application　the　content　of　the　categorical　imperative；　which　must
  contain　the　principle　of　all　duty　if　there　is　such　a　thing　at　all。
  We　have　not　yet；　however；　advanced　so　far　as　to　prove　a　priori　that
  there　actually　is　such　an　imperative；　that　there　is　a　practical　law
  which　commands　absolutely　of　itself　and　without　any　other　impulse；　and
  that　the　following　of　this　law　is　duty。
  With　the　view　of　attaining　to　this；　it　is　of　extreme　importance　to
  remember　that　we　must　not　allow　ourselves　to　think　of　deducing　the
  reality　of　this　principle　from　the　particular　attributes　of　human
  nature。　For　duty　is　to　be　a　practical；　unconditional　necessity　of
  action；　it　must　therefore　hold　for　all　rational　beings　（to　whom　an
  imperative　can　apply　at　all）；　and　for　this　reason　only　be　also　a　law
  for　all　human　wills。　On　the　contrary；　whatever　is　deduced　from　the
  particular　natural　characteristics　of　humanity；　from　certain
  feelings　and　propensions；　nay；　even；　if　possible；　from　any
  particular　tendency　proper　to　human　reason；　and　which　need　not
  necessarily　hold　for　the　will　of　every　rational　being；　this　may　indeed
  supply　us　with　a　maxim；　but　not　with　a　law；　with　a　subjective
  principle　on　which　we　may　have　a　propension　and　inclination　to　act；
  but　not　with　an　objective　principle　on　which　we　should　be　enjoined
  to　act；　even　though　all　our　propensions；　inclinations；　and　natural
  dispositions　were　opposed　to　it。　In　fact；　the　sublimity　and
  intrinsic　dignity　of　the　command　in　duty　are　so　much　the　more　evident；
  the　less　the　subjective　impulses　favour　it　and　the　more　they　oppose
  it；　without　being　able　in　the　slightest　degree　to　weaken　the
  obligation　of　the　law　or　to　diminish　its　validity。
  Here　then　we　see　philosophy　brought　to　a　critical　position；　since　it
  has　to　be　firmly　fixed；　notwithstanding　that　it　has　nothing　to　support
  it　in　heaven　or　earth。　Here　it　must　show　its　purity　as　absolute
  director　of　its　own　laws；　not　the　herald　of　those　which　are
  whispered　to　it　by　an　implanted　sense　or　who　knows　what　tutelary
  nature。　Although　these　may　be　better　than　nothing；　yet　they　can
  never　afford　principles　dictated　by　reason；　which　must　have　their
  source　wholly　a　priori　and　thence　their　commanding　authority；
  expecting　everything　from　the　supremacy　of　the　law　and　the　due　respect
  for　it；　nothing　from　inclination；　or　else　condemning　the　man　to
  self…contempt　and　inward　abhorrence。
  Thus　every　empirical　element　is　not　only　quite　incapable　of　being　an
  aid　to　the　principle　of　morality；　but　is　even　highly　prejudicial　to
  the　purity　of　morals；　for　the　proper　and　inestimable　worth　of　an
  absolutely　good　will　consists　just　in　this；　that　the　principle　of
  action　is　free　from　all　influence　of　contingent　grounds；　which　alone
  experience　can　furnish。　We　cannot　too　much　or　too　often　repeat　our
  warning　against　this　lax　and　even　mean　habit　of　thought　which　seeks
  for　its　principle　amongst　empirical　motives　and　laws；　for　human　reason
  in　its　weariness　is　glad　to　rest　on　this　pillow；　and　in　a　dream　of
  sweet　illusions　（in　which；　instead　of　Juno；　it　embraces　a　cloud）　it
  substitutes　for　morality　a　bastard　patched　up　from　limbs　of　various
  derivation；　which　looks　like　anything　one　chooses　to　see　in　it；　only
  not　like　virtue　to　one　who　has　once　beheld　her　in　her　true　form。*
  *To　behold　virtue　in　her　proper　form　is　nothing　else　but　to
  contemplate　morality　stripped　of　all　admixture　of　sensible　things
  and　of　every　spurious　ornament　of　reward　or　self…love。　How　much　she
  then　eclipses　everything　else　that　appears　charming　to　the　affections；
  every　one　may　readily　perceive　with　the　least　exertion　of　his
  reason；　if　it　be　not　wholly　spoiled　for　abstraction。
  The　question　then　is　this：　〃Is　it　a　necessary　law　for　all　rational
  beings　that　they　should　always　judge　of　their　actions　by　maxims　of
  which　they　can　themselves　will　that　they　should　serve　as　universal
  laws？〃　If　it　is　so；　then　it　must　be　connected　（altogether　a　priori）
  with　the　very　conception　of　the　will　of　a　rational　being　generally。
  But　in　order　to　discover　this　connexion　we　must；　however
  reluctantly；　take　a　step　into　metaphysic；　although　into　a　domain　of　it
  which　is　distinct　from　speculative　philosophy；　namely；　the
  metaphysic　of　morals。　In　a　practical　philosophy；　where　it　is　not　the
  reasons　of　what　happens　that　we　have　to　ascertain；　but　the　laws　of
  what　ought　to　happen；　even　although　it　never　does；　i。e。；　objective
  practical　laws；　there　it　is　not　necessary　to　inquire　into　the
  reasons　why　anything　pleases　or　displeases；　how　the　pleasure　of　mere
  sensation　differs　from　taste；　and　whether　the　latter　is　distinct
  from　a　general　satisfaction　of　reason；　on　what　the　feeling　of　pleasure
  or　pain　rests；　and　how　from　it　desires　and　inclinations　arise；　and
  from　these　again　maxims　by　the　co…operation　of　reason：　for　all　this
  belongs　to　an　empirical　psychology；　which　would　constitute　the
  second　part　of　physics；　if　we　regard　physics　as　the　philosophy　of
  nature；　so　far　as　it　is　based　on　empirical　laws。　But　here　we　are
  concerned　with　objective　practical　laws　and；　consequently；　with　the
  relation　of　the　will　to　itself　so　far　as　it　is　determined　by　reason
  alone；　in　which　case　whatever　has　reference　to　anything　empirical　is
  necessarily　excluded；　since　if　reason　of　itself　alone　determines　the
  conduct　（and　it　is　the　possibility　of　this　that　we　are　now
  investigating）；　it　must　necessarily　do　so　a　priori。
  The　will　is　conceived　as　a　faculty　of　determining　oneself　to
  action　in　accordance　with　the　conception　of　certain　laws。　And　such　a
  faculty　can　be　found　only　in　rational　beings。　Now　that　which　serves
  the　will　as　the　objective　ground　of　its　self…determination　is　the　end；
  and；　if　this　is　assigned　by　reason　alone；　it　must　hold　for　all
  rational　beings。　On　the　other　hand；　that　which　merely　contains　the
  ground　of　possibility　of　the　action　of　which　the　effect　is　the　end；
  this　is　called　the　means。　The　subjective　ground　of　the　desire　is　the
  spring；　the　objective　ground　of　the　volition　is　the　motive；　hence
  the　distinction　between　subjective　ends　which　rest　on　springs；　and
  objective　ends　which　depend　on　motives　valid　for　every　rational　being。
  Practical　principles　are　formal　when　they　abstract　from　all　subjective
  ends；　they　are　material　when　they　assume　these；　and　therefore
  particular　springs　of　action。　The　ends　which　a　rational　being　proposes
  to　himself　at　pleasure　as　effects　of　his　actions　（material　ends）　are
  all　only　relative；　for　it　is　only　their　relation　to　the　particular
  desires　of　the　subject　that　gives　them　their　worth；　which　therefore
  cannot　furnish　principles　universal　and　necessary　for　all　rational
  beings　and　for　every　volition；　that　is　to　say　practical　laws。　Hence
  all　these　relative　ends　can　give　rise　only　to　hypothetical
  imperatives。
  Supposing；　however；　that　there　were　something　whose　existence　has　in
  itself　an　absolute　worth；　something　which；　being　an　end　in　itself；
  could　be　a　source　of　definite　laws；　then　in　this　and　this　alone
  would　lie　the　source　of　a　possible　categorical　imperative；　i。e。；　a
  practical　law。
  Now　I　say：　man　and　generally　any　rational　being　exists　as　an　end
  in　himself；　not　merely　as　a　means　to　be　arbitrarily　used　by　this　or
  that　will；　but　in　all　his　actions；　whether　they　concern　himself　or
  other　rational　beings；　must　be　always　regarded　at　the　same　time　as
  an　end。　All　objects　of　the　inclinations　have　only　a　conditional　worth；
  for　if　the　inclinations　and　the　wants　founded　on　them　did　not　exist；
  then　their　object　would　be　without　value。　But　the　inclinations；
  themselves　being　sources　of　want；　are　so　far　from　having　an　absolute
  worth　for　which　they　should　be　desired　that　on　the　contrary　it　must　be
  the　universal　wish　of　every　rational　being　to　be　wholly　free　from
  them。　Thus　the　worth　of　any　object　which　is　to　be　acquired　by　our
  action　is　always　conditional。　Beings　whose　existence　depends　not　on
  our　will　but　on　nature's；　have　nevertheless；　if　they　are　irrational
  beings；　only　a　relative　value　as　means；　and　are　therefore　called
  things；　rational　beings；　on　the　contrary；　are　called　persons；
  because　their　very　nature　points　them　out　as　ends　in　themselves；
  that　is　as　something　which　must　not　be　used　merely　as　means；　and　so
  far　therefore　restricts　freedom　of　action　（and　is　an　object　of
  respect）。　These；　therefore；　are　not　merely　subjective　ends　whose
  existence　has　a　worth　for　us　as　an　effect　of　our　action；　but　objective
  ends；　that　is；　things　whose　existence　is　an　end　in　itself；　an　end
  moreover　for　which　no　other　can　be　substituted；　which　they　should
  subserve　merely　as　means；　for　otherwise　nothing　whatever　would　possess
  absolute　worth；　but　if　all　worth　were　conditioned　and　therefore
  contingent；　then　there　would　be　no　supreme　practical　principle　of
  reason　whatever。
  If　then　there　is　a　supreme　practical　principle　or；　in　respect　of　the
  human　will；　a　categorical　imperative；　it　must　be　one　which；　being
  drawn　from　the　conception　of　that　which　is　necessarily　an　end　for
  everyone　be