Underthewill，takengenerally，maybeincludedthevolitionalactofchoice，andalsothemereactofwish，insofarasreasonmaydeterminethefacultyofdesireinitsactivity。Theactofchoicethatcanbedeterminedbypurereasonconstitutestheactoffree—will。Thatactwhichisdeterminableonlybyinclinationasasensuousimpulseorstimuluswouldbeirrationalbrutechoice（arbitriumbrutum）。Thehumanactofchoice，however，ashuman，isinfactaffectedbysuchimpulsesorstimuli，butisnotdeterminedbythem;anditis，therefore，notpureinitselfwhentakenapartfromtheacquiredhabitofdeterminationbyreason。Butitmaybedeterminedtoactionbythepurewill。Thefreedomoftheactofvolitionalchoiceisitsindependenceofbeingdeterminedbysensuousimpulsesorstimuli。Thisformsthenegativeconceptionofthefree—will。Thepositiveconceptionoffreedomisgivenbythefactthatthewillisthecapabilityofpurereasontobepracticalofitself。Butthisisnotpossibleotherwisethanbythemaximofeveryactionbeingsubjectedtotheconditionofbeingpracticableasauniversallaw。Appliedaspurereasontotheactofchoice，andconsideredapartfromitsobjects，itmayberegardedasthefacultyofprinciples;and，inthisconnection，itisthesourceofpracticalprinciples。Henceitistobeviewedasalaw—givingfaculty。Butasthematerialuponwhichtoconstructalawisnotfurnishedtoit，itcanonlymaketheformoftheformofthemaximoftheactofwill，insofarasitisavailableasauniversallaw，thesupremelawanddeterminingprincipleofthewill。Andasthemaxims，orrulesofhumanactionderivedfromsubjectivecauses，donotofthemselvesnecessarilyagreewiththosethatareobjectiveanduniversal，reasoncanonlyprescribethissupremelawasanabsoluteimperativeofprohibitionorcommand。
　　Thelawsoffreedom，asdistinguishedfromthelawsofnature，aremorallaws。Sofarastheyreferonlytoexternalactionsandtheirlawfulness，theyarecalledjuridical;butiftheyalsorequirethat，aslaws，theyshallthemselvesbethedeterminingprinciplesofouractions，theyareethical。Theagreementofanactionwithjuridicallawsisitslegality;theagreementofanactionwithethicallawsisitsmorality。Thefreedomtowhichtheformerlawsrefer，canonlybefreedominexternalpractice;butthefreedomtowhichthelatterlawsreferisfreedomintheinternalaswellastheexternalexerciseoftheactivityofthewillinsofarasitisdeterminedbylawsofreason。So，intheoreticalphilosophy，itissaidthatonlytheobjectsoftheexternalsensesareinspace，butalltheobjectsbothofinternalandexternalsenseareintime;
　　becausetherepresentationsofboth，asbeingrepresentations，sofarbelongalltotheinternalsense。Inlikemanner，whetherfreedomisviewedinreferencetotheexternalortheinternalactionofthewill，itslaws，aspurepracticallawsofreasonforthefreeactivityofthewillgenerally，mustatthesametimebeinnerprinciplesforitsdetermination，althoughtheymaynotalwaysbeconsideredinthisrelation。
　　II。THEIDEAANDNECESSITYOFAMETAPHYSICOFMORALS。
　　IthasbeenshowninTheMetaphysicalPrinciplesoftheScienceofNaturethattheremustbeprinciplesaprioriforthenaturalsciencethathastodealwiththeobjectsoftheexternalsenses。
　　Anditwasfurthershownthatitispossible，andevennecessary，toformulateasystemoftheseprinciplesunderthenameofa"metaphysicalscienceofnature，"asapreliminarytoexperimentalphysicsregardedasnaturalscienceappliedtoparticularobjectsofexperience。Butthislatterscience，ifcarebetakentokeepitsgeneralizationsfreefromerror，mayacceptmanypropositionsasuniversalontheevidenceofexperience，althoughiftheterm"universal"betakeninitsstrictsense，thesewouldnecessarilyhavetobededucedbythemetaphysicalsciencefromprinciplesapriori。
　　ThusNewtonacceptedtheprincipleoftheequalityofactionandreactionasestablishedbyexperience，andyetheextendeditasauniversallawoverthewholeofmaterialnature。Thechemistsgoevenfarther，groundingtheirmostgenerallawsregardingthecombinationanddecompositionofthematerialsofbodieswhollyuponexperience;andyettheytrustsocompletelytotheuniversalityandnecessityofthoselawsthattheyhavenoanxietyastoanyerrorbeingfoundinpropositionsfoundeduponexperimentsconductedinaccordancewiththem。
　　Butitisotherwisewithmorallaws。These，incontradistinctiontonaturallaws，areonlyvalidaslaws，insofarastheycanberationallyestablishedaprioriandcomprehendedasnecessary。Infact，conceptionsandjudgementsregardingourselvesandourconducthavenomoralsignificance，iftheycontainonlywhatmaybelearnedfromexperience;andwhenanyoneis，sotospeak，misledintomakingamoralprincipleoutofanythingderivedfromthislattersource，heisalreadyindangeroffallingintothecoarsestandmostfatalerrors。
　　Ifthephilosophyofmoralswerenothingmorethanatheoryofhappiness（eudaemonism），itwouldbeabsurdtosearchafterprinciplesaprioriasafoundationforit。Forhoweverplausibleitmaysoundtosaythatreason，evenpriortoexperience，cancomprehendbywhatmeanswemayattaintoalastingenjoymentoftherealpleasuresoflife，yetallthatistaughtonthissubjectaprioriiseithertautological，orisassumedwhollywithoutfoundation。Itisonlyexperiencethatcanshowwhatwillbringusenjoyment。Thenaturalimpulsesdirectedtowardsnourishment，thesexualinstinct，orthetendencytorestandmotion，aswellasthehigherdesiresofhonour，theacquisitionofknowledge，andsuchlike，asdevelopedwithournaturalcapacities，arealonecapableofshowinginwhatthoseenjoymentsaretobefound。And，further，theknowledgethusacquiredisavailableforeachindividualmerelyinhisownway;anditisonlythushecanlearnthemeansbywhichbehastoseekthoseenjoyments。Allspeciousrationalizingapriori，inthisconnection，isnothingatbottombutcarryingfactsofexperienceuptogeneralizationsbyinduction（secundumprincipiageneralianonuniversalia）;andthegeneralitythusattainedisstillsolimitedthatnumberlessexceptionsmustbeallowedtoeveryindividualinorderthathemayadaptthechoiceofhismodeoflifetohisownParticularinclinationsandhiscapacityforpleasure。And，afterall，theindividualhasreallytoacquirehisprudenceatthecostofhisownsufferingorthatofhisneighborstheformButitisquiteotherwisewiththeprinciplesofmorality。Theylaydowncommandsforeveryonewithoutregardtohisparticularinclinations，andmerelybecauseandsofarasheisfree，andhasapracticalreason。Instructioninthelawsofmoralityisnotdrawnfromobservationofoneselforofouranimalnature，norfromperceptionofthecourseoftheworldinregardtowhathappens，orhowmenact。*Butreasoncommandshowweoughttoact，evenalthoughnoexampleofsuchactionweretobefound;nordoesreasongiveanyregardtotheadvantagewhichmayaccruetousbysoacting，andwhichexperiencecouldaloneactuallyshow。For，althoughreasonallowsustoseekwhatisforouradvantageineverypossibleway，andalthough，foundingupontheevidenceofexperience，itmayfurtherpromisethatgreateradvantageswillprobablyfollowontheaveragefromtheobservanceofhercommandsthanfromtheirtransgression，especiallyifprudenceguidestheconduct，yettheauthorityofherpreceptsascommandsdoesnotrestonsuchconsiderations。Theyareusedbyreasononlyascounsels，andbywayofacounterpoiseagainstseductionstoanoppositecourse，whenadjustingbeforehandtheequilibriumofapartialbalanceinthesphereofpracticaljudgement，inordertherebytosecurethedecisionofthisjudgement，accordingtothedueweightoftheaprioriprinciplesofapurepracticalreason。