illusions of optimal motion relationism and …

Forthcomingin:PacificPhilosophicalQuarterlyThedefinitiveversionwillbeavailableatwww.wileyonlinelibrary.com

ILLUSIONSOFOPTIMALMOTION,RELATIONISM,ANDPERCEPTUALCONTENT

SANTIAGOECHEVERRI

Abstract:Austererelationismrejectstheorthodoxanalysisofhallucinationsandillusionsasincorrectperceptualrepresentations.Inthispaper,Iarguethatillusionsofoptimalmotion(IOMs)presentaseriouschallengeforthisview.First,Isubmitthataustere-relationistaccountsofmisleadingexperiencescannotbeadaptedtoaccountforIOMs.Second,IshowthatanyattemptatelucidatingIOMswithinanaustere-relationistframeworkunderminestheclaimthatperceptualexperiencesfundamentallyinvolverelationstomind-independentobjects.Third,IdeveloparepresentationalistmodelofIOMs.Theproposedanalysiscombinestwoideas:Evans’(1981)dynamicmodesofpresentationandFine’s(2007)relationalsemanticsforidentity.

Keywords:Perceptualcontent,naïverealism,illusion,hallucination,phiphenomenon,apparentmotion,objectperception.

Acentralquestionincontemporaryphilosophyofperceptioniswhether

representationalcontentsmustfigureinananalysisofthestructureofperceptual

experiences.Therearetwoprominentresponsestothisquestion.Austererelationism

holdsthatrepresentationalcontentsareunnecessaryforanalyzingthestructureof

perceptualexperiences.Italsoholdsthatperceptualexperiencesfundamentallyinvolve

relationstomind-independentobjectssuchastrees,tables,andstones(Antony2011;

Brewer2011,forthcoming;Campbell2002,2009,2014;Genone2014;Johnston2014;

Raleigh2015;Travis2004).Representationalism,bycontrast,holdsthat

representationalcontentsarenecessaryforanalyzingthestructureofperceptual

experiences(Burge2010;Byrne2009;Peacocke1992;Searle1983;Siegel2010;Pautz

2010,2011).1

Misleadingexperienceshaveoftenbeencitedinsupportofrepresentationalism.

Onthisaccount,misleadingexperiencesareincorrectperceptualrepresentations.

Defendersofaustererelationismhavechallengedthisassumption,though.Somehave

arguedthatrepresentationalismprovidesaninadequateaccountofhallucinationsand

illusions(Brewer2011;Campbell2014;Johnston2014),whileothershaveclaimedthat

itmischaracterizesthephenomenologyofperceptualexperiences(Raleigh2015;Travis

2004).Anumberofphilosophershaveevenputforwardaccountsofmisleading

experiencesthatdonotintroduceperceptualcontents(Antony2011;Brewer2011,

forthcoming;Campbell2014;Fish2009;Genone2014;Kalderon2011;Martin2004,

2006).2

Thegoalofthispaperistoexaminearatherneglectedclassofmisleading

experiencesthatpresentsaseriouschallengeforaustererelationism.Icallthem—

followingMaxWertheimer(1912)—‘illusionsofoptimalmotion’(IOMs).Theseare

experiencesofapparentmotioninwhichsubjectsreportoneobjectmovingfromone

locationtoanotherwhen,infact,therearetwostationaryobjects.Interestingly,these

casesdonotclearlyfitintotheorthodoxphilosophicaldichotomyofhallucinationsand

illusions.

IshallarguethataustererelationismcannotadequatelyaccountforIOMs.In

addition,anyattemptataccountingforthesecaseswithoutintroducingperceptual

contentsthreatenstheaustere-relationistclaimthatrelationstomind-independent

objectsconstitute“themostfundamentalcharacterizationofourexperience”(Brewer

2011:92;seealso:62-3).Iprovidethreeargumentsinfavoroftheseclaims.

First,theaustere-relationistaccountofhallucinationscannotbegeneralizedto

IOMsbecauseitisonlytailoredfortotalhallucinations.Indeed,ifoneappliesthe

austere-relationistaccountofhallucinationstoIOMs,oneisledtoneglector

mischaracterizethecontributionoftheexternalworldtotheirphenomenalcharacter.

Second,theaustere-relationistaccountofillusionscannotbegeneralizedtoIOMs

becauseperceptualrelationstophysicalobjectsdonotconstituteanadequatebasisto

groundtheirphenomenalcharacter.Indeed,therearegoodreasonstoholdthatthe

itemsinvolvedinIOMsarenotsuccessfullyperceived.

Third,ifoneinsistsonprovidinganaustere-relationistaccountofIOMs,onehas

tocharacterizethesubjectasbeingperceptuallyrelatedtoentitiesotherthanmind-

independentobjects.Withsomeadditionalassumptions,thisconclusionunderminesthe

austere-relationistclaimthatrelationstomind-independentobjectsofferthemost

fundamentalcharacterizationofperceptualexperiences.

Intheremainderofthepaper,Idevelopanaccountofperceptualcontent

designedtoaccountforIOMsand,moregenerally,forourexperienceofobjectsas

persistingovertime.Ontheproposedview,whenasubjectispreytoanIOM,she

misrepresentsphasesofnumericallydifferentobjectsasphasesofthesameobject.By

contrast,whenasubjectperceivesanobjectaspersistingovertime,shecorrectly

representsphasesofoneobjectasphasesofthesameobject.Thisaccountcombinestwo

ideas:Evans’(1981)insightthatperceptualtrackingrequiresdynamicmodesof

presentationandFine’s(2007)relationalsemanticsforidentity.Asitturnsout,the

proposedviewdiffersfromotherFregeanaccountsthatintroducedereordedicto

modesofpresentation.

Thepaperfallsintosevensections.Sections1to3setoutthetermsofthedebate:

IintroduceIOMs(Section1),defendmydescriptionofthem(Section2),anddefine

austererelationism(Section3).Next,Iexaminethetwomainstrategiesavailableto

austererelationismtoaccountforIOMs:accountsthattreatthemashallucinations

(Section4)andaccountsthatassimilatethemtoillusions(Section5).InSection6,I

sketchanaccountofperceptualcontentthatelucidatesIOMsand,moregenerally,our

experienceofobjectsaspersistingovertime.Iconcludewithsomeimplicationsofthe

proposedaccountforthebroaderdebateonthestructureofperceptualexperiences

(Section7).

1. IllusionsofOptimalMotion

Illusionsofoptimalmotion(IOMs)belongtothebroadclassofexperiencesof

apparentmotion.Intheso-calledϕphenomenon,twonumericallydifferentimagesa

andb(e.g.twodots)areprojectedatdifferentlocationslaandlbatdifferenttimes.

Wertheimer(1912:32-3)introducedϕasavariableforanyeventthattakesplace

betweenlaandlbduringthetemporalintervalthatmediatesthepresentationofaandb.

Withlongintervals,observershaveanexperienceasofthesuccessionoftwodifferent

images.Withveryshortintervals,theyhaveanexperienceasoftwoimagespresented

simultaneously.Theinterestingphenomenaoccurwhentheintervalsliebetweenthe

longandtheveryshortones.Inthesecases,mostobserversreportanexperienceasof

movementbetweenlaandlb.Sincethereisnomovement,allthesecasesinvolve

apparentmotion.Apparentmotioncantakedifferentforms.Insomecases,the

movementis‘dual’:onecanhaveanexperienceasofamovingalittlebittowardb,then

disappearing,andthenanotherexperienceasofbstartingitsmovementjustafterthe

midpointthatseparatesafrombuptolb.Inothercases,observersreportanexperience

asofwhatWertheimercalls‘optimal’or‘definite’motion.Ashemakesclear,thesecases

are“exactlyaswouldbeexperiencedwhenviewinganobjectthatactuallymovesfrom

onelocationtoanother”(Wertheimer1912:7).3

OnereasonwhyIOMsaretheoreticallychallengingisthattheydonotseemtofit

intothephilosophicaldichotomyofhallucinationsandillusions.Indeed,theyseemto

havefeaturesofbothtypesofmisleadingexperiences.4

Ontheorthodoxview,ahallucinationisacaseinwhichasubjecthasan

experienceasofanitemandthatitemisnotthere.Thus,FionaMacphersonwrites:

Whenphilosopherstalkofhallucinations,theytypicallyimaginecasesinwhichone’sperceptual

experienceiscompletelyhallucinatory.Thatis,theyimaginethatoneisseeingnothingandthat

eachelementofone’sperceptualexperienceishallucinatory(Macpherson2013:8).

Similarly,JohnCampbellpointsout:

Thephilosophers’ideaofahallucination(asopposedtotheempiricalphenomenonof

hallucination)istheideaofamentalstatethatisintrinsicallyjustlikeseeingsomething,but

withouttheexternalworldbeingthere(Campbell2014:92).5

Consideraparadigmaticexampleofaphilosophicalhallucination.Supposethat

Macbeth’svisualcortexisstimulatedinexactlythesamewayinwhichitisactivated

whenheisseeingadaggerinfrontofhim.Inthiscase,hecouldhaveanexperiencethat

exactlymatchesasuccessfulvisualexperienceasofadaggerinfrontofhim.Contraryto

thiscase,however,IOMsarenotproducedbydirectlystimulatingtheperceptualsystem

butbypresentingsomedistalitemsatsomelocationsandseparatedbysometemporal

intervals.Thus,thereisasenseinwhichtheseexperiencesarenotcompletely‘empty’.

Theworldoutthereseemstoplayadecisiverole.Whatgoeswrongisthecardinalityof

theitemsthatseemtobepresentedinthescene.Insteadofhavinganexperienceasof

twodots,thesubjecthasanexperienceasofonedotmovingfromonelocationto

another.

Theorthodoxviewalsotellsusthatanillusionisanexperienceinwhicha

perceivedobjectseemstoinstantiateapropertyitdoesnotinstantiate.Thus,Bill

Brewerwrites:

Inanillusionaphysicalobject,o,looksF,althoughoisnotactuallyF(Brewer2011:64).

Similarly,MichaelTyesubmits:

[I]ncasesofillusiontheperceivedobjectappearsotherthanitis.Insuchcases[…]theobjectis

notasitappearstobe(Tye2011:172-3).6

TheMüller-Lyerdiagramisanillusioninphilosophers’sensebecausethetwo

mainsegmentsseemtoinstantiateapropertytheydonothave.Thesegmentwith

outward-extendingslashesseemstobelongerthanthesegmentwithinward-extending

slashes.Yet,theformerdoesnotinstantiatethepropertyofbeinglongerthanthelatter.

InIOMs,subjectscertainlyexperienceatleastonepropertythatisnotinstantiatedin

theworld:motion.Nevertheless,thisdoesnotseemtobesufficienttoclassifyitasan

illusioninthetraditionalsenseofthattermbecauseitisunclearwhattheobjectof

perceptionis.WhileBrewer’sandTye’sdefinitionsrequirethataperceivedobjectlook

orappearotherthanitis,thisconditiondoesnotseemtobesatisfiedinIOMs,wherethe

subjectgetsthenumericalidentityofthedotswrong.7

Althoughthefirststudiesontheϕphenomenonwerecarriedoutmorethana

centuryago,thisphenomenonhasplayedarathermarginalroleincontemporary

philosophyofperception.8ItcertainlyplayedaroleinGoodman’s(1978)argumentfor

constructivismandinDennett’s(1991)defenseofthemultipledrafttheoryof

consciousness.Illusionsofapparentmotionhavealsoplayedaroleinrecentworkon

temporalexperience(e.g.,Dainton2000;Grush2008).Nevertheless,thefactthatthey

donotseemtofitintothephilosophicaldichotomyofhallucinationsandillusionshas

notreceivedsufficientattentionincontemporaryworkonthestructureofperceptual

experiences.Idothink,however,thatthisveryfactmakesthemideallysuitedtotestthe

availableviewsonthestructureofperceptualexperiences.9

Iwillarguethataustererelationismlacksthetheoreticalresourcestoaccountfor

IOMswhileremainingfaithfultoitsmainmotivation:toassignafundamentalroleto

perceptualrelationstomind-independentobjectsinanaccountofthephenomenal

characterofperceptualexperiences.Hence,wehavegoodreasonstorevisethisclaim

andpositperceptualcontents.BeforeIpresentmyarguments,letmedefendthe

previousdescriptionofIOMsasinvolvingnumericalidentity.

2. TheIdentityInterpretationDefended

Inthissection,IdefendmydescriptionofIOMsasinvolvingnumericalidentity.

Tothisend,Iexamineandrejecttwoalternativecharacterizations.

2.1. IllusionsofOptimalMotionDoNotInvolveObjects

OnemightgrantthatIOMsconstituteasuigenerisclassofmisleading

experiences,yetdenythattheyarerelevanttoassessaustererelationism,whichis

mainlyconcernedwiththeperceptionofobjectssuchastrees,tables,andstones.Inthe

presentcase,therelevantitemsarenotobjectsbutdotsorflashespresentedin

succession.

Ifindthisrestrictionontheitemsofperceptionunmotivated.Afterall,wedonot

merelyperceiveobjectsbutalsorainbows,soapbubbles,flames,explosions,andmany

otherentities.Moreover,althoughcasesofapparentmotiondonotinvolveobjectslike

trees,tablesorstones,theyinvolveitemsthatdisplaysomeofthemainsignature

propertiesofobjects.AsPalmer(1999:498)pointsout,themechanismsthatcompute

apparentmotionaresensitivetohigh-levelphenomenasuchaspositionconstancy,

objectrigidity,andocclusion/dissoclusionevents.10Moreover,asGoodman(1978:80)

rightlyindicates,pathsofapparentmotiondonotcross.Aplausibleexplanationisthat

theydonotcrossbecausetheentitiesinvolvedareparsedasobjects,andobjectsdonot

crosstheirowntrajectories.

2.2. IllusionsofOptimalMotionConcernQualitativeIdentity

OnemightgrantthatIOMsarerelevanttoassessaustererelationismbutdeny

thattheyinvolvenumericalidentity.Tothisend,onemightre-describethosecasesas

involvingaqualitativesimilaritybetweentwoobjects.Hence,incasesofoptimalmotion,

thereisnoexperienceasofoneobjectmovingfromlatolb.Instead,thereisan

experienceasoftwoqualitativelysimilarobjectsatlaandlb,accompaniedbya

connectingmovementinbetween.

Althoughthislineofreplyisrelativelypopularamongphilosophers,Ihavenever

encountereditamongpsychologistsandnon-philosophers,whograntthatIOMs

concernnumericalidentity.11Interestingly,thereisexperimentalevidenceinfavorof

thenumerical-identitydescription.KolersandPomerantz(1971)comparedtwo

scenarios.Inthefirstone,twodotswereflashedatanintervalthatwouldnormallylead

toanIOM.Hence,observersreportedthefirstdotasfollowingastraighttrajectory

towardthelocationoftheseconddot.Inthesecondone,avirtualbarrierwas

interposedbetweenlocationslaandlb,andthedotswereflashedatthesametemporal

interval.Theyfoundthat,ratherthanexperiencingthedotaspassing‘through’the

barrierinastraightline,mostobserversreportedthefirstdotasmovingindepth

aroundit.Theseexperimentsprovidecompellingevidenceinfavorofthenumerical-

identitydescription.IfIOMsmerelyconcernedthequalitativesimilarityoftwoobjects,

itwouldbedifficulttoexplainthechangeofdirectioninthepresenceofabarrier.12

Thisverdictisconfirmedbyadditionalexperimentsinwhichobserversreportan

objectchangingqualities.OnecanhaveIOMsinwhichagreendotfollowsareddotora

longlinefollowsashortline.Inthesecases,observersreportanexperienceasofone

objectchangingcolororsize(Goodman1978;KolersandvonGrünau1976;Sekuler

2012;Wertheimer1912).

IconcludethatwehavegoodreasonstouseIOMsasalitmustestforaustere

relationismandinterpretthemasinvolvingnumericalidentity.Inthenextsection,I

offeraprecisecharacterizationofaustererelationism.

3. NaïveRealismandAustereRelationism

Naïverealismcharacterizesperceptualexperiencesasfundamentallyinvolving

relationsbetweensubjectsandmind-independententities(Martin2004,2006;Soteriou

2010).Therearetwoinfluentialversionsofthisview.Oneofthemtakestherelevant

entitiestobemind-independentobjectslikestones,tables,andtrees(Brewer2011,

forthcoming;Campbell2002,2009,2014;Genone2014;Johnston2014).Anothertakes

themtobecomplexentitieslikefactsorstatesofaffairs(Dokic2000;Fish2009;

McDowell1996).Althoughmyconclusionsapplytobothviews,mymainfocuswillbe

onversionsofnaïverealismoftheformersort.Brewer(2011,forthcoming)callsitthe

‘objectview’andCampbell(2002,2009,2014)the‘relationalview’.13

LetusfollowBrewer,andcharacterizetheobjectviewastheconjunctionoftwo

claims:

(I) Physicalobjectsaremind-independent.

(II) Physicalobjectsarethedirectobjectsofperception.

Thesetwoclaimsarticulatetheideathatphysicalobjectsprovide“themost

fundamentalcharacterizationofourexperience”(Brewer2011:92;seealso:62-3).In

otherwords,thephenomenalcharacterofperceptualexperiences—‘whatitislike’to

havethem—istobecharacterizedbycitingmind-independentobjectsintheworld(see

alsoCampbell2014:33,41,51;Genone2014;Soteriou2010).14

AsBrewerinterpretsit,claim(II)turnstheobjectviewintoaradicalformof

naïverealism.By‘direct’hemeansthatperceptualexperiencesdonotfundamentally

involverepresentationalcontents(orsensedata).Thus,representationalcontentsare

unnecessaryforanalyzingperceptualexperiences.Theobjectviewisthereforeaformof

austererelationism.

Thereisonedialecticalreasonwhyaustererelationismistheoretically

interesting.Defendersofthisviewoftenadvertiseitasthebestarticulationofour

commonsenseviewofperceptualexperiences.Whereascommonsensetakesfor

grantedthatwearepresentedwithstones,tables,andtreesinperceptualexperiences,

theexistenceofperceptualcontentsisunobvious,soitshouldbeestablishedby

argument.Inthisrespect,thestatusofperceptualrepresentationsisarguablysimilarto

thatoftheoreticalentitieslikesensedata,qualia,andnon-existentobjects(Campbell

2014:20-2,42-3,88;Cassam2014:136;Raleigh2015).Intheremainderofthispaper,I

shallgrantthatperceptualcontentsaretheoreticalentities.

Whatismeantby‘representationalcontent’?Therearemanydifferentwaysof

developingthisidea(Brogaard2014;Pautz2011;Schellenberg2014;Siegel2010).For

mypresentpurposes,Iwillpresupposeaminimalandrelativelyuncontroversial

analysis.Arepresentationalcontentwillbeunderstoodasanabstractentity.Typical

examplesofcontentsarepropositions.Ishallsaythatrepresentationalcontents

determinecorrectnessconditions.Thelatteraresituationsunderwhicha

representationalcontentiscorrectorincorrect.Theproposition<<John>,beingadog>

iscorrectifandonlyifJohnexemplifiesthepropertyofbeingadog.Itisincorrect

otherwise.Iwillusetheadjective‘correct’asagenerictermcoveringavarietyof

evaluationsliketruthandaccuracy.Mypositiveclaimisthatentitiesthatdetermine

correctnessconditionsofferaplausibleexplanationofIOMs.Whethertheseentitiesare

propositionsisaquestionIwillnotaddresshere.

Ithasbeenpointedoutthatonecanassociateperceptualcontentswith

perceptualexperiencesand,still,thoseperceptualcontentsneednotoffera

fundamentalcharacterizationofthoseexperiences(Brogaard2014;Pautz2011;

Schellenberg2014;Siegel2010).Agoodwayofshowingthatperceptualcontentsare

nottriviallyassociatedwithperceptualexperiencesistoarguethattheyhavesome

explanatoryrolestoplay.Myaimispreciselytoshowthatperceptualcontentsoffera

plausibleexplanationofIOMs.

HowcouldaustererelationistsaccountforIOMswithoutintroducingperceptual

contents?Giventhatcurrentproposalshavemostlyfocusedonphilosophers’

hallucinationsandillusions,theymighttrytoreduceIOMstoanyofthesecategories.I

willarguethatneitheroftheseapproachesisplausible.

4. TheEpistemicAccountofHallucinations

RecallthatIOMsdonotseemtofitintothephilosophicaldichotomyof

hallucinationsandillusions(Section1).Nevertheless,austererelationistsmightinsist

thatIOMsareplausiblycharacterizedashallucinationsasofonemovingobject.

Arguably,thisviewdoesnotneedtointroduceanon-existent,intentionalobjectbecause

thephrase‘onemovingobject’appearsaftertheintensionalexpression‘hallucinationas

of’.IwillsubmitthattherearedecisiveasymmetriesbetweenIOMsandphilosophers’

hallucinationsthatpreventaustererelationistsfromadaptingtheirpreferredanalysisof

hallucinationstoIOMs.Tothisend,Iwillarguethattheepistemicaccountof

hallucinationscannotbeappliedtoIOMs.Attheend,Iwillgeneralizemyconclusionsto

anyattemptatassimilatingIOMstophilosophers’hallucinations.

Theepistemicaccountofhallucinationisaparadigmaticwayofanalyzing

misleadingexperienceswithoutintroducingperceptualcontents.Itseekstoexplain

whatitistohaveahallucinatoryexperienceintermsofacounterfactualcondition.Ifa

subject,S,hasahallucinationofanF,Shasanexperiencethatcouldnotbe

discriminated⎯byreflectionalone⎯fromacorrespondingsuccessfulperceptionofan

F.15Theconceptofindiscriminabilityistobeunderstoodinepistemicterms.The

hallucinationofanFisacaseinwhichitisnotpossibletoknow“thatitisnotoneofthe

[successful]perceptions”ofFs(Martin2006:364).Inotherwords,itisacasethatis

unknowablydistinctfromacorrespondingsuccessfulexperience(Martin2004:77).

Thisepistemicanalysisenablestheaustererelationisttoaccountforhallucinations

withoutintroducingperceptualcontents.16

Theepistemicconceptionofhallucinationhasbeenstronglycriticized(Hellie

2013;Siegel2008;Sturgeon2008).AlthoughIamsympathetictosomeofthese

objections,Iwillassume—forthesakeoftheargument—thataustererelationistscould

respondtothem.Eveninthishappyscenario,however,theepistemicaccountof

hallucinationcannotbeusedtoaccountforIOMs.

Inhiselaborationoftheepistemicaccount,MichaelMartinwrites:

[T]hedisjunctivistiscommittedtosayingthat,atleastwhenitcomestoamentalcharacterization

ofthehallucinatoryexperience,nothingmorecanbesaidthantherelationalandepistemological

claimthatitisindiscriminablefromtheperception(Martin2004:72).

IftheepistemicanalysiscouldbegeneralizedtoIOMs,itshouldexplainwhy

theseexperiencesseemtopresentoneobjectinmotionjustbyinvokingtheir

indiscriminabilityfromacorrespondingsuccessfulexperience.Unfortunately,thisis

implausible.Theepistemicanalysisexplainsthephenomenalcharacterofhallucination

byabstractingfromanyrelationbetweenthetargethallucinationandtheactualworld.

Thisisinadequateinthepresentcase,however,forthephenomenalcharacterofIOMsis

alsodeterminedbyotherfactors:twomind-independentdotsandtheirproperties,their

respectivelocations,andaspecifictemporalintervalthatmediatestheirpresentation.

Indeed,whenscientistsengineertheirexperiments,theydonotdirectlyactivatethe

visualcortexofsubjects.Instead,theyinterveneonsomedistalitemsintheworld.Ifone

treatedIOMsasphilosophers’hallucinations,onewouldhavetoassumethatsubjects

whoexperiencethemarecompletelyoutoftouchwithreality.Thisisimplausible,

however,forsubjectsdogetanumberofthingsright:theysuccessfullyperceivethe

colors,sizes,andshapesofthedots,theirinitialandfinallocation,andthetemporal

intervals.Thesesuccessfullyperceivedfeaturesworkascuesthatleadtheirperceptual

systemsastray.17Hadsubjectsmisperceivedthem,thephenomenalcharacteroftheir

experienceswouldchangeaccordingly.

Tosumup,theepistemicaccountwasinitiallydesignedtodealwithtotal

hallucinations(Section1).Unfortunately,IOMsarenottotalhallucinations,forthey

involvedistalobjectsandpropertiesthatmakeacontributiontotheirphenomenal

character.Therefore,theepistemicaccountcannotbegeneralizedtoIOMs.

Defendersoftheepistemicanalysismightwanttoresistthisobjection,though.

Theymightgrantthattheworlddoesmakeacontributiontothephenomenalcharacter

ofIOMsbutmaintainthattheepistemicanalysiscanbeadapted.Tothisend,theymight

exploitanatomisticstrategyhintedatbyMartin:

Togeneralizetheaccount,wewouldneedtofixonthevariousaspectsofastateofperceptual

awareness,thewaysinwhichitmaybethesameordifferentfromothersuchstatesofawareness.

Focusingjustoncasesofveridicalperception,wecansaythattheseaspectswillallinvolvethe

presentationofthatentityasitis.Inturn,asensoryexperienceofthatsortistheoccurrenceofa

situationwhichisindiscriminableinthisparticularrespectfromaperceptionoftheelementin

question(Martin2004:81).

ConsiderIOMs.Ontheonehand,theyaresuccessfulexperiencesofanumberof

features:thecolors,sizes,andshapesofthedots,theirinitialandfinallocation,andtheir

temporalintervals.Ontheotherhand,theyaremisleadingexperiencesasofoneobject

movingfromonelocationtoanother.Onemightthereforetreattheexperienceasa

compositeofsuccessfulperceptionandhallucination.Itshallucinatorydimensioncould

betakenasindiscriminablefromacorrespondingperceptionofoneobjectmovingfrom

onelocationtoanother.

Unfortunately,asMartinhimselfrecognizes,thisapproachremainsseriously

incomplete.Indeed,thedefenderoftheepistemicaccountshouldsaymoreinorderto

“accommodateaspectsofthephenomenalcharacterofexperiencewhicharisefrom

globalpropertiesofthescene,thecombinationofelements,ratherthanjustatomic

elementsofthepresentationofobjectsorcolorpointsinagivenscene”(Martin2004:

Martin’sstrategycanonlybegeneralizedtopartialhallucinationsifonecantreat

theperceptualandhallucinatorycomponentsasindependentvariationdimensionsof

IOMs.Alas,thisisnotaplausibleclaimtomakeinrelationtoIOMsbecausethe

perceptualcomponentofIOMsbearsanexplanatoryrelationtoitshallucinatory

component,andthisexplanatoryrelationisnotcapturedbytheatomisticstrategy.

Indeed,itisbecausesubjectssuccessfullyperceivethefeaturesmentionedabovethat

theyhaveamisleadingexperienceasof—letussay—onereddotbecominggreen.

Hence,thesesuccessfullyperceivedfeaturesarenotseparablefromthemisleading

characteroftheexperience.Ifsubjectsfailedtosuccessfullyperceiveanyofthese

features,thephenomenalcharacteroftheexperiencewouldchangeaccordingly.

Tosumup,theepistemicanalysisofhallucinationcannotbegeneralizedtoIOMs

becausethelatterarenotplausiblyconstruedastotalhallucinations.Besides,one

cannotadapttheaccountbypursuinganatomisticstrategy,forthephenomenal

characterofIOMsseemstobeinextricablyrelatedtothesuccessfullyperceivedfeatures

inthescene.ThisconclusiongeneralizestoanyotherattemptatassimilatingIOMsto

philosophers’hallucinations.Thesameconsiderationswouldholdevenifonetriedto

replacetheepistemicrelationofindiscriminabilitywithanon-epistemicrelation(Pautz

2010)orheldthathallucinationslackphenomenalcharacter(Fish2009:81,93-ff.).

Iconcludethattheworldmakesanon-eliminableandnon-atomisticcontribution

tothephenomenalcharacterofIOMs.Asaresult,onemightbetemptedtoanalyzethem

onthemodelofphilosophers’illusions.Inthenextsection,Iarguethattheaustere-

relationistaccountofillusionscannotbegeneralizedtoIOMseither.Withsome

additionalassumptions,thisconclusionunderminestheaustere-relationistaccountof

thephenomenalcharacterofperceptualexperiences.18

5. TheEpistemicAccountofIllusions

Inthissection,Iarguethatitisimplausibletoconstruethecontributionofthe

worldtothephenomenalcharacterofIOMsonthemodelofphilosophers’illusions.The

latterrequirethatthesubjectsuccessfullyperceivemind-independentobjects.

Unfortunately,thereisnoplausiblewayofconstruingIOMsasgroundedinobject

perception.IproposetofocusonBrewer’s(2011,forthcoming)view⎯oneofthemost

sophisticatedaustere-relationistaccountsofillusions.Lateron,Igeneralizethe

conclusionstoanyotherattemptatanalyzingIOMsasphilosophers’illusions.

HereisBrewer:

Thecoreofthe[ObjectView]accountoflooksisthatanobjectofacquaintance,o,thinlylooksFiff

ohas,fromthepointofviewandinthecircumstancesofperceptioninquestion,appropriate

visuallyrelevantsimilaritieswithparadigmexemplarsofF.[…]Furthermore,some,butnotall,of

thesethinlookswillbesalienttousinanyparticularcase,forexample,asweswitchbetweenthe

duckandrabbitlooksoftheduck-rabbitfigure.Isaythatanobject,o,thicklylooksFiffothinly

looksFandthesubjectregistersitsvisuallyrelevantsimilaritieswithparadigmexemplarsofF

(Brewerforthcoming:2).

Letusbracketthecontrastbetweenthinandthicklooksinordertofocusonthe

two-stagestructureofBrewer’sanalysis,whichiscommontomanyotherepistemic

accountsofillusions.19Onthisview,illusionshavetwocomponents:First,subjectsare

perceptuallyrelatedtoobjectsintheworld.Thoseobjectsstandinarelevantsimilarity

relationtoparadigmcasesinwhichaniteminstantiatesarelevantproperty.Second,the

illusionarisesbecausethesubjectcognitivelyreacts(orcanreact)tothatsimilarity.Her

reactionmayconsistintheformationofacorrespondingjudgmentorbelief.20

Consideranexample.IntheMüller-Lyerillusion,thesubjectisfirstperceptually

relatedtothelinesinthediagram.Theselinesstandinarelevantsimilarityrelationto

otherpairsoflines:“onelongerandmoredistantthantheplaneofthediagram,one

shorterandlessdistant”(Brewer2011:102).Becausetheperceiverwasprobably

raisedinacarpenteredworldwherelineswithinward-slantingslashesreliablyindicate

lessdistantplanesthanlineswithoutward-slantingslashes,shemayjudgeorbelieve

thattheformerlinesareshorterthanthelatter.

Therearetwoaspectstothisaccount.First,perceptualrelationstoobjectsfigure

inthefirststage.ThisenablesBrewertopreservetheoriginalclaimthatperceptual

experienceisfundamentallycharacterizedbycitingmind-independentobjects.Second,

theaccountintroducesapost-perceptualstageinwhichthesubjectregistersthe

relevantsimilarity.Itisonlyatthislevelthatrepresentationalcontentsareinvolved.

Sincethosecontentsarepost-perceptual,defendersofthetwo-stageanalysiscanavoid

theintroductionofperceptualcontentstoexplainillusions.

Thetwo-stagemodelrequiresthatonefirstidentifywhatisperceived.Thisis

necessaryinordertodefinethesimilarityrelationtorelevantparadigms.Letuscallthis

the‘perceptualbasis’oftheillusion.Therearetworeasonswhythisperceptualbasis

oughttobecharacterizedbymeansofperceivedobjects.First,thisfollowsfrom

philosophers’definitionofillusionasacaseinwhichaperceivedobjectseemsto

instantiateapropertyitdoesnotinstantiate(Section1).Second,itfollowsfromthe

definitionoftheobjectview,whichconceivesofperceptualrelationstoobjectsas“the

mostfundamentalcharacterizationofourexperience”(Brewer2011:92;seealso:62-3)

(Section3).Thisraisesthequestion:Whatobjectsconstitutetheperceptualbasisof

Aneasyanswerwouldbe:theillusioninvolvesonenon-existentobjectbesidethe

tworealdots.Onehastheimpressionoftrackingonemovingobjectbecauseanon-

existentobjectfollows(orseemstofollow)aspatiotemporaltrajectory,andthis

trajectoryissufficientlysimilartothetrajectoriesfollowedbyparadigmaticrealobjects

inourworld.Yet,introducingnon-existentobjectswouldbeahighpricetopay.Indeed,

Brewer’sandCampbell’sformulationsofaustererelationismseektoavoidthe

introductionofmysteriousentitieslikenon-existentobjects.Thismakesgoodsensein

thepresentdialecticalcontext.Ifonefindsperceptualcontentsmysterious,oneoughtto

findnon-existentobjectsatleastequallymysterious(Section3).Therefore,theaustere

relationisthasonlythreeremainingoptionsinordertoanalyzeIOMsastraditional

illusions:

(1) Explaintheillusionbymeansofaperceptualrelationtothefirstobject

(e.g.areddotatlocationla).

(2) Explaintheillusionbymeansofaperceptualrelationtothesecond

object(e.g.agreendotatlocationlb).

(3) Explaintheillusionbymeansofaperceptualrelationtobothobjects.

Iproposetoexaminethesethreeoptionsbyfocusingoncasesinvolvingnotonly

apparentmotionbutalsoapparentchange.Supposethatareddotisfollowedbyagreen

dot.Inthiscase,observershaveanexperienceasofareddotchanginglocationand

switchingtogreeninmidcourse.Myclaimisthatoptions1-3donotofferplausible

characterizationsoftheperceptualbasisoftheseIOMs.

Option1holdsthattheperceptualbasisoftheillusionisnothingbutthe

perceptualrelationtothereddot.AsGoodman(1978)andDennett(1991)madeclear,

thissolutionisforlorn.Plausiblyenough,theappearanceoftheseconddotatlocationlb

isnecessarytogeneratetheexperienceasofonemovingdotswitchingtogreen.Thus,

thisapproachwouldonlyworkifthevisualsystemcouldpredictthattherewouldbea

greenobjectatlocationlb.Butthishypothesislackssupport.Ontheonehand,the

experienceofqualitativechangeisequallyrobustwhensubjectsarepresentedwith

IOMsforthefirsttime.Ontheotherhand,therearesomanyvariationsofIOMsthat

thereisnoreasontothinkthatthebrain‘knows’(eitherbyevolutionorpriortraining)

whichpropertieswillbeexemplifiedbytheseconditemandwhereitwillappear.For

thesereasons,Goodman(1978:83)rejectsapproachesalongtheselinesasinvolving“a

beliefinclairvoyance”(seealsoDennett1991:120andGrush2008:155).

Option2positsarelationtotheseconddotasthesolebasistodefinearelevant

similarityrelationwithaparadigmobject.Butthissolutionisimplausibleaswell.Ifthe

seconddotcontributestotheexperienceasofareddotbecominggreen,itisnoless

truethatthefirstdotplaysanon-eliminableroleaswell.

Apreliminaryconclusionisthatthetwodotsmustbetakenintoaccountinorder

tocharacterizetheperceptualbasisofIOMs.Hence,theaustererelationistcould

developanalternativeproposalalongthefollowinglines.First,thesubjectseesdotAat

la.Second,thevisualsystemunconsciouslyregistersB’sappearanceatlb.Upon

registeringB’sappearanceatlb,thesubjectisledtoexperiencedotAasmovingtolband

switchingtogreeninmidcourse.Theresultingproposalintegratestheintuitionbehind

option1thatonlythefirstdotisconsciouslyperceivedandtheintuitionthatthesecond

dotsomehowcontributestothephenomenalcharacteroftheillusoryexperience.21

Unfortunately,thisproposalraisesanumberofquestions.Whyshouldwetreat

dotsAandBdifferently?WhatcouldjustifytheclaimthatdotAisconsciouslyperceived

whiledotBisjustunconsciouslyregistered?Introspectionalonedoesnotseemtoyield

aclearverdictonthisissue.Inaddition,itwouldbehastytoconcludethatdotAis

consciouslyperceivedjustbecauseitwasflashedfirst.Afterall,thereseemtobecasesin

whichtheappearanceofaseconditempreventsthefirstitemfrombeingconsciously

perceived.Thus,onemightwonderwhetherthisisnotwhatoccursinthepresent

case.22

Supposenowthatthereisasatisfactorywayofrespondingtotheseobjections.

Eveninthiscase,theproposedaccountwouldfaceatleasttwoadditionalproblems:the

iterationproblemandthegapproblem.

Theiterationproblem:Inmanyexperimentalsetups,observersarepresented

withalternatingdotsattwolocations:la,lb,la,lb…(Wertheimer1912)Thus,observers

haveexperiencesasofonedotmovingfromlatolb,thenfromlbtola,andagainfromlato

lb,andsoon.TheseiteratedIOMsunderminetheproposalunderconsideration.By

hypothesis,dotAatlaisconsciouslyperceivedatt1.Byhypothesis,dotBatlbisnot

consciouslyperceivedatt2.Still,observershaveanexperienceasofonedotmoving

fromlbatt2tolaatt3.Thisleadstheaustererelationisttoadilemma:IfdotBisnot

consciouslyperceivedatlb,thentheconsciousperceptionofthefirstdotinagiven

temporalintervalisnotnecessarytoexplainIOMs.IfdotBisconsciouslyperceivedatlb,

thentheproposalunderconsiderationismistaken.23

Thegapproblem:Thepresentproposalpresupposestheexistenceofasharp

dividebetweentwolevels:theconsciousperceptionofdotAandtheunconscious

registrationofdotB.Thisraisesaproblem:Ifthereisasharpdistinctionbetweenthe

twolevels,whyisthissharpdistinctionnotreflectedinthephenomenologyofthe

experience?Ifobserversareconsciouslyawareofthereddotatlocationlabutmerely

unconsciouslyregisterthegreendotatlocationlb,whyistherenogapbetweentheir

consciousperceptionofastaticreddotatlocationlaandtheunconsciousregistrationof

agreendotatlocationlb?Theabsenceofanysuchgapinconsciousnessstrongly

suggeststhat,ifdotAisconsciouslyperceived,dotBisconsciouslyperceivedtoo.24

Themainlessonfromthepreviousanalysisisthereforethat,iftheaustere

relationistwantstotreatIOMsasphilosophicalillusions,sheshouldnotonlyascribea

causalroletotheseconddotinthegenerationoftheillusion.Sheshouldalsoholdthat

bothdotsreachphenomenalconsciousness.Thisleadsustooption3above.

Accordingtooption3,thesubjectisperceptuallyrelatedtothereddotandthe

greendot.25Inordertoexplaintheillusoryexperience,itisnecessarytodepictthetwo

dotsasstandinginasimilarityrelationtoaparadigm.Whenthetemporalinterval

betweenthetwodotsisfrom10to45milliseconds,subjectsreportanexperienceasof

onemovingdot.Thus,inordertoexperiencethereddotandthegreendotasoneobject,

theremustbeasignificantnumberofobjectsinthesubject’senvironmentthatcovera

similardistanceinanintervalofbetween10and45milliseconds.Inotherwords,the

reddotandthegreendotmustexemplifyaspatiotemporalvariationsimilartothe

spatiotemporalvariationexemplifiedbyparadigmsofpairsofobject-phaseslike

Unfortunately,thissolutionfacestwomajorproblems:itdepartsfromtheletter

ofaustererelationismandconflictswithsomewell-entrenchedintuitionsonsuccessful

objectperception.Letmeelaborate.

Noticethatitisnotsufficienttobeperceptuallyrelatedtoareddotandagreen

dotinordertohaveanexperienceasofareddotbecominggreen.Itisalsonecessary

thatthetwodotsbeparsedinaspecificorder:thereddotfirstly,thegreendotsecondly.

Afterall,ifonepermutestheorder,oneobtainsadifferentillusion:anexperienceasofa

greendotbecomingred.Atraditionalwayofrepresentingtheorderingrelationbetween

twoentitiesisbymeansofaset-theoreticalrepresentation.Theobserverisperceptually

relatedtotheorderedpair:<reddot,greendot>.

Moreover,beingperceptuallyrelatedtotheorderedpair<reddot,greendot>is

notsufficientinordertohaveanexperienceasofareddotbecominggreen.Afterall,

pairsofentitiesbythemselvescannotstandinsimilarityrelationstootherpairsof

entities.AsGoodman(1972:473-ff.)madeclear,similarityisrelative,variable,and

highlycontext-dependent.Indeed,inordertocompareapair1withanotherpair2,one

mustspecifyinwhichrespectoneisconsideringtheentitiesinpair1andtheentitiesin

pair2respectively.Inotherwords,itisnecessarytoconsiderthereddotandthegreen

dotinthepair<reddot,greendot>inaspecificrespectbeforeonecancomparethem

withapairofobject-phasesin<object-phase1,object-phase2>.Ifoneabstractsfrom

thespatiotemporalrelationsbetweenthetwodotsintheinitialpair,onewillbeunable

togroundthesimilarityrelationbetweentheperceptualbasisandthetwophasesofa

singleobjectcoveringthesamedistance.Afterall,whatgeneratesIOMsisthe

spatiotemporalrelationbetweenthetwodots,notthepairofdotsitself.

Thiscreatesaproblem,though.Iftheperceptualbasisofthesimilarityrelationis

notthepairofdotsitselfbutthepairofdotsasbeingrelatedinaspecificway,wehave

somethingquitedifferentfromtheobjectslistedintheoriginalcharacterizationof

austererelationism(Section3).Wehaveanorderedpairofdotsthatstandinaspecific

spatiotemporalrelationtoeachother.Wecanrepresentthisentityasfollows:

<<reddot,greendot>,beinginsuchandsuchspatiotemporalrelation>

Unfortunately,thiscomplexisnotoneofthephysicalobjectsBrewerandother

austererelationiststypicallylistasmind-independentphysicalobjects,whichinclude

trees,tables,andstones.Thiscomplexisratherakintoafactorstateofaffairs(Dokic

2000;Fish2009;McDowell1996).

ThepreviousargumentshowsthatanyaccountofIOMswoulddepartfromthe

letterofaustererelationism,foritwouldhavetointroduceentitiesotherthanbare

mind-independentobjectstogroundtheirphenomenalcharacter.Somemightreply,

however,thatfactsorstatesofaffairsarestillcongenialwiththespiritofaustere

relationism,formind-independentobjectsstillplayafundamentalroleinthe

characterizationofperceptualexperience.Unfortunately,theobjectsthatconstitute

thesefactsorstatesofaffairsarenotsuccessfullyperceivedinIOMs,orsoIshallargue.

Brewer(2011:71)insiststhattheremustbe“limitsonthenatureandextentof

anyerrorsinvolved”inillusion.Onhisview,beyondsomelimits,thesubjectdoesnot

countassuccessfullyperceivingtherelevantobject.Supposeyouarelookingata

square,anditseemstoyouthatthereisanelephantthere.AccordingtoBrewer(2011:

71-3),itwouldbewrongtosaythatyouseethesquareanditlookselephantinetoyou.

Rather,oneshouldsaythatyoudonotseethesquareatall.Thesameholdsifonetries

toaccountforIOMsbymeansoffactsorstatesofaffairs.Inordertoperceivethe

complex<<reddot,greendot>,beinginsuchandsuchspatiotemporalrelation>,itis

necessarytoseethereddotasnumericallydifferentfromthegreendot.Unfortunately,

observersdonotseethereddotasnumericallydifferentfromthegreendot.Therefore,

itisamistaketoholdthattheyperceivethecomplex<<reddot,greendot>,beingin

suchandsuchspatiotemporalrelation>,andthatthiscomplexgroundsthephenomenal

characterofIOMs.

Wecansubstantiatethisconclusionbymeansofanintuitiveconstrainton

successfulobjectperception.Philosophersofallstripeshaveinsistedthatperceptual

differentiationisanecessaryconditionforobjectperception(Campbell2002:7-ff.;

Dretske1969:20-9).Thisplausibleintuitionhasthefollowingconsequence:

Ifavisualscenecontainsobjectsoiandoj,then:Ifasubject,S,seesoiandoj,S

differentiatesoifromoj.

IOMsarecasesinwhichsubjectsfailtodifferentiatethetwoobjectspresentina

scene.Thetwodotsseemtobe‘fused’or‘merged’intoasingle,movingobject.

Therefore,subjectscannotbedescribedassuccessfullyperceivingthetwodots.27

ItisthereforeimplausibletoaccountforthephenomenalcharacterofIOMsby

positingaperceptualrelationtothetwodots,evenifthelatterareconstruedas

constituentsoffactsorstatesofaffairs.Sincephilosophers’illusionsrequiresuccessful

perceptualrelationstoatleastoneobject,thepresentargumentunderminesany

accountofIOMsasphilosophers’illusions.

Letusbringtogethertheresultssofar.Wehavegoodreasonstothinkthatdistal

objectsandtheirpropertiesmakeanon-eliminableandnon-atomisticcontributionto

thephenomenalcharacterofIOMs(Section4).Thus,IOMsarenotcasesinwhich

subjectsarecompletelyoutoftouchwiththeworld,asthehallucinationaccountwould

predict.Nevertheless,wehavealsogoodreasonstothinkthatthetworelevantobjects

somehowreachconsciousexperiencebutarenotsuccessfullyperceived(Section5).

Hence,ifanaustererelationistwantstoprovideanaccountofthesecases,sheshould

considerthemasacounterexampletoBrewer’sclaimthatphysicalobjectsarethedirect

objectsofperception(Section3).IOMsarecasesinwhichdirectperceptualrelationsto

physicalobjectsdonotprovide,paceBrewer,“themostfundamentalcharacterizationof

ourexperience”(Brewer2011:92).Inthesecases,ourperceptualexperiencereaches

outintoaworldinvolvingexternalobjects,yetthoseobjectsarenotsuccessfully

perceived.

Austererelationistsmightgrantthispointbutholdthatitdoesnotundermine

thespiritoftheirview.Tothisend,theymightreasonasfollows.Althoughphysical

objectsarenotalwaysthedirectobjectsofperception,theyoftenare.Thus,austere

relationistscouldjustbroadentheclassofmind-independententitiesinorderto

accommodateIOMs.Thisisconsistentwithsomeformulationsofnaïverealism,suchas

Sturgeon’s(2008:116):“Good[orsuccessfulphenomenal]characterderivesfrombitsof

thephysicalworldstandinginanexplanatorilybasicrelationtopercipients”.Onthis

view,thelistofmind-independentobjectscaninclude,notonlyparadigmaticobjects

liketrees,tables,andstones,butalsowhateverbitsofthephysicalworldonemightneed

inordertoaccountforIOMsandotherpuzzlingcases.

Alas,thislineofreplyraisesaproblem.Recallthatsubjectsreportanexperience

asofonemovingobjectinIOMs(sections1-2).Inotherwords,theirexperiencesseem

topresentoneobject.Ifonepositsrelationstoentitiesotherthanobjectsinorderto

accountforIOMs,onehastherebyconcededthatperceptualrelationstomind-

independentobjectsneednotbetakenasfundamentalforanaccountofexperiences

thatseemtopresentmind-independentobjects.Afterall,ifonecanexplainIOMsby

introducingperceptualrelationstoentitiesotherthanmind-independentobjects,there

isnoreasonnottogeneralizethisconclusiontoallotherexperiencesasofmind-

independentobjects.

Thereareatleasttwowaysofmotivatingtheproposedgeneralization.First,it

woulddeliveramoreparsimoniousaccountofexperiencesasofmind-independent

objects.Second,theresultingaccountwouldnotbepreytoRobinson’s(1994:154)

famousargumentagainstnaïverealism.Ifnaïverealistswantedtoprovidedifferent

accountsofthephenomenalcharacterofIOMsandsuccessfulexperiencesofobjects,

theyshouldassumethatthebraincouldmysteriouslyknowwhetherthecaseisoneof

successfulperception(sothatitstandsinaperceptualrelationtoanobject)oronein

whichanentityotherthanamind-independentobjectismistakenforanobject(sothat

theseemingrelationtoanobjectisderivativefromarelationtosomethingelse).

Unfortunately,thereisnogoodreasontothinkthatthebrainhasthismysterious

knowledge.

Theimportanceofthepresentchallengemightbeobscuredbythefactthatnaïve

realistsareratherunclearonwhattheymeanbyobjects.Ifwetakeseriouslytheir

paradigmexamples—i.e.,trees,tables,andstones—,thenmind-independentobjectsare

thesortsofthingsthatpersistovertime.28Giventhedescriptionofferedinsections1-2,

IOMsareplausiblycharacterizedasillusionsofpersistence.Afterall,subjectsreport

experiencesasofoneobjectchangingqualitiesandlocation.Hence,theseillusions

cannotbeexplainedbyinvokingprimitiverelationstomind-independententitieswhose

persistenceisimmediatelyappreciatedbytheobserver.

TherepresentationalistcanthereforeuseIOMstoprovideafundamental

characterizationofperceptualexperiencesthatdoesnotinvokeperceptualrelationsto

objectsconsideredaspersistingentities.Shecanconstrueexperiencesofobjectsas

persistingovertimeasderivativefromperceptualrelationstomoreprimitive,non-

persistingentities.Theseentitiesmightbeshort-livedeventsorobject-phases(see,e.g.,

Smith1996:117-35).

Iexplorethissuggestioninthenextsection.Tothisend,Isketchanaccountof

therepresentationalcontentsrequiredtoexperienceobjectsaspersistingovertime,

andapplythemtoIOMs.

6. Object-DirectedExperiencesandPerceptualContent

Inthissection,Idevelopanaccountofperceptualcontentdesignedtoexplain

IOMsand,moregenerally,experiencesofobjectsaspersistingovertime.Theproposed

accountbuildsontwoideas:Evans’(1981)insightthatperceptualtrackingrequires

dynamicmodesofpresentationandFine’s(2007)relationalsemanticsforidentity.

6.1. DynamicModesofPresentation

IOMshavetwosalientfeatures:theyinvolveapparentmotionandareillusory.

Hence,inordertousethemtodrawgenerallessonsonthestructureofperceptual

experiences,weshouldgeneralizefromIOMsintwoways.First,weoughttoshowthat

IOMsmayteachussomethingaboutthefundamentalnatureofsuccessfulperceptual

experiencesofobjectsaspersistingovertime.Second,weoughttoshowthatthese

illusionsarerevelatory,notonlyofthenatureofexperiencesasofmovingobjects,but

alsoofexperiencesasofstaticobjects.Iconsidereachgeneralizationinturn.

Firstgeneralization:Imagineasubjectwhoiskeepingtrackofawomanover

time.Barringoccludersormomentarydistraction,visualexperiencecouldputour

subjectinapositiontoformthefollowingseriesofthoughts:

(A) P1 Thatwomanisrunning.

P2 Thatwomanisjumping.

C Therefore,thatwomanisrunningandjumping.

AsCampbell(2002:129)comments:“Recognizingthevalidityoftheinference

requiresthatyourexperienceshouldmakethesamenessoftheobjecttransparentto

you”(seealsoCampbell2014:34-5).FollowingEvans(1981),wecouldsaythatthe

numericalidentityofthewomanistransparenttoyoubecauseitisperceivedunderthe

same‘dynamicmodeofpresentation’.Adynamicmodeofpresentationfixesthe

referencetothewomanandenablestheobservertokeeptrackofthatwomanas

persistingovertime.29

WecangeneralizethisaccounttoIOMsbysayingthatdynamicmodesof

presentationnotonlycapturecasesinwhichnumericalidentityisperceptuallyobvious

butalsocasesinwhichonemerelyseemstobepresentedwithoneobjectaspersisting

overtime.WecanfleshoutthissuggestionbycomparingcasesoftypeAwithIOMs.

CasesoftypeAarescenariosinwhichtheco-referenceofthetwodemonstrativesis

perceptuallymanifesttotheobserver.IOMsarecasesinwhichonehasanexperienceas

ofco-referencebutthisisanerror.

Recallthat,insomeexperimentalsetups,observersarepresentedwith

alternatingdotsattwolocations:la,lb,la,lb,…(Section5)Supposenowthatanobserver

whoisunfamiliarwiththesetupiswatchingthesealternatingpresentations.Inthis

case,itwouldbenaturalforhertoproducethefollowingseriesofthoughts:

(B) P1 Thatdotwasatlocationla.

P2 Thatdotwasatlocationlb.

C Therefore,thatdot(atla)isthesameasthatdot(atlb).

IncaseB,theobservertakestheoccurrencesof‘thatdot’asco-referential.

Indeed,theexperiencethatseemstojustifythemovefromP1-P2toCseemstopresent

asingleobjectmovingfromonelocationtotheother.Hence,itsharesaphenomenal

featurewithcasesoftypeA.Still,contrarytocasesoftypeA,thetwooccurrencesof

‘thatdot’arenotco-referential.

ItisreasonabletointerpretthesimilaritiesbetweencasesoftypeAandIOMsas

anargumenttointroducearepresentationalistanalysisofourperceptualexperienceof

objectsaspersistingovertime.Indeed,therepresentationalistmightreasonasfollows:

thesubjectiveimpressionthattheoccurrencesof‘thatdot’co-referisgroundedinhow

thingsareperceptuallyrepresented;differentdot-phasesareperceptuallyrepresented

asonemovingdot.ThesimilaritybetweenIOMsandsuccessfultrackingistherefore

explained:bothcasesinvolverepresentationsofdifferentphasesasonemovingobject.

Insuccessfultracking,thephasesrepresentedasphasesofoneobjectareinfactphases

ofoneobject.InIOMs,bycontrast,theyarephasesofnumericallydifferentobjects.30

Secondgeneralization:Oursecondquestionwaswhetherwecouldgeneralizethe

presentanalysistoexperiencesasofstaticobjects.Idothinkso.Indeed,our

understandingofobjectsisparasiticonourunderstandingofthewaytheymove.This

assumptionunderliessomeofthemostsuccessfulstudiesonobjectperceptionin

cognitivescience.Developmentalpsychologistshaveexaminedinfants’perceptionof

objectsbyevaluatingtheirabilitytoparsesomewholesaskeepingtheirpartsbound

togetherwhilefollowingrelativelycontinuoustrajectoriesthroughspace.Anotherreason

whyinfantsarethoughttoperceiveobjectsisthattheycountthesewholesasthesame

evenwhentheyfailtoregisterchangesinqualitieslikesize,shapeorcolor(Carey

2009).

Anumberofphilosophershavemadesimilarpoints.Evans(1981:311)famously

heldthat“thestaticnotionof‘havingholdofanobjectatt’isessentiallyanabstraction

fromthedynamicnotionof‘keepingtrackofanobjectfromttot’’”.Inaddition,one

mightholdthattheabilitytokeeptrackofobjectsovertimeisconstitutiveoftheability

toperceiveobjectstoutcourtbecausetrackingiswhatenablesustodistinguish

persistentobjectsfromotherentities.Indeed,Burge(2010:80,198-9,444-7,459,469)

haspersuasivelyarguedthatwedistinguishobjectsfromeventsandshapesbecausewe

expecttheformer—butnotthelatter—tokeeptheirboundaryintegrityovertime.One

mightthereforeclaimthatIOMsareincorrectrepresentationsoftwoeventsorshapes

asonepersistingobject.Inwhatfollows,Ipresentaformalanalysisthatcapturesthe

gistofEvans’andBurge’sremarks,avoidssomeproblems,andlocatesthepresent

proposalwithinthewiderfamilyofneo-Fregeanaccountsofperceptualcontent.

6.2. TheCommonContentofObject-DirectedExperiences

Onacommon-factoranalysis,thevisualsystemrepresentssomephasesas

bearingsomespatiotemporalrelationstoeachother.Ceterisparibus,ifthevisualsystem

representsmobject-phasesasstandinginspatiotemporalrelationstoeachotherthat

aresufficientlysimilartotherelationsthatnphasesofoneobjectbeartoeachother

whenitisfollowingarelativelycontinuoustrajectory,theperceptualexperienceisasof

oneobject.Thecontentofthisexperienceiscorrectwhenthemobject-phasesare

appropriatelycausedbymobject-phasesofoneobject.Itisincorrectotherwise.Ifthese

spatiotemporalrelationsaredifferent,theperceptualexperienceisasoftwoobjects.

Thiswilloccurwhentheintervalistoobriefortoolong.Wecanarticulatethisproposal

byintroducingthefollowing,relationalsemanticsforobject-directedexperiences(Fine

2007):

Theperceptualcontentofanobject-directedexperience|E|isthefunctionf(|P1,

P2,…,Pm|)ofthesequence|P1,P2,…,Pm|onthephasesP1,P2,…,Pm.31

Theargumentofthisfunctionisasequenceofphases.Inordertobepartofthis

sequence,thephasesmustbeparsedasstandinginsomespatiotemporalrelationsto

eachother.Onecouldgeneralizethisanalysistoexperiencesasofstaticobjectsby

substitutingstaticobject-partsforobject-phases(Echeverriforthcoming).

Morecouldbesaidonwhatmakestherelevantcausalrelationappropriate.Since

appropriatecausalrelationsareinvokedbyanyrepresentationalisttheory,Iproposeto

focusonthemaintheoreticalinnovationofthepresentanalysis.Thiswillenableusto

seehowthepresentproposalaccommodatesEvans’andBurge’sremarks,howitavoids

someproblems,andhowitrelatestothewiderfamilyofneo-Fregeanaccountsof

perceptualcontent.

Therelationalfunctionhasa‘relationalsemantics’:theargumentsarenotthe

phasestakenindividuallybutsequencesofphases.ThisaccommodatesEvans’(1981:

311)ideathat“thestaticnotionof‘havingholdofanobjectatt’isessentiallyan

abstractionfromthedynamicnotionof‘keepingtrackofanobjectfromttot’’”.32Inhis

developmentofsemanticrelationism,Fine(2007)interpretseachelementofthe

sequenceasstandingforoneobject.However,thiswouldnotenableustopreserve

Burge’s(2010)insightthatasubject’sperceptualappreciationofsomethingasanobject

persistingovertimemaybederivativefrom—notpriorto—atemporallyextended

trackingepisode(Section6.1).Forthisreason,IproposetodepartfromFineand

interprettheargumentsofthefunctioninamoreaustereway.33Onmyview,thevisual

systeminitiallyrepresentsvariousphasesinaneutralwayastowhethertheyare

phasesofoneobject.Itisthevalueoftherelationalfunctionthatyieldsacommittal

representation,i.e.arepresentationofthesephasesasphasesofoneobject.This

representationmightbeconstruedasanobjectfile,i.e.amentalrepresentationthathas

thefunctionofrepresentingobjectsasnumericallyidenticalovertime(Carey2009;

Echeverriforthcoming).Thecommittalrepresentationistokenedonlyifthevarious

phasesstandinsomespatiotemporalrelationstoeachother.34

Fine’sinterpretationwouldalsohavetwoundesirableconsequences.First,itwas

alreadypointedoutthatsubjectsfailtodifferentiatethetwodotsinIOMs(Section5).

Thus,thetwodot-phasesshouldnotappearasdifferentiatedintheargumentsofthe

function.Second,Fine’saccountwouldleadustointroduceanimpossiblecontentinto

thephenomenologyoftheexperience.Acontentcisimpossiblejustincasethereisno

possibleworldinwhichcistrue.Onastandardview,contradictorycontentsare

impossibleinthissense.Now,ifnumericallydifferentobjectsoiandojfigureas

argumentsoftherelationalfunction,thereisasenseinwhichtheexperiencerepresents

animpossiblecontent:thedotsarerepresentedastwointheargumentofthefunction

andasoneinthevalueofthefunction.ThetroublehereisthatIOMsdonotseemto

presentanimpossiblestateofaffairs,contrarytowhatoccursinotherwell-knowncases

likethewaterfallillusion,inwhichastationaryobjectseemstomoveandstandstillat

thesametime(Pautz2010:274).

Theseproblemsshouldnotariseifwecarefullydistinguishthewaythedotsare

givenintheargumentofthefunctionfromthewaytheyarerepresentedinthevalueof

thefunction.Thetwodotsarenotrepresentedasdifferentiatedintheargumentofthe

function.Instead,theyfigureaselementsofasequencethatisindiscriminablefromthe

sequencesformedbyobject-phasesofoneobject.Thisexplainswhyitistemptingto

holdthatthetwodotsappeartobe‘fused’or‘merged’intoasingle,movingobject

(Section5).ThisapproachalsoenablesustodistinguishIOMsfromillusionsthatseem

topresentimpossiblestatesofaffairs.Thesubjectcanexperiencetwonumerically

differentdotsasphasesofonemovingdotwithoutbeingawareoftheimpossible

characterofthatstateofaffairsbecausethetwodot-phasesfallunderthesamedynamic

modeofpresentation.Thisdynamicmodeofpresentationmaskstheimpossibilityfrom

thesubject’sperspective.Inanutshell:eventhoughitismetaphysicallyimpossiblethat

twonumericallydifferentobjectsbeoneobject,thismetaphysicalimpossibilitydoesnot

reachphenomenalconsciousnessbecausethetwodotsaregivenasmeredot-phases

andthesedot-phasesfallunderthesamedynamicmodeofpresentation.

Theaboveanalysisshouldalsomakeclearwhytherelationalfunctiondiffers

fromtwootherFregeanaccountsofcontent:dedictoandderemodesofpresentation.

Dedictomodesofpresentationimposesomeconditionsthattheobjectof

perceptualexperiencemustsatisfyinordertobethereferentofthatexperience.The

relationalfunction,bycontrast,imposessomeconditionsthatphasesmustsatisfyin

ordertobeexperiencedasphasesofthesameobject(seeEcheverriforthcoming,for

discussion).

“[D]eremodesofpresentationareinherentlyrelationalinthatwhatobjector

propertyinstancethesubjectisrelatedtomakesaconstitutivedifferencetothenature

oftheensuingcontent”(Schellenberg2013:303;seealsoPeacocke1981).Inthis

framework,eitherthemodeofpresentationis‘filled’byoneobjectoritisgappy.The

relationalfunctiondiffersfromderemodesofpresentationbecauseitmakesroomfora

thirdpossibility.Therearecasesofreferentialfailurethatdonotarisefromtheabsence

ofobjects—asinthehallucinatorycase—butfromthepresenceofdifferentobjects

withinaspatiotemporalrangethatisnormallyfilledbyphasesofasingleobject.Hence,

thosearecasesinwhichtherelationalfunctionis‘filled’byphasesofnumerically

differentobjects,theexperienceinvolvesoneobjectfile,butthatobjectfilefailstorefer

tooneobject.

7. ConcludingRemarks

Ithasoftenbeenclaimedthat,whereasrepresentationalismtreatsperceptual

experiencesasobject-independent,naïverealismtakesmind-independentobjectsas

constituentsofexperiences.Theargumentsfromthispapersuggestthattheseclaims

areambiguous.Sincethecontentsofobject-directedexperiencesmaybedefinedover

object-phases,theyneednotbeconstruedasobject-independent.Nevertheless,there

arereasonstotreatperceptualexperiencesasindependentfromobjectsconsideredas

persistingovertime.Afterall,wemayneedtopositperceptualcontentsinorderto

accountforthephenomenalcharacterofmisleadingexperiencesasofpersistingobjects.

Considernowthenaïve-realistclaimthatobjectsfigureasconstituentsofexperiences.If

wereaditastheclaimthatourperceptualappreciationofobjectpersistenceis

fundamental,itisanunwarrantedclaim.Afterall,onecanintroducedynamicmodesof

presentationrangingovermoreprimitiveentitiesinordertoelucidateourappreciation

ofobjectsaspersistingovertime.

Theseremarksaredirectlyrelevanttoaseriesofrecentattemptsatreconciling

representationalismwithnaïverealism(see,e.g.,Hellie2013;Kennedy2013;McDowell

2013;Schellenberg2014;Siegel2010;Soteriou2010).Beforeonetriestobuildrelations

tomind-independentobjectsintoperceptualcontents,oneoughttobeclearonwhatit

meansforperceptualexperiencestohaveobjectsasconstituents.

IOMscertainlyraisemanyotherinterestingissues.Myaiminthispaperwasto

examinetheprospectsofaustererelationismtoaccountfortheseintriguingcasesandto

formulateanalternative,representationalistaccount.Ihopeaustererelationistswill

takethischallengeasanopportunitytorespondtomyobjections.Ifthearguments

presentedherearecorrect,IOMscompelustogetridoftheprocrusteandichotomyof

hallucinationandillusion.Besides,theycastdoubtontheprioritygiventomind-

independentobjectsinthecharacterizationofthephenomenalcharacterofperceptual

experiences.35

DépartementdePhilosophieUniversitédeGenève

1Ihaveborrowedthephrase‘austererelationism’fromSchellenberg(2014).Therearealsocompatibilistaccountsthatcombinerelationismandrepresentationalism(e.g.,Hellie2013;Kennedy2013;McDowell2013;Schellenberg2014;Siegel2010;Soteriou2010).Imakesomeremarksoncompatibilisminfootnote13andSection7.So-calledsensedatumtheories(e.g.,Robinson1994;Russell1912)donotfallintothisdichotomy,fortheyneitheranalyzeperceptualexperiencesasinvolvingrelationstomind-independentobjects,norpositperceptualcontents.Iwillnotexaminethesetheorieshere.2Ishalluse‘misleadingexperiences’todenoteillusoryandhallucinatoryperceptualexperiencesand‘successfulexperiences’todenotenon-illusory,non-hallucinatoryperceptualexperiences.Thus,Iwillnotexamineso-called‘veridical’illusionsandhallucinations.Thesephrasesarealsomeanttobeneutralonwhetherperceptualexperiencesfundamentallyinvolverepresentationalcontents.3Foranon-linedemonstration,see:http://www.michaelbach.de/ot/col-colorPhi/index.html.Thereissomeconfusiononwhatismeantbytheϕphenomenon.ItisoftentakentorefertowhatIamcalling‘optimalmotion’.Othersuseittoreferto“perceivedmotionwithoutobjectsbeingperceivedasmoving”(Wagemansetal.2012:1206).Forausefuldiscussion,seeHoerl(2015).4Inwhatfollows,IonlyofferprimafacieconsiderationsfortheclaimthatIOMsdonotclearlyfitintothephilosophicaldichotomyofhallucinationsandillusions.Isubstantiatetheseconsiderationsinsections4and5.5SeealsoBrewer(2011:64),Fish(2009:80),Martin(2006:394),andPautz(2010:280),amongothers.6SeealsoFish(2009:45,146-7)andSmith(2002:23),amongothers.7IwillcomebacktothispointinSection5.Someaustererelationistshavecriticizedrepresentationalaccountsofillusionsbyarguingthatmanyordinaryillusionsandhallucinationsdonotfitintothetraditionaldichotomy(Campbell2014;Genone2014;Kalderon2011).Isharethespiritofthecriticismbutnottheanti-representationalistconclusion.Myviewisthatadescriptivelycorrectaccountofillusionsmayleadustoreviseourviewsontherepresentationalstructureofperceptualexperiencesbutnottorejectperceptualrepresentationsaltogether.8Forsomerelevantstudies,seeKolers(1972),KolersandvonGrünau(1976),Palmer(1999:Chapter10),andSekuler(2012).9Genone(2014:359)mentionstheϕphenomenonasapotentialcounterexampletothetraditionaldichotomyofhallucinationsandillusionsbutdoesnotofferananti-representationalistaccountthereof.Hoerl(2015)offersananalysisofillusionsofpuremotionwithinaustererelationism.Bythishemeansasub-classofillusionsofimperfectmotioninwhichthesubjecthastheimpressionthatthereismovement,withoutanyawarenessofasinglebearerofthatmovement.Unfortunately,Hoerldoesnotaccountforeitherexperiencesofdualmotion,orexperiencesofoptimalmotion.10Burge(2010)arguesthatperceptualconstancyissufficientforobjectivity.11SeeCarey(2009:72-ff.),Pylyshyn(1999:356),SigmanandRock(1974),Wertheimer(1912),amongothers.Therearealsomanyphilosopherswhograntthedescriptionintermsofnumericalidentity.SeeBurge(2010:463),Genone(2014:359),Goodman(1978),andMatthen(2012:55-6).12SeealsoShepardandZare(1983)andSigmanandRock(1974).13Therearedifferentcharacterizationsofnaïverealismintheliterature.Somerelyontheconceptofessence,othersontheconceptoffundamentality,andstillothersontheconceptofconstituency.Whilesomeofthemwillleadtotheconclusionthatnaïverealismisanti-representationalist,otherswillmakeroomforcompatibilistaccounts.Byqualifyingperceptualexperiencesasfundamentallyinvolvingrelationsbetweensubjectsandmind-independententitiesImeantoremainneutralonwhetherthenaïverealistmayintroducerepresentationalcontentstoaccountforsomeaspectsofperceptualexperiences.

Fortunately,takingsidesonthisissueisnotdecisiveforthemaingoalofthispaper,whichconcernstheroleofperceptualcontentsinaphilosophicalaccountofthestructureofperceptualexperience.14Mostversionsofnaïverealismalsointroducerelationstomind-independentproperty-instancesortropesintheirfundamentalcharacterizationofperceptualexperiences.Icomebacktotheroleofproperty-instancesinSection5.15Foreaseofexposition,Iwillignorethequalification‘byreflectionalone’.16AlthoughMartinhascriticizedsomeargumentsinfavorofperceptualcontent,itisnotentirelyclearwhetherheisanaustererelationist.Inhis(2004:71),heleavesopenthepossibilityofaccountingforimperfecthallucinationsintermsofrepresentationalcontentsorsensedata.Nevertheless,inthesamepaper,healsosuggeststhathisepistemicaccountofhallucinationcouldbegeneralizedtoothermisleadingexperiences(2004:81-ff.).Bethatasitmay,theepistemicanalysishasbeeninvokedtoaccountformisleadingexperienceswithinanaustere-relationistframework.SeeBrewer(2011:101-ff.).17Iamusingtheword‘feature’inatheory-neutralwaytodenoteanybitoftheworldthatmaycontributetothephenomenalcharacterofIOMs.18Itisworthstressingthatsomenaïverealistsrejecttheepistemicanalysisofhallucination.SeeCampbell(2014:92-ff.)andJohnston(2014).19SeealsoAnthony(2011:40),Campbell(2014:85-90),Fish(2009:172-7),Genone(2014),andTravis(2004).Althoughtheseviewsdifferinimportantrespects,theproblemsIshallformulategeneralizetoanyanalysisofillusionsthatpositsasimilartwo-stagestructure.20Itisnotalwaysclearwhetherthecognitivereactionisconstitutiveoftheillusoryexperience.Althoughthispointisphilosophicallyimportant,itwillnotaffecttheargumentstofollow.21Iowethissuggestiontoarefereeofthisjournal.22Ihaveinmindthephenomenonofmetacontrast(Breimayer1984).Supposethatthefirststimulusisadiscandthesecondonearingthatfitscloselyoutsidethespacewherethediscwasdisplayed.Inthiscase,observersreportthattheydidnotseethediscbutonlythering.Thisphenomenonisstandardlyinterpretedasacaseinwhichthediscwas‘masked’bythering(DennettandKinsbourne1992:193-ff.).23Tobesure,defendersofaustererelationismcouldtrytotreatsimpleanditeratedIOMsdifferently.Butthiswouldyieldanadhocandextremelycomplexaccount.24Idonotmeantoimplythatunconsciousperceptualprocessingcannothavebehavioralandcognitiveeffectsonus.Indeed,primingeffectsareexamplesoftheeffectsofunconsciousperceptualprocessing.Thetroublehereisthattheeffectsrequiredtovindicatetheapproachunderconsiderationseemverydifferentfromotherwell-knowneffectsofunconsciousprocessing.WhenoneexperiencesanIOM,itisnotasifonecouldguess(asinaforcedchoiceparadigm)thatthereddotwasfollowedbyagreendot.Instead,itappearstobecomegreenjustinthemidpointthatseparateslocationslaandlb.25Soteriou(2010:234)arguesthatrelationistscanpositacquaintancewithoccurrenceswithtemporalextension.26AlthoughIamusingtheword‘phase’todescribethesecases,Iamneutralonanytheoryofpersistence.Thereaderisinvitedtosubstitutetherelevantexpressionswithherpreferredones.27Somereadersmightinsistthatthesubjectdoesseethetwodotsasnumericallydifferentbutisunabletoreportthemasnumericallydifferent.Unfortunately,thisreplywouldbeself-defeating.Ifverbalreportsarenottakenasreliablemeanstodeterminewhatisperceived,naïverealistsarenotentitledtorelyontheirownverbalreportstomotivatetheclaimthatmind-independentobjectsareconstituentsoftheirsuccessfulexperiences.28ThatobjectsareexperiencedaspersistingovertimeplaysacentralroleinBrewer’s(2011:69-70)argumentsagainstrepresentationalism.ItalsoplaysadecisiveroleinCampbell’s(2002,2009)workofperceptualtracking.29SinceCampbellisananti-representationalist,hecannotintroducedynamicmodesofpresentation.Instead,heintroduces‘mannersofpresentation’thatdonotfixthereferencetotheobjectbutonlycapturethetransparencyoftheco-referenceofthetwooccurrencesof‘thatwoman’.Aswillbecomeclear

later,Campbell(2002:79,129;2014:46-7)iswrongtothinkthatrepresentationalistscannotaccountfortrackingovertime.30Pautz(2010:284)hasarguedthatacommon-factoranalysisofphenomenologydoesnotentailacommonfactoranalysisofperceptualreference(seealsoKennedy2013).Thepreviousconsiderationssuggestthatphenomenologyisnotorthogonaltoperceptualreference.Indeed,acommon-factoranalysisofsomespecificformsofphenomenologyseemstogohandinhandwithafactorizationofperceptualsuccess.ThephenomenologicalcommonalitiesbetweencasesoftypeAandcasesoftypeBsuggestthatperceptualreferencetoobjectsconsideredaspersistingovertimeisnotprimitive.InIOMs,thereisaperceptualmisrepresentationoftwodot-phasesasphasesofonedot.ItisnaturaltoholdthatthismisrepresentationisabyproductofareferentialmechanismthatworkswellincasesoftypeA.31Thisfunctiononlyconsiderstheobjectsideofperceptualcontent.Thus,itshouldbesupplementedwithanaccountofperceptualattributionofcolor,shape,size,andsoon.SeeEcheverri(forthcoming),fordiscussion.32Itmightturnoutthatsomeoftheargumentsofthefunctionconsistofphasesthataremerelyanticipatedbythevisualsystem(Burge2010).33ThisisnotintendedasacriticismofFine’sframework,whichwasdesignedtoaccountforco-referenceinlanguageandthought.Mypointisthattheframeworkshouldberevisedinordertoaccountforourexperienceofobjectsaspersistingovertime.34Therelationalfunctionshouldnotbeconstruedasasufficientconditionfortheexperienceofvariousphasesasphasesofoneobject.Afterall,IOMscanbecancelledbybackgroundevents,suchastheappearanceofvirtualoccluders(SigmanandRock1974).Thus,amoredetailedanalysisshouldmakeroomforcontextualmodulationsoftherelationalfunction.Iwillexaminethisissueinfuturework.35Ipresentedearlierversionsofthispaperatthe21stMeetingoftheEuropeanSocietyforPhilosophyandPsychology(9-12July2013),the5thGraduateSummerSchoolinCognitiveSciencesandSemantics:Perception(19-29July2013),theXVIIInter-AmericanCongressofPhilosophy(7-11October2013),theWorkshop:AbilitiesinPerception(29-30November2013),andtheColombo-BrazilianMeetingofAnalyticPhilosophy(5-6December2013).Iamgratefultotheaudiencesfortheircomments,especiallytoTomCrowther,PascalEngel,MichaelMartin,BenceNanay,andBarryC.Smith.IamalsoindebtedtoFabriceTeroniandtwoanonymousrefereesfortheirwrittencommentsonearlierdraftsofthispaper.IwouldalsoliketothankJamesGenoneforafruitfulemailexchangeonthetopicsofthispaper.ThisworkwasfundedbytheSwissNationalScienceFoundation(researchgrantNo.100012-150265/1).

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