ILLUSION ARGUMENT FROM COLOUR AND THE CAMERON YETMAN 3 2 1 offoasis inthe distance. says “qualitatively indistinguishable”—as the experience of anactual Furthermore,oasis. the experience isthe exact same—Ayer of amirage something), but itisnot caused byareal physical object; there isno example, isanexperience amirage withadefinite content (itisof experiences which of things do not exist world. inthe external For illusion.from The argument follows. goes as Sometimes, people have causally dependent on the of state the observer. appearances world inthat of things canbedelusive and are, to some extent, have no direct perceptive world access to the material because the considered byitself .itisnot possible tell whether itisveridical or between the from isthat “[t]he character the fact two: of aperception perception of the world isdirect. systematically rejects Ayer’s arguments, concluding our that normal the to us properties inour experiences. things Austin of material J.L. “sense-data,”are which caused byimmaterial somehow represent explanation of colour, Austin’s theory proves unsatisfactory. particularly although neitherUltimately, Ayer nor Austin canprovide asatisfactory ideas bylooking at how they deal withthe phenomenon of colour. ABSTRACT I. AYER AND ILLUSION INTRODUCTION

twin somewhere behindit. effect whereby seeingyourselfinamirror looksthe sameasseeingyour sort, includingastraightstickwhich appearsbentunderwaterandthe Ayer, “Argument from Illusion,” 217.Ayer provides otherexamplesofthis and MichaelBratman(Oxford: Oxford UniversityPress, 1993),219-27. Philosophy: ClassicalandContemporary Readings,2nded.,ed.JohnPerry J. L.Austin,“ARefutationoftheArgument from Illusion,”inIntroduction to wording Iwillactlikehedoes. does notexplicitlyagree withthisargumentinthetext,butforeaseof Michael Bratman(Oxford: Oxford UniversityPress, 1993),215-18.Ayer Classical andContemporaryReadings,2nded.,ed.JohnPerry A. J.Ayer, “TheArgumentfrom Illusion,”inIntroduction toPhilosophy: philosophers’ ideas how byexamining they deal withthe phenomenon of colour. perception, and indeed, that, perception our normal isdirect. Ichallenge both thethat occurrence of delusions does not preclude the of direct possibility in our experiences. Austin systematically J.L. rejects Ayer’s arguing claims, which“sense data” somehow represent the to us properties things of material the world directly. He argues instead perceptions that are caused byimmaterial For J.Ayer, A. the occurrence of delusions confutes the notion we that perceive Ayer introduces the theory of the interms of argument sense-data In “The Argument Illusion,” from J.Ayer A. contends humans that 3 There issimply no way to tell the difference 2 Ipropose to challenge both philosophers’ 1 Instead, perceptions 13 Colour and the Argument from Illusion 14 Stance Volume 12 / April 2019 directly (i.e. without mediation). change their colours”) demonstrates we that do not perceive colour like appear mescal makes to “things drugs brain-altering ingesting relies on the of state internal the observer (shown that bythe fact function Additionally, of sense-data. colour that the fact perception isthus perceived things, of material a property through amysterious this function isor how itworks, he Colour, isnot admits, certain. as 7 6 5 4 cannot also bebent. thing,” of because amaterial thereal stick quality isstraight and thus submerged inwater, we what seeof the submerged section “isnot the For example, Ayer inthe that, of case astraight maintains stick half- one ishaving anexperience of something which isnot really there. begin, he argues itisnot that delusive.” such as through ingesting certain drugs, thus changes perception.such drugs, through as certain ingesting intotranslates coloured perceptual experiences. the brain, Changing into sense-data the eyes,bearing which the brain then somehow colour isnothing more the than reception information- of certain is unclear how could those disrupt perceptions. adrug So, for Ayer, which hold the sense-data inrelation to those things. the through properties some things “presentative of material function” For Ayer,sense-data. to give serve sense-data us indirect knowledge of through the same means are as delusions (i.e. sense-data). (there isno etc.), world mirage, the material must only beperceivable shown delusions that do not depend on the physical of the facts world caused byincorporeal Therefore, sense-data. because Ayer already has sensory access to the physical world, while delusive perceptions are absurd to suppose veridical that perceptions are caused by one’s direct causes to have qualitatively different effects. For this reason, itseems completely differentas one things, would expect different of sorts experiences are often indistinguishable they cannot becaused by Ayermirages. goes on to argue because that veridical and delusive perceptions are susceptible to serious skeptical doubt, we as do with cupmorning of coffee is somehow misleading; we do believe such any way. Few would doubt, for example, their that perception of their intheof world, things which do not seem to deceive or delude us in II. AUSTIN’S CRITIQUE OF AYER Ayer, “Argumentfrom Illusion,”216. Ayer, “Argumentfrom Illusion,”216. Ayer, “Argument from Illusion,” 215. Ayer, “Argument from Illusion,” 217. Austin criticizes theAustin basic premises criticizes theory. of sense-data To Perceptions of colour seem to fit wellframework within the of 4 By“veridical,” Ayer to our everyday isreferring perceptions 7 Inresponse, Austin retorts, iswrong, “[w]hat the case, inmost of Ayer’s examples, that 6 Ifwe directly perceived colour, it 5 Exactly what what Exactly crux of the problem.crux For Austin, delusions of have types—those two experiences. But for what, Austin, even are delusions? isreally the This an altered mental state, and so itisno wonder they are having delusive presumably reply the that person under the influence isin of the drug of putting on of What the Ayer’s glasses. mescal example? Austin would and thenglasses, the wall looks blue. One cannot simply ignorethe act conditions, and itlooks blue. Inthe other, we put on coloured strange looking bent sometimes?” isevenwhat inthe idea faintly surprising, of astick’s being straight but 10 9 8 experiences are very different. while we may say ineither the that case wall “looks blue,” the two seeingexact same ablue as justification wall. His for isthat, this claim he argues seeing that awhitewall through blue isnot glasses the only treatmentHis of colour inthe text comes 225,where on page directly perceived, have some cause. alternate we directly perceive world the material and delusions, that ifnot also fact findeven this remotely Likewise, surprising. itcould well bethat machine, but the result isthe same either way. We do not generally trajectory of abaseball: the cause may beahuman pitcher, or apitching the same must have the of same cause. sort could Ananalogy bethe It issimply not evident, for which Austin, things two appear that perceptive experiences, perceptions—demand there beone common cause for all delusions—even argues there that isno reason to suggest the that existence of occasional so their delusions occurunder special circumstances. Indeed, Austin person perceiving isclearly of state mind, not amirage and inatypical already have for aname delusions mirages of thissort: . Furthermore, the believe thisnecessitates the introduction of atheory we as of sense-data, of simplein terms phenomena. external Austin but agrees does not of water. But These seem of what to have mirages? no explanation place:the stickis taking looks bent due to the refractive properties Austin, one cannot abstract the from conditions inwhich the delusion real butnot simply astick that half-submerged inwater looks bent. For when we know itisstraight does not necessitate the that bent is part Austin, “Refutation ofArgumentfrom Illusion,”225. Austin, “Refutation ofArgumentfrom Illusion,”226. Austin, “RefutationofArgumentfrom Illusion,” 222.Italicsmine. It isunclear how Austin willdeal withthe phenomenon of colour. perceiving onesortofthing isexactly like perceivinganother? too. For why onearthshould itnotbethe casethat, insomefewinstances, we should notbeobligedtoextend this admissiontothe ‘normal’cases no reasontomake) that inthe ‘abnormal’ casesweperceivesense-data, [f]or even ifwemake the prioradmission(which wehave sofarfound when they appear identical non-deluded to normal, 8 The fact that asubmerged that The fact stick looks bent 10 Inone, we walk up to awall innormal 9 15 Colour and the Argument from Illusion 16 Stance Volume 12 / April 2019 13 12 11 a dress was uploaded to the internet which caused widespread debate. colour-blindness card itseems the as to trump be. thebegging question. such, As one cannot Idid (as take for along time) back without to the itstruth brain, assuming further evidence would be incomplete information to the brain. While thisresponse gives priority optical instruments perceptions cause atypical isbecause they deliver eyes? Well, one could potentially argue the that only reason atypical nullify the example, because the defect isnot inthe mind but inthe respond appropriately wavelengths to certain of light. Does thisfact blind defective person certain has cells intheir retina which to fail information itreceives. Inthe of case colour-blindness, the colour- in our optical instruments, or inour mind’s processing of the visual differenceThis incolour manifestmust be either inthe apple itself, and red, sees the seeitas while exact myfriend same apple brown. as delusion isthe existence of colour-blindness. Imay look at anapple most obvious point insupport to raise of the notion colour that isa delusions, and their ubiquity The does nothing thisfact. to mask something isconjured that up bythe mind—colour perceptions are delusive—right? perceptionlike sense-data, of colour must bedirect and not everyday perception of the world isdirect and unmediated by anything ubiquitous experiences as can get. Surely, ifAustin our that claims avoid. But of what colour? Experiences of colour are just about as andin rare specific circumstances, which we can predict and usually hallucinating, someone examples seeing mirages—are only that occur delusion—aactual medical patient seeing pink aperson rats, on drugs have no grounding ineveryday experience. Every example he cites of are perceptions strange and sensations conjured up bythe mind which direct perception Why isfalse. is this? Recall for that, Austin, delusions everyday perceptive experience isadelusion, itmust bethe that case belief and of perception. delusion, the mind conjures up something which does not really exist. wrong, and more, what’s wrong withthe person them.” who has are amuch more serious illusions matter [than ]—something isreally suggest something unreal, totally not really there at all.delusions illusions they inthat are creations of the mind: “the ‘delusion’ term does III. CHALLENGING AUSTIN Adam Rogers,“The ScienceofWhyNoOneAgrees onThe ColourofThis Austin, “Refutation ofArgumentfrom Illusion,”220. his discussiononpage220. Austin doesnotmakethisdistinction explicit,butitisquiteobviousfrom There are further examples to consider. In2015, aphotograph of Not quite. According to Austin’s definition of delusion— Here ismychallenge to Austin: ifIcanshow of some that our part 11 Delusions of perception

are differentfrom 12 Ina 13

the sensations corresponding to the five ‘classical senses.’” sensory modalities, involving the specific areas cortical responsible for excitationThis inthe occurs brain and canbeconsidered “afusion of light, the reflectance being the light reflecting off the object. about the reflectance”—the actual illuminant being the background throw away information about the illuminant and information extract chromatic the bias as way inwhich “[our] system visual issupposed to neuroscientist Jay Neitz the from University of Washington describes consistent; we still thinkitiswhite. Inan interview withWIRED, the change inambient light insuch away the that paper’s colour seems the paper suddenly yellow turns because our for brains are correcting a room litwithanincandescent bulb, we shocked are not typically that a sheet of printer paper the from whitelight bright of the outdoors into allow for better of distinguishing colours. For instance, when carrying one’s brain subtracts the hue of ambient light one’s from perceptions to chromatic bias indifferent ways. Chromatic isthe bias effect whereby but the basic explanation different isthat people were correcting for complex neurological explanation for thisdiscrepancy inperception, saw blue-and-black, and some white-and-gold. There isarelatively The issue was everyone that seemed to seeitscolour differently: some triggers stimulationtriggers inacompletely different sensory modality.” synesthesia ingeneral where occurs “the excitation of one sense explains in“Synesthesia: AMultimodal Combination of Senses,” sounds. Jean-Pierrecolour Ternaux As certain aresult as of hearing with chromesthesia, asubset of synesthesia, experience sensations of brain ingeneral canaffect which colours we see. situations,illuminating jump itseems asmall to the conclusion the that Ifthe brain canaffectin neural which activity. colours we seeincertain well functioning. The discrepancy inperception iscaused bydifferences instance of the dress, the optical apparatus of observers and are normal word synesthesia.” cortex inthe absence of stimulation visual inasubject withcolour- clearlyresonance indicated imaging activation visual of the primary Ternaux notes “[recent] that investigations functional using magnetic directly stimulated bysomething inthe outside world. Furthermore, mixed up withand stimulates another, though only been thehas first the areaterms, of the brain responsible for one sense-experience gets 17 16 15 14 Ternaux, “Synesthesia,” 322. Ternaux, “Synesthesia,” 322. Leonardo 36,no.4(2003):321. Jean-Pierre Ternaux, “Synesthesia:AMultimodal Combination ofSenses,” Rogers, “TheScience.” 2018, www.wired.com/2015/02/science-one-agrees-colour-dress/. Dress,”, lastmodifiedFebruary26,2015, accessedNovember25, Wired I willuse one more example to help illustrate mypoint. People 17 For this subject, hearing certain words For certain thissubject, elicits hearing 16 In layman’s Inlayman’s 14 Inthe 15

17 Colour and the Argument from Illusion 18 Stance Volume 12 / April 2019 up inthe mind. believe one sees something inthe real world, when itisconjured infact are not delusions of belief except inthe sense they that may makeone in the same way one adelusion has of colour. Delusions of perception conjured up bythe mind). One does not have adelusion of grandeur because they are perceived of sense-experience, (interms whether real or foundation delusions inreality, of perception are entirely different grandeur or of persecution without these convictions having any Furthermore, one that while itistrue canexperience delusions of simply Lies belying. cannot account for allreported of cases delusion. of pink rats would not say they are, and, ifthey did, they would world.external Secondly, someone who isnot having anexperience since pink rats do not exist, thisexperience cannot come the from one isseeing pink ratsifone isnot having anexperience of them. Firstly, are having thisexperience. there as rats, to speak of. Instead, isno they image simply believe they this isthe case, the person’s mind does not conjure of pink up animage matter of grossly disordered beliefs,” so are delusions of perception. perhaps, just delusions as of grandeur or a persecution are “primarily perception earlier because they seemed completely unrelated. But describes—those of beliefs. Idistinguished these delusions from of them. potential This rebuttal plays off the other of sort delusion Austin believes they are seeing pink without rats, perceiving of some image 19 18 to suggest our perception of colour heavily relies upon neural activity, . sees pink rats”)isnot seeing. like normal between seeing the floor and seeingThis seeing rats. pink (“the patient their mental issimply state such they that cannot tell the difference perceiving some of conjured-up sort image of pink ratsbut rather that for example, Austin the could that person maintain isnot so much not understood hisview. Inthe of case apatient seeing pink rats, and vividness accompanying direct retinal stimulation. inthisway,arises though of course withthe much-improved definition sensory modalities—it seems reasonable to suggest colour that always experiences of colour canbeconjured up inthe brain—albeit other via experiences of colour, allwithout retinal stimulation. Thus, if CONCLUSION IV. A POTENTIAL REBUTTAL Austin, “Refutation ofArgumentfrom Illusion,”220. Austin, “Refutation ofArgumentfrom Illusion,”220. This explanationThis solves nothing because there isno reason to believe Returning to colour,Returning Iconclude because that there issolid evidence Austin might respond to mychallenge Ihave that byarguing 18 Instead, the person 19 If from what isnot. what from reconsider hisgrounds for perceptions distinguishing of isreal what must back fall on the premises theory, of sense-data and Austin must to beaveryand thisfails explanation illuminating at all.Thus, Ayer does Ayer, allhe as cansay they isthat are both caused bysense-data, perceptions or at least of their distinguishing causes. course, Of neither Austinthat no goodway has of veridical distinguishing delusive from (I have theory well), qualmswithsense-data as many itdoes mean case, direct perception While isfalse. thisdoes not mean Ayer iscorrect acceptable one, on the assumption mypremises Ifthisisthe are correct. sense conjured up inthe mind. The latter option seems the only (audition, olfaction, etc.) are direct, or else allperception isinsome perception isanoutlier and allother perception of aspects normal leavesThis us withanuncomfortable decision to make: either colour such perception isconjured up inthe mind and isthus adelusion. 19 Colour and the Argument from Illusion 20 Stance Volume 12 / April 2019 of language, and ancientof language, physics. include epistemology, philosophy academic history. His art interests technology withacertificate in and the history of science and honours degree inphilosophy where he acombined ispursuing NovaCollege inHalifax, Scotia, student at the University of King’s Cameron Yetman isathird-year ABOUT THEAUTHOR: 21 Colour and the Argument from Illusion