,Dennett, D.D. C.C. (1995).(1995). Darwin'sDarwins dangerousdangerous idea.idea. NewNew York:York: SimonSimon && Schuster.Schuster. Dennett,Dennett, D.D. C.C. (2003).(2003). FreedomFreedomevolves.evolves. NewNew York:York:Viking. Viking. Leibniz,Leibniz,G. G.W. W. (1898).(1898).Monadology Monadology(R.(R. Latta, Latta,Trans.). Trans.).Oxford: Oxford:Oxford OxfordUniversity UniversityPress.Press. (Origi(Origi­ nalnalwork work publishedpublished 1714)1714)