Nyya Perceptual Theory: Disjunctivism or Anti-Individualism? Anand Jayprakash Vaidya Philosophy East and West, Volume 63, Number 4, October 2013, pp. 562-585 (Article) Published by University of Hawai'i Press For additional information about this article Access provided by San Jose State University (26 Oct 2013 19:52 GMT) http://muse.jhu.edu/journals/pew/summary/v063/63.4.vaidya.html
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Nyya Perceptual Theory: Disjunctivism or Anti-Individualism? · Nyāya misplacement theory of illusion, or MTI. In the sixth, I argue that MTI (a) offers a metaphysical distinction
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Ny�ya Perceptual Theory: Disjunctivism or Anti-Individualism?
Anand Jayprakash Vaidya
Philosophy East and West, Volume 63, Number 4, October 2013, pp.562-585 (Article)
Published by University of Hawai'i Press
For additional information about this article
Access provided by San Jose State University (26 Oct 2013 19:52 GMT)
Misperceptionispartofthehumancondition.Consideraclassiccaseofcoming to confirmthatonehashadamisperception.Onastrollthroughthewoodsyousee,inthedistance,whatseemstobeaperson.Asyoudrawnear,whatlookedlikeapersonnowappearstobeawoodenpostwithahatonit.Onarrivalyoutouchtheposttoconfirm that it isnotaperson.Fromapre-theoreticalperspective,whathashap-pened?Onyourapproachyoujudgedthattherewasaperson,basedonwhatyousaw.Whennear,youjudgedthatitwasapostandnotaperson,andthenbytouchyouconfirmedthatwhatyouinitiallysawwasamisperception.
Inexaminingcasesofmisperceptionitisimportanttoask:whatroledoescon-ceptpossessionplayinexplainingthemisperception?Theconceptualistansweristhatanecessaryconditiononxmisperceivingapostasapersonisthatxpossessboththeconceptofapostandtheconceptofaperson,sothatxcanbeinacognitiveposition tomisperceive thepost foraperson.Theguiding idea is that ifonepos-sessesneithertheconceptofapostnortheconceptofaperson,itisunintelligiblehowonecouldhavesuchamisperception.Forhowcouldonejudgeonthebasisofone’sperceptionalonethatonapproachitwasapersonbutthatuponarrivalitwasapost, ifone failed topossess theseconcepts?Theconceptualistmaintains thatasubject’smisperceptionsarecontrolledbytheconceptualschemethattheypossess.In general, our conceptual schemes determine a limit boundary to what we canmisperceiveandwhatotherscantakeustohavemisperceived.1
Philosophers both East andWest have taken note of the fact that at least insomecasestheincoherenceofmisperceptionwithoutconceptpossessionyieldstotheviewthaterrororfalsecognitiondependsontruthortruecognition.Theviewthaterrormetaphysicallydependson truth,but truthdoesnotmetaphysicallyde-pendonerroriscalledtheasymmetric dependenceoferrorontruthortheparasit-ism of error on truth. The guiding idea of asymmetric dependence is that thepossibility of false cognition depends on a prior true cognition, and as a conse-quenceerrorisparasiticontruth.Ifoneneverperceivedcorrectlythenonecouldnotmisperceive.
In his illuminating comparative essay Parasitism and Disjunctivism in Nyāya Epistemology,MatthewDasti(2012)carefullyarguesthattheNyāyaschoolofclassi-calIndianphilosophyofferedmanyargumentsfortheparasitismoferrorontruth,
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andthatthepositionstheyheldrelativetotheseargumentsanticipatetheepistemo-logicaldisjunctivismofcontemporaryWesternepistemology,especiallythatofJohnMcDowell(1996,2009).2Disjunctivism,ingeneral,is,roughly,adenialoftheclaimthatthereisacommonkindofexperiencebetweenmisperceptionsandperceptionsthatisofrobustexplanatoryvalueforthepurposesofthephilosophyofperception.Atahighlevelofabstraction,disjunctivismclaimsthatperceptionsandmispercep-tionsaresimilarinthesamewaythatsuperficiallysimilar,butchemicallydistinct,compoundsaresimilar.Forexample,goldandfool’sgoldorjadeiteandnephritearemacroscopicallysimilarbutchemicallydistinctsubstances.Byanalogy,atadeeperlevel of explanation, disjunctivism claims that perceptions and misperceptions,thoughphenomenologically similar,are fundamentallydistinctandshouldnotbecategorizedasbeingofthesameepistemickind.
Iftheconceptcowreferstocows,thenasubjectthatisinanenvironmentcannotpossess the concept cow unless there is some causal chain terminating in cowsthroughwhichthepersoncouldhavelearnedtheconcept.Thecentralideaofasym-metricdependencecanbeunpackedasacommitment to twoclaims,oneaboutconceptpossessionandoneaboutmisapplication:
1. Possession.IfanindividualApossessesaconceptCattimet,then,priortot, A must have correctly applied C. Concept possession requires correctapplication.
2. Misapplication. A necessary condition on an individual A misapplying aconceptCisthatApossessC.IfAdoesnotpossessC,thenAcannotmis-applyC.
Tyler Burge on Anti-IndividualismTylerBurge(1979and1986)defendsanti-individualismwithregardtomentalcon-tent.Anti-individualismwith regard tomentalcontentcanbe statedbroadlyasathesisabouttheindividuationofcontent.Burge’santi-individualismmaintainsthat
(1) Foran individual topossessacertainclassofconcepts,naturalkindsandsocialkindsinparticular,it isnecessarythattheindividualbeinacertainkindofphysicalandsocialenvironment.
(2) Itispossiblefortwoindividualstobeintrinsicduplicatesofeachother,whilepossessingdistinctconceptsbecause theyare in, andcome from,distinctphysicalandsocialenvironments.
Althoughanti-individualismwithregardtomentalcontentisnotuncontroversial,itis supported by a host of thought experiments and considerations. Burge (1986)advances the thesis by considering terms such as ‘arthritis’ and ‘sofa.’ AlthoughBurge’santi-individualismisnotidenticaltoPutnam’s(1973)semanticexternalism,boththesesgainsupportfromtheTwinEarththoughtexperimentpropoundedini-tiallybyPutnamandexaminedlaterbyBurge.5Inhisthoughtexperiment,Putnaminvitesus toconsider two individuals indistinctpossibleworlds thatare intrinsicduplicatesofoneanother.
OscarandTwinOscar liveinphysicalandsocialenvironments thatareexactduplicatesofeachotherineveryway,exceptforonefeature.OscarlivesonEarthinanenvironmentwhereH2Oispresent,and‘water’referstoH2O.TwinOscarlivesonTwinEarthwhereXYZispresent,and‘water’isusedtorefertoXYZ.XYZisasub-stancethatisdistinguishablefromH2Oonlyatthelevelofmicrostructureandnotatthe levelofmacroscopic features suchas taste, color, andboilingpoint,or func-tional features such asdrinking, bathing, andwashing.Moreover, everything thatH2OisusedonEarth,XYZisusedonTwinEarth,andviceversa.
Thefundamentalideaofanti-individualismisthattheindividuationconditionsfor mental content depend on factors that go outside the head of the individual.OscarandTwinOscarareintrinsicduplicates.Partofwhatmakesit thecasethat‘water’forOscarreferstoH2OandnotXYZisthefactthatOscarispartofanH2O,andnotanXYZ,environmentandcommunity.Partofwhatmakesit thecasethat‘water’forTwinOscarreferstoXYZandnotH2OisthefactthatTwinOscarispartofanXYZ,andnotanH2O,environmentandcommunity.
John McDowell’s Epistemic DisjunctivismMcDowell’sepistemicdisjunctivism,ED,isofferedasanalternativetothehighest common factorviewofexperience.Thehighestcommonfactorviewofexperience,HCF,maintainsthatveridicalandnon-veridicalcasesshareacommonkindofmen-talstate.TheHCFismotivatedinpartbytheargumentfromillusionthathasbeenprevalentinmanydiscussionsanddebatesonperception,fromDescartesandHumetoAyerandAustin.McDowelldescribestheHCFandthelineofreasoningleadingtoit:
[T]heargumentisthatsincetherecanbedeceptivecasesexperientiallyindistinguishablefrom non-deceptive cases, one’s experiential intake—what one embraces within thescopeofone’sconsciousness—mustbethesameinbothkindsofcase.Inadeceptivecase,one’sexperientialintakemustex hypothesifallshortofthefactitself,inthesenseofbeingconsistentwiththerebeingnosuchfact.So,thatmustbetrue,accordingtotheargument,inanon-deceptivecase,too.One’scapacityisacapacitytotellbylooking:thatis,onthebasisofexperientialintake.Andevenwhenthiscapacitydoesyieldknowl-edge,wehavetoconceivethebasisasahighest common factorofwhatisavailabletoexperienceinthedeceptiveandnon-deceptivecasesalike,andhenceassomethingthatisatbestadefeasiblegroundfortheknowledge,thoughavailablewithacertaintyinde-pendentofwhatevermightputtheknowledgeindoubt.(McDowell2009,p.80)
Epistemicskepticismwithrespect toapotentialdomainofknowledgeis theviewthathumansubjectsdonothaveknowledgeofpotentiallyknowableitemsinthatdomain.AtleastpartofMcDowell’s(2008)motivationforadvancingepistemicdis-junctivism is his belief that it provides resources for a transcendental argument
Burge’scriticismofMcDowell’sepistemicdisjunctivismisanattempttoevaluatethetruth of epistemic disjunctivismandnot the claim that it provides transcendentalreasonsforrejectingepistemicskepticismabouttheexternalworld.Hisassessmentand evaluation of epistemic disjunctivism rests on an examination of perceptualpsychologyandvisionscience.Hismeta-theoreticalaccountof thephilosophyofperceptionmaintainsthatanytheoryofperceptualcontentmustpayrespecttoper-ceptualpsychologyandthevisionsciences.Itisinconsistencywithvisionsciencethatrendersatheoryimplausible.
Inhisworkonperceptualpsychology,Burgehasargued thatperceptualanti-individualismisconsistentwithcontemporaryperceptualpsychologyandthat,in-deed,thevisionsciencespresupposethetruthofit.Perceptual anti-individualism,PAI,isthethesisthata constitutively necessary condition on perceptual representa-tion by an individual is that any such representation be associated with a background of some veridical perceptual representations (Burge2005,p.1). IncontrasttoPAI,Burgeargues thatepistemicdisjunctivismandnaive realismaboutperceptionareuntenable theses.Thecoreclaimsof theseviewscannotbemadeconsistentwithcontemporaryworkinperceptualpsychology:
Given thatdifferentdistalcausescanyieldproximal stimulation that is relevantlythesame,perceptionofentitiesinthedistalenvironmentisfallible.TheProximalityPrin-ciple,togetherwiththisempiricalfact,entailsthatthesametypeofperceptualstatecanbe veridical or non-veridical, perceptually referential or non-referential. (Burge 2005,p.27)
holding constant the antecedent psychological set of the perceiver, a given type of proximal stimulation (over the whole body), together with the associated inter-nal afferent and efferent input into the perceptual system, will produce a given type of perceptual state, assuming that there is no malfunctioning in the system and no interference with the system.
Supposethatoneseesanobject.Thenasoneblinks,theobjectisremovedandreplacedbyaduplicate thatonecannotdiscern fromtheoriginal in thecontext.Asoneblinksagain, the duplicate is removed. One is induced by an abnormal confluence of lighttohaveavisualillusionasofanobjectthatisindiscriminablefromtheoriginallyseenobject.Thelightarrayhittingtheretinais,weshallsuppose,type-identicalinthethreecases—oratleastsufficientlysimilarthattheperceptualsystemcannotmakeuseofthedifference.(Burge2005,p.26)
PPrequires thatonehaveageneralability tousetheinformationincommonbe-tweenthethreecases.InBurge’saccounttheabilityisexplanatoryforhowwecometohaveaperceptualsystematall.Werewenottohaveageneralabilitytousetheinformation in common between the three states, we could not have evolved tohave a perceptual system. Of course, the possibility of the system evolving alsorequires that thereareveridicalstates.ED,bycontrast,denies that there isanex-planatorilyrelevantkindincommonbetweenthethreestates.WhilePAIindividu-atesperceptionatatype-levelcommonality,EDdoessobyvirtueoftheveridicality
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conditions at the token level. Given that in the three cases the perceptual state isonlyphenomenallysimilar,andnot targetsimilar,EDmaintains that thestatesaredifferentinanexplanatorilyrobustmannerrelevanttotheclassificationofepistemickinds.
InunderstandingPAI,itis ofcentral importancetotakenoteofthekindofac-countthatBurgebelievesthattheproximalityprincipledelivers.Inhisaccount,PPissupposedtodeliverstatesthatarenotmerelyofthesub-personalvisualprocessingsystem.RatherPPgovernsthelevelofperceptualstatesthatareattributabletoindi-vidualsasconsciousperceivers.ThistheoreticalstanceonPPisimportantbecauseofapotentialobjection thatonecanmake to the relevanceofvisionscience to thephilosophyofperception.IfPPonlyexplainedsub-personalvisualprocessingbelowthelevelofphenomenalconsciousness,itwouldbepossibleforanepistemicdis-junctivisttorespondasfollows:sinceEDisathesisthatappliesatthepersonallevelofperceptual theorizing,andnotat the sub-personal system-processing level, themechanismbywhichpersonal-levelperceptionisdeliveredisirrelevanttothedis-junctivist thesis. In effect, the disjunctivist would block the significance of PP asprovidingaproblemfortheplausibilityofED.
IbelievethatBurge’sworkisusefulata theoretical levelwhereitcanbede-ployedasamechanismfordisentanglingtherelationsbetweenasymmetric depen-dence, anti-individualism, and epistemic disjunctivism. In theaccount Iwilloffer,McDowellandBurgecanbeseentobeinagreementovertheimportancethattheasymmetricdependenceoferrorontruthplaysinatheoryofperception.Thatis,theyagreethatveridicalityisanecessaryconditionforthepossibilityofperception.Con-cept possession and perceptual capacities are enabled by veridicality. However,whattheydisagreeoniswhatfollowsfromasymmetricdependence.Inshort,PAImaintains that veridicality is necessary for a perceptual system to arise, but thatveridicalityisnotanessentialpropertyofaperceptualtype.
For the purposes of distinguishing further between ED and PAI, consider thefollowingcases:
mightfurtherask:whatfollowsfromasymmetricdependence?Therearethreeargu-mentsrelatingasymmetricdependence toepistemicdisjunctivism.Eachargumentmoves from thepremiseconcerningasymmetricdependence to someclaimcon-cerningepistemicdisjunctivism.Onemightlegitimatelyaskif(2)through(4)belowfollowfrom(1):
4. So, a veridical perception cannot be factored into an appearance and theobjectivefactthatmakesitaveridicalperception(non-factorizability).
Inanalyzingtheargument,weneedtotakenoteofthenatureofeachoftheclaims.Asymmetric dependence isametaphysicalclaimabouttherelationbetweentruthanderrorastheyapplytothethingsthatcanbethebearersoftruthanderror—truth-evaluable contents. The metaphysical distinctness of veridical and non-veridicalstatesisametaphysicalthesisaboutthepropertaxonomyofperceptualstates.Theasymmetric warrantbetweenveridicalandnon-veridicalstatesisanepistemicprin-cipleconcerningepistemicwarrantforbelief.Andthenon-factorizabilityofveridicalstatesisametaphysicalclaimaboutthecomponentsinvolvedinaveridicalstate.
ThedistinctionbetweenBurge’sPAIandMcDowell’sEDcanbeunderstoodasaquestioningofeachoftheinferencesfrom(1).WhileMcDowellisfarmoreopento inferring fromasymmetricdependencevariouscomponentsofED,Burge is farmore cautious. In Burge’s account, asymmetric dependence is amenable to anti-individualism,understoodastheideathatperceptiononlymakessenseagainstthebackgroundofveridicalstates.Thismetaphysicalclaim,whichisconstitutiveofper-ceptionforBurge,entailsneitherthatthereisnocommonfactorofexplanatoryim-portance between veridical and non-veridical perception nor that veridical andnon-veridicalstateshaveasymmetricwarrant.6TheBurge-McDowelldebateleavesuswiththefollowingquestion:isperceptualanti-individualismorepistemicdisjunc-tivismasuperiorplatformforfurthertheorizingaboutperceptionandforcategoriz-ingNyāyaepistemologyandperceptualtheory?
IV. Dasti on Disjunctivism from Parasitism
Matthew Dasti maintains that “Nyāya [epistemology] privileges veridical truth-entailing mental states and considers error conceptually parasitical upon knowl-edge.” And that “This [asymmetric dependence] entails a disjunctive account ofpramana andnon-pramanastates”(Dasti2012,p.3).InhisaccountofNyāyaepis-temologyandphilosophyofmindtherearethreeformsofargumentfromparasitism:
(3) Parasitism of content or meaning.Divorcedfromconnectionwithexternalreality,conceptswouldbedrainedofcontent,aswould thewordswhosemeaningsaretiedtotheconceptstheyexpress.
Hemustbeaskedhowconsciousnessarisesinthat very form(theformofspecificob-jects). Ifconsciousness takes the formofblood, thenyoumustexplainwhatblood is.Similarly,theformofwaterandrivermustbeexplained.Inthesentence,“theyseeariverofpus,”eachword,whenexaminedindividually,isfoundtobemeaningless,iftherearenorealexternalobjects.(Dasti2012,p.7)
1. Default Trust. Arguments from parasitism show that the default epistemicpositiononeshouldtakeistrustandnotdoubt.
2. Denial of HCF. Argumentsfromparasitismtendtoblocktheneedtofindacommonstatebetweenveridicalandnon-veridicalperception.
3. Metaphysical Distinctness. Non-veridical states are fake perceptual states;they are only phenomenally indistinguishable from genuine or veridicalperception.
vidualis that any such representation be associated with a background of some ve-ridical perceptual representation”(Burge2005,p.1;emphasisadded).ItakeBurge,inmakingthisclaim,tobeendorsingtheviewthaterrordependsontruth,buttruthdoesnotdependonerror,atleastwithrespecttothegenerationofperceptualstates.For in saying thataconditiononany perceptual representation is that therebeabackgroundofveridicalrepresentation,Burgeismaintainingthatthepossibilityofhavingarepresentationatalldependsonveridicality.ThecoreclaimofparasitisminNyāya,asDastiargues, is thaterrorandnon-veridicalcognitionareconceptuallyparasiticontruth.Thepassageshecitesshowthisclearlytobethecase.However,BurgearguesthatPAIisconsistentwiththeProximality Principle,andthatEDisnot.GiventheargumentationbetweenBurgeandMcDowell,twoquestionsarise.
First,ifBurgeiscorrectinarguingthatEDisinconsistentwiththevisionsciences,weareleftwithanevaluativequestion:shouldwetakeseriouslytheNyāyapercep-tual theoryas aworthy theoryof study for theorizing further aboutperception incontemporaryphilosophy?Onemightwonder,whatcanwelearnfromatheorythatisinconsistentwithaprinciplethatisthebenchmarkforcontemporaryresearchonperception?Second,giventhatNyāyaperceptualtheory,Burge’sPAI,andMcDowell’sEDallendorsetheasymmetricdependenceoferrorontruth,weareleftwithaninter-pretive question:giventhatBurgeandMcDowelldisagreeover theconsequencesthatfollowfromasymmetricdependence,mightthereberoomtoinvestigatecriti-callywhetherNyāyaperceptualtheoryalsoleansmoretowardPAIthanED?
Second,neitherepistemic,causal,normeaningparasitismshowthatthere is nocommonkindofmentalstatebetweenveridicalandnon-veridicalstatesthatplaysanimportantexplanatoryrole.Atbesttheseformsofparasitism,asDastipointsout,showaresistancetofindingahighestcommonfactorfromacertainphilosophicalframeofinvestigation.Thatisaphilosophicalframethatdoesnotattemptatheoryofperceptionbasedonanattempttoansweratotalizingformofepistemicskepticism.GiventhatNyāyaperceptualtheoryaimsatprovidinganetiologicalaccountofthesourcesof knowledge, itmaynotneed to findan internal componentof a givensourcethatisalsoatplayincaseswhereknowledgeisnotproduced.Moreover,itmaybethecasethatwerethecertaincomponentsoftheirviewsatisfied,thetheorywould be amenable to the existence of an important explanatory factor betweenveridicalandnon-veridicalcasesofperception.
Third, the three forms of parasitism that Dasti draws attention to—epistemic,causal,andmeaning—donotleandirectlytowardED.Ontheonehand,epistemicparasitismappearstobeathesisaboutwhatisanecessaryconditionforidentifying
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andrecognizingafalsecaseofperception.Itdoesnotrequirethattherebe no com-mon kind of elementbetweenveridicalandnon-veridicalstates.WhatitrequiresisthatknowledgeofFisimplicatedinrecognizingthatsomethingisanon-F.Theclaimofepistemicparasitismisquiteinnocuous:to identify that a zebra is not a cow, one must know what a cow and a zebra are(thinkhereoftheMenoproblem).Ontheotherhand,causalparasitismappearstobenomorethanthethesisofasymmetricdependence,whilemeaningparasitismappearstobeanoutrightexampleofanti-individualismaboutmeaning.
Keepinginmindthecentralthesisofanti-individualism,parasitism of content or meaningmaintainsthatdivorcedfromaconnectionwithexternalreality,conceptswouldbedrainedofcontent,aswouldthewordswhosemeaningsaretiedtotheconcepts they express.The thesis leans strongly toward the central idea of anti-individualism:content and meaningare determined by factors outside the psychol-ogy of the individual,becausewhatisemphasizedistheroleoftheexternalworldindeterminingcontent.Parasitismofcontentandmeaningdoesnot lean towardEDmorethanPAI.
Finally,itisshouldbenotedthatMcDowell’sEDisinpartmotivatedbyanat-tempttoprovideatranscendentalargumentagainstepistemicskepticism.Intermsofaphilosophicalpointofdeparture,epistemicdisjunctivismappearsasaresponsetotheCartesian skeptical frame. It isgeneratedasaresponsetoa traditionofphilo-sophicaltheorizingintheModernperiodofWesternphilosophythatturnedtowardtakingtheskepticalargumentandthemethodofdoubtasastartingpointforphilo-sophicalreasoning.OneofDasti’skeycomparativeinsightsisthatNyāyaepistemol-ogystartsfromthedefaultpositionoftrustasopposedtodoubt.Ifhisunderstandingofthisclaimiscorrect,thentheclassicalIndianframeforphilosophicalreasoningwouldnotbesimilartotheCartesian skeptical frame,andourinterpretationofanydisjunctive-likecomponentsofNyāyashouldbereadinanappropriatelyadjustedmanner.InthemodelofinterpretationthatIfavor,ImaintainthatamotivationfortheNyāyaaccountisthesearchforcriteriabywhichonecanexplainhowperceptionisan instrument of knowledge by looking at how the causal processes involved inmisperceptionaredistinctfromthoseinvolvedinperception.Ibelievethatthiscom-ponentalsomakestheirviewamenabletoBurge’sPAI.
V. Misplacement as a Route to Metaphysical Disjunctivism
ThecoreofMTIasanaccountofmisperceptions,andnotofhallucinations,canbegraspedthroughanextendedexaminationofacaseofcoming to confirmthatonehashadamisperception.Supposethatuponapproachingfromadistanceoneseesasnake,butasonecomesnearitisrevealedtobearope.Furthermore,asoneleansforwardtograbitoneconfirmsthatitisaropeandnotasnake.Inthissuccessionofeventswehaveamisperceptionthatyieldstoaperceptionthatisthenconfirmedviaadistinctperceptualmodality—tactileperception.ThestandardNyāyaanalysisofthissequenceofeventsisasfollows.
First,ontheapproachtotherope,foronetoseetheropeasasnakeandthenasarope,onemustfirstpossesstheconceptofasnakeandtheconceptofarope.Forifonehasneverseenasnakebefore,thenonecannotseetheropeinfrontofone,firstas a snakeandsubsequentlyas a rope.Second,inseeingtheropeas a snake,whathashappenedisthatthenormalcausalprocessbywhichonewouldseetheropeasaropehasbeeninterruptedbyamemory.Thememoryofasnakehasariseninoneandhasbeenimposedintoawareness.Bycontrast,whenonecomesclosertothe ropeand sees the ropeasa rope,nomemoryhas intervened into thecausalstreamthatbringsabouttheawareness.Rather,thecausalconditionsthatgiverisetotheawarenessaretruthproductive.
On a further elaboration of MTI, Bimal Krishna Matilal explains the view byclaimingthatthemisperceptionisitselfbasedonobjectivefeaturesofthesituation.MorepreciselyheclaimsthatitisveryunlikelythatasubjectcanmisperceiveAasB iftherearenofeaturesincommonwherebyAcanbeconfusedwithorseentobeBbyanimpositionfrommemory.Inthecaseofthesnake-ropemisperception,itisbecausearopecanlook like a snake thatitcanbemisperceivedasasnakebytheimpositionof thememoryofa snake into thecausal streamof theperceiver.Thepointisthatwhileitislikelythatamemorycaninterveneandcausearopetobeseenasasnake,itisunlikelythatamemorycaninterveneandcause,forexample,anoceantobeseenasaspider.Thelattercasewouldlikelybeahallucinationofaspiderimposedonanocean,ratherthanamisperception.Moreover,theobjectivepropertiesoftherelevantobjectsplayakeyroleinexplainingthepossibilitiesformisperceptionthroughtheperceptualsystem.
HerewetouchtheheartofNyāyarealism....Snakehoodisavailabletobecomeillusorypredicationcontentthroughpreviousveridicalexperiencesofsnakes.Itgetsfusedintoacurrentperceptionby means of a foul-up in the normal causal processthroughthearous-ingofasnake-hoodmemoryformedbypreviousexperiencesofsnakes.Thecontentofanillusionistobeexplainedcausallyasgeneratedbyrealfeaturesofrealthingsjustasve-ridicalperceptionistoo,althoughillusioninvolvestheprojectionintocurrentperceptionofpredicationcontentpreservedinmemorywhereasatleastinsomecases(forexample,thosewhereanindeterminateperceptionfurnishesthequalifier)veridicalperceptionisnotshapedbymemory.(Phillips2004,p.111;emphasisadded)
Thegroundofthedistinctionistherecognitionof“afoul-upinthenormalcausalprocess.”Veridicalcases for theNyāyaaremetaphysicallycasesofpropercausalfunctioningacrossallcausallyrelevantfactors.Non-veridical(atleastcaseswhereasubjectisperceivedtoseeanobjectwithapropertyitdoesnothave)arecaseswherethereisanerrorinthenormalcausalprocessing.Themetaphysicaldistinctionbe-tween the two cases comes from the main factor that produces each, the causalnexus.IntheNyāyaaccountveridicalperceptioncomesaboutwhenourmemorydoes not interveneintheproductionofacognitionthatarises fromsensecontactwithanobject.Innon-veridicalperception,atleastinmisperception,ourmemoryintervenesandintroducesintothecausalpathwayacontentthatisimproper.
ItisunclearwhetherNyāyaepistemologywouldendorse(1).Whileitmaybethecasethattheirepistemologyisinterestedintheideathatperceptionisaninstrumentforknowledge,itisnotatallclearthattheiraccountconceivesofperceptionasacapacitytoknowinthewayexplainedbyMcDowell:“Aperceptualcapacity...isacapacity—ofcoursefallible—togetintopositionsinwhichonehasindefeasiblewarrantforcertainbeliefs.”ThemainissueisthataperceptualcapacityinMcDowell’saccountisacapacityonehasinordertogetintoapositionwhereonehasindefea-siblewarrant.InorderfortheNyāyaaccounttobesimilartoMcDowell’saccountitwouldhavetobethecasethatdefeasibleandindefeasiblewarrantareimportantfac-torswithinNyāyaepistemologyandperceptualtheory.Additionally,theclaimthatperception isacapacity toknowis toobroad. Inparticular,Burge’sPAIdoesnotpreclude perception from being a capacity for knowledge. It simply explains the
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detailsbywhichperceptionisacapacityforknowledgeinadistinctmanner.Whatisimportantinidentifyingperceptionasacapacityforknowledgeishowatheoryframes fallibility.BurgeandMcDowellagree thatperception is fallible;what theydisagreeonistheproperwaytounderstandfallibilityinperception.8
ThereisstrongevidencethatNyāyaepistemologywouldendorse(2),theclaimthatveridicalstatesandnon-veridicalstatesaremetaphysicallydistinct.However,itshouldbenotedthattheirreasonforacceptingthisclaimisbasedontheideathatthecausalprocessesthatgointoveridicalperceptionaredistinctfromthosethatgointo non-veridical perception. In advancing this metaphysical account they differfromthedisjunctivistinsofarasthedisjunctivistemphasizesthatthedifferencebe-tweenveridicalstatesandnon-veridicalstatesstemsfromthefactthattheyareonlysuperficiallyorphenomenologicallysimilar,andthatphenomenologicalsimilarityisnotsufficientforcategorizingepistemickinds.Ingeneral,thefactthattwoaccountsofferametaphysicaldistinctionbetweenveridicalandnon-veridical statesentailsneither that both accounts offer the same distinction between veridical and non-veridicalstatesnorthattheyofferthedistinctionforthesamereason.
ItislikelythatNyāyaepistemologywouldalsodeny(3),theclaimthatveridicalstatesandnon-veridicalstateshaveasymmetricwarrant,forreasonssimilartothosepresentintherejectionof(1).Theideaofjustificationasacomponentofknowledgeprovidedbyperception isnotoperative in the frameofperceptualandepistemictheorizing that is present in Nyāya epistemology. Moreover, Nyāya epistemologydoesnotappeartoengagethe internalist intuitionthat justificationasanecessaryconditionofknowledgerequiresthecapacitytoarticulatereasonsinargumentation.Inparticular,giventhat(a)theideaofasymmetricwarrantisproposedagainstthebackgroundoftheCartesian frame of skepticismandtheargumentfromillusion,inwhichinternalismoperates,and(b)thesecomponentsareabsentinNyāyaepiste-mology,itisunlikelythattheiraccountwouldendorse(3).
Ontheonehand,MTIallowsonetoclaimthatamisperceptioncanbefactoredinto object, sense organ, and memory, and perception can only be factored intoobjectandsenseorgan.Asaconsequence,MTIallowsfor theviewthatveridicalperceptionisnon-factorizablebecauseitdeniesthepresenceofthememorystate,whichispresentinnon-veridicalperception.
Thenon-factorizabilityclaimamountstoapositionontheelementsofexplanatoryrelevanceforastatebeingveridical.Thestateisaveridicalappearancebecauseitisanoccurrencebasedonsomethingbeingperceptuallypresenttoone.Objectivere-alitybeingpresentiswhatexplainstheveridicalityoftheperception.Theveridicalstatecannotbefactoredintothenon-mentalconditionsthatbringitaboutandthementalconditionsthatbringitabout.Thestructureoftheobjectiveworldisanes-sentialingredientinexplainingtheveridicality.ThestructureofMcDowell’saccountofnon-factorizabilitydoesnotallowforacleanlocationoftheviewinNyāyaepis-temologybecausewhileMTIdoesgiveusanaccountofmisperceptionitdoesnotgiveusadirectpositiveaccountofperception.TheconditionsthatNyāyaimposeonperception, for examplebeingnon-erroneous, are statedasnecessary conditions,andnotaspositiveexplanatoryconditions.
Perceptualanti-individualismoffersabetteroptionforcategorizingMTI.Therearetwocentralreasonswhy.First,PAIandMTIrequirethattherebeobjectivefea-tures of the perceiver’s environment that can play an explanatory role in how amisperceptionisproduced.RecallthatPAImaintainsthatallperceptionrequiresabackground of veridical perception. MTI also maintains that a misperception re-quiresabackgroundofveridicalperceptionwherebythemisperceptioncanoccur.Onewaytoseethispointisbylookingathowobjectivesimilarityintheperceiver’senvironmentisusedtoexplainmisperception.Inordertomisperceivetheropeasasnakeonemustcorrectlyperceiveobjectivefeaturesof theropewherebyitcanbemisperceivedasasnake.Ifoneweretofailtoseethecoiledropeascoiledina specific way, it is unlikely that one would misperceive it as a snake.The ob-jective similaritybetweencoiled ropeandcoiled snakeenables thepossibilityofmisperception.
Second,theproximalityprinciple,PP,isconsistentwithMTI.PPstatesthathold-ingconstanttheantecedentpsychologicalsetoftheperceiver,agiventypeofproxi-malstimulation(overthewholebody),togetherwiththeassociatedinternalafferentandefferentinputintotheperceptualsystem,willproduceagiventypeofpercep-tualstate, assuming that there is no malfunctioning in the system and no interference with the system.AsnotedearlierinPhilips’explanationofMTI,thekeyfeatureofthetheoryisthat“Snakehoodisavailabletobecomeillusorypredicationcontentthroughpreviousveridicalexperienceofsnakes.[Thisisbecause]itgetsfusedintoacurrentperceptionby means of a foul-up in the normal causal processthroughthearousingofasnake-hoodmemoryformedbypreviousexperiencesofsnakes”(Philips2004,p.111;emphasisadded).
Whatboththeoriestakeintoconsiderationistheimportanceofproperfunction-ingandnon-interferencewiththecausalsystem.PPmaintainsthatacertaintypeofperceptualstateis theoutputof therelevantcausalprocessas long as there is no malfunction or interference.MTImaintainsthatmisperceptionisaconsequenceofaninterferencewiththecausalsystem.Thus,Nyāyaepistemologycanmaintainthatin casesof perception the causal systemacross all relevant factors is functioningproperly,butwhenamisperceptionoccursitisbecauseinterferencehasoccurredinthenormalcausalprocessing.9
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Ultimately, it is theemphasisonobjectiveproperties in theworldandcausalprocessingthatmakesPAIasaferpositioningforMTIthanED.
First, there is themethodologicalpointconcerning (1) the relationbetweenathesisandtheframeofinquiryfromwhichthethesisisadvanced,and(2)whateffectaframeofinquiryhasonthedevelopmentofaspecificthesis.Thefactthatcontem-poraryepistemicdisjunctivism,atleastintheworkofMcDowell,findsitsrootsinareactiontoCartesianskepticismmakesitthecasethatithasaquitedifferentframeofinquiryfromthetheorizingthatgoesintotheworkofNyāyaepistemology.Thelatter’sadvancementofametaphysicaldistinctionbetweenveridicalandnon-veridicalstatesdoesnotdepartfromaconcernforrefutingskepticismoftheCartesiankind.InthisregardDastiiscorrecttopointoutthatNyāyaepistemologydepartsfromade-fault positionof trustasopposedtoCartesiandoubt.Thedeparturepointchangeshowweshouldunderstandtheimportandconsequencesoftheformofthepercep-tualtheoryrendered.
Third,muchofthecontemporarydebateconcerningskepticisminanalyticphi-losophyconcernseitherCartesian skepticismordiscussionsofPutnam’sbrain-in-a-vathypothesis.Inbothofthesecasesweareconcernedwithatotalizingformofskepticism. In the former, thestrong formcomesaboutbecauseanevildemon ishypothesizedtobeproducingourperceptions;inthelatterthestrongformcomesaboutbecauseamadscientisthaspluggedourbrainsuptoacomputer.Bothoftheseformsofskepticismdepartfromanunnaturalsource.Whilebotharelogicalpossi-bilitiesthatthestrongestformofanti-skepticismmustrespondto,neitherarenaturalpossibilities that a weaker form of anti-skepticism would respond to. In terms ofprovidinganaturalizedaccountofhowtoexplainmisperception, theNyāyaMTIaccountfocusesonafeatureofmisperceptionthat,althoughnon-scientificallypre-sented, isnevertheless insightful.Theaccount focuseson theway inwhich somemisperceptionsmustbeafunctionofageneralizedformformisperception:x canbemisperceivedforybyagentAbecausex hassomepropertiesobjectivelyincommonwithythat,alongwiththeemotionsandconceptsthatAhas,provideforanaccountofanaturaldispositiononA’sparttomisperceivexforyincertaincircumstances.
1–Itisimportanttonotethatevenincaseswhereasubjectmaylackrobustcon-cepts,suchascow and zebra,itispossibleforthemisperceptionofacowforazebratobevoicedintermsofdemonstrativeconcepts.Forexample,onemightonapproachthink,“thatobjectlookslikethat,”wherethefirstdemonstrativepicksoutacowandthesecondazebra,inapasturewherebothzebrasandcowsarepresentandthestatementisunderstoodtobeacomparativejudgmentalongasetofproperties.However,onarrival,onemightrecoilfromone’sini-tialjudgmentandthink,“Thatobjectdoesnotlooklikethat,”recognizingthatfromadistanceonehadamisperceptionofsimilarityandthatthetwoanimalsinone’sperceptualfieldarenotsimilarbecausetheyarenotbothcowsorbothzebras.
3–InAnglo-Americanphilosophytheterm‘asymmetricdependence’ismostoftenassociatedwithJerryFodor’sworkinsemantics(1987).Whiletherearesomecomponents incommonbetween thatusageand theuse Imakehereof theterm,IwanttonotethatFodor’saccountisnottheonethatisunderdiscussionhere.Rather, thesimple idea thatgetting things right isprior togetting themwrongiswhatisofcentralimportancetotheuseof‘asymmetricdependence’inthisessay.
4–It is important tonote that thereare issuessurrounding therelationbetweenconceptpossessionandthecompleteandincompleteunderstandingofacon-ceptthatarerelevanttotheissueofasymmetricdependencethatgobeyondthescopeof thisessay.Forexample, itappears tobepossible foroneto incom-pletelyunderstandaconceptonepossesses.OnecanpossesstheconceptofarighttrianglewithoutgraspingthatthePythagoreanTheoremholds.However,itappearsimpossibletopossesstheconceptofarighttriangleanddenythatitisathree-sidedclosed-planefigure.Thus,thefollowingquestionarises:whichjudgmentsaboutagivenconceptarenecessarysothatonecanbesaidtopos-sesstheconceptsoastobeabletomisapplyitinagivencase?
5–ItisimportanttorecognizethatBurgeandPutnamdifferintheirunderstandingofwhatexactlyfollowsfromtheTwinEarththoughtexperiment.Anti-individualismisnotthesameassemanticexternalism.Atleastonekeydifferencebetweenthetwoviewsisconcernedwiththerelationbetweensenseandreference.Itisabitodd to present Burge’sAnti-individualism through theuseof Putnam’sTwinEarthcase;however,Idosobecauseofthepopularityoftheexampleandthefactthatitcanbeusedtoestablishthebasicpointthatfactorsoutsideanindi-vidual’sinternalpsychologyarerelevantforindividuationofmentalcontent.
6–There is another way to separate the difference between perceptual anti-individualismandepistemicdisjunctivism.Thedifferencecomesinlookingatan analogybetween chemical kinds and epistemic kinds. In thebasic case,
10–Whileabrief surveyof the literatureshowsnoserious investigationofemo-tional states and perception in analytic epistemology, I doubt that the samewouldbe trueofEuropeanphilosophy. Iam inclined to think thatEuropeanphilosophers have discussed in some depth the relation between emotionalstatesandperceptualstates.
References
Burge,Tyler.1979.“IndividualismandtheMental.”InPeterA.French,TheodoreE.Uehling,andHowardK.Wettstein,eds.,Midwest Studies in Philosophy (Min-neapolis:MinnesotaUniversityPress)4,no.1:73–121.