to　the　convenience　of　a　court　of　justice。
  For　everything　alienable　must　be　capable　of　being　acquired　by
  anyone。　The　rightfulness　of　acquisition；　however；　rests　entirely
  upon　the　form　in　accordance　with　which　what　is　in　possession　of
  another；　is　transferred　to　me　and　accepted　by　me。　In　other　words；
  rightful　acquisition　depends　upon　the　formality　of　the　juridical　act
  of　commutation　or　interchange　between　the　possessor　of　the　thing　and
  the　acquirer　of　it；　without　its　being　required　to　ask　how　the　former
  came　by　it；　because　this　would　itself　be　an　injury；　on　the　ground
  that：　Quilibet　praesumitur　bonus。　Now　suppose　it　turned　out　that　the
  said　possessor　was　not　the　real　owner；　I　cannot　admit　that　the　real
  owner　is　entitled　to　hold　me　directly　responsible；　or　so　entitled　with
  regard　to　any　one　who　might　be　holding　the　thing。　For　I　have　myself
  taken　nothing　away　from　him；　when；　for　example；　I　bought　his　horse
  according　to　the　law　（titulo　empti　venditi）　when　it　was　offered　for
  sale　in　the　public　market。　The　title　of　acquisition　is　therefore
  unimpeachable　on　my　side；　and　as　buyer　I　am　not　bound；　nor　even　have　I
  the　right；　to　investigate　the　title　of　the　seller；　for　this　process　of
  investigation　would　have　to　go　on　in　an　ascending　series　ad　infinitum。
  Hence　on　such　grounds　I　ought　to　be　regarded；　in　virtue　of　a　regular
  and　formal　purchase；　as　not　merely　the　putative；　but　the　real　owner　of
  the　horse。
  But　against　this　position；　there　immediately　start　up　the
  following　juridical　principles。　Any　acquisition　derived　from　one　who
  is　not　the　owner　of　the　thing　in　question　is　null　and　void。　I　cannot
  derive　from　another　anything　more　than　what　he　himself　rightfully　has；
  and　although　as　regards　the　form　of　the　acquisition　the　modus
  acquirendi…　I　may　proceed　in　accordance　with　all　the　conditions　of
  right　when　I　deal　in　a　stolen　horse　exposed　for　sale　in　the　market；
  yet　a　real　title　warranting　the　acquisition　was　awanting；　for　the
  horse　was　not　really　the　property　of　the　seller　in　question。　However　I
  may　be　a　bona　fide　possessor　of　a　thing　under　such　conditions；　I　am
  still　only　a　putative　owner；　and　the　real　owner　has　the　right　of
  vindication　against　me　（rem　suam　vindicandi）。
  Now；　it　may　be　again　asked；　what　is　right　and　just　in　itself
  regarding　the　acquisition　of　external　things　among　men　in　their
  intercourse　with　one　another…　viewed　in　the　state　of　nature
  according　to　the　principles　of　commutative　justice？　And　it　must　be
  admitted　in　this　connection　that　whoever　has　a　purpose　of　acquiring
  anything　must　regard　it　as　absolutely　necessary　to　investigate　whether
  the　thing　which　he　wishes　to　acquire　does　not　already　belong　to
  another　person。　For　although　he　may　carefully　observe　the　formal
  conditions　required　for　appropriating　what　may　belong　to　the
  property　of　another；　as　in　buying　a　horse　according　to　the　usual　terms
  in　a　market；　yet　he　can；　at　the　most；　acquire　only　a　personal　right　in
  relation　to　a　thing　（jus　ad　rem）　so　long　as　it　is　still　unknown　to　him
  whether　another　than　the　seller　may　not　be　the　real　owner。　Hence；　if
  some　other　person　were　to　come　forward　and　prove　by　documentary
  evidence　a　prior　right　of　property　in　the　thing；　nothing　would
  remain　for　the　putative　new　owner　but　the　advantage　which　he　has　drawn
  as　a　bona　fide　possessor　of　it　up　to　that　moment。　Now　it　is　frequently
  impossible　to　discover　the　absolutely　first　original　owner　of　a
  thing　in　the　series　of　putative　owners；　who　derive　their　right　from
  one　another。　Hence　no　mere　exchange　of　external　things；　however　well
  it　may　agree　with　the　formal　conditions　of　commutative　justice；　can
  ever　guarantee　an　absolutely　certain　acquisition。
  Here；　however；　the　juridically　law…giving　reason　comes　in　again　with
  the　principle　of　distributive　justice；　and　it　adopts　as　a　criterion　of
  the　rightfulness　of　possession；　not　what　is　in　itself　in　reference
  to　the　private　will　of　each　individual　in　the　state　of　nature；　but
  only　the　consideration　of　how　it　would　be　adjudged　by　a　court　of
  justice　in　a　civil　state；　constituted　by　the　united　will　of　all。　In
  this　connection；　fulfillment　of　the　formal　conditions　of
  acquisition；　that　in　themselves　only　establish　a　personal　right；　is
  postulated　as　sufficient；　and　they　stand　as　an　equivalent　for　the
  material　conditions　which　properly　establish　the　derivation　of
  property　from　a　prior　putative　owner；　to　the　extent　of　making　what
  is　in　itself　only　a　personal　right；　valid　before　a　court；　as　a　real
  right。　Thus　the　horse　which　I　bought　when　exposed　for　sale　in　the
  public　market；　under　conditions　regulated　by　the　municipal　law；
  becomes　my　property　if　all　the　conditions　of　purchase　and　sale　have
  been　exactly　observed　in　the　transaction；　but　always　under　the
  reservation　that　the　real　owner　continues　to　have　the　right　of　a　claim
  against　the　seller；　on　the　ground　of　his　prior　unalienated　possession。
  My　otherwise　personal　right　is　thus　transmuted　into　a　real　right；
  according　to　which　I　may　take　and　vindicate　the　object　as　mine
  wherever　I　may　find　it；　without　being　responsible　for　the　way　in　which
  the　Seller　had　come　into　possession　of　it。
  It　is　therefore　only　in　behoof　of　the　requirements　of　juridical
  decision　in　a　court　（in　favorem　justitae　distributivae）　that　the　right
  in　respect　of　a　thing　is　regarded；　not　as　personal；　which　it　is　in
  itself；　but　as　real；　because　it　can　thus　be　most　easily　and
  certainly　adjudged；　and　it　is　thus　accepted　and　dealt　with　according
  to　a　pure　principle　a　priori。　Upon　this　principle；　various　statutory
  laws　come　to　be　founded　which　specially　aim　at　laying　down　the
  conditions　under　which　alone　a　mode　of　acquisition　shall　be
  legitimate；　so　that　the　judge　may　be　able　to　assign　every　one　his
  own　as　easily　and　certainly　as　possible。　Thus；　in　the　brocard；
  〃Purchase　breaks　hire；〃　what　by　the　nature　of　the　subject　is　a　real
  right…　namely　the　hire…　is　taken　to　hold　as　a　merely　personal　right；
  and；　conversely；　as　in　the　case　referred　to　above；　what　is　in　itself
  merely　a　personal　right　is　held　to　be　valid　as　a　real　right。　And
  this　is　done　only　when　the　question　arises　as　to　the　principles　by
  which　a　court　of　justice　in　the　civil　state　is　to　be　guided；　in
  order　to　proceed　with　all　possible　safety　in　delivering　judgement　on
  the　rights　of　individuals。
  40。　IV。　Acquisition　of　Security　by　the　Taking　of　an　Oath。
  （Cautio　Juratoria）。
  Only　one　ground　can　be　assigned　on　which　it　could　be　held　that　men
  are　bound　in　the　juridical　relation　to　believe　and　to　confess　that
  there　are　gods；　or　that　there　is　a　God。　It　is　that　they　may　be　able　to
  swear　an　oath；　and　that　thus　by　the　fear　of　an　all…seeing　Supreme
  Power；　whose　revenge　they　must　solemnly　invoke　upon　themselves　in　case
  their　utterance　should　be　false；　they　may　be　constrained　to　be
  truthful　in　statement　and　faithful　in　promising。　It　is　not　morality
  but　merely　blind　superstition　that　is　reckoned　upon　in　this　process；
  for　it　is　evident　it　implies　that　no　certainty　is　to　be　expected
  from　a　mere　solemn　declaration　in　matters　of　right　before　a　court；
  although　the　duty　of　truthfulness　must　have　always　appeared
  self…evident　to　all；　in　a　matter　which　concerns　the　holiest　that　can
  be　among　men…　namely；　the　right　of　man。　Hence　recourse　has　been　had　to
  a　motive　founded　on　mere　myths　and　fables　as　imaginary　guarantees。
  Thus　among　the　Rejangs；　a　heathen　people　in　Sumatra；　it　is　the　custom…
  according　to　the　testimony　of　Marsden…　to　swear　by　the　bones　of
  their　dead　relatives；　although　they　have　no　belief　in　a　life　after
  death。　In　like　manner　the　negroes　of　Guinea　swear　by　their　fetish；　a
  bird's　feather；　which　they　imprecate　under　the　belief　that　it　will
  break　their　neck。　And　so　in　other　cases。　The　belief　underlying　these
  oaths　is　that　an　invisible　power…　whether　it　has　understanding　or　not…
  by　its　very　nature　possesses　magical　power　that　can　be　put　into　action
  by　such　invocations。　Such　a　belief…　which　is　commonly　called　religion；
  but　which　ought　to　be　called　superstition…　is；　however；
  indispensable　for　the　administration　of　justice；　because；　without
  referring　to　it；　a　court　of　justice　would　not　have　adequate　means　to
  ascertain　facts　otherwise　kept　secret；　and　to　determine　rights。　A
  law　making　an　oath　obligatory　is　therefore　only　given　in　behoof　of　the
  judicial　authority。
  But　then　the　question　arises　as　to　what　the　obligation　could　be
  founded　upon　that　would　bind　any　one　in　a　court　of　justice　to　accept
  the　oath　of　another　person　as　a　right　and　valid　proof　of　the　truth
  of　his　statements　which　are　to　put　an　end　to　all　dispute。　In　other
  words；　what　obliges　me　juridically　to　believe　that　another　person　when
  taking　an　oath　has　any　religion　at　all；　so　that　I　should　subordinate
  or　entrust　my　right　to　his　oath？　And；　on　like　grounds；　conversely；　can
  I　be　bound　at　all　to　take　an　oath？　It　is　evident　that　both　these
  questions　point　to　what　is　in　itself　morally　wrong。
  But　in　relation　to　a　court　of　j