undertaking。
  *Just　as　pure　mathematics　are　distinguished　from　applied；　pure　logic
  from　applied；　so　if　we　choose　we　may　also　distinguish　pure
  philosophy　of　morals　（metaphysic）　from　applied　（viz。；　applied　to　human
  nature）。　By　this　designation　we　are　also　at　once　reminded　that　moral
  principles　are　not　based　on　properties　of　human　nature；　but　must
  subsist　a　priori　of　themselves；　while　from　such　principles　practical
  rules　must　be　capable　of　being　deduced　for　every　rational　nature；
  and　accordingly　for　that　of　man。
  Such　a　metaphysic　of　morals；　completely　isolated；　not　mixed　with　any
  anthropology；　theology；　physics；　or　hyperphysics；　and　still　less
  with　occult　qualities　（which　we　might　call　hypophysical）；　is　not
  only　an　indispensable　substratum　of　all　sound　theoretical　knowledge　of
  duties；　but　is　at　the　same　time　a　desideratum　of　the　highest
  importance　to　the　actual　fulfilment　of　their　precepts。　For　the　pure
  conception　of　duty；　unmixed　with　any　foreign　addition　of　empirical
  attractions；　and；　in　a　word；　the　conception　of　the　moral　law；
  exercises　on　the　human　heart；　by　way　of　reason　alone　（which　first
  becomes　aware　with　this　that　it　can　of　itself　be　practical）；　an
  influence　so　much　more　powerful　than　all　other　springs*　which　may　be
  derived　from　the　field　of　experience；　that；　in　the　consciousness　of
  its　worth；　it　despises　the　latter；　and　can　by　degrees　become　their
  master；　whereas　a　mixed　ethics；　compounded　partly　of　motives　drawn
  from　feelings　and　inclinations；　and　partly　also　of　conceptions　of
  reason；　must　make　the　mind　waver　between　motives　which　cannot　be
  brought　under　any　principle；　which　lead　to　good　only　by　mere
  accident　and　very　often　also　to　evil。
  *I　have　a　letter　from　the　late　excellent　Sulzer；　in　which　he　asks　me
  what　can　be　the　reason　that　moral　instruction；　although　containing
  much　that　is　convincing　for　the　reason；　yet　accomplishes　so　little？　My
  answer　was　postponed　in　order　that　I　might　make　it　complete。　But　it　is
  simply　this：　that　the　teachers　themselves　have　not　got　their　own
  notions　clear；　and　when　they　endeavour　to　make　up　for　this　by　raking
  up　motives　of　moral　goodness　from　every　quarter；　trying　to　make
  their　physic　right　strong；　they　spoil　it。　For　the　commonest
  understanding　shows　that　if　we　imagine；　on　the　one　hand；　an　act　of
  honesty　done　with　steadfast　mind；　apart　from　every　view　to　advantage
  of　any　kind　in　this　world　or　another；　and　even　under　the　greatest
  temptations　of　necessity　or　allurement；　and；　on　the　other　hand；　a
  similar　act　which　was　affected；　in　however　low　a　degree；　by　a
  foreign　motive；　the　former　leaves　far　behind　and　eclipses　the
  second；　it　elevates　the　soul　and　inspires　the　wish　to　be　able　to　act
  in　like　manner　oneself。　Even　moderately　young　children　feel　this
  impression；　ana　one　should　never　represent　duties　to　them　in　any　other
  light。
  From　what　has　been　said；　it　is　clear　that　all　moral　conceptions　have
  their　seat　and　origin　completely　a　priori　in　the　reason；　and　that；
  moreover；　in　the　commonest　reason　just　as　truly　as　in　that　which　is　in
  the　highest　degree　speculative；　that　they　cannot　be　obtained　by
  abstraction　from　any　empirical；　and　therefore　merely　contingent；
  knowledge；　that　it　is　just　this　purity　of　their　origin　that　makes　them
  worthy　to　serve　as　our　supreme　practical　principle；　and　that　just　in
  proportion　as　we　add　anything　empirical；　we　detract　from　their　genuine
  influence　and　from　the　absolute　value　of　actions；　that　it　is　not
  only　of　the　greatest　necessity；　in　a　purely　speculative　point　of　view；
  but　is　also　of　the　greatest　practical　importance；　to　derive　these
  notions　and　laws　from　pure　reason；　to　present　them　pure　and　unmixed；
  and　even　to　determine　the　compass　of　this　practical　or　pure　rational
  knowledge；　i。e。；　to　determine　the　whole　faculty　of　pure　practical
  reason；　and；　in　doing　so；　we　must　not　make　its　principles　dependent　on
  the　particular　nature　of　human　reason；　though　in　speculative
  philosophy　this　may　be　permitted；　or　may　even　at　times　be　necessary；
  but　since　moral　laws　ought　to　hold　good　for　every　rational　creature；
  we　must　derive　them　from　the　general　concept　of　a　rational　being。　In
  this　way；　although　for　its　application　to　man　morality　has　need　of
  anthropology；　yet；　in　the　first　instance；　we　must　treat　it
  independently　as　pure　philosophy；　i。e。；　as　metaphysic；　complete　in
  itself　（a　thing　which　in　such　distinct　branches　of　science　is　easily
  done）；　knowing　well　that　unless　we　are　in　possession　of　this；　it　would
  not　only　be　vain　to　determine　the　moral　element　of　duty　in　right
  actions　for　purposes　of　speculative　criticism；　but　it　would　be
  impossible　to　base　morals　on　their　genuine　principles；　even　for　common
  practical　purposes；　especially　of　moral　instruction；　so　as　to
  produce　pure　moral　dispositions；　and　to　engraft　them　on　men's　minds　to
  the　promotion　of　the　greatest　possible　good　in　the　world。
  But　in　order　that　in　this　study　we　may　not　merely　advance　by　the
  natural　steps　from　the　common　moral　judgement　（in　this　case　very
  worthy　of　respect）　to　the　philosophical；　as　has　been　already　done；　but
  also　from　a　popular　philosophy；　which　goes　no　further　than　it　can
  reach　by　groping　with　the　help　of　examples；　to　metaphysic　（which
  does　allow　itself　to　be　checked　by　anything　empirical　and；　as　it
  must　measure　the　whole　extent　of　this　kind　of　rational　knowledge；　goes
  as　far　as　ideal　conceptions；　where　even　examples　fail　us）；　we　must
  follow　and　clearly　describe　the　practical　faculty　of　reason；　from
  the　general　rules　of　its　determination　to　the　point　where　the　notion
  of　duty　springs　from　it。
  Everything　in　nature　works　according　to　laws。　Rational　beings
  alone　have　the　faculty　of　acting　according　to　the　conception　of
  laws；　that　is　according　to　principles；　i。e。；　have　a　will。　Since　the
  deduction　of　actions　from　principles　requires　reason；　the　will　is
  nothing　but　practical　reason。　If　reason　infallibly　determines　the
  will；　then　the　actions　of　such　a　being　which　are　recognised　as
  objectively　necessary　are　subjectively　necessary　also；　i。e。；　the
  will　is　a　faculty　to　choose　that　only　which　reason　independent　of
  inclination　recognises　as　practically　necessary；　i。e。；　as　good。　But　if
  reason　of　itself　does　not　sufficiently　determine　the　will；　if　the
  latter　is　subject　also　to　subjective　conditions　（particular
  impulses）　which　do　not　always　coincide　with　the　objective
  conditions；　in　a　word；　if　the　will　does　not　in　itself　completely
  accord　with　reason　（which　is　actually　the　case　with　men）；　then　the
  actions　which　objectively　are　recognised　as　necessary　are　subjectively
  contingent；　and　the　determination　of　such　a　will　according　to
  objective　laws　is　obligation；　that　is　to　say；　the　relation　of　the
  objective　laws　to　a　will　that　is　not　thoroughly　good　is　conceived　as
  the　determination　of　the　will　of　a　rational　being　by　principles　of
  reason；　but　which　the　will　from　its　nature　does　not　of　necessity
  follow。
  The　conception　of　an　objective　principle；　in　so　far　as　it　is
  obligatory　for　a　will；　is　called　a　command　（of　reason）；　and　the
  formula　of　the　command　is　called　an　imperative。
  All　imperatives　are　expressed　by　the　word　ought　＇or　shall＇；　and
  thereby　indicate　the　relation　of　an　objective　law　of　reason　to　a　will；
  which　from　its　subjective　constitution　is　not　necessarily　determined
  by　it　（an　obligation）。　They　say　that　something　would　be　good　to　do
  or　to　forbear；　but　they　say　it　to　a　will　which　does　not　always　do　a
  thing　because　it　is　conceived　to　be　good　to　do　it。　That　is　practically
  good；　however；　which　determines　the　will　by　means　of　the　conceptions
  of　reason；　and　consequently　not　from　subjective　causes；　but
  objectively；　that　is　on　principles　which　are　valid　for　every
  rational　being　as　such。　It　is　distinguished　from　the　pleasant；　as　that
  which　influences　the　will　only　by　means　of　sensation　from　merely
  subjective　causes；　valid　only　for　the　sense　of　this　or　that　one；　and
  not　as　a　principle　of　reason；　which　holds　for　every　one。*
  *The　dependence　of　the　desires　on　sensations　is　called
  inclination；　and　this　accordingly　always　indicates　a　want。　The
  dependence　of　a　contingently　determinable　will　on　principles　of　reason
  is　called　an　interest。　This　therefore；　is　found　only　in　the　case　of
  a　dependent　will　which　does　not　always　of　itself　conform　to　reason；　in
  the　Divine　will　we　cannot　conceive　any　interest。　But　the　human　will
  can　also　take　an　interest　in　a　thing　without　therefore　acting　from
  interest。　The　former　signifies　the　practical　interest　in　the　action；
  the　latter　the　pathological　in　the　object　of　the　action。　The　former
  indicates　only　dependence　of　the　will　on　principles　of　reason　in
  themselves；　the　second；　dependence　on　principles　of　reason　for　the
  sake　of　inclination；　reason　supplying　only　the　practical　rules　how　the
  requirement　of　the　inclination　may　be　satisfied。　In　the　first　case　the
  action　interests　me；　in　the　second　the　object　of　the　action　（because
  it　is　pleasant　to　me）。　We　have　seen　in　the　first