“Kant's Diagnosis of the Unity of Skepticism”

volume14,no.14 may2014

“Kant’s Diagnosis of the

Unity of Skepticism”

Matthew A. KelseyTarrant County College – South Campus

© 2014 MatthewA.KelseyThis work is licensed under a Creative Commons

Attribution-NonCommercial-NoDerivatives 3.0 License. <www.philosophersimprint.org/014014/>

R ecentdecadeshave seen a sea change inwork in theAnglo-phoneworldonKant’sviewofskepticism.Earlierscholars–fol-lowingseminalreadingsbyP.F.StrawsonandJonathanBennett

–readKantasdirectly refutingtheradicalskepticbysomehowprovidingamore-or-lessdemonstrativeproofofsomemetaphysicalfactthatpre-cludesskepticaldoubts.1Morerecently,however,scholarshaverecog-nizedthatKant’sdiagnosticandmethodologicalreadingofskepticismisfarmorecomplex,andevenambivalent,thanthis.WhenKantexplic-itlydiscussesthese“nomadic”“benefactorsofhumanreason,”hechar-acterizestheirpositionasahigh-levelmetaphilosophical stance:awholeclusterofattitudesandbeliefsabouttheroles,aims,andproceduresofphilosophicalreflection,whichtheCriticalphilosophermustappreci-ateandlearnfrom(cf.Aix–xiiandA377–378,respectively).2Onlyadi-agnosticunderstandingofskepticismdeepenoughtoidentifybothitsremarkableappealanditspivotalassumptionscouldsucceedincastingdoubtonsuchmetaphilosophicalcommitments.Forthisreason,Kantargues, skepticismrewardsclosescrutiny,even if its true lessonsarenotwhattheskepticherselfthoughtshewasteachinginadvancinghergloomyverdictonthehumanepistemicsituationingeneral.3

1. Here,IhaveinmindStrawson’sBounds of SenseandBennett’sKant’s Analytic, bothpublishedin1966.

2. Quotations fromKant’sworksare from theAkademie Ausgabe,with theCri-tique of Pure ReasoncitedsimplybythestandardA/Beditionpagination,andtheotherworksbybothvolumeandpage.TranslationsandeditionsarefromtheCambridgeedition,as indicatedinthereferences.Specifictextsareab-breviatedasfollows:

Letters:Kant’sCorrespondenceNotes:Kant’sNotes and FragmentsPro: Prolegomena to Any Future MetaphysicsG: Groundwork of the Metaphysics of MoralsMF: Metaphysical Foundations of Natural Science“O”:“WhatDoesitMeantoOrientOneselfinThinking?”CPrR: Critique of Practical Reason“D”:“OnaDiscoveryWherebyAnyNewCritiqueofPureReasonisto

BeMadeSuperfluousbyanOlderOne”RP: What Real Progress Has Metaphysics Made in Germany Since the Time

of Leibniz and Wolff?Jäsche: The Jäsche Logic

3. Insightfulproponentsof themorenuancedviewofKanton skepticism in-cludeAmeriks2005;Anderson2001;Engstrom1994;Forster2008;Hatfield

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propose,canservetoilluminatethesebroaderdevelopments,aswellastoclarifythenatureofKant’sownapproach.

Ageneraloutlineof theKantiandiagnosisof skepticism iseasyenoughtoprovide.ForKant,allformsofphilosophicallymotivatedskepticism–i. e.,allformsthatpurporttoberational,ratherthande-scentsintomeremisology–arearticulationsofacreepingdistrustofreason,asensethatreason’s“peculiarfate”ofconfrontingunanswer-ablemetaphysicalquestionsalreadyamountstotheskeptic’sgloomyverdict(Avii).ThecruxofKant’sengagementwiththeskepticishisattempttoprogressivelyreinterpretvariousskepticalargumentsasmoreorlessadequatearticulationsofaradicalunderlyingsuspicionconcerning the nature (or even the existence) of “human reason.”As we shall see, Kant does not regard skepticism as a fixed pack-ageofarguments,butasaguiding thoughtormaxim,common toallwhophilosophizeskeptically:“howlittlecausehavewetoplacetrust inour reason if inoneof themost importantpartsofourde-sireforknowledge[viz.,metaphysics]itdoesnotmerelyforsakeusbutevenenticesuswithdelusionsandintheendbetraysus!”(Bxv)Thus,“Kantianskepticism”–skepticismasKantunderstandsit–isintentionally unified:disparatestrategiesarerelatedasmeanstoasin-gularskepticalend.(“Kantiandogmatism”likewisecomprisesdispa-ratemeanstotheendofattainingknowledgeofthingsastheyareinthemselves.)Bypursuingthislineofthought,Kantproceedsfromvague doubts about human knowledge to a specific (and soluble)problemforpurereason.Asheseesit,transcendentalphilosophy’schargeistoenableusto“becomecritical”–toreflectivelyregainourtrustinreason,withoutfallingbackintothedogmatist’snaïvefaithinourpowersofrationalinsight.6

readingsofKanthimself,byBird2006,Mosser2008,andevenP.F.Strawsonin1985,lateronhiscareer.

6. Compare“D”8:226–7:“BydogmatisminmetaphysicstheCritiqueunderstandsthis:thegeneraltrustinitsprinciples,withoutapreviouscritiqueofthefacultyofreasonitself,merelybecauseofitssuccess;by skepticism,however,thegen-eralmistrustinpurereason,withoutapreviouscritique,merelybecauseofthefailureofitsassertions.Thecriticismoftheprocedureconcerningeverything

ThisdevelopmentwithinKantscholarshipisofwiderphilosophi-calinterest,sinceitdovetailswithagreatdealofcontemporaryworkon skepticism. Many epistemologists now argue that a direct refu-tation of skepticism is impossible. In place of such straightforwardproofs, these philosophers recommend a variety ofdiagnostic strate-gies,whichaim to show(asBarryStroudputs it) that skepticism ismerely“conditionallycorrect”:inescapableifcertaininitiallyplausiblepremisesaregranted,andyetcapableofbeingturnedasideindirectly, so longasoneof thosekeypremises turnsout tobesomethingwecansatisfactorilydowithout(1984:179).4Indeed,thisisthedominantapproachtoskepticismincontemporaryepistemology,rivaledonlybybroadlyWittgensteinianattemptstoshow,“therapeutically,”thatskep-ticalchallengesareinsomewaynonsensical,orperpetuallydialecti-cally inappropriate.5 Closer attention to Kant’sbattlewithskepticism,I

2001 and 2003; Henrich 1989; Kitcher 1995; Kuehn 1987; Neiman 1994;Proops2003;Stapleford2007;Stern2006and2008;andVelkley1989.Mygoalinthisessayistocontributetothisbodyofworkbyhighlightinganas-pectofKant’stheoryofskepticismwhichthesescholarsgenerallydownplayoroverlook.

4. Forvaluablestudiesofdiagnostic(ornonrefutational)approachestoskepti-cism,seePritchard2001andWilliams1996.

5. Candidates for “the lessonof skepticism” arewidely varied andhotly con-tested. Here is a sampler of possibilities: hard-to-abandon internalist de-mandsmakeasatisfyinganswerimpossible(Fumerton1995);stopassumingthatknowledgeand its ascriptionare context-invariant (Cohen 1999,DeR-ose 1995,Williams 1996); knowledge is not, after all, closedunder knownentailment (Dretske 2003, Nozick 1981); the traditional conception of theobjectivityof theworld isunworkable (Rorty 1981);badmetaphorsof themindasaperceptualspacecreatethewholeproblematic(Fischer2010,fol-lowing Wittgenstein); we should have remained direct realists all along(Huemer 2001); experience is through-and-through conceptual, as Hegelsaw(McDowell1996);or,wecanandshouldgroundourcognitivelivesonanexistential-epistemic“leapoffaith”(Foley1993,Lehrer1997).Whattheseallhaveincommonisarejectionbothofskepticism,andofanyattempttodirectly guarantee our knowledge. Therapeutic responses to skepticism in-cludeAustin’sordinary-languagephilosophy,as inhis 1962;Carnap’s 1950distinctionbetweenframework-internalandframework-externalquestions;Cavell’sdoubtsabouttheskeptic’sabilityto“saywhatshemeans”inhis1979;and, perhaps,Wittgenstein’s (1969)quietism– alongwithWittgensteinian



thelegitimateaimandstartingpointofepistemology–assumptionswhich,asitturnsout,couldonlybemotivatedbythethreatofamostfundamentalmode of skepticism. Thus, I shall say that one skepti-calargumentreducestoanotherwhenitturnsoutthatthereducingproblematicprovides thecrucialdialecticalcontext for the reducedone.Ifocusonthestrongunitythesishere,sinceitsdefenseentailstheweakerthesisaswell.

By showinghowdeeplybothunity theses structureKant’s think-ing,Idefendthreerelatedclaims:(1)wecanonlygraspthepointofKant’s arguments in lightof theunity theses; (2)bothof these twothesesareatleastmoreplausiblethantheymayseematfirstblush;and (3)Kant’s diagnosis of the skeptic incorporates certain insightsthatsuggestanovelconceptionofthenatureandresponsibilitiesofthehumancognitivesubject.IwillnotbegivingthefullKantiandiag-nosisofskepticism,however.Thatwouldrequireamuchmoreexpan-sivetreatmentthanispossiblehere.Ibegininsteadwithapictureofdisunity,andthentracethebroadoutlinesofKant’sresponsetotheskeptic, toshowthat themyriadvarietiesheengageswithall shareacommonroot.Fortunately,IcanrelyhereonsomeexcellentrecentworkonKantianskepticism.PaulGuyerandMichaelForsterbothpro-videausefulinitialtaxonomyofthreetraditionallyprominentskepti-cal arguments: theCartesian,Humean,andPyrrhonian (seeForster2008:3–5,andGuyer2008:27–52).AndtothistrioIaddtheAgrippanskepticismanalyzedbyPaulFranksinhisworkonpost-KantianGer-manIdealism(seehis2005:8–10and17–19).

Cartesianskepticism,initsparadigmaticcontemporaryform,isanunderdeterminationargument, contending thataprivilegedclassofpropositions(e. g.,concerning“innersense”)inadequatelygroundsadistinctproblematicclass(e. g.,concerning“theexternalworld”).Hu-meanskepticismattacksbroaddomainsofourknowledgebydenyingthatcertainessentialconceptshaveanyvalidgrounding,ofjustifica-tionorofcontent,sufficientforustoclaimobjectivepurportforthem.Pyrrhonianskepticismisademandforsuspensionofjudgmentthatismotivatedbythedialecticalmethodofjuxtaposingapparentlyequally

Whatthattrustamountsto,howitistobereachedandthensus-tained,andtheprecisewayitismeanttotakethestingoutofreason’s“peculiarfate,”areallverycomplexquestions–andtoomuchformetoaddresshere.Inordertogetagriponthissubject,then,Ifocusinthisessayonasingle,crucial,butoftenoverlookedelementofKant’sdiagnosisofskepticism.ThisiswhatIwillcalltheunity of skepticism thesis, or just the “unity thesis” for short: Kant’s claim that beneaththediversityofskepticalargumentsliesaunifyingmetaphilosophicalmaxim,which canbeunearthedand repudiatedbyCriticalphiloso-phy.Even thosewho takeabroadlydiagnosticapproach to readingKantagainsttheskepticgenerallydosopiecemeal,byfocusingonthisorthatparticularskepticalproblematic,andsoignoreKant’sexplicitclaimthatthereistrulyonlyonewaytobeaskeptic.YetonlytheunitythesiscouldallowaKantiantoentertainhopesofdiagnosticallyturn-ingasideskepticismüberhaupt.

This refusal to take Kant at hisword is quite odd, since, asweshall see, he is committed not just to thisweaker unity thesis, buttoastrongeroneaswell:thattheskeptic’smeansarerelatedhierar-chically, such thatproblematics loweron thehierarchy inherit theirforcefromthosehigherup.Accordingtotheweakunitythesis,thatis,skepticalarguments,inalltheirvariety,arejustsomanyattemptstophilosophicallyexpressadistinctiveconceptionofthescopeandna-tureofhumancognitivefinitude.Suchanexplanationofskepticismisreductive,notintheclassicalintertheoreticsense,butinthebroadersense of an attempt to explain diverse phenomena as local expres-sionsofunderlyingpatterns.Thestrongunitythesisislikewisereduc-tive,butinadeepersense.Here,theclaimisthatallformsofskepti-calargumentembodycertainmetaphilosophicalassumptionsabout

pertainingtometaphysics(thedoubtofdeferment)is,ontheotherhand,themaximofageneralmistrustofallitssyntheticpropositions,untilauniversalgroundoftheirpossibilityhasbeendiscernedintheessentialconditionsofourcognitivefaculty.”Onthis“trust”or“faith”inreason,inrelationtoskepti-cism,seeBxv,A237–9/B296–8,A709–11/B737–9,A741–3/B769–71,A751–2/B779–80,A756–69/B784–97,andA827/B855;Pro4:257–8,4:262–4,4:351–4,and4:360–2;“O”8:138n,8:140–3,and8:145–6;RP20:262–4and20:319–20;Jäsche9:73–5and9:83–4;andNotes16:459.



The extension of skepticism even to the principles ofknowledgeofthesensible,andtoexperienceitself,can-notproperlybeconsideredaseriousviewthathasbeencurrent in any period of philosophy, but has perhapsbeenachallengetothedogmatists,todemonstratethosea prioriprinciplesonwhichtheverypossibilityofexperi-encedepends[that is, topursueKant’s immanentmeta-physicsoftheunderstanding];andsincetheycouldnotdothis,awayofpresentingthoseprinciplestothemasdoubtfultoo.(RP20:264)

KanthasclearsystematicreasonsforneglectingCartesianskepti-cisminthisway:hisinterestinthepossibilityofmetaphysics,ratherthanknowledgemoregenerally;hisoft-affirmedviewthatmetaphys-ics is not foundational in thewayDescartes assumed, such that ev-erydayknowledgedemandsthatwefirstovercomeextravagantdoubtbyinferencefrommetaphysicaltruths;andhisconvictionthatCarte-sianskepticismisanunnaturalreactiontotheverynaturalfailuresofphilosophicaldogmatism.9These thesescombine inKant’s rejectionofCartesianattemptstoforceustogroundourknowledgeoftheex-ternalworldonourrelatively“safe”accesstoinnerseemings–arejec-tionwhich is itselfofapiecewithKant’s fundamentalaimof show-ingthatourvariousepistemicfacultiescanworkinharmonywithin

Wolff1963.PerhapsthemostsophisticatedversionisPaulGuyer’s1987Kant and the Claims of Knowledge(thoughGuyerhasreworkedsomeoftheseviewsmorerecently).Suchinterpretationsarenolongermuchinvogue,anditisclearwhynot:theyareincompatiblewithvirtuallyeverythingKanttellsusaboutwhatheisdoing.Forcritiquesstressingthispoint,seeAmeriks2000,Bird2006,Caranti2007,andForster2008.

9. ForKant’srejectionoftheCartesianprojectofphilosophizingindependentlyofexperience,seeBviii–xxii,Bxxv–xxvi,B18,B120,A422–5/B450–3,A468–71/B496–9,A710–1/B738–9,andA842–4/B870–2;“D”8:226–7and8:226n;RP 20:262 and 20:318–20; Jäsche 9:83–4; and Notes 16:459, 18:283–284,18:628–629,and18:434–437.Cf.Kant’sassertionsoftheactualityofsynthetica priori knowledge, e. g., atB19–24,B127–8, andA762–3/B791–2;Pro 4:255,4:272–5,and4:327;RP20:323;andCPrR5:13–14.

justifiedpropositions.Lastly,Agrippanskepticismarguesthatalljus-tifications, if challenged, lead to one of three equally unacceptableoptions:aninfiniteregress,adogmaticallyarbitraryassumption,oraviciouscircle.All fouroftheseformsofskepticismareradical, inun-derminingallornearlyallhumanknowledge,andphilosophical,inthattheyturnonverygeneralfeaturesofknowledgethataretakentoputitsattainmentoutofourreach.Furthermore,allfourarewell-known,bothtousnowandformuchofthetradition.Theyareinitiallyquitedistinct,too,andsoaffordagoodtestofKant’sabilitytobringthemtounity,bothweakandstrong.7Intheend,Ishallargue,KantregardsAgrippan“skepticism”asanaccurate,butnonskeptical,descriptionofthehumanepistemicsituation.

IbeginwithCartesianskepticism.Althoughsomescholars– fol-lowingStrawson’slead–stillpersistinattemptingtofindadirectref-utationofCartesianskepticismsomewhere inKant’s transcendentaltheoryofexperience,thisismisguided.8KantgrantsCartesianskepti-cismnomethodologicalroleinhissystem:

7. Asananonymousreadernoted,mycharacterizationoftheseskepticalprob-lematicsisontheunderdevelopedside.MybriefdefinitionofCartesianskep-ticism,forinstance,doesnotengagewiththedetailsofDescartes’effortsintheMeditations; norwith suchputatively crucial premises as epistemologi-calinternalism,variouscommitmentsinthephilosophyofmind,theclosureprinciple,oranyothersuchassumptions;norwithquestionsconcerningtheexacttargetortargetsofanyfullydetailedarguments.Butthissketchinessisdeliberate.Afterall, it iscentral toKant’sdiagnosis thatmanyparticulararguments be found to exemplify these general stratagems. Accordingly,Kantiscommittedtotheviewthatwecanunderminetheseproblematicsassuch,withoutpreciselyspecifyingthestrongestinterpretationsofthestron-gestargumentsfirst.For thatmatter, Idonotclaimexhaustiveness formylisteither.AlthoughIthinkKanthastheresourcestoincorporatestillmoreformsofskepticismintohisdiagnosis,thesefourvarietiesrepresenttheclas-sicalproblematicswithwhichheismostexplicitlyengaged.Expandingmyfocustomoreobscurevariantsofskepticismwouldcertainlybeuseful,butwould also complicatematters enormously. This is particularly sowith re-spect topost-Kantian formsof skepticism,of the sort suggestedby Jacobi’sandMaimon’sobjectionstotheCriticalphilosophy.SuchchallengesclaimtograntallofKant’spremisesaboutthestructureofhumanknowledge,andyettojustifyanegativeverdictonthepossibilityofhumanknowledgeanyway.Idiscussthembrieflyinnotes36and38.

8. For influential readings of this sort, see Strawson 1966, Bennett 1966, and



basedonthemistakenassumptionsthatknowledgeoftheworldde-pendsonknowledgeofinnersense,orthatknowledgeofexperiencedependsontranscendentmetaphysics.

Ifwerefusetomakesuchinvidiousdistinctions,Cartesianskepti-cism isphilosophically idle:wemaybewrong inmanydetails, butthoseerrors(potentialoractual)giveusnoreasontopictureourselvesastrappedwithinabubbleofprivateexperiences.(Wemayevenbebrainsinvats,asamatteroffact,butthisunlikelyempiricalhypoth-esiswouldnotbeasourceofphilosophicalskepticism.)Kant’scounter-proposalisquitebold:hepromisesawayofunderstandingourtotalepistemicsituationwhichdoesnotforceustoadmitradicalpriorityrelationshipsofthissort,atanypoint.12Thisistranscendentalphiloso-phy’snormative model of reason:asystemofmetaphysical-epistemolog-icalnormsorprincipleswhichformsanintegrativewholegoverningandlicensinganyandallknowledgeclaimswemakeaboutthepublic,humanworld.(Ofcourse,thisisavery largepromissorynote;Icon-siderthestandingof“humanreason,”asasystematictheoreticalentity,attheendofthisessay.)

MakingmethodologicaluseofCartesiandoubtswouldmeanfor-feitingthisaimrightatthebeginning,bygrantingthathumanreasonas suchisproblematic,ratherthanmerelypronetomisuse,andthusinneedofsomeindependentverificationfromprivilegedfoundationsifitistoclaimanyauthority.(RecallDescartes’torturedattemptstodi-vinethetrustworthinessofhiscreator.)ThisiswhyKant’sbest-knowndiscussionofCartesianskepticism,theRefutationofIdealism,occursmanypagesintotheCritique,andrelieslittleontheDeduction.Indeed,theRefutationitselfisnewtothesecondedition,andtuckedawayinthemiddleofthediscussionofthePostulatesofEmpiricalThinkinginGeneral,after the vast bulk of the constructivework of theTran-scendentalAnalytic(cf.Bxxix).InthefirsteditionoftheCritique,Kant

12. ThisisnotacoherentistdirectrefutationofCartesianskepticism,sinceitsaysnothingaboutthestructureofempiricalknowledge.Kant’sconcernisinsteadwith thepostulatedsystemofnormsgoverning thatknowledge–asystemwhichalreadydistinguishesthehumanepistemicsituationfromthatoftheCartesianmind,ifitcouldsomehowbevindicated.

experience,ratherthanatcross-purposes.CloseattentiontoKantianarguments sometimes read as direct refutations ofCartesian skepti-cism,sufficestoshowthatheregardssuchargumentsasmuddledandderivativebyproductsofthegenuineskepticalmaxim.

Consider theTranscendentalDeduction, as adirect refutationofCartesianskepticism.Onsuchreadings,itintendstoshowthathumanexperience,inthe“thin”senseofapurelysubjectivefluxofsensations,ispossibleonlyif it iscategoriallystructured,andhencenecessarilydemon-free.Butthisisaforcedreadingofanargumentwhichquiteexplicitlyemploysa“thick”senseofexperiencethatalreadyamountstocognitionofanobjectiveworld.10 AsKarlAmeriksremarks,inKant’sstandardusageErfahrung“isnotdefinedintermsofprivateso-called‘Cartesian’ representations, but instead designates a cognitive situa-tionoccurring,roughlyspeaking,atalevelnolowerthanthatofthecoreperceptualjudgmentsofcommonsense”(2003:5).Suchobserva-tionspromptalternativereadingsoftheDeduction,onwhichitiscon-cernedtodevelopanotionof“experience”thatpermitsustodrawaprincipleddistinctionbetween“good”and“bad”formsofmetaphysics.AstheseinterpretersreadKant,theDeductionpavesthewayforanimprovedantidogmaticargumentagainstourapparentneedtomaketranscendentmetaphysicalclaims.11Itsantiskepticalpointissimplytopreventus fromdrawing invidiousdistinctionsbetweenourbeliefs

10. SeeBxvii–xviii,B132,B147,B165–6,B218–9,B234,andB276–7,aswellasPro 4:275,4:300,and4:304,andRP20:276.AtA736–7/B764–5,Kantaffirmsthethoroughgoing contingencyof “possibleexperience” itself.Thesepassagesallhaveincommonanaffirmationoftheepistemicimmediacyofintuition,whichleavesthepureconceptsofreasonandtheunderstandingasthesolefocusofKant’sjustificatoryefforts(seeA19/B33,A68/B93,andA371).

11. ThusKant’s remark that the “subtle inquiry” of theDeduction is valuableonlybecause itmakes thenegative,antidogmatic sideof theCriticalproj-ectpossible–otherwise, “we learnnothingmorethanwhatweshould inanycasehavepracticed in themerelyempiricaluseof theunderstanding”(A237/B296).Principalexponentsofthisviewincludemanycommentatorscitedinnote3,aswellasGardner1999.ThesecommentatorsfindinKantaspecificallydialecticalresponsetotheskeptic,whichenableshimtodefendtheveracityofexperiencewithoutpresupposinganythingaboutitsultimatenoumenalgrounds.



experience in human cognition that we already have independentgroundstoreject.ThatiswhyherunsareductioargumentagainsttheCartesian,eventhoughhebelievesthatnothingpositive(suchasanantiskepticaltruth)canbeproveninthisway(cf.A789–94/B817–22).In the end, then, theRefutationmerely restatesKant’s earlier claimthat inner and outer are epistemically continuous, by highlightingthe fact thatonecannotmakeknowledgeclaimsonlyaboutoneortheother, taken in isolation. Indeed, the argument in theBEditionmightbetterbecalled“theSelf-RefutationofIdealism,”becauseKant’saimthereistoshowthatthereisnoevenminimallystableviewhere-abouts for theCartesian “skeptic” tocling to– thus, “thegame thatidealismplayshaswithgreaterjusticebeenturnedagainstit”(B276).Kantdoesnottherebyclaimknowledgeofthefalsityofskepticalsce-narios, inageneralway,butonlythatconsideringsuchscenarios isasirrelevantforphilosophicalreflectionasitisforjustifyingordinaryknowledgeclaims.Wealreadyknowhowtojustifysuchclaims,afterall,withoutappealtothefoundationsCartesiansinsistupon.Onlyapriormistrustofreasoncouldevermakeheroicdogmaticeffortsseemphilosophicallymandatory.13

Kant’s glancing engagementwith theCartesian evinces a key in-sight:skepticismmustbenatural tobeofanyphilosophical interest.Insofaras the skepticaims to secureour rational surrenderofallorverymanyofourclaimstojustification,shemustleveragestandardsof justification towhichwe are already committed.Otherwise, anyskeptical argument is merely a reductio of whatever alien assump-tionstheskepticmakes,evenifthismoverequiressomerevisionsin

13. NeimanoffersasimilarlydismissivetakeontheRefutation’ssystematicim-portanceinher2001.ShesuggeststhatKant’sfamouscharacterizationofCar-tesianskepticismas “ascandalofphilosophyanduniversalhumanreason”atBxxxixnismeanttoinvoketheBiblicalconnotationsofSkandal,asanin-ducementtosin–namely,todogmatism.KantthusechoesMichaelWilliams’pointthatDescartes’modernizedmethodologicalskepticismisquiteunlikeitsancientpredecessors,inwaysdesignedtoenforceadogmaticfoundation-alist solution (seeWilliams 1998and2010).The fact thatCartesian skepti-cism poses a question towhich the only conceivable answer is dogmaticmetaphysicsis,byKantianlights,asuresignofitsunnaturalness.

simplynotesthatsensation,andthecoherenceofexperience,arethecriteriaofactuality(e. g.,A225–6).Hisclaimisthatwealreadyknow,andinordinaryexperiencereadilyapply,theruleslicensingvariousknowledgeclaims.Kant’sindignationisunderstandable,then,whenhe complains against his critics that “what I called [transcendental]idealism did not concern the existence of things (the doubting ofwhich, however, properly constitutes idealism according to the re-ceived[empiricalorCartesian]meaning), for itnevercameintomymindtodoubtthat”(Pro4:293).

Admittedly, Kant doeswork to undermine the Cartesian projectin the first edition’s Fourth Paralogism, by flatly rejecting the asym-metrybetweenmindandbodythatmakesitseemmandatoryforus(A366–80;cf.Pro4:336–7).Byputtingthedeliverancesof innerandoutersenseonanepistemicpar,KantrefusestograntDescartes’invid-iousdistinctionbetweenprivilegedandproblematic,therebydefusingthiscentralvariantoftheCartesianchallenge.ButwecanstillacceptKant’sclaimthatthisformofskepticism“nevercameintohismind,”byaddingaminorqualification:thatthe“skepticalidealist”isreallyaformofdogmatist,whomakesontologicalclaimsabouttheepistemi-callyirrelevantmind-independentinnernatureofsensibleobjects,ofthesortthatreallycouldbejustifiedonlybyclaimingfoundationalon-tologicalknowledge.Thus,KantregardstheusualformofCartesian“skepticism”asatypeoftranscendentalrealism:theidentificationofappearancesandthingsinthemselves.It“nevercameinto[his]mind,”then,preciselyasa formofskepticism.That iswhyKantattempts toturnhisobjectionstotranscendentmetaphysicsagainstCartesianism,quaincitementtodogmatism.

ItisalsowhytheRefutation,whenitfinallyarrives,offersaninter-nalcritique,byarguingthatCartesianinnerexperience(“themere,butempiricallydetermined,consciousnessofmyownexistence”)alreadyentailsclaimsaboutpersistingouterobjects(seeA377–9andB274–5).Thatisnottosaythatsuchclaimsarenecessarilyveridical,however.Rather,Kant’spointisthatCartesianskepticismisultimatelytheresultofapresuppositionconcerningtheroleof“thin”orpurelysubjective



be the correct one, it already tells uswhenwe can rightly claim toknowparticular experiential objects.Unlesswewillfully forget thatfact,thereisnowaytoattaintheradicallysubjectivestandpointoftheCartesianmeditator.(ThisisonewayofunderstandingtheproblemoftheCartesiancircle.)Thus,therealimpetusofKantianskepticismmustlieinthisbroadly“metaphysical”domain.

Thisis,ineffect,areductionofradicalCartesianskepticismtoskep-ticismaboutmetaphysics.Theintractabilityoftranscendentmetaphys-icscastssuspiciononreason’sexercisebeyondtheboundsofsense;thiscallsintoquestionthesynthetica prioriprinciplesexercisedwith-inordinaryexperience;andonlythenmightiteveroccurtous(ratio-nally)toquestionthetruthofordinaryexperienceitself,ortoembarkfromthereuponthedesperateprojectofCartesianfoundationalism.Wehavean“originaltitle”tosynthetica prioriclaims,sincetheyaretheconstitutiveexerciseofthatsamereasonthatisexpressedinalljudg-mentsassuch.Deeperformsofskepticismchallengethattitle,and,iftheycanbeaddressedinawaythatrespectsthelawfulneutralityofreason,Cartesianskepticismisotiose.Asitturnsout,then,HumeanskepticismhaspriorityovertheCartesian:

[T]hatscience[mathematics],sohighlyesteemedforitsapodictic certainty, must also succumb to empiricism in principles on the samegroundonwhichHumeput cus-tomintheplaceofobjectivenecessityintheconceptofcause;despite all itspride, itmust consent to lower itsbold claims commanding a priori assent and expect ap-proval of theuniversal validity of its propositions fromthekindnessofobserverswho,aswitnesses,wouldnotrefuse to admit that what the geometer propounds asprinciplestheyhavealwaysperceivedaswell,andwhowouldthereforeallowittobeexpectedinthefutureeventhoughitisnotnecessary.InthiswayHume’sempiricisminprinciplesalso leadsunavoidably to skepticismevenwith respect tomathematicsandconsequently inevery

ourownepistemicprinciples.Theskepticalwaysbearstheburdenofmakingus feel the ineluctableparadoxicality ofherargument– thatis why diagnostic responses to skepticism are possible in the firstplace.14 Indeed, such revisionary efforts are how thewhole contem-poraryantiskepticalprojecttendstohandleCartesianskepticism:bydebatingthecomparativemeritsofadoptingexternalism,embracingcontextualism,rejectingtheclosureprinciple,orwhathaveyou.YetKant’sviewisclearlythatCartesianskepticismisnotatrueparadox,evenofthemanageablevariety–thattheinvidious,once-and-for-alldistinctionbetweeninnerandouter,andmanyotherslikeit,arejustwrongheadedphilosophicalpictureswecaneasilyrelinquish,evenaswecontinuetopursueourgenuinephilosophicalquestions.

Kant’sinsighthereexplainshiscomfortininvestigatingtheques-tionofhowsynthetica priori judgmentsarepossibleontheassump-tionthatwepossesssuchknowledgealready.GivenKant’sclaimthatwe are “naturally predisposed” to metaphysics, doubts about suchknowledge could only be rationally motivated by a truly paradoxi-calcrisisofmetaphysics(eventually,weshallseethatthePyrrhonianchallengeisthatcrisis).ForKant,nomerefailurewithinexperience,and no decisive encounter with the supersensible, could impel ustomistrust basicmetaphysical principles– after all, suchprinciplespurporttojudgeexperience,nottheotherwayaround(cf.Bxiii–xiv).Doubtsaboutourprinciplescanariseonlywithinoursystemofprinci-plesitself.(AndtheCartesianmustadmitasmuch,ininsistingonthesubjective indistinguishability of her skeptical scenarios.) Cartesianskepticism,Kantcontends,presumesfarmorethanafair“neutrality”ofreasonbetweencompetingalternatives–itdemandstheoutrightself-destructionofreasonasapreconditionofanywell-groundedin-quiry(A756–7/B784–5;cf.Jäsche9:31,aswellasA751–2/B779–80andA760–2/B788–90).Whicheversetofepistemicprincipleshappensto

14. Stroud 1984 andWilliams 1996 discuss the preconditions of diagnostic re-sponses to skepticism.Ribeiro 2004 is an insightful analysis ofwhat is re-quired ifweare to “insulate”ordinary justificatorypractices fromskepticalarguments.



In the passage just quoted, Kant blamesHume’s “empiricism inprinciples”forthetroublesofCartesianskepticism.Buttherealprob-lemisnotHume’sempiricismper se,butthewayitundercutsthenor-mativestatusofmetaphysicalclaimstoidentifythemwithbrutepsy-chologicalfacts.Kant’sdiagnosticthoughthereisthatHumeerrsbytakinganessentially third-personalviewofprinciples that canonlybeendorsedfirst-personally.ThatiswhyKant’sattackagainstHumerunsexactlyparalleltotheobjectionhelodgesagainsttherationalist thesisofa“preformation-system”or“preestablishedharmony”under-lyingourknowledge,inwhichGodgrantsusinnatea prioriconceptsand thenstructures theworldaccordingly.Bothviewscommandusto take up a third-personal explanatory perspective on our deepestnormativeprinciples.Anysuchhypothesis,Kantdeclares,“isprecise-lywhat the skepticwishesmost, for thenallofour insight throughthesupposedobjectivevalidityofour[evenempirical]judgmentsisnothingbutsheerillusion,andtherewouldbenoshortageofpeoplewhowouldnotconcedethissubjectivenecessity(whichmustbefelt)ontheirown;atleastonewouldnotbeabletoquarrelwithanyoneaboutthatwhichmerelydependsonthewayinwhichhissubjectisorganized”(B167–8;cf.B127–8andPro4:319n).17ThepointKanthasinmind is thatviewingourselvesasmerelycompelled tousecertainprinciples,asamatterofbrutenaturalorsupernaturalcausality,alsomakesitimpossibleforustoviewtheseprinciplesasnormativeinanygenuinesense.Wewouldthenbetrappedwithinoursubjectivesitua-tion,withoutresourcessufficienttomakeobjectivelyvalidjudgments–justastheHumeanskepticpicturesus.

whytheradicalskepticalcrisisHumedepictsinthoseworkseventuallyleadshimtoquestionwhetherwecancountasrationalbeingsatall.Thus,Humerejects the “trite topics”of simpleperceptualerrorasarguments forskepti-cism inhisEnquiry, 12.5 and 12.21–2 (cf.Kant’s similar remarks at B278–9,A376–7,andA447–51/B475–9).Thusitisthat,inbothworks,HumerejectsCartesian skepticism out of hand (e. g., atEnquiry 12.3 andTreatise 1.4.1.7).(Throughout, I reference theTreatisebyBook,part, section,andparagraphnumber,andtheEnquirybysectionandparagraphnumber.)

17. Foracontemporaryattempttomakeuseofthisinsight,seeMacarthur2006.

scientifictheoreticaluseofreason(forthisbelongseithertophilosophyortomathematics).[…][A]universalskep-ticismwill have to follow (though itwould, admittedly,concernonlythelearned).(CPrR5:52)

ThispassagebringsHumeanskepticismdecisivelyintothepicturebyraisingHume’sworrythatourprinciplesaresimultaneouslynonra-tionalandcompulsory.TheHumeanarguesthat,inoneormorecru-cialdomainsofjudgment,atrulyobjectiveworldplaysnoroleinthefixationofourbeliefs.Thus,oursystemofknowledge-licensingprin-ciplesmayindeedbecompleteandharmoniouslyintegrated,inawaytheCartesiandenies,buthasnogriponaworldwhichdeservestobecalled“objective.”15Kant’stakeonHumeisoneofhisfavoriteself-pre-sentationaldevices,andheofferslengthyvariationsofthestoryseventimesinthemajorworks,atB19–24,B127–9,andA758–69/B786–97;Pro4:257–63and4:310–7;andCPrR5:12–14and5:50–7,alongwithnumerousincidentalremarks.ThepassagejustquotedisofparticularinterestbecauseofhowitconnectsCartesianandHumeanskepticism– here, Kant suggests that skepticism about ordinary experience de-pendsuponapriorskepticismaboutmetaphysics,sinceyoucanonlyrejectordinaryknowledge in the “right”way, soas togetCartesianskepticism,ifyoufirstregardtheseprinciples(rationalisticallyorem-piricistically)butquasi-naturalistically,asHumebadeusdo.Cartesianskepticism,thatis,isreallywhatGuyerdubsa“gastricrefluxofdoubt”from themetaphysical level,atwhich theHumean’schallengeoper-ates(2008:7–9).16

15. Abroadlyanti-Humean readingofKant is currentlypopular,owing to thetroublesencounteredbyStrawson’sreadingofKant,anditskeynotionofa“transcendentalargument”(seeespeciallyStroud2000).GivenHume’sprom-inence inhis own right, anti-Humeanism is anatural fallbackposition forreaderswhorejectanti-Cartesianism,butstillsupposeKantmust(somehow)directlyrefutetheskeptic.RobertSternmakesthenaturalnessofthisretreatexplicitinhis2000.

16. ItisnotnotedoftenenoughthatHumedeliberatelycentershisskepticismonmetaphysicstoo,intheintroductionstotheTreatiseandtheEnquiry.Thatis



theburdenofprooftellssoundlyagainstHume,ashehimselfshouldadmit.Wecouldthenrejectdogmatismwhilestilllayingclaimtoau-tonomy. Andwe should do this because philosophers should avoidwillfulparadoxes–suchasarationallybasedpictureofourselvesasnonrational.KantthusaimsforastablepositionthatisuntouchedbyschizophrenicHumeanoscillationsbetweenphilosophicalskepticismand ordinary life.18 Diagnostically, then, Kant claims that Humeanskepticism rests on tendentious assumptions about the nature ofmetaphysics.ThisiswhyKantintroducestheDeductiontousas“the explanation of the way in which concepts can relate to objects a priori,” and why he claims that one relatively simple point – that synthetic a priori knowledge is possible if and only if a shared faculty of under-standing makes fully human cognitive experience possible – should be

“sufficient by itself” for his aims (see A84/B117 and Axvii, respectively).That this isKant’s line onHumean skepticism is also clear from

the Analogies, which are often wrongly read as direct refutationsof this mode of skepticism.19 There, Kant’s crucial point is that as-cribing metaphysical principles like causality to “custom” or “habit”

18. Kant often says theCritical philosophy is essentiallynegative,with the po-lice’s function ofmaintaining the peace, rather than the legislature’s of in-stitutingnewlaws(seeBxxvi,A11,B25,A89/B121,andA795–6/B823–4;andPro4:350–2,4:354–5,and4:362–3).That isonemajor reason to think thatKant’sbasicaimmustbetobeatHumeathisownantidogmaticgame(andcf. A470–1/B498–9, A764/B792 and A767–9/B795–7; Pro 4:257, 4:259–62,4:312–13,and4:351–4;andCPrR5:52–3).SeeStroud2011forabroadlyKan-tianargumentthatHumeanreductionsofkeymetaphysicalconceptsshouldneverrationallysatisfyus.

19. AfewcommentatorslocatethisresponseinthetwoIntroductionstothethirdCritique instead(seeGuyer2008:213–22,forcriticaldiscussion).There,Kantdefends,asa“transcendentalprincipleofthepowerofjudgment,”aprincipleofsystematicityopposedtoHume’sskepticismabout induction.But this isawholly inadequatedirect refutation, ifmeantas such–afterall,Kant, instressing the “heautonomy”of thepowerof judgment,admits that thekeyprinciplederivesfromourrationalinterestinprogressiveempiricalinquiry,ratherthananylegislativedemandswecanmakeontheexperientialworld.Onitsown,thatismoreofacapitulationtoHumethanarefutationofhim.But in the broader context of all threeCritiques, Kant is on better footing,sincetheprincipleofsystematicityisjustoneorganicelementofhisoverallnormativemodelofreason.

Atthispoint,topreserveourself-imageasrationalcreatures,non-skepticalphilosophersmustfindsomeradicalalternative.Thekeyistotakeourprinciplesseriously,withoutlapsingintodogmaticclaimsthattheyarebrutefactsaboutusortheworld.ForKant,everythingturnsondistinguishinganimmanentmetaphysicsoftheunderstand-ingfromatranscendentmetaphysicsofintellectualintuition–adis-tinctionheclaimscanachieveeverythingHumedoesagainstthedog-matist,butatafarcheaperprice.Thus,KantintroducestheDeductionbypromisingto“steerhumanreasonbetweenthesetwocliffs[dogma-tismandskepticism],assignitsdeterminateboundaries,andstillkeepopentheentirefieldofitspurposiveactivity”(B127).AlthoughKantpraisesHumeforhisrigor,then,heobjectsthatHumeoverlooksthepossibilityofanimmanent,transcendentalmetaphysics:

Since he [Hume] could not explain at all how it is pos-sible for the understanding to think of concepts that inthemselvesarenotcombinedintheunderstandingasstillnecessarilycombinedintheobject,anditneveroccurredtohimthatperhapstheunderstandingitself,bymeansoftheseconcepts,couldbetheoriginatoroftheexperienceinwhich itsobjectsareencountered,he thus,drivenbynecessity,derivedthemfromexperience(namelyfromasubjective necessity arisen from frequent association inexperience,which is subsequently falselyheld tobeob-jective,i. e.,custom);howeverhesubsequentlyproceededquiteconsistentlyindeclaringittobeimpossibletogobe-yondtheboundaryofexperiencewiththeseconceptsandtheprinciplesthattheyoccasion(B127–8;cf.A760/B788).

OnKant’sreading,Humearguesthatourprinciplesareeitherdog-maticallyjustifiedorbrutelynatural;theformerisimpossible;thus,weareforcedintoradicalempiricism;andthisinturnyieldsaskepticalverdictonhumanknowledge.Kant’scounterproposalisthat,ifwefindanalternativeandgenuinelynormativemodelof reasontoendorse,



thencanweseethat theyare trustworthyexpressionsofoursharedprojectofsortingandcategorizingtheimpressionsofexperience.Andthat standpoint in turn showsus howobjective reasoning about ex-perience is possible, thereby undercuttingHumeanworries that theresultingcognitionisbasicallyirrationalor“merelypsychological” insomeway.

Kant’sapproachtoHumeanskepticismagainevincesakeendiag-nostic insight, akin to that pressed against theCartesian: that eventheskepticmustsignontoourbasicself-imageasautonomousratio-nalagents,insofarashergoalis(again)torationallypersuadeustowithdrawourclaimstoknowledge.AsHumewellknows,losingourgriponourownrationalitydestabilizesanyphilosophicalself-concep-tionwemightendorse, skepticalorotherwise.21YetHume’snatural-izingskepticism,consistentlypursued, forces rationalagencyoutofthepicture,makinghisaself-defeatingenterprisethatopenlyinvitesredoubleddogmatic efforts, launchedwhenour fondly rational self-imageisintheascendancy.Hume’spositionthenthreatenstodissolveinto the “indeterminate recommendations ofmoderation” thatKantrightlydeemsinadequateforcurbingdogmaticpretensionstoknowl-edge(e. g.,atB128).SuchacollapsewouldleaveHumefailingevenbyhisownphilosophicalstandards.ForKant,then,theonlyappropriateresponse is to reconceivemetaphysics,not to forswear it entirely. Ifthereisanywaytodosothatpermitsustocontinuetoviewourselvesasbasically rational cognitiveagents, thatwouldbephilosophicallypreferabletoskepticism–evenbyHume’sownlights.

Yetallthismerelyexacerbatesthedeeperworrythatreasonitselfmayprovedialectical.ThatthreatwouldstillmakeamockeryofKantasmuchasHume,byprovingtheimpossibilityofreflectivestability

21. SeeTreatise 1.4.1.12,whereHume grounds his skepticism on a putative di-rectdemonstrationoftheincoherenceofreason.Relationsofideas,ofcourse,areofnohelpatthispoint,sincetheconnectionswescrutinizeinreflectionstand revealed as arbitrary inventions, which are inconceivable as contri-butionstoarationalprojectofknowingobjects.Thisismorethanasimplelimitonhumancognition,then–Humeinfactentirelyjettisonsreason,initsbroadsense,asafacultyofknowledge.

irrevocablyalters them, so that they canno longerplaya trulynor-mativerole.Humeseessuchprinciplesasvastlyetiolatedderivationsfromexperience:supremelyabstract,andsoquitedispensable,hyper-generalizationsfromoureverydaylinkagesofperceptionsviapsycho-logicalassociationofideas.InHumeanpseudo-judgments,weemploywarpedempiricistfacsimilesoftheconceptualabilitiescentraltoourreasoning,andasaresult“custom(asubjectivenecessity)ofperceivingcertainthingsortheirdeterminations[…]is insensiblytakenforanobjectivenecessityofputting sucha connection in theobjects them-selves” (CPrR 5:51; compareA91/B123–4;CPrR 5:12and5:53–4; andPro4:298–301and4:312–4).20Thisis,again,“whattheskepticwishesmost”:ademonstrationthatmerehabitplaysthesupremeroleinhu-mancognition, rather thanour rational reactions to genuineobjects in experience (B167–8). Sucharguments “deny to reason the abilitytojudgeanobject,thatis,tocognizeitandwhatbelongstoit”(CPrR 5:12).Kant’s labors in theAnalogies,by contrast, carefully frameanalternativewayofgivingcontenttotheseprinciples,viathetemporalschematizationofthepureconceptsoftheunderstanding,thatdoesnot have this disastrous consequence. By doing so, Kant hopes toshowwhyprinciplesoftheunderstandingcannotbeextendedtothesupersensible–butalsowhy(andhow)theycanserveaselementsoftheself-understandingofautonomousrationalagents.Crucially,thisCriticalprojectneednotinvolveanyclaimstodirectdogmaticinsightintoouressentialnature.

The Analogies have the same systematic goal as the Deduction,then – Kant seeks to duplicate Humean accomplishments at lowercost, throughsuperiorrationalself-knowledge.ThisdiagnosticmoveisthelinchpinofKant’sreplytoHume,sinceitallowshimtodisplayourmetaphysicalprinciplespreciselyasprinciples,withoutforcingusto“really”putthemdowntoeitherbrutefactordivineimposition.Only

20.NoticethatthismovealsorevealsHume’sdoubtsaboutinductionasbasicallyCartesianinstructure–animpossibledemandthatwedemonstrateuniversallawsfromamanifestlyinadequateinferentialbaseofparticularexperiences(cf.CPrR5:52).



Thecritiqueofantinomy-pronedogmaticmetaphysicsintheDia-lecticis,generallyandrightly,regardedasthecoreofKant’sanswertothePyrrhonian.But,as thestrongunity thesis implies, theso-calledpositive and negative portions of theCritique – the TranscendentalAnalytic and theTranscendentalDialectic, respectively– are in facttwosidesofasingleantiskepticalstrategy.IntheAnalytic,Kantoffersa self-conception of “pure reason,” and its correspondingly abstractobjectofknowledge,intendedtonondogmaticallysecuremetaphysi-calclaimswithrespecttoexperience.IntheDialectic,bycontrast,hediagnosesthetranscendentalillusionsofdogmaticmetaphysics,andrelieves the philosophical pressure on our ordinary, commonsensi-calworldview–withitscauses,events,persistingobjects,pluralityofagents,andsoforth–byshowingthattheprinciplesofexperiencedonotcommitustotranscendentmetaphysicalclaims.Theseargumentshaveasingleconclusion:“humanexperience”isasingle,independent,internallyconsistentnormativeproject.Kant’stwo-prongedapproachallowsustoendorseanormativemodelofreason as normative, forusandforotherswhoshareinourrationality, inabasicexerciseofourauthoritytodefineourownnorms. Inpursuitofthisgoal,Kant’spairedargumentsfortranscendentalidealism–thatitaccountsforthedisparateepistemicrolesofconceptsandintuitions,andthatitistheonlymeansofescapefromtheantinomies–makeasinglepoint intwoways,namelythatdealingwithskepticismrequiresreason’scom-pleteself-knowledge.OnlybyunderstandingourtaskinthiswaycanweattempttheCopernicanmoveofdefiningthenormsofexperiencebyreferencetotherationalagentofthatexperience.23

O’Shea1996).ThatisHume’sownskepticism,anditis“mitigated”onlybyacceptingourentirefragmentaryhumannature,onitsownterms,anyway(seeTreatise 1.4.7.11 andEnquiry 5.5–9). In thisway,Humehimselfunifies“Humean”andPyrrhonian skepticism.And this isKant’s readingofHumetoo.ForKant,afterall,Humeisa“geographerofhumanreason,”“especiallyconstituted for equilibriumof judgment,”whooffersus crucial assistancepreciselybyindicatingthegroundofreason’sdialectic(seeA745/B773andA760/B788,aswellasChance2012:329–30).

23. Fortheskepticalmethod,seeA388–9,A421–5/B449–53,A485–90/B513–18,A502–7/B530–5,A710–1/B738–9,andA768–9/B794–5.Theideasofreason

onceandforall.Thus,KantcanclaimthattheindiscriminateHumeanrejectionofmetaphysicsbegsthequestionagainsttranscendentalphi-losophyonlyintheabsenceofthesuspensionofourinitialfaithinrea-sonembodiedbyKantianskepticism.Thatlossoffaithis,Kantthinks,spurredby the crisis ofmetaphysics, and specificallyby thePyrrho-niandialecticoftheantinomies.WithoutananswertothePyrrhonian,wecannothope foraconstructiveresponse to theHumean. Indeed,without thePyrrhonianattack therewouldbenoneed to constructanexplicitmodelofreasonatall,sincewewouldlackanycompellingreason to challenge thedogmatically unselfconscioususeof reasonin the first place. The problem of skepticism, then, is really ameta-skeptical problem– theworry thatwe cannot attain stable rationalself-knowledge,knowledgeofourselvesjustinsofaraswearethepur-posiveagentsofourowncognitions.Here,theskeptic’srootmaximcomesclearlyintoview,asthebasisoftheweakunityofskepticism:theskeptic’sdiversestratagemsarerevealedassomanyattemptsatself-knowledge of a certain special, “philosophical” sort, meant togroundafar-reachingmistrustoftheauthorityofourcommonhumanreason.Inthewidercontext,thisalsorepresentsanothermovetowardunityinthestrongsense–inthelastanalysis,Kantargues,HumeanskepticismreducestoPyrrhonianskepticism.22

22. Indeed,thisseemstobeHume’sactualview.HumeregardshisempiricismaloneasinsufficienttomotivatetheskepticalcrisissomemorablyportrayedattheconclusionofthefirstBookoftheTreatise.Instead,heoffersusacare-fuldissectionofthedialecticofreasonintermsofanantinomialconflictbe-tween“vulgar”and“philosophical”waysofframingasystematicviewoftheworld.Thevulgarsystemregardsperceptionsandtheirobjectsasidentical,andhenceasopen todirectempiricalevidence; thephilosophical systemproposestheir“doubleexistence,”whereinobjectscauseperceptionswhicharethemselvesdependentonusfortheirexistence.YetHumedoesnoten-dorse either of these systems, even though he regards them as exhaustiveandexclusive.Ashesaysafterrejectinganumberofpossibleescaperoutes,“there is a direct and total opposition betwixt our reason and our senses;ormoreproperlyspeaking,betwixtthoseconclusionsweformfromcauseand effect, and those that persuade us of the continu’d and independentexistenceof body” (Treatise 1.4.4.15; cf. 1.4.2–4, 1.4.7.4, and 1.4.7.7, aswellasEnquiry 12.7–16).Norationalsystematizationofourbeliefs isworkable,andsowefaceaPyrrhonianoscillationbetweenirreconcilablechoices(cf.



that“Itwas[…]theantinomyofpurereason[…][which]firstarousedmefrommydogmaticslumberanddrovemetothecritiqueofreasonitself”(Letters 12:257–8).Thatiswhyhepropoundsaspecial“skepticalmethod,” whichturnsouttobethePyrrhonianoneofdialecticalop-positions, asessentialforhisCriticalenterprise.25 Clearly,then,Kantregards Pyrrhonian skepticism as methodologically central to tran-scendentalphilosophy.26

Itisrarelynoticed,but,atthispoint,KantoffersanargumenttotheeffectthatwecanrejectPyrrhonianskepticismwithoutevenlooking,asitwere.AnentiresectionoftheantinomyisdevotedtoKant’sclaimthat the Pyrrhonian’s “transcendental problems of pure reason […]

25. Indeed, according to Kant, the Pyrrhonian challenge of the antinomies ofpurereasonisreason’sdefinitivefelix culpa–“themostbeneficialerrorintowhich human reason could ever have fallen, inasmuch as it finally drivesustosearchforthekeytoescapefromthislabyrinth”(CPrR5:107;compareB18,A423–5/B451–3,A468–71/B496–9,andA747/B775;Pro4:338–40,4:341n,4:365,and4:379;“D”8:226–7and8:226n;andRP20:262and20:318–9).Evi-dently,then,ChanceerrsinclaimingthattheskepticalmethodisinessentialtoKant’sstrategyinthefirstCritique.Kant’sresponsetoskepticismrequiresthatmetaphysicalprinciplesbe called intoquestion in a very specificway,andonlythePyrrhoniandialecticsuffices(compareChance2012:321–9).IfwerejecttheCartesianandHumeanproblematicsasill-formed,asKantdoes,theneventhenondialectical illusionsof theParalogismsandtheIdealcanonlyberationallycalledintoquestionbyatrulyantinomialthreat.

26.Ofcourse,KantalsofamouslysuggeststhatHumewokehimfromhis“dog-maticslumbers.”Buttheseaccountsarenotinconflict, ifHumeanandPyr-rhonianskepticismareunifiedasIsuggest(cf.Pro4:260).HumeearnsspecialmentioninsomecontextsbecausehisempiricismaidsKantinsharpeninghisdistinctionbetween immanentand transcendentmetaphysics.That iswhytheCritique of Pure Reason is“theelaborationoftheHumeanprobleminitsgreatest possible amplification”: via the antinomies, Kant is able to gener-alizeHume’sproblembeyondrelativelylimitedworriesaboutcausationorsubstantiality,tothreatenmetaphysicsassuch.This“amplification”ofHumebringsthecrisisofmetaphysicsto itshighestpitch,becauseitdisplaysthefullcostofthatskepticismaboutmetaphysicswhichisotherwiseanaturalconsequenceofourquietrevocationoftrustin(seeminglydialectical)reason.ThatcostconfirmstheunacceptabilityofHumeanskepticism,which“merelylimitsourunderstandingwithoutdrawingboundariesforit,andbringsaboutageneraldistrustbutnodeterminateknowledgeoftheignorancethatisun-avoidableforus”(A767/B795).Amongstcontemporaryphilosophers,Fogelin1994ablyarguesthatPyrrhonism–inaquiteKantianform–istheskepticalproblematicpar excellence.

Thus,althoughtheAnalyticandtheDialecticsupportandextendeachother,theydonotconstituteself-standingrepliestoessentiallyindependentformsofskepticism.24 ThestrongunityofHumeanandPyrrhonianskepticismalsoexplainsKant’smethodologicalemphasisontheantinomies,whichisdrivenbyhisconvictionthatcritiquecanonlybe rationallymotivatedby an internal conflictof reason.Thus,KantadviseshisreadersintheProlegomena thattheyshouldtaketheantinomyastheultimatearbiterofhissuccess,“becausenatureitselfseemstohavesetituptomakereasonsuspiciousinitsboldclaimsand to force a self-examination” (Pro 4:341n; cf. 4:379). Earlier, in anotedating to thecompositionof thefirstCritique, Kantwrites thatwhenhefirstsetouttoassesstheprospectsformetaphysics“Itriedquiteearnestlytoprovepropositionsandtheiropposite,notinordertoestablishaskepticaldoctrine,butratherbecauseIsuspectedIcoulddiscoverinwhatanillusionoftheunderstandingwashiding”(Notes 18:69).Likewise, ina 1798 letter toChristianGarve,Kantproclaims

discussedintheParalogismsandtheIdealare,ofcourse,justasdialecticalforKantastheantinomies.Buttheyare,wemightsay,purelydialecticalorillusory–theycannotmotivatethecriticalprojectbecausetheyoffernoclearconflictof reasonwith itself (seeA407/B433–4).Moreover, these ideaspre-supposecertainanswerstovariousantinomies.Forinstance,talkofsubstan-tialsouls involvesapriorcommitmenttotheideaofmetaphysicalsimplesdiscussedinthesecondantinomy;andonemustaffirmthepossibilityofanecessarybeing“eitherintheworldoroutsidetheworld”toevenraisethequestionofGod’sexistence.Onecould,inprinciple,composeempiricistan-titheses to thepropositionsof theParalogismsand the Ideal,butdoingsowouldbepointlessforKant’spurposes,sincehethinksthattherearenotrueinterestsofreasondrivingustowardthoseformsofdogmatism(cf.A462–76/B490–504).Aswithmany aspects ofKant’s diagnostic approach to skepti-cism,however, theskepticalmethod is infrequentlydiscussed(thoughseeChance2012:320n19).

24.Kant states this explicitly at the end of theDialectic, in reference to the“logicofillusion”hehascompiled:onlyourperennialtendencytodogmaticbackslidingmakeshisinvestigationsnecessary–anothersignthattheyarenot an independent coreof theCritical project (cf.A702–4/B730–2).YetKantalsodownplaystheAnalyticattimes,asatMF4:474n,wherehearguesthatthefullstoryof“howthecategoriesmake[…]experiencepossible[…]isinnowaycompulsory,butmerelymeritorious,”sincetheessentialpointissimplythatimmanentandtranscendentmetaphysicalsystemscanberigor-ouslydistinguished.



seekstodobyunderminingthetranscendentallyrealisticdogmatismunderlyingtheantinomies.ThisisathirdandfinalvariationonKant’sdiagnosticpointthatskepticsmustoffernaturalorinternalcritiquesofreason.Trulyphilosophicalformsofskepticism,includingPyrrhonianskepticism,arepeculiarlytimeless,sincetheyarisefromthegeneralprojectofassessingourtotalepistemicsituation.Insofarasskepticismpurportstotellusthefinaltruthofourepistemicdysfunctionality,itisdirectedatwhatKantcalls“purereason,”becauseonlyinthatexalt-edcontextcantheskepticmaketheglobalclaimsshewantstomake.Oncewe see this,we see thatKant’s engagementwith Pyrrhonismdoesnotdependoncontentiousdetailsofthisorthatargumentintheantinomychapter.Rather,itgoestowhatisclearlythemostseriousskepticalworryimaginable,theclaimthatourtotalepistemicsituationisdeeplyincoherent.

Nowwecanfinallyseeatleastthepossibilityofafullysatisfactoryresponse to Kantian skepticism. FollowingKant’s diagnostic insightthattheinterminableconflictbetweenskepticismanddogmatismis“ameremisunderstandinginjudgingthetruevocationofourreasonanditsprinciples,”wecannowseektoresolvethatmisunderstandingbyexercisingourrationalauthoritytospecifyanauthoritativelynor-mativemodelofreasonitself(Pro4:350).Transcendentalphilosophyaimsnotatultimatereality,then,inaflat-footedlydirectway,butatouressentialnormativeprinciples.27 Thepresupposedavailabilityof

27. This isonecrucial implicationofKant’sdoctrineof transcendental illusion.Againstdogmaticmetaphysicians,Kantpointsout inavarietyofwaysthatwe cannever infer fromhowwemustor should think, to theultimateorunconditionaltruthofsomematter.Humanreasonsimplydoesnotconstrainrealityasitisinitselfinthatway.Thus,thereisafailureoftransparencywithrespecttometaphysicalquestionsconcerningtheultimateprinciplesregulat-ingourknowledge. Inordinarycontextsweanswerthequestion“shouldIthinkthatp?”byinquiringwhetherp istrueornot,but inmetaphysicalorphilosophical contextswemusthalt at the formerquestion and answer itsolelyinitsownright,onourownauthorityasrationalagentstointention-allydetermineourcognitivepurposes inevaluatingexperience.Butpursu-ingthislineofthoughtanyfurtherwouldleadusintoKant’scomplementarydiagnosisofdogmatism,astherationalcounterpartofskepticism–soImustdesist.Forrelevantdiscussionsoftranscendentalillusion,seeA297–8/B354–5,A341/B399,A396–7,A407/B434,B427,A422/B450,A484/B512,andA570/

absolutelymustbecapableofa solution” (A476–84/B504–12; cf. Axii–xiv, B23, A612–4/B640–2, A756–64/B784–92, A763/B791, A775/B803, and A823/B851, as well as Pro 4:348–57 and 4:360–2). There,Kantarguesthatreason’sessentialcapacitytodetermineforitselfthenatureofitsownobjectofpossibleknowledgemeansthatitmustalsobeinapositiontodeterminewhetherornotinsightintothatobjectisagenuinepos-sibilityforit.Itisnotuptothevagariesofexperiencetodeterminethespecificationsofthisnormativeobjectofhumanknowledgeingeneral,sincethecontextofpurereasonabstractsfromsuchcontingenciestofocusonwhatisessentialtousasnormativeagents.Thusitturnsoutthat,simplyinvirtueofgrantingthatthereisa“contextofpurereason”at all, theKantian skeptic licensesus to engage inKant’sprojectofseekingoutareflectivelystableself-conceptionofreason:

Since,therefore,thesolutiontotheseproblemscanneveroccur inexperience, youcannot say that it isuncertainwhatistobeascribedtotheobjectregardingthem.Foryourobjectismerelyinyourbrainandcannotbegivenat all outside it; hence all you have to worry about isagreeingwithyourself,andavoidingtheamphibolythatwouldmakeyour idea intoaputativerepresentationofsomething given empirically, and thus of an object tobecognized inaccordancewith the lawsofexperience.Thusthedogmaticsolution[aswellastheskepticalone]is notmerely uncertain, but impossible. The critical so-lution,however,whichcanbecompletely certain,doesnotconsider thequestionobjectivelyatall,but insteadasksaboutthefoundationsofthecognitioninwhichitisgrounded.(A484/B512)

Here, Kant sees that philosophical skepticism unavoidably pre-tendstoabsoluteself-knowledge,andforthatreasonisbestopposedviarivalclaimstoself-knowledgethatdobetterjusticetoourprephi-losophical image of ourselves as rational agents. That iswhatKant



mistrustfulfearthataterribleepistemicdeficiencycorruptsallhumanreasoning. And Kant’swhole diagnosis of skepticism aims to showthatthisfearisgroundless.

Toseethispointmoreclearly,wecandistinguishbetweenwhatwemightcallformulaicandzeteticformsofAgrippanskepticism.Thefor-merisasimple,all-purposerecipeforgeneratingallegedlydamninginfiniteregressesofjustification.Thisisthe“philosophical”versionofthe Agrippan doctrine, which Kant rejects. Zetetic Agrippan skepti-cism,bycontrast,actuallypursuesgiveninquiriesasfarastheycanbetaken, and consequently sees the various skeptical “recipes” as con-creteresearchprojects,pursuedindefiniteparticularcontexts.Zetet-icskepticismshows itswork,and therebygrantswhatKantwantedallalong:areturntothe“fertilebathos”ofordinaryexperience(Pro 4:374n).KantseesthisversionoftheAgrippandoctrineasanaccuratedescriptionofthehumanepistemiccondition.Therereallyisnoendtothequestionswhichwecanandshouldpursueinourongoingin-vestigations–butthisishardlyadisaster,oncewerecognizethatwecanautonomouslyregulateandprioritizeour inquiries intoprogres-siveresearchprogramsthatanswertospecificcontroversies.

Oncewerestoreourtrustinreason,wecanacknowledgethattheconstantquestformore,andmoresystematic,knowledgeisitselfcon-stitutiveofhumannature,initstheoreticaldimension.Infact,thisisapromisingwaytotakeacentralimplicationofKant’sdifficultdoctrineoftranscendentalidealism.Thekeypointisnotthattheappearancesweperceiveare free-floating illusions,but that theyareepistemically autonomous, in thatexperientialknowledge,definedby reference toourepistemiccapacities,neithercommitsusto,nordependson,anythesesabouttheorderofthingsconsideredastheyareinthemselves.28 28.Kant’s “appearances”arenotaway(eithergoodorbad)ofknowingthings

inthemselves(seePro4:353,andA29–30/B45,A34–6/B51–3,A38–41/B55–8,B69–71,A44/B62,B69–71,A155–7/B194–6,A190–1/B235–6,A222–3/B269–70, A276/B332, A379–380, and A489–90/B517–8). Things in themselves,then,arethehighestgroundoftheappearancesonlyinthesensethattheyhaveontologicalprimacy– theyarenot implicated inourcognition. In fact,knowledgeofthingsastheyareinthemselveswouldbepositivelydisastrous,sinceitwouldforceustoendorseourhighestprinciplesdogmatically,rather

anevaluativestandpointof“purereason” already showsthatthishigh-est-ordercontexthas therequisite internalcoherence torespondtothePyrrhonian,whetherwecandetail that responseornot.Wherereason’s problems provide sufficient rational guidance, philosophy’scentraltaskisonlytofindawayofproceedingthatrepresentsalegiti-matealternativetobothdogmatismandskepticism(cf.A407/B433–4).Itisthus,bymeansofrationalself-knowledge,thatKanthopestodojustice to,withoutdirectly refuting,Cartesian,Humean,andPyrrho-nianskepticism–allatonce.

Unfortunately,KantneverexplicitlydiscussesAgrippanskepticism.Yetit isclearwhathisresponsemustbe:anyconceivablerefutationof theAgrippanwould be an unmitigated disaster for us. For Kant,thatis,afullawarenessofourunsettledempiricalestateisthetruthofskepticism,yetisnotitselfskepticism.Kantadmitswewillalwaysbetroubledbytheinfiniteregressofjustification,andsobytranscen-dentalillusion.Yet,althoughherefusesanyspecificallyphilosophicalanswerstotheAgrippanchallenge,Kantalsodeniesthatthisamountstoskepticism.Ournorms,afterall,areimmunetoAgrippanattack,be-causethereisnoneedtoexplainthemintermsofsomefurtherfact(notbecausewecannotdoso,asWittgensteinsupposes,butbecauseweneednotdoso,invirtueoftheautonomyofreason).Ourempiricalknowledgeisradicallyincompleteandfallible,butinawaythatoffersusacoherentproject,topursueintime.TheAgrippanmustadmitasmuch, insofarasshe isattemptingtoenforcerationalsuspensionofourbeliefs,asanyphilosophicalskepticmustdo.Putstillanotherway,thefrankrecognitionthatourknowledgewillalwaysandinevitablyfallshortofwhatwewouldlikeittobe,andthatanyofourempiricalbeliefsmightbecalledintoquestionifweprogressfarenoughalongsome lineof inquiryorother, isnot, forKant, a formof skepticismatall.Itisrathertherootofphilosophicalwisdomitself,andassuchis theultimateendofallphilosophizing.Theinfinitudeof thetasksofreasonturnsskepticalonlyifconjoinedwiththeKantianskeptic’s

B598.ThesepassagesareskillfullydiscussedinAllison2004,Ameriks2006,andGrier2001.



Atthispoint,Kant’sargumentforthestrongunitythesisis,ifnotcomplete,atleastcompletelysketchedout.Cartesianskepticismturnsout todemanda startingpointwhich thenonskepticalphilosopherhasnorealreasontoadopt,unlessbasicdoubtsaboutmetaphysicsassucharequietlygrantedfirst.BothHumeanandAgrippanskepticism,whichatfirstglanceareequallycapableofinducingustorejecteventhemostbasicclaimstoknowledge,presupposeinturnagenuinepos-sibilitythathumanreasonwillproveintrinsicallydialectical, leavingusinneedofphilosophicalguaranteesofourfundamentalprinciples.AndonlythespecterofPyrrhonismcouldrationallyleadustoendorsethatconceptionoftheendoraimofphilosophyitself.WhenIstatedthestrongunitythesisatthebeginningofthisessay,Iputitintermsofthesereductionrelationshipsbetweenapparentlyindependentprob-lematics.Butwecanseenowthatunravelingtheseinterlacingexpres-sionsoftherootskepticalmaximofmistrustingreasonalsoyieldsarichcropofinsightsintotheskeptic’sdefiningmetaphilosophicalas-sumptions– insightswhicharenowavailable forcooptationbythetranscendental philosopher.Where direct refutations take amerelynegativeattitudetowardtheskeptic,then,Kant’sdiagnosticapproachallowshimtolearnfromskepticismwithouttacitlyretreatingbeforeitsonslaught.Intheremainderofthisessay,Idrawouttheseconstruc-tiveimplicationsoftheargumentagainstKantianskepticism.

Kant’santi-Agrippanmovefromaconstitutivetoaregulativecon-ception of the ideas of reason alters the fundamental nature of the

rejects bare challenges. But an unresolved crisis ofmetaphysics suspendsourdefaulttrustinreason,makingusvulnerabletoradicalskepticism.Oncethatbackgroundofcrisis isdissolved,however, it isopentoKanttoadoptthe“default-and-challenge”modelofjustificationMichaelWilliamsdeploysagainstAgrippanskepticism.ForWilliams,theAgrippanerrsbyfreelyhelp-ingherselftoinfinitelyiterablechallenges,onthebasisofaradicalprincipleof “claimant-challenger asymmetry” which assigns exclusive responsibilityforknowledgeclaimstotheoneenteringthem.Hearguesthatthisdivisionof theburdensof justification isnot a featureof ourordinary justificatorypractice,andthusthatwehavenoreasontotakeformulaicAgrippanismse-riously. (UnlikeKant, however,Williams repudiates any attempts to philo-sophicallyevaluatethetotalhumanepistemicsituation.)CompareWilliams2001,chapters5and13,and2004.

Forus,asexperientialcreatures,everythingislocatedinthecontextofourown“purereason,”sothatthereisnoinhumanlysituation-andinterest-independent “orderof reasons,”as theskeptic supposes.AsKanthasit, theappearancesarenotgiventousasadeterminateto-tality(seeA498–9/B526–7,A504–6/B532–4,andA521/B549).Thatiswhythemetaphysicalprinciples(norms)governingreason’squestarenotpassivelyreceived,butmustbeintentionallyprojectedbyreason,asattemptstomakesenseofexperience.29 All imaginablesolutionstotheAgrippangroundingproblemsaretherebytransformedintoregu-lative ideas,which indeed set unbounded tasks for us – butwhich,forthesamereason,neednotbeverifiedorevenclaimedtobetrueapart fromourongoingstruggle to reasonand judge inaccordancewiththem(cf.A516–7/B544–5).AdecisivedirectrefutationofAgrip-panskepticismwouldrequirethatwebe(orbecome)somethingotherthanfinitehumancognizers–whereas,forKant,oneofthechiefrolesofphilosophicalthoughtispreciselytosubstantiatethatself-concep-tion.ItwouldbefollytodemandacompletesolutiontotheAgrippantaskfromthebareresourcesof thea prioriphilosophicalstandpoint,andKant’sfulldiagnosisofskepticism,ifsuccessful,showsusthatthiswasneveranythingofvalueanyway.30Thus,finally,wereduceAgrip-pantoPyrrhonianskepticism–quaskepticism,atanyrate.

than critically (see B163–4, B409–10, andA743–4/B771–2;Pro 4:311, 4:353,and4:362–3;CPrR5:146–8;and“O”8:138n).Allais2007andAmeriks2011defendKant’sattempttoavoiddeflatingempiricalknowledgeintosomethingsecond-rateorillusory.

29.CompareKant’swayofproposingtheCopernicanturn(Bxiii):“Reason,inorder tobe taughtbynature,must approachnaturewith itsprinciples inonehand,accordingtowhichalonetheagreementamongappearancescancountaslaws,and,intheotherhand,theexperimentsthoughtoutinaccor-dancewiththeseprinciples–yetinordertobeinstructedbynaturenotlikeapupil,whohasrecitedtohimwhatevertheteacherwantstosay,butlikeanappointedjudgewhocompelswitnessestoanswerthequestionsheputstothem.”

30.Pyrrhonian andAgrippan skepticism share themethod of opposition. ButthePyrrhoniangivesspecificequipoisedarguments,whereastheformulaicAgrippanadvances“barechallenges”:why-questionsnotbackedbyevidenceforacompetingposition.Ordinarily–andalwayswithinexperience–Kant



phynotasafoundationalsuper-scienceor“scienceofsciences,”butasa“doctrineofwisdom”thatisconcernedwithcontextualizingandreinterpretingthevariousnaturalandculturalexertionsofreasonasaharmoniouslyunifiedvocation:

[P]hilosophyisthescienceoftherelationofallcognitiontotheessentialendsofhumanreason(teleologia rationis humanae),andthephilosopherisnotanartistofreasonbutthelegislatorofhumanreason.[…]Themathemati-cian,thenaturalist,thelogicianareonlyartistsofreason,however eminent the formermay be in rational cogni-tions and howevermuch progress the lattermay havemadeinphilosophicalcognition.Thereisstillateacherintheideal,whocontrolsalloftheseandusesthemastoolstoadvancetheessentialendsofhumanreason.Himalonewemustcallthephilosopher.(A839/B867)32

Thewholepointofphilosophy,then,istomakepossibleacritical faithinthevocationofhumanreason,asthefullysufficientgroundofknowledgeandaction.Ifthisprojectsucceedsinsettingforththesta-bleandsystematicself-knowledgeofreason,ourtrustinreasonisvin-dicated.Yetitneverstopsbeingamatteroftrust,bywhichweventuretoframeandpursuenormativeprojectsofindefinitescope.Through

“certainlyerectssecureprinciples,butnotdirectlyfromconcepts,butratheralwaysonly indirectly throughtherelationof theseconcepts tosomethingentirelycontingent,namelypossibleexperience”(A737/B765;cf.Kantonthediscursivityofallphilosophizing,atA712–38/B740–66).

32. Thisideaispervasive:seeA463/B491,A839–40/B867–8,A744–55/B772–83,andA849–51/B877–9;Pro4:256;G4:403–5;CPrR5:108–9,5:141,and5:163;RP 20:259–60, 20:272–3, and 20:301; Jäsche 9:22–3 and 9:25–6; andNotes 17:552–3,17:557,17:559–60,18:5–7,18:14,18:59,18:87,18:93,18:284–5,18:445–6,and18:689.Theideathatphilosophyseekswisdom,quaself-knowledge,isalsothebasisofKant’s insistencethatphilosophybefullysystematic–forhim,partialcontextualizationsofhumanmoralandcognitiveexertionsdon’tevencountasphilosophy,sincetheyhavenothingtodowithreasonproper(ingeneral,überhaupt),exceptinsofarastheyatleastaimat,butfallshortof,thatmaximallywidecontext.

standardofhumanknowledge, from insight into things as they areinthemselves,tooneofmaximalconformitywiththeidealendsandinterestsofreason.TheinitialremarksKantmakesbywayofintroduc-ingtheideasofreason,suchasthePlatonicideaofaperfectlyjustso-ciety,makeitclearthatwhathesaysaboutthatcaseismeanttoapplyequallytoallgenuinelynormativeideas:

Even though thismay never come to pass, the idea ofthismaximumisneverthelesswhollycorrectwhen it issetforthasanarchetype,inordertobringthelegislativeconstitutionofhumanbeings evernearer to apossiblegreatest perfection. For whatevermight be the highestdegreeofperfectionatwhichhumanitymust stop, andhowevergreatagulfmustremainbetweentheideaanditsexecution,noonecanorshouldtrytodeterminethis,justbecauseitisfreedomthatcangobeyondeverypro-posedboundary.(A317/B373–4)

Philosophy cannot determine ex ante the extent towhich experi-enceconformstoour“commandingreason”(A653/B681).Ourlimits,whatever they are, lie onlywithin the progress ofnonphilosophicalexperience.AnyconceivabledirectrefutationofAgrippanskepticismattempts just such a reduction of the ordinary to the philosophical,and that iswhyKant rejectsall suchrefutationsoutofhand.GivenhisCriticalproject,therecanbenosuchauthoritativephilosophicaldictates,sincetheseareinconsistentwithbothhumanautonomyandhumanfinitude.31 Positively speaking, then,Kant conceives philoso-

31. SeeKant’slateandintemperateresponsetoFichte’sattemptat“cullingarealobjectoutof logic” (Letters 12:370).Kant’sattack isunfair,butunderscoreshisown,morelimited,conceptionoftheambitionsandauthorityofphilos-ophy.TheproblemKant raises for Fichte is just theonebrought uphere:philosophicalattemptstosatisfyanyimaginableAgrippandemandmustig-noreexperienceentirely,infavorofachimericalsortof“purereasons.”ThatiswhytheGermanIdealistsuniteindoingawaywiththethinginitself,aswell–theymustdosoinordertorejectthebrutecontingencyofpossibleexperience. But Kant accepts that contingency: transcendental philosophy



critiquemeansthatreason’s“peculiarfate”turnsouttobesomethingwecanwholeheartedlyembrace,oncewehavedispelledtheskeptic’sforlornattitudeofmistrust.

Thisisafascinatingproject.35Andyetmyanalysisconsiderablyex-acerbatesanobviousKantianproblem: is there sucha thingas “hu-manreason,”afterall,suchthatitmakessensetodefinephilosophythereby?Even ifphilosophicalskepticismmustassumethat there is,wemaynowbalkatthatheftyassumption.Kanthimselfneverwaversinhisconvictionthat “purereason”designatesa theoreticallycoher-ententity.Hiswholeargumentaimstorestoreourtrustinreason,nottodemonstrate itsexistencefromindependentfirstprinciples.(Andhowwouldthatgo,anyway?)But,nowadays,weeasilyworrythat“rea-son”isamirage–anamefornothingatall.Inourlesshopefultimes,then,understandingKant’sprojectintermsofKantianskepticismcanmakeitseemmorealienandunpromisingthanever.36 Thisisahardproblemformyreading,andsoIwanttoclosewithsometelegraphicreflectionsonhowlatter-dayKantianscouldrespond.Mythought,inbrief,isthatthisprecariousconditioniswhereweshouldhopetoendup.AsHilaryPutnamonceremarked, reason isboth immanentand transcendent.Itmustbeimmanenttoourpracticesifwearetofindourselvesinit,andtherebyacknowledgeitsauthority;butitmustalsobetranscendent,theexclusivepropertyofnopersonandnotradition,tohaveanycriticalbite.37Thisisaparadoxicalstatus,tobesure,but

35. Idiscussthedetailsofitsexecution,anditswidermetaphilosophicalramifi-cations,inKelsey2013.

36.Radicalrelativismmayseemanobviousthreathere,butitisnotoriouslyhardtosustain.Morepromisingobjectionsdrawonpost-Kantianskepticism,suchastheargumentsframedbyFriedrichHeinrichJacobiandSalomonMaimon.Jacobiarguesthatphilosophicalreflectionnecessarilyleadstonihilism:ato-talpictureoftheworldwithnoplaceforthehumansubject.Thisisarestate-mentof thechallenge toactuallydelineateaphilosophicalself-conceptioncapableofadoptionfromournonphilosophicalstandpoints.Maimon,ontheotherhand, claims thatwhileKanthas successfullydefined thenormativeparadigmofexperienceforhumanbeings,hefailstodemonstrateitsactual-izability.Forespeciallyusefuldiscussions,seeBeiser1987,chapters2and4;diGiovanni2005,chapter4;Franks1999;andFreudenthal2004.

37. Ontheimmanenceandtranscendenceofreason,seePutnam(1987:228and

philosophy,we acquire no newworldly knowledge at all, either ofthingsinthemselvesorofobjectsofexperience–butwedodevelopabetterunderstandingofjustwhatwedowhenwereason,andwhy.That isKantianwisdom,bycontrastwiththeheapingofknowledgeuponknowledgepursuedindogmaticquestsforasuper-authoritative“scienceofsciences.”ThisiswhattheKantianresponsetoskepticismcomestointheend,then:wedroptheideathatwerelatetotheulti-mateprinciplesofourknowledgebygrasping theontological struc-tureof anobjective “orderof reasons,” and replace itwith the ideathat we relate to them by intentionally conjoining them under theunifyingendofreason.ThatisthefinalimportofKant’sproposalto“denyknowledgeinordertomakeroomforfaith”(Bxxix–xxx).33Initsmostgeneralcontours,thisthoughtisthenowfamiliaronecapturedbyCavell’sfamoussuggestionthat“thehumancreature’sbasisintheworldasawhole,itsrelationtotheworldassuch,isnotthatofknow-ing,anywaynotwhatwethinkofasknowing”(1979:241).34InKant’sversionofthisidea,thepossibilityofrationalself-knowledgethrough

33. TheimmediateimportofKant’sremarkistodrawattentiontohisreconceptionofspecificallyreligiousfaithasacommitmenttothepostulatesofpracticalreason(thenotionofVernunftglaube).ButmydiscussionofKantianwisdomhere,aswellasKant’sownreflectionsontheneedforageneral“orientationin thought,”on thepartof apowerof reasonwhich is atbottompractical,aremeant to show that ananalogous formofnormative commitment is acentralconsequenceofKant’stheoreticalresponsetononreligiousformsofskepticismaswell.WeshouldnotthinkofKantianrationalself-knowledgeasakintoknowledgeeitherofanempiricalorasupersensibleobject.Ithankananonymousrefereeforpressingmeonthispoint.

34.Cavellthinkstheright“basis”isanoncognitiveacceptanceofothers.Otherssuggestafirst-personalcommitment toourselvesasnatural creatures (Ma-carthur2006);aformofexternalisticknowledgewesharewithnonrationalbeings(Sosa2009);agroundlessexistentialcommitment(Foley1993);theforceofnaturalnecessity,overcoming thequibblesof reason(Hume);ourBildungasmembersofaparticularlinguisticcommunity(McDowell1996);oranessentiallyunphilosophicaldisposition tonaturalisticquestionsandan-swers(Maddy2011).Thesedivergentviews,ofcourse,haveverydistinctiveimplicationsforothermattersofphilosophicalinterest,asdoestheKantiansearchfora“doctrineofwisdom.”Fornow,though,mypointisonlythattheattitudeKantintendstoachieveisnotknowledge,atleastasitisunderstoodbythe(transcendentallyrealistic)tradition.



cism,andadeeprethinkingofwhatphilosophyisandcouldbe.Thatsurelymakesitworthtakingseriously.39

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Allison,HenryE.(2004)Kant’s Transcendental Idealism: An Interpretation and Defense(secondedition).YaleUniversityPress.

Ameriks,Karl.(2000)Kant and the Fate of Autonomy: Problems in the Ap-propriation of the Critical Philosophy.CUP.

——.(2003)Interpreting Kant’s Critiques.OUP.——. (2005) “ACommonsense Kant?”Proceedings and Addresses of the

American Philosophical Association,79(2),19–45.——. (2006) “TheCritiqueofMetaphysics:TheStructureandFateof

Kant’sDialectic.”InAmeriks,Kant and the Historical Turn: Philosophy as Critical Interpretation,134–160.OUP.

——.(2011)“Kant’sIdealismonaModerateInterpretation.”InDennisSchultingandJaccoVerburgt(eds),Kant’s Idealism: New Interpreta-tions of a Controversial Doctrine,29–53.Springer.

Anderson,R.Lanier.(2001)“Synthesis,CognitiveNormativity,andtheMeaningofKant’sQuestion,‘Howaresyntheticcognitionsa priori possible?’”European Journal of Philosophy,9(3),275–305.

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Beiser,FrederickC. (1987)The Fate of Reason: German Philosophy from Kant to Fichte.HarvardUniversityPress.

Bennett,Jonathan.(1966)Kant’s Analytic.CUP.Bird,Graham.(2006)The Revolutionary Kant: A Commentary on the Cri-

tique of Pure Reason.CarusPublishing.Caranti,Luigi.(2007)Kant and the Scandal of Philosophy: The Kantian Cri-

tique of Cartesian Skepticism.UniversityofTorontoPress.

39.Forhelpfulcommentsonvariousiterationsofthisessay,IthankKarlAmeriks,AndrewCutrofello,JasonRheins,andJ.D.Trout,aswellastwoanonymousrefereesforPhilosophers’ Imprint.

it is justthestatusthat idealsalwayshave–theypersistasstandinggroundsforcriticizingthepresentorder,buttheycannevervouchsafetheirownrealizability.Idealsareoperativewithintheworldonlyifwetakethemtoheartasthestandardsofouractionsandourjudgments,andintheprocesstaketheirattainabilityon(hopefullyrational)faith.Reason,quaideal,mustbeproblematicinjustthisway,ifitistoplayitsessentialnormativerole–andsomustleaveusvulnerabletothetribulationsattendantonfaith.Kant’squestforphilosophicalwisdom,then,confrontsuswiththevitallyimportanttaskofrelatingourselvestoreasonsoastoavoidfalsifyingitsnaturebytreatingitasaneutralobjectof third-personaldescription.38Only ifwe learnthe lessonofskepticismbyrelinquishingthatmisbegottenaimcanweavoidadi-sastrousfracturingofourself-conceptionasrationalagents.Ifthisisright,thenKant’stwounitytheses,ratherthanmakingmattersworse,pointthewaytobothasurprisinglysophisticateddiagnosisofskepti-

242):“Ontheonehand,thereisnonotionofreasonablenessatallwithoutcultures,practices,procedures;ontheotherhand,theculture,practices,pro-ceduresweinheritarenotanalgorithmtobeslavishlyfollowed.[…]Reasonis,inthissense,bothimmanent(nottobefoundoutsideofconcretelanguagegamesandinstitutions)andtranscendent(aregulative ideathatweusetocriticizetheconductofallactivitiesandinstitutions).[…]Ifreasonisbothtranscendent and immanent, then philosophy, as culture-bound reflectionandargumentabouteternalquestions, isboth in timeand ineternity.Wedon’thaveanArchimedeanpoint;wealwaysspeakthelanguageofatimeandplace;buttherightnessandwrongnessofwhatwesayisnotjustforatimeandaplace.”

38.ForaKantiandefenseofideals,seeStratton-Lake1993.JamesChaseandJackReynolds (2010) also argue that transcendental arguments intrinsically de-mandarationalfaithinreasonitself.Kant’sbesthopeforovercomingpost-Kantianskepticism lies inarguing that reason isdistant fromus inexactlythewayidealsaredistantfromthosewhoseektorealizethem(cf.note36).Thefirstmovehere involvesKant’s little-noticed claim, at thevery endoftheCritique,thatthePhilosopheris“ateacherintheideal”who“isstillfoundnowhere,although the ideaofhis legislation is found ineveryhumanrea-son”(A839/B867).Thissuggeststhatphilosophy,asaspecialdiscourse,doesnotunproblematicallyspeakforreason–andsocanerrasKantdid–butinsteadhasitsowndefiningregulativeidea,asallrationaldiscoursesdo(cf.A642–50/B670–8).Ifdeveloped,thisthoughtallowsustoexcisethelinger-ingvestigesofdogmaticallypresumptuousauthorityfromKant’sconceptionofphilosophy.



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“Kant's Diagnosis of the Unity of Skepticism”