HeteronomyoftheWillastheSourceofallspuriousPrinciplesofMoralityIfthewillseeksthelawwhichistodetermineitanywhereelsethaninthefitnessofitsmaximstobeuniversallawsofitsowndictation，consequentlyifitgoesoutofitselfandseeksthislawinthecharacterofanyofitsobjects，therealwaysresultsheteronomy。Thewillinthatcasedoesnotgiveitselfthelaw，butitisgivenbytheobjectthroughitsrelationtothewill。Thisrelation，whetheritrestsoninclinationoronconceptionsofreason，onlyadmitsofhypotheticalimperatives：\"IoughttodosomethingbecauseIwishforsomethingelse。\"Onthecontrary，themoral，andthereforecategorical，imperativesays：\"Ioughttodosoandso，eventhoughIshouldnotwishforanythingelse。\"E。g。，theformersays：\"I
oughtnottolie，ifIwouldretainmyreputation\"；thelattersays：
\"Ioughtnottolie，althoughitshouldnotbringmetheleastdiscredit。\"Thelatterthereforemustsofarabstractfromallobjectsthattheyshallhavenoinfluenceonthewill，inorderthatpracticalreason（will）maynotberestrictedtoadministeringaninterestnotbelongingtoit，butmaysimplyshowitsowncommandingauthorityasthesupremelegislation。Thus，e。g。，Ioughttoendeavourtopromotethehappinessofothers，notasifitsrealizationinvolvedanyconcernofmine（whetherbyimmediateinclinationorbyanysatisfactionindirectlygainedthroughreason），butsimplybecauseamaximwhichexcludesitcannotbecomprehendedasauniversallawinoneandthesamevolition。
ClassificationofallPrinciplesofMoralitywhichcanbefoundedontheConceptionofHeteronomyHereaselsewherehumanreasoninitspureuse，solongasitwasnotcriticallyexamined，hasfirsttriedallpossiblewrongwaysbeforeitsucceededinfindingtheonetrueway。
Allprincipleswhichcanbetakenfromthispointofviewareeitherempiricalorrational。Theformer，drawnfromtheprincipleofhappiness，arebuiltonphysicalormoralfeelings；thelatter，drawnfromtheprincipleofperfection，arebuilteitherontherationalconceptionofperfectionasapossibleeffect，oronthatofanindependentperfection（thewillofGod）asthedeterminingcauseofourwill。
Empiricalprinciplesarewhollyincapableofservingasafoundationformorallaws。Fortheuniversalitywithwhichtheseshouldholdforallrationalbeingswithoutdistinction，theunconditionalpracticalnecessitywhichistherebyimposedonthem，islostwhentheirfoundationistakenfromtheparticularconstitutionofhumannature，ortheaccidentalcircumstancesinwhichitisplaced。Theprincipleofprivatehappiness，however，isthemostobjectionable，notmerelybecauseitisfalse，andexperiencecontradictsthesuppositionthatprosperityisalwaysproportionedtogoodconduct，noryetmerelybecauseitcontributesnothingtotheestablishmentofmorality—sinceitisquiteadifferentthingtomakeaprosperousmanandagoodman，ortomakeoneprudentandsharp—sightedforhisowninterestsandtomakehimvirtuous—butbecausethespringsitprovidesformoralityaresuchasratherundermineitanddestroyitssublimity，sincetheyputthemotivestovirtueandtoviceinthesameclassandonlyteachustomakeabettercalculation，thespecificdifferencebetweenvirtueandvicebeingentirelyextinguished。Ontheotherhand，astomoralfeeling，thissupposedspecialsense，*theappealtoitisindeedsuperficialwhenthosewhocannotthinkbelievethatfeelingwillhelpthemout，eveninwhatconcernsgenerallaws：andbesides，feelings，whichnaturallydifferinfinitelyindegree，cannotfurnishauniformstandardofgoodandevil，norhasanyonearighttoformjudgementsforothersbyhisownfeelings：neverthelessthismoralfeelingisnearertomoralityanditsdignityinthisrespect，thatitpaysvirtuethehonourofascribingtoherimmediatelythesatisfactionandesteemwehaveforheranddoesnot，asitwere，tellhertoherfacethatwearenotattachedtoherbyherbeautybutbyprofit。
*Iclasstheprincipleofmoralfeelingunderthatofhappiness，becauseeveryempiricalinterestpromisestocontributetoourwell—beingbytheagreeablenessthatathingaffords，whetheritbeimmediatelyandwithoutaviewtoprofit，orwhetherprofitberegarded。Wemustlikewise，withHutcheson，classtheprincipleofsympathywiththehappinessofothersunderhisassumedmoralsense。
Amongsttherationalprinciplesofmorality，theontologicalconceptionofperfection，notwithstandingitsdefects，isbetterthanthetheologicalconceptionwhichderivesmoralityfromaDivineabsolutelyperfectwill。Theformeris，nodoubt，emptyandindefiniteandconsequentlyuselessforfindingintheboundlessfieldofpossiblerealitythegreatestamountsuitableforus；moreover，inattemptingtodistinguishspecificallytherealityofwhichwearenowspeakingfromeveryother，itinevitablytendstoturninacircleandcannotavoidtacitlypresupposingthemoralitywhichitistoexplain；
itisneverthelesspreferabletothetheologicalview，first，becausewehavenointuitionofthedivineperfectionandcanonlydeduceitfromourownconceptions，themostimportantofwhichisthatofmorality，andourexplanationwouldthusbeinvolvedinagrosscircle；and，inthenextplace，ifweavoidthis，theonlynotionoftheDivinewillremainingtousisaconceptionmadeupoftheattributesofdesireofgloryanddominion，combinedwiththeawfulconceptionsofmightandvengeance，andanysystemofmoralserectedonthisfoundationwouldbedirectlyopposedtomorality。
However，ifIhadtochoosebetweenthenotionofthemoralsenseandthatofperfectioningeneral（twosystemswhichatleastdonotweakenmorality，althoughtheyaretotallyincapableofservingasitsfoundation），thenIshoulddecideforthelatter，becauseitatleastwithdrawsthedecisionofthequestionfromthesensibilityandbringsittothecourtofpurereason；andalthoughevenhereitdecidesnothing，itatalleventspreservestheindefiniteidea（ofawillgoodinitselffreefromcorruption，untilitshallbemorepreciselydefined。
FortherestIthinkImaybeexcusedherefromadetailedrefutationofallthesedoctrines；thatwouldonlybesuperfluouslabour，sinceitissoeasy，andisprobablysowellseenevenbythosewhoseofficerequiresthemtodecideforoneofthesetheories（becausetheirhearerswouldnottoleratesuspensionofjudgement）。
Butwhatinterestsusmorehereistoknowthattheprimefoundationofmoralitylaiddownbyalltheseprinciplesisnothingbutheteronomyofthewill，andforthisreasontheymustnecessarilymisstheiraim。
Ineverycasewhereanobjectofthewillhastobesupposed，inorderthattherulemaybeprescribedwhichistodeterminethewill，theretheruleissimplyheteronomy；theimperativeisconditional，namely，iforbecauseonewishesforthisobject，oneshouldactsoandso：henceitcannevercommandmorally，thatis，categorically。Whethertheobjectdeterminesthewillbymeansofinclination，asintheprincipleofprivatehappiness，orbymeansofreasondirectedtoobjectsofourpossiblevolitiongenerally，asintheprincipleofperfection，ineithercasethewillneverdeterminesitselfimmediatelybytheconceptionoftheaction，butonlybytheinfluencewhichtheforeseeneffectoftheactionhasonthewill；Ioughttodosomething，onthisaccount，becauseIwishforsomethingelse；andheretheremustbeyetanotherlawassumedinmeasitssubject，bywhichInecessarilywillthisotherthing，andthislawagainrequiresanimperativetorestrictthismaxim。Fortheinfluencewhichtheconceptionofanobjectwithinthereachofourfacultiescanexerciseonthewillofthesubject，inconsequenceofitsnaturalproperties，dependsonthenatureofthesubject，eitherthesensibility（inclinationandtaste），ortheunderstandingandreason，theemploymentofwhichisbythepeculiarconstitutionoftheirnatureattendedwithsatisfaction。Itfollowsthatthelawwouldbe，properlyspeaking，givenbynature，and，assuch，itmustbeknownandprovedbyexperienceandwouldconsequentlybecontingentandthereforeincapableofbeinganapodeicticpracticalrule，suchasthemoralrulemustbe。Notonlyso，butitisinevitablyonlyheteronomy；
thewilldoesnotgiveitselfthelaw，butisgivenbyaforeignimpulsebymeansofaparticularnaturalconstitutionofthesubjectadaptedtoreceiveit。Anabsolutelygoodwill，then，theprincipleofwhichmustbeacategoricalimperative，willbeindeterminateasregardsallobjectsandwillcontainmerelytheformofvolitiongenerally，andthatasautonomy，thatistosay，thecapabilityofthemaximsofeverygoodwilltomakethemselvesauniversallaw，isitselftheonlylawwhichthewillofeveryrationalbeingimposesonitself，withoutneedingtoassumeanyspringorinterestasafoundation。
Howsuchasyntheticalpracticalaprioripropositionispossible，andwhyitisnecessary，isaproblemwhosesolutiondoesnotliewithintheboundsofthemetaphysicofmorals；andwehavenothereaffirmeditstruth，muchlessprofessedtohaveaproofofitinourpower。Wesimplyshowedbythedevelopmentoftheuniversallyreceivednotionofmoralitythatanautonomyofthewillisinevitablyconnectedwithit，orratherisitsfoundation。Whoeverthenholdsmoralitytobeanythingreal，andnotachimericalideawithoutanytruth，mustlikewiseadmittheprincipleofitthatishereassigned。Thissectionthen，likethefirst，wasmerelyanalytical。
Nowtoprovethatmoralityisnocreationofthebrain，whichitcannotbeifthecategoricalimperativeandwithittheautonomyofthewillistrue，andasanaprioriprincipleabsolutelynecessary，thissupposesthepossibilityofasyntheticuseofpurepracticalreason，whichhoweverwecannotventureonwithoutfirstgivingacriticalexaminationofthisfacultyofreason。Intheconcludingsectionweshallgivetheprincipaloutlinesofthiscriticalexaminationasfarasissufficientforourpurpose。
THIRDSECTION
TRANSITIONFROMTHEMETAPHYSICOFMORALSTOTHE
CRITIQUEOFPUREPRACTICALREASON
TheConceptofFreedomistheKeythatexplainstheAutonomyoftheWillThewillisakindofcausalitybelongingtolivingbeingsinsofarastheyarerational，andfreedomwouldbethispropertyofsuchcausalitythatitcanbeefficient，independentlyofforeigncausesdeterminingit；justasphysicalnecessityisthepropertythatthecausalityofallirrationalbeingshasofbeingdeterminedtoactivitybytheinfluenceofforeigncauses。
Theprecedingdefinitionoffreedomisnegativeandthereforeunfruitfulforthediscoveryofitsessence，butitleadstoapositiveconceptionwhichissomuchthemorefullandfruitful。
Sincetheconceptionofcausalityinvolvesthatoflaws，accordingtowhich，bysomethingthatwecallcause，somethingelse，namelytheeffect，mustbeproduced；hence，althoughfreedomisnotapropertyofthewilldependingonphysicallaws，yetitisnotforthatreasonlawless；onthecontraryitmustbeacausalityactingaccordingtoimmutablelaws，butofapeculiarkind；otherwiseafreewillwouldbeanabsurdity。Physicalnecessityisaheteronomyoftheefficientcauses，foreveryeffectispossibleonlyaccordingtothislaw，thatsomethingelsedeterminestheefficientcausetoexertitscausality。Whatelsethencanfreedomofthewillbebutautonomy，thatis，thepropertyofthewilltobealawtoitself？Buttheproposition：\"Thewillisineveryactionalawtoitself，\"onlyexpressestheprinciple：\"Toactonnoothermaximthanthatwhichcanalsohaveasanobjectitselfasauniversallaw。\"Nowthisispreciselytheformulaofthecategoricalimperativeandistheprincipleofmorality，sothatafreewillandawillsubjecttomorallawsareoneandthesame。
Onthehypothesis，then，offreedomofthewill，moralitytogetherwithitsprinciplefollowsfromitbymereanalysisoftheconception。
However，thelatterisasyntheticproposition；viz。，anabsolutelygoodwillisthatwhosemaximcanalwaysincludeitselfregardedasauniversallaw；forthispropertyofitsmaximcanneverbediscoveredbyanalysingtheconceptionofanabsolutelygoodwill。Nowsuchsyntheticpropositionsareonlypossibleinthisway：thatthetwocognitionsareconnectedtogetherbytheirunionwithathirdinwhichtheyarebothtobefound。Thepositiveconceptoffreedomfurnishesthisthirdcognition，whichcannot，aswithphysicalcauses，bethenatureofthesensibleworld（intheconceptofwhichwefindconjoinedtheconceptofsomethinginrelationascausetosomethingelseaseffect）。Wecannotnowatonceshowwhatthisthirdistowhichfreedompointsusandofwhichwehaveanideaapriori，norcanwemakeintelligiblehowtheconceptoffreedomisshowntobelegitimatefromprinciplesofpurepracticalreasonandwithitthepossibilityofacategoricalimperative；butsomefurtherpreparationisrequired。
FreedommustbepresupposedasaPropertyoftheWillofallRationalBeingsItisnotenoughtopredicatefreedomofourownwill，fromWhateverreason，ifwehavenotsufficientgroundsforpredicatingthesameofallrationalbeings。Forasmoralityservesasalawforusonlybecausewearerationalbeings，itmustalsoholdforallrationalbeings；andasitmustbededucedsimplyfromthepropertyoffreedom，itmustbeshownthatfreedomalsoisapropertyofallrationalbeings。Itisnotenough，then，toproveitfromcertainsupposedexperiencesofhumannature（whichindeedisquiteimpossible，anditcanonlybeshownapriori），butwemustshowthatitbelongstotheactivityofallrationalbeingsendowedwithawill。NowIsayeverybeingthatcannotactexceptundertheideaoffreedomisjustforthatreasoninapracticalpointofviewreallyfree，thatistosay，alllawswhichareinseparablyconnectedwithfreedomhavethesameforceforhimasifhiswillhadbeenshowntobefreeinitselfbyaprooftheoreticallyconclusive。*NowIaffirmthatwemustattributetoeveryrationalbeingwhichhasawillthatithasalsotheideaoffreedomandactsentirelyunderthisidea。Forinsuchabeingweconceiveareasonthatispractical，thatis，hascausalityinreferencetoitsobjects。Nowwecannotpossiblyconceiveareasonconsciouslyreceivingabiasfromanyotherquarterwithrespecttoitsjudgements，forthenthesubjectwouldascribethedeterminationofitsjudgementnottoitsownreason，buttoanimpulse。Itmustregarditselfastheauthorofitsprinciplesindependentofforeigninfluences。Consequentlyaspracticalreasonorasthewillofarationalbeingitmustregarditselfasfree，thatistosay，thewillofsuchabeingcannotbeawillofitsownexceptundertheideaoffreedom。Thisideamustthereforeinapracticalpointofviewbeascribedtoeveryrationalbeing。
*Iadoptthismethodofassumingfreedommerelyasanideawhichrationalbeingssupposeintheiractions，inordertoavoidthenecessityofprovingitinitstheoreticalaspectalso。Theformerissufficientformypurpose；foreventhoughthespeculativeproofshouldnotbemadeout，yetabeingthatcannotactexceptwiththeideaoffreedomisboundbythesamelawsthatwouldobligeabeingwhowasactuallyfree。Thuswecanescapeherefromtheonuswhichpressesonthetheory。
OftheInterestattachingtotheIdeasofMoralityWehavefinallyreducedthedefiniteconceptionofmoralitytotheideaoffreedom。Thislatter，however，wecouldnotprovetobeactuallyapropertyofourselvesorofhumannature；onlywesawthatitmustbepresupposedifwewouldconceiveabeingasrationalandconsciousofitscausalityinrespectofitsactions，i。e。，asendowedwithawill；andsowefindthatonjustthesamegroundswemustascribetoeverybeingendowedwithreasonandwillthisattributeofdeterminingitselftoactionundertheideaofitsfreedom。
Nowitresultedalsofromthepresuppositionoftheseideasthatwebecameawareofalawthatthesubjectiveprinciplesofaction，i。e。，maxims，mustalwaysbesoassumedthattheycanalsoholdasobjective，thatis，universalprinciples，andsoserveasuniversallawsofourowndictation。ButwhythenshouldIsubjectmyselftothisprincipleandthatsimplyasarationalbeing，thusalsosubjectingtoitallotherbeingendowedwithreason？Iwillallowthatnointeresturgesmetothis，forthatwouldnotgiveacategoricalimperative，butImusttakeaninterestinitanddiscernhowthiscomestopass；forthisproperlyan\"Iought\"isproperlyan\"Iwould，\"validforeveryrationalbeing，providedonlythatreasondeterminedhisactionswithoutanyhindrance。Butforbeingsthatareinadditionaffectedaswearebyspringsofadifferentkind，namely，sensibility，andinwhosecasethatisnotalwaysdonewhichreasonalonewoulddo，forthesethatnecessityisexpressedonlyasan\"ought，\"andthesubjectivenecessityisdifferentfromtheobjective。
Itseemsthenasifthemorallaw，thatis，theprincipleofautonomyofthewill，wereproperlyspeakingonlypresupposedintheideaoffreedom，andasifwecouldnotproveitsrealityandobjectivenecessityindependently。Inthatcaseweshouldstillhavegainedsomethingconsiderablebyatleastdeterminingthetrueprinciplemoreexactlythanhadpreviouslybeendone；butasregardsitsvalidityandthepracticalnecessityofsubjectingoneselftoit，weshouldnothaveadvancedastep。Forifwewereaskedwhytheuniversalvalidityofourmaximasalawmustbetheconditionrestrictingouractions，andonwhatwegroundtheworthwhichweassigntothismannerofacting—aworthsogreatthattherecannotbeanyhigherinterest；andifwewereaskedfurtherhowithappensthatitisbythisaloneamanbelieveshefeelshisownpersonalworth，incomparisonwithwhichthatofanagreeableordisagreeableconditionistoberegardedasnothing，tothesequestionswecouldgivenosatisfactoryanswer。
Wefindindeedsometimesthatwecantakeaninterestinapersonalqualitywhichdoesnotinvolveanyinterestofexternalcondition，providedthisqualitymakesuscapableofparticipatingintheconditionincasereasonweretoeffecttheallotment；thatistosay，themerebeingworthyofhappinesscaninterestofitselfevenwithoutthemotiveofparticipatinginthishappiness。Thisjudgement，however，isinfactonlytheeffectoftheimportanceofthemorallawwhichwebeforepresupposed（whenbytheideaoffreedomwedetachourselvesfromeveryempiricalinterest）；butthatweoughttodetachourselvesfromtheseinterests，i。e。，toconsiderourselvesasfreeinactionandyetassubjecttocertainlaws，soastofindaworthsimplyinourownpersonwhichcancompensateusforthelossofeverythingthatgivesworthtoourcondition；thiswearenotyetabletodiscerninthisway，nordoweseehowitispossiblesotoact—inotherwords，whencethemorallawderivesitsobligation。
Itmustbefreelyadmittedthatthereisasortofcircleherefromwhichitseemsimpossibletoescape。Intheorderofefficientcausesweassumeourselvesfree，inorderthatintheorderofendswemayconceiveourselvesassubjecttomorallaws：andweafterwardsconceiveourselvesassubjecttotheselaws，becausewehaveattributedtoourselvesfreedomofwill：forfreedomandself—legislationofwillarebothautonomyand，therefore，arereciprocalconceptions，andforthisveryreasononemustnotbeusedtoexplaintheotherorgivethereasonofit，butatmostonlylogicalpurposestoreduceapparentlydifferentnotionsofthesameobjecttoonesingleconcept（aswereducedifferentfractionsofthesamevaluetothelowestterms）。
Oneresourceremainstous，namely，toinquirewhetherwedonotoccupydifferentpointsofviewwhenbymeansoffreedomwethinkourselvesascausesefficientapriori，andwhenweformourconceptionofourselvesfromouractionsaseffectswhichweseebeforeoureyes。
Itisaremarkwhichneedsnosubtlereflectiontomake，butwhichwemayassumethateventhecommonestunderstandingcanmake，althoughitbeafteritsfashionbyanobscurediscernmentofjudgementwhichitcallsfeeling，thatallthe\"ideas\"thatcometousinvoluntarily（asthoseofthesenses）donotenableustoknowobjectsotherwisethanastheyaffectus；sothatwhattheymaybeinthemselvesremainsunknowntous，andconsequentlythatasregards\"ideas\"ofthiskindevenwiththeclosestattentionandclearnessthattheunderstandingcanapplytothem，wecanbythemonlyattaintotheknowledgeofappearances，nevertothatofthingsinthemselves。Assoonasthisdistinctionhasoncebeenmade（perhapsmerelyinconsequenceofthedifferenceobservedbetweentheideasgivenusfromwithout，andinwhichwearepassive，andthosethatweproducesimplyfromourselves，andinwhichweshowourownactivity），thenitfollowsofitselfthatwemustadmitandassumebehindtheappearancesomethingelsethatisnotanappearance，namely，thethingsinthemselves；althoughwemustadmitthatastheycanneverbeknowntousexceptastheyaffectus，wecancomenonearertothem，norcanweeverknowwhattheyareinthemselves。Thismustfurnishadistinction，howevercrude，betweenaworldofsenseandtheworldofunderstanding，ofwhichtheformermaybedifferentaccordingtothedifferenceofthesensuousimpressionsinvariousobservers，whilethesecondwhichisitsbasisalwaysremainsthesame，Evenastohimself，amancannotpretendtoknowwhatheisinhimselffromtheknowledgehehasbyinternalsensation。Forashedoesnotasitwerecreatehimself，anddoesnotcomebytheconceptionofhimselfaprioributempirically，itnaturallyfollowsthathecanobtainhisknowledgeevenofhimselfonlybytheinnersenseand，consequently，onlythroughtheappearancesofhisnatureandthewayinwhichhisconsciousnessisaffected。Atthesametimebeyondthesecharacteristicsofhisownsubject，madeupofmereappearances，hemustnecessarilysupposesomethingelseastheirbasis，namely，hisego，whateveritscharacteristicsinitselfmaybe。Thusinrespecttomereperceptionandreceptivityofsensationshemustreckonhimselfasbelongingtotheworldofsense；butinrespectofwhatevertheremaybeofpureactivityinhim（thatwhichreachesconsciousnessimmediatelyandnotthroughaffectingthesenses），hemustreckonhimselfasbelongingtotheintellectualworld，ofwhich，however，hehasnofurtherknowledge。Tosuchaconclusionthereflectingmanmustcomewithrespecttoallthethingswhichcanbepresentedtohim：itisprobablytobemetwitheveninpersonsofthecommonestunderstanding，who，asiswellknown，areverymuchinclinedtosupposebehindtheobjectsofthesensessomethingelseinvisibleandactingofitself。Theyspoilit，however，bypresentlysensualizingthisinvisibleagain；thatistosay，wantingtomakeitanobjectofintuition，sothattheydonotbecomeawhitthewiser。
Nowmanreallyfindsinhimselfafacultybywhichhedistinguisheshimselffromeverythingelse，evenfromhimselfasaffectedbyobjects，andthatisreason。Thisbeingpurespontaneityisevenelevatedabovetheunderstanding。Foralthoughthelatterisaspontaneityanddoesnot，likesense，merelycontainintuitionsthatarisewhenweareaffectedbythings（andarethereforepassive），yetitcannotproducefromitsactivityanyotherconceptionsthanthosewhichmerelyservetobringtheintuitionsofsenseunderrulesand，thereby，tounitetheminoneconsciousness，andwithoutthisuseofthesensibilityitcouldnotthinkatall；whereas，onthecontrary，reasonshowssopureaspontaneityinthecaseofwhatI
callideas[idealconceptions]thatittherebyfartranscendseverythingthatthesensibilitycangiveit，andexhibitsitsmostimportantfunctionindistinguishingtheworldofsensefromthatofunderstanding，andtherebyprescribingthelimitsoftheunderstandingitself。
Forthisreasonarationalbeingmustregardhimselfquaintelligence（notfromthesideofhislowerfaculties）asbelongingnottotheworldofsense，buttothatofunderstanding；hencehehastwopointsofviewfromwhichhecanregardhimself，andrecogniselawsoftheexerciseofhisfaculties，andconsequentlyofallhisactions：first，sofarashebelongstotheworldofsense，hefindshimselfsubjecttolawsofnature（heteronomy）；secondly，asbelongingtotheintelligibleworld，underlawswhichbeingindependentofnaturehavetheirfoundationnotinexperiencebutinreasonalone。
Asarationalbeing，andconsequentlybelongingtotheintelligibleworld，mancanneverconceivethecausalityofhisownwillotherwisethanonconditionoftheideaoffreedom，forindependenceofthedeterminatecausesofthesensibleworld（anindependencewhichreasonmustalwaysascribetoitself）isfreedom。
Nowtheideaoffreedomisinseparablyconnectedwiththeconceptionofautonomy，andthisagainwiththeuniversalprincipleofmoralitywhichisideallythefoundationofallactionsofrationalbeings，justasthelawofnatureisofallphenomena。
Nowthesuspicionisremovedwhichweraisedabove，thattherewasalatentcircleinvolvedinourreasoningfromfreedomtoautonomy，andfromthistothemorallaw，viz。：thatwelaiddowntheideaoffreedombecauseofthemorallawonlythatwemightafterwardsinturninferthelatterfromfreedom，andthatconsequentlywecouldassignnoreasonatallforthislaw，butcouldonly[present]itasapetitioprincipiiwhichwelldisposedmindswouldgladlyconcedetous，butwhichwecouldneverputforwardasaprovableproposition。
Fornowweseethat，whenweconceiveourselvesasfree，wetransferourselvesintotheworldofunderstandingasmembersofitandrecognisetheautonomyofthewillwithitsconsequence，morality；
whereas，ifweconceiveourselvesasunderobligation，weconsiderourselvesasbelongingtotheworldofsenseandatthesametimetotheworldofunderstanding。
HowisaCategoricalImperativePossible？
Everyrationalbeingreckonshimselfquaintelligenceasbelongingtotheworldofunderstanding，anditissimplyasanefficientcausebelongingtothatworldthathecallshiscausalityawill。Ontheothersideheisalsoconsciousofhimselfasapartoftheworldofsenseinwhichhisactions，whicharemereappearances[phenomena]ofthatcausality，aredisplayed；wecannot，however，discernhowtheyarepossiblefromthiscausalitywhichwedonotknow；butinsteadofthat，theseactionsasbelongingtothesensibleworldmustbeviewedasdeterminedbyotherphenomena，namely，desiresandinclinations。IfthereforeIwereonlyamemberoftheworldofunderstanding，thenallmyactionswouldperfectlyconformtotheprincipleofautonomyofthepurewill；ifIwereonlyapartoftheworldofsense，theywouldnecessarilybeassumedtoconformwhollytothenaturallawofdesiresandinclinations，inotherwords，totheheteronomyofnature。（Theformerwouldrestonmoralityasthesupremeprinciple，thelatteronhappiness。）Since，however，theworldofunderstandingcontainsthefoundationoftheworldofsense，andconsequentlyofitslawsalso，andaccordinglygivesthelawtomywill（whichbelongswhollytotheworldofunderstanding）directly，andmustbeconceivedasdoingso，itfollowsthat，althoughontheonesideImustregardmyselfasabeingbelongingtotheworldofsense，yetontheothersideImustrecognizemyselfassubjectasanintelligencetothelawoftheworldofunderstanding，i。e。，toreason，whichcontainsthislawintheideaoffreedom，andthereforeassubjecttotheautonomyofthewill：
consequentlyImustregardthelawsoftheworldofunderstandingasimperativesformeandtheactionswhichconformtothemasduties。
Andthuswhatmakescategoricalimperativespossibleisthis，thattheideaoffreedommakesmeamemberofanintelligibleworld，inconsequenceofwhich，ifIwerenothingelse，allmyactionswouldalwaysconformtotheautonomyofthewill；butasIatthesametimeintuitemyselfasamemberoftheworldofsense，theyoughtsotoconform，andthiscategorical\"ought\"impliesasyntheticaprioriproposition，inasmuchasbesidesmywillasaffectedbysensibledesiresthereisaddedfurthertheideaofthesamewillbutasbelongingtotheworldoftheunderstanding，pureandpracticalofitself，whichcontainsthesupremeconditionaccordingtoreasonoftheformerwill；preciselyastotheintuitionsofsensethereareaddedconceptsoftheunderstandingwhichofthemselvessignifynothingbutregularformingeneralandinthiswaysyntheticaprioripropositionsbecomepossible，onwhichallknowledgeofphysicalnaturerests。
Thepracticaluseofcommonhumanreasonconfirmsthisreasoning。
Thereisnoone，noteventhemostconsummatevillain，providedonlythatbeisotherwiseaccustomedtotheuseofreason，who，whenwesetbeforehimexamplesofhonestyofpurpose，ofsteadfastnessinfollowinggoodmaxims，ofsympathyandgeneralbenevolence（evencombinedwithgreatsacrificesofadvantagesandcomfort），doesnotwishthathemightalsopossessthesequalities。Onlyonaccountofhisinclinationsandimpulseshecannotattainthisinhimself，butatthesametimehewishestobefreefromsuchinclinationswhichareburdensometohimself。Heprovesbythisthathetransfershimselfinthoughtwithawillfreefromtheimpulsesofthesensibilityintoanorderofthingswhollydifferentfromthatofhisdesiresinthefieldofthesensibility；sincehecannotexpecttoobtainbythatwishanygratificationofhisdesires，noranypositionwhichwouldsatisfyanyofhisactualorsupposableinclinations（forthiswoulddestroythepre—eminenceoftheveryideawhichwreststhatwishfromhim）：hecanonlyexpectagreaterintrinsicworthofhisownperson。Thisbetterperson，however，heimagineshimselftobewhenbetransfershimselftothepointofviewofamemberoftheworldoftheunderstanding，towhichheisinvoluntarilyforcedbytheideaoffreedom，i。e。，ofindependenceondeterminingcausesoftheworldofsense；andfromthispointofviewheisconsciousofagoodwill，whichbyhisownconfessionconstitutesthelawforthebadwillthathepossessesasamemberoftheworldofsense—alawwhoseauthorityherecognizeswhiletransgressingit。Whathemorally\"ought\"isthenwhathenecessarily\"would，\"asamemberoftheworldoftheunderstanding，andisconceivedbyhimasan\"ought\"onlyinasmuchashelikewiseconsidershimselfasamemberoftheworldofsense。
OftheExtremeLimitsofallPracticalPhilosophy。
Allmenattributetothemselvesfreedomofwill。Hencecomealljudgementsuponactionsasbeingsuchasoughttohavebeendone，althoughtheyhavenotbeendone。However，thisfreedomisnotaconceptionofexperience，norcanitbeso，sinceitstillremains，eventhoughexperienceshowsthecontraryofwhatonsuppositionoffreedomareconceivedasitsnecessaryconsequences。Ontheothersideitisequallynecessarythateverythingthattakesplaceshouldbefixedlydeterminedaccordingtolawsofnature。Thisnecessityofnatureislikewisenotanempiricalconception，justforthisreason，thatitinvolvesthemotionofnecessityandconsequentlyofaprioricognition。Butthisconceptionofasystemofnatureisconfirmedbyexperience；anditmustevenbeinevitablypresupposedifexperienceitselfistobepossible，thatis，aconnectedknowledgeoftheobjectsofsenserestingongenerallaws。Thereforefreedomisonlyanideaofreason，anditsobjectiverealityinitselfisdoubtful；whilenatureisaconceptoftheunderstandingwhichproves，andmustnecessarilyprove，itsrealityinexamplesofexperience。
Therearisesfromthisadialecticofreason，sincethefreedomattributedtothewillappearstocontradictthenecessityofnature，andplacedbetweenthesetwowaysreasonforspeculativepurposesfindstheroadofphysicalnecessitymuchmorebeatenandmoreappropriatethanthatoffreedom；yetforpracticalpurposesthenarrowfootpathoffreedomistheonlyoneonwhichitispossibletomakeuseofreasoninourconduct；henceitisjustasimpossibleforthesubtlestphilosophyasforthecommonestreasonofmentoargueawayfreedom。Philosophymustthenassumethatnorealcontradictionwillbefoundbetweenfreedomandphysicalnecessityofthesamehumanactions，foritcannotgiveuptheconceptionofnatureanymorethanthatoffreedom。
Nevertheless，eventhoughweshouldneverbeabletocomprehendhowfreedomispossible，wemustatleastremovethisapparentcontradictioninaconvincingmanner。Forifthethoughtoffreedomcontradictseitheritselfornature，whichisequallynecessary，itmustincompetitionwithphysicalnecessitybeentirelygivenup。
Itwould，however，beimpossibletoescapethiscontradictionifthethinkingsubject，whichseemstoitselffree，conceiveditselfinthesamesenseorintheverysamerelationwhenitcallsitselffreeaswheninrespectofthesameactionitassumesitselftobesubjecttothelawofnature。Henceitisanindispensableproblemofspeculativephilosophytoshowthatitsillusionrespectingthecontradictionrestsonthis，thatwethinkofmaninadifferentsenseandrelationwhenwecallhimfreeandwhenweregardhimassubjecttothelawsofnatureasbeingpartandparcelofnature。Itmustthereforeshowthatnotonlycanboththeseverywellco—exist，butthatbothmustbethoughtasnecessarilyunitedinthesamesubject，sinceotherwisenoreasoncouldbegivenwhyweshouldburdenreasonwithanideawhich，thoughitmaypossiblywithoutcontradictionbereconciledwithanotherthatissufficientlyestablished，yetentanglesusinaperplexitywhichsorelyembarrassesreasoninitstheoreticemployment。Thisduty，however，belongsonlytospeculativephilosophy。Thephilosopherthenhasnooptionwhetherhewillremovetheapparentcontradictionorleaveituntouched；forinthelattercasethetheoryrespectingthiswouldbebonumvacans，intothepossessionofwhichthefatalistwouldhavearighttoenterandchaseallmoralityoutofitssupposeddomainasoccupyingitwithouttitle。
Wecannothoweverasyetsaythatwearetouchingtheboundsofpracticalphilosophy。Forthesettlementofthatcontroversydoesnotbelongtoit；itonlydemandsfromspeculativereasonthatitshouldputanendtothediscordinwhichitentanglesitselfintheoreticalquestions，sothatpracticalreasonmayhaverestandsecurityfromexternalattackswhichmightmakethegrounddebatableonwhichitdesirestobuild。
Theclaimstofreedomofwillmadeevenbycommonreasonarefoundedontheconsciousnessandtheadmittedsuppositionthatreasonisindependentofmerelysubjectivelydeterminedcauseswhichtogetherconstitutewhatbelongstosensationonlyandwhichconsequentlycomeunderthegeneraldesignationofsensibility。Manconsideringhimselfinthiswayasanintelligenceplaceshimselftherebyinadifferentorderofthingsandinarelationtodetermininggroundsofawhollydifferentkindwhenontheonehandhethinksofhimselfasanintelligenceendowedwithawill，andconsequentlywithcausality，andwhenontheotherheperceiveshimselfasaphenomenonintheworldofsense（ashereallyisalso），andaffirmsthathiscausalityissubjecttoexternaldeterminationaccordingtolawsofnature。Nowhesoonbecomesawarethatbothcanholdgood，nay，mustholdgoodatthesametime。Forthereisnotthesmallestcontradictioninsayingthatathinginappearance（belongingtotheworldofsense）issubjecttocertainlaws，ofwhichtheverysameasathingorbeinginitselfisindependent，andthathemustconceiveandthinkofhimselfinthistwofoldway，restsastothefirstontheconsciousnessofhimselfasanobjectaffectedthroughthesenses，andastothesecondontheconsciousnessofhimselfasanintelligence，i。e。，asindependentonsensibleimpressionsintheemploymentofhisreason（inotherwordsasbelongingtotheworldofunderstanding）。
Henceitcomestopassthatmanclaimsthepossessionofawillwhichtakesnoaccountofanythingthatcomesundertheheadofdesiresandinclinationsand，onthecontrary，conceivesactionsaspossibletohim，nay，evenasnecessarywhichcanonlybedonebydisregardingalldesiresandsensibleinclinations。Thecausalityofsuchactionsliesinhimasanintelligenceandinthelawsofeffectsandactions[whichdepend]ontheprinciplesofanintelligibleworld，ofwhichindeedheknowsnothingmorethanthatinitpurereasonaloneindependentofsensibilitygivesthelaw；moreoversinceitisonlyinthatworld，asanintelligence，thatheishisproperself（beingasmanonlytheappearanceofhimself），thoselawsapplytohimdirectlyandcategorically，sothattheincitementsofinclinationsandappetites（inotherwordsthewholenatureoftheworldofsense）cannotimpairthelawsofhisvolitionasanintelligence。Nay，hedoesnotevenholdhimselfresponsiblefortheformerorascribethemtohisproperself，i。e。，hiswill：heonlyascribestohiswillanyindulgencewhichhemightyieldthemifheallowedthemtoinfluencehismaximstotheprejudiceoftherationallawsofthewill。
Whenpracticalreasonthinksitselfintoaworldofunderstanding，itdoesnottherebytranscenditsownlimits，asitwouldifittriedtoenteritbyintuitionorsensation。Theformerisonlyanegativethoughtinrespectoftheworldofsense，whichdoesnotgiveanylawstoreasonindeterminingthewillandispositiveonlyinthissinglepointthatthisfreedomasanegativecharacteristicisatthesametimeconjoinedwitha（positive）facultyandevenwithacausalityofreason，whichwedesignateawill，namelyafacultyofsoactingthattheprincipleoftheactionsshallconformtotheessentialcharacterofarationalmotive，i。e。，theconditionthatthemaximhaveuniversalvalidityasalaw。Butwereittoborrowanobjectofwill，thatis，amotive，fromtheworldofunderstanding，thenitwouldoverstepitsboundsandpretendtobeacquaintedwithsomethingofwhichitknowsnothing。Theconceptionofaworldoftheunderstandingisthenonlyapointofviewwhichreasonfindsitselfcompelledtotakeoutsidetheappearancesinordertoconceiveitselfaspractical，whichwouldnotbepossibleiftheinfluencesofthesensibilityhadadeterminingpoweronman，butwhichisnecessaryunlessheistobedeniedtheconsciousnessofhimselfasanintelligenceand，consequently，asarationalcause，energizingbyreason，thatis，operatingfreely。Thisthoughtcertainlyinvolvestheideaofanorderandasystemoflawsdifferentfromthatofthemechanismofnaturewhichbelongstothesensibleworld；anditmakestheconceptionofanintelligibleworldnecessary（thatistosay，thewholesystemofrationalbeingsasthingsinthemselves）。Butitdoesnotintheleastauthorizeustothinkofitfurtherthanastoitsformalconditiononly，thatis，theuniversalityofthemaximsofthewillaslaws，andconsequentlytheautonomyofthelatter，whichaloneisconsistentwithitsfreedom；
whereas，onthecontrary，alllawsthatrefertoadefiniteobjectgiveheteronomy，whichonlybelongstolawsofnatureandcanonlyapplytothesensibleworld。
Butreasonwouldoverstepallitsboundsifitundertooktoexplainhowpurereasoncanbepractical，whichwouldbeexactlythesameproblemastoexplainhowfreedomispossible。
Forwecanexplainnothingbutthatwhichwecanreducetolaws，theobjectofwhichcanbegiveninsomepossibleexperience。Butfreedomisamereidea，theobjectiverealityofwhichcaninnowisebeshownaccordingtolawsofnature，andconsequentlynotinanypossibleexperience；andforthisreasonitcanneverbecomprehendedorunderstood，becausewecannotsupportitbyanysortofexampleoranalogy。Itholdsgoodonlyasanecessaryhypothesisofreasoninabeingthatbelievesitselfconsciousofawill，thatis，ofafacultydistinctfrommeredesire（namely，afacultyofdeterminingitselftoactionasanintelligence，inotherwords，bylawsofreasonindependentlyonnaturalinstincts）。Nowwheredeterminationaccordingtolawsofnatureceases，thereallexplanationceasesalso，andnothingremainsbutdefence，i。e。，theremovaloftheobjectionsofthosewhopretendtohaveseendeeperintothenatureofthings，andthereuponboldlydeclarefreedomimpossible。Wecanonlypointouttothemthatthesupposedcontradictionthattheyhavediscoveredinitarisesonlyfromthis，thatinordertobeabletoapplythelawofnaturetohumanactions，theymustnecessarilyconsidermanasanappearance：thenwhenwedemandofthemthattheyshouldalsothinkofhimquaintelligenceasathinginitself，theystillpersistinconsideringhiminthisrespectalsoasanappearance。Inthisviewitwouldnodoubtbeacontradictiontosupposethecausalityofthesamesubject（thatis，hiswill）tobewithdrawnfromallthenaturallawsofthesensibleworld。Butthiscontradictiondisappears，iftheywouldonlybethinkthemselvesandadmit，asisreasonable，thatbehindtheappearancestheremustalsolieattheirroot（althoughhidden）
thethingsinthemselves，andthatwecannotexpectthelawsofthesetobethesameasthosethatgoverntheirappearances。
Thesubjectiveimpossibilityofexplainingthefreedomofthewillisidenticalwiththeimpossibilityofdiscoveringandexplaininganinterest*whichmancantakeinthemorallaw。Neverthelesshedoesactuallytakeaninterestinit，thebasisofwhichinuswecallthemoralfeeling，whichsomehavefalselyassignedasthestandardofourmoraljudgement，whereasitmustratherbeviewedasthesubjectiveeffectthatthelawexercisesonthewill，theobjectiveprincipleofwhichisfurnishedbyreasonalone。
*Interestisthatbywhichreasonbecomespractical，i。e。，acausedeterminingthewill。Hencewesayofrationalbeingsonlythattheytakeaninterestinathing；irrationalbeingsonlyfeelsensualappetites。Reasontakesadirectinterestinactionthenonlywhentheuniversalvalidityofitsmaximsisalonesufficienttodeterminethewill。Suchaninterestaloneispure。Butifitcandeterminethewillonlybymeansofanotherobjectofdesireoronthesuggestionofaparticularfeelingofthesubject，thenreasontakesonlyanindirectinterestintheaction，and，asreasonbyitselfwithoutexperiencecannotdiscovereitherobjectsofthewilloraspecialfeelingactuatingit，thislatterinterestwouldonlybeempiricalandnotapurerationalinterest。Thelogicalinterestofreason（namely，toextenditsinsight）isneverdirect，butpresupposespurposesforwhichreasonisemployed。
Inorderindeedthatarationalbeingwhoisalsoaffectedthroughthesensesshouldwillwhatreasonalonedirectssuchbeingsthattheyoughttowill，itisnodoubtrequisitethatreasonshouldhaveapowertoinfuseafeelingofpleasureorsatisfactioninthefulfilmentofduty，thatistosay，thatitshouldhaveacausalitybywhichitdeterminesthesensibilityaccordingtoitsownprinciples。
Butitisquiteimpossibletodiscern，i。e。，tomakeitintelligibleapriori，howamerethought，whichitselfcontainsnothingsensible，canitselfproduceasensationofpleasureorpain；forthisisaparticularkindofcausalityofwhichasofeveryothercausalitywecandeterminenothingwhateverapriori；wemustonlyconsultexperienceaboutit。Butasthiscannotsupplyuswithanyrelationofcauseandeffectexceptbetweentwoobjectsofexperience，whereasinthiscase，althoughindeedtheeffectproducedlieswithinexperience，yetthecauseissupposedtobepurereasonactingthroughmereideaswhichoffernoobjecttoexperience，itfollowsthatforusmenitisquiteimpossibletoexplainhowandwhytheuniversalityofthemaximasalaw，thatis，morality，interests。Thisonlyiscertain，thatitisnotbecauseitinterestsusthatithasvalidityforus（forthatwouldbeheteronomyanddependenceofpracticalreasononsensibility，namely，onafeelingasitsprinciple，inwhichcaseitcouldnevergivemorallaws），butthatitinterestsusbecauseitisvalidforusasmen，inasmuchasithaditssourceinourwillasintelligences，inotherwords，inourproperself，andwhatbelongstomereappearanceisnecessarilysubordinatedbyreasontothenatureofthethinginitself。
Thequestionthen，\"Howacategoricalimperativeispossible，\"canbeansweredtothisextent，thatwecanassigntheonlyhypothesisonwhichitispossible，namely，theideaoffreedom；andwecanalsodiscernthenecessityofthishypothesis，andthisissufficientforthepracticalexerciseofreason，thatis，fortheconvictionofthevalidityofthisimperative，andhenceofthemorallaw；buthowthishypothesisitselfispossiblecanneverbediscernedbyanyhumanreason。Onthehypothesis，however，thatthewillofanintelligenceisfree，itsautonomy，astheessentialformalconditionofitsdetermination，isanecessaryconsequence。
Moreover，thisfreedomofwillisnotmerelyquitepossibleasahypothesis（notinvolvinganycontradictiontotheprincipleofphysicalnecessityintheconnexionofthephenomenaofthesensibleworld）asspeculativephilosophycanshow：butfurther，arationalbeingwhoisconsciousofcausalitythroughreason，thatistosay，ofawill（distinctfromdesires），mustofnecessitymakeitpractically，thatis，inidea，theconditionofallhisvoluntaryactions。Buttoexplainhowpurereasoncanbeofitselfpracticalwithouttheaidofanyspringofactionthatcouldbederivedfromanyothersource，i。e。，howthemereprincipleoftheuniversalvalidityofallitsmaximsaslaws（whichwouldcertainlybetheformofapurepracticalreason）canofitselfsupplyaspring，withoutanymatter（object）ofthewillinwhichonecouldantecedentlytakeanyinterest；andhowitcanproduceaninterestwhichwouldbecalledpurelymoral；orinotherwords，howpurereasoncanbepractical—
toexplainthisisbeyondthepowerofhumanreason，andallthelabourandpainsofseekinganexplanationofitarelostanItisjustthesameasifIsoughttofindouthowfreedomitselfispossibleasthecausalityofawill。ForthenIquitthegroundofphilosophicalexplanation，andIhavenoothertogoupon。Imightindeedrevelintheworldofintelligenceswhichstillremainstome，butalthoughIhaveanideaofitwhichiswellfounded，yetI
havenottheleastknowledgeofit，noranIeverattaintosuchknowledgewithalltheeffortsofmynaturalfacultyofreason。ItsignifiesonlyasomethingthatremainsoverwhenIhaveeliminatedeverythingbelongingtotheworldofsensefromtheactuatingprinciplesofmywill，servingmerelytokeepinboundstheprincipleofmotivestakenfromthefieldofsensibility；fixingitslimitsandshowingthatitdoesnotcontainallinallwithinitself，butthatthereismorebeyondit；butthissomethingmoreI
knownofurther。Ofpurereasonwhichframesthisideal，thereremainsaftertheabstractionofallmatter，i。e。，knowledgeofobjects，nothingbuttheform，namely，thepracticallawoftheuniversalityofthemaxims，andinconformitywiththisconceptionofreasoninreferencetoapureworldofunderstandingasapossibleefficientcause，thatisacausedeterminingthewill。Theremustherebeatotalabsenceofsprings；unlessthisideaofanintelligibleworldisitselfthespring，orthatinwhichreasonprimarilytakesaninterest；buttomakethisintelligibleispreciselytheproblemthatwecannotsolve。
Herenowistheextremelimitofallmoralinquiry，anditisofgreatimportancetodetermineitevenonthisaccount，inorderthatreasonmaynotontheoneband，totheprejudiceofmorals，seekaboutintheworldofsenseforthesuprememotiveandaninterestcomprehensiblebutempirical；andontheotherhand，thatitmaynotimpotentlyflapitswingswithoutbeingabletomoveinthe（forit）
emptyspaceoftranscendentconceptswhichwecalltheintelligibleworld，andsoloseitselfamidstchimeras。Fortherest，theideaofapureworldofunderstandingasasystemofallintelligences，andtowhichweourselvesasrationalbeingsbelong（althoughwearelikewiseontheothersidemembersofthesensibleworld），thisremainsalwaysausefulandlegitimateideaforthepurposesofrationalbelief，althoughallknowledgestopsatitsthreshold，useful，namely，toproduceinusalivelyinterestinthemorallawbymeansofthenobleidealofauniversalkingdomofendsinthemselves（rationalbeings），towhichwecanbelongasmembersthenonlywhenwecarefullyconductourselvesaccordingtothemaximsoffreedomasiftheywerelawsofnature。
ConcludingRemarkThespeculativeemploymentofreasonwithrespecttonatureleadstotheabsolutenecessityofsomesupremecauseoftheworld：thepracticalemploymentofreasonwithaviewtofreedomleadsalsotoabsolutenecessity，butonlyofthelawsoftheactionsofarationalbeingassuch。Nowitisanessentialprincipleofreason，howeveremployed，topushitsknowledgetoaconsciousnessofitsnecessity（withoutwhichitwouldnotberationalknowledge）。Itis，however，anequallyessentialrestrictionofthesamereasonthatitcanneitherdiscernthenecessityofwhatisorwhathappens，norofwhatoughttohappen，unlessaconditionissupposedonwhichitisorhappensoroughttohappen。Inthisway，however，bytheconstantinquiryforthecondition，thesatisfactionofreasonisonlyfurtherandfurtherpostponed。Henceitunceasinglyseekstheunconditionallynecessaryandfindsitselfforcedtoassumeit，althoughwithoutanymeansofmakingitcomprehensibletoitself，happyenoughifonlyitcandiscoveraconceptionwhichagreeswiththisassumption。Itisthereforenofaultinourdeductionofthesupremeprincipleofmorality，butanobjectionthatshouldbemadetohumanreasoningeneral，thatitcannotenableustoconceivetheabsolutenecessityofanunconditionalpracticallaw（suchasthecategoricalimperativemustbe）。Itcannotbeblamedforrefusingtoexplainthisnecessitybyacondition，thatistosay，bymeansofsomeinterestassumedasabasis，sincethelawwouldthenceasetobeasupremelawofreason。Andthuswhilewedonotcomprehendthepracticalunconditionalnecessityofthemoralimperative，weyetcomprehenditsincomprehensibility，andthisisallthatcanbefairlydemandedofaphilosophywhichstrivestocarryitsprinciplesuptotheverylimitofhumanreason。