mind；　nor　mind　without　nature。　An　important　step　has　been　taken；　when　we　cease　in　thinking　to
  use　phrases　like：　Of　course　something　else　is　also　possible。　While　we　speak；　we　are　still　tainted
  with　contingency：　and　all　true　thinking；　we　have　already　said；　is　a　thinking　of　necessity。
  In　modern　physical　science　the　opposition；　first　observed　to　exist　in　magnetism　as　polarity；　has
  come　to　be　regarded　as　a　universal　law　pervading　the　whole　of　nature。　This　would　be　a　real
  scientific　advance；　if　care　were　at　the　same　time　taken　not　to　let　mere　variety　revert　without
  explanation；　as　a　valid　category；　side　by　side　with　opposition。　Thus　at　one　time　the　colours　are
  regarded　as　in　polar　opposition　to　one　another；　and　called　complementary　colours：　at　another　time
  they　are　looked　at　in　their　indifferent　and　merely　quantitative　difference　of　red；　yellow；　green；　etc。
  （2）　Instead　of　speaking　by　the　maxim　of　Excluded　Middle　（which　is　the　maxim　of　abstract
  understanding）　we　should　rather　say：　Everything　is　opposite。　Neither　in　heaven　nor　in　Earth；　neither
  in　the　world　of　mind　nor　of　nature；　is　there　anywhere　such　an　abstract　'either…or'　as　the
  understanding　maintains。　Whatever　exists　is　concrete；　with　difference　and　opposition　in　itself。　The
  finitude　of　things　will　then　lie　in　the　want　of　correspondence　between　their　immediate　being；　and
  what　they　essentially　are。　Thus；　in　inorganic　nature；　the　acid　is　implicitly　at　the　same　time　the　base：
  in　other　words；　its　only　being　consists　in　its　relation　to　its　other。　Hence　also　the　acid　is　not
  something　that　persists　quietly　in　the　contrast：　it　is　always　in　effort　to　realise　what　it　potentially　is。
  Contradiction　is　the　very　moving　principle　of　the　world：　and　it　is　ridiculous　to　say　that　contradiction
  is　unthinkable。　The　only　thing　correct　in　that　statement　is　that　contradiction　is　not　the　end　of　the
  matter；　but　cancels　itself。　But　contradiction；　when　cancelled；　does　not　leave　abstract　identity；　for
  that　is　itself　only　one　side　of　the　contrariety。　The　proximate　result　of　opposition　（when　realised　as
  contradiction）　is　the　Ground；　which　contains　identity　as　well　as　difference　superseded　and
  deposited　to　elements　in　the　completer　notion。
  §　120
  Contrariety　then　has　two　forms。　The　Positive　is　the　aforesaid　various　（different）
  which　is　understood　to　be　independent；　and　yet　at　the　same　time　not　to　be
  unaffected　by　its　relation　to　its　other。　The　Negative　is　to　be；　no　less
  independently；　negative　self…relating；　self…subsistent；　and　yet　at　the　same　time　as
  Negative　must　on　every　point　have　this　its　self…relation；　i。e。　its　Positive；　only　in
  the　other。　Both　Positive　and　Negative　are　therefore　explicit　contradiction；　both　are
  potentially　the　same。　Both　are　so　actually　also；　since　either　is　the　abrogation　of　the
  other　and　of　itself。　Thus　they　fall　to　the　Ground。　Or　as　is　plain；　the　essential
  difference；　as　a　difference；　is　only　the　difference　of　it　from　itself；　and　thus
  contains　the　identical：　so　that　to　essential　and　actual　difference　there　belongs　itself
  as　well　as　identity。　As　self…relating　difference　it　is　likewise　virtually　enunciated　as
  the　self…identical。　And　the　opposite　is　in　general　that　which　includes　the　one　and
  its　other；　itself　and　its　opposite。　The　immanence　of　essence　thus　defined　is　the
  Ground。
  （iii）　The　Ground
  §　121
  The　Ground　is　the　unity　of　identity　and　difference；　the　truth　of　what　difference
  and　identity　have　turned　out　to　be　…　the　reflection…into…self；　which　is　equally　a
  reflection…into…other；　and　vice…versa。　It　is　essence　put　explicitly　as　a　totality。
  The　maxim　of　Ground　runs　thus：　Everything　has　its　Sufficient　Ground：　that　is；　the
  true　essentiality　of　any　thing　is　not　the　predication　of　it　as　identical　with　itself；　or
  as　different　（various）；　or　merely　positive；　or　merely　negative；　but　as　having　its
  Being　in　an　other；　which；　being　the　self…same；　is　its　essence。　And　to　this　extent　the
  essence　is　not　abstract　reflection　into　self；　but　into　an　other。　The　Ground　is　the
  essence　in　its　own　inwardness；　the　essence　is　intrinsically　a　ground；　and　it　is　a
  ground　only　when　it　is　a　ground　of　somewhat；　of　an　other。
  §　121n
  We　must　be　careful；　when　we　say　that　the　ground　is　the　unity　of　identity　and　difference；　not　to
  understand　by　this　unity　an　abstract　identity。　Otherwise　we　only　change　the　name；　while　we　still
  think　the　identity　（of　understanding）　already　seen　to　be　false。　To　avoid　this　misconception　we　may
  say　that　the　ground；　besides　being　the　unity；　is　also　the　difference　of　identity　and　difference。　In　that
  case　in　the　ground；　which　promised　at　first　to　supersede　contradiction；　a　new　contradiction　seems
  to　arise。　It　is　however；　a　contradiction；　which；　so　far　from　persisting　quietly　in　itself；　is　rather　the
  expulsion　of　it　from　itself。　The　ground　is　a　ground　only　to　the　extent　that　it　affords　ground：　but　the
  result　which　thus　issued　from　the　ground　is　only　itself。　In　this　lies　its　formalism。　The　ground　and
  what　is　grounded　are　one　and　the　same　content：　the　difference　between　the　two　is　the　mere
  difference　of　form　which　separates　simple　self…relation；　one　the　one　hand；　from　mediation；　or
  derivativeness　on　the　other。　Inquiry　into　the　grounds　of　things　goes　with　the　point　of　view　which；　as
  already　noted　（§　112n）；　is　adopted　by　Reflection。　We　wish；　as　it　were；　to　see　the　matter　double；
  first　in　its　immediacy；　and　secondly　in　its　ground；　where　it　is　no　longer　immediate。　This　is　the　plain
  meaning　of　the　Law　of　Sufficient　Ground　is　that　things　should　essentially　be　viewed　as　mediated。
  The　manner　in　which　Formal　Logic　establishes　this　law　sets　a　bad　example　to　other　sciences。
  Formal　Logic　asks　these　sciences　not　to　accept　their　subject…matter　as　it　is　immediately　given；　and
  yet　herself　lays　down　a　law　of　thought　without　deducing　it　…　in　other　words；　without　exhibiting　its
  mediation。　With　the　same　justice　as　the　logician　maintains　our　faculty　of　thought　to　be　so
  constituted　that　we　must　ask　for　the　ground　of　everything；　might　the　physicist；　when　asked　why　a
  man　who　falls　into　water　is　drowned；　reply　that　man　happens　to　be　so　constituted　that　he　cannot
  live　under　water；　or　the　jurist；　when　asked　why　a　criminal　is　punished；　reply　that　civil　society
  happens　to　be　so　constituted　that　crimes　cannot　be　left　unpunished。
  Yet　even　if　logic　be　excused　the　duty　of　giving　a　ground　for　the　law　of　sufficient　ground；　it　might　at
  least　explain　what　is　to　be　understood　by　a　ground。　The　common　explanation；　which　describes　the
  ground　as　what　has　a　consequence；　seems　at　first　glance　more　lucid　and　intelligible　than　the
  preceding　definition　in　logical　terms。　If　you　ask　however　what　the　consequence　is；　you　are　told　that
  it　is　what　has　a　ground；　and　it　becomes　obvious　that　the　explanation　is　intelligible　only　because　it
  assumes　what　in　our　case　has　been　reached　as　the　termination　of　an　antecedent　movement　of
  thought。　And　this　is　the　true　business　of　logic：　to　show　that　those　thoughts；　which　as　usually
  employed　merely　float　before　consciousness　neither　understood　nor　demonstrated；　are　really
  grades　in　the　self…determination　of　thought。　It　is　by　no　means　that　they　are　understood　and
  demonstrated。
  In　common　life；　and　it　is　the　same　in　the　finite　sciences；　this　reflective　form　is　often　employed　as　a
  key　to　the　secret　of　the　real　condition　of　the　objects　of　investigation。　So　long　as　we　deal　with　what
  may　be　termed　the　household　needs　of　knowledge；　nothing　can　be　urged　against　this　method　of
  study。　But　it　can　never　afford　definitive　satisfaction；　either　in　theory　or　practice。　And　the　reason
  why　it　fails　is　that　the　ground　is　yet　without　a　definite　content　of　its　own；　so　that　to　regard　anything
  as　resting　upon　a　ground　merely　gives　the　formal　difference　of　mediation　in　place　of　immediacy。
  We　see　an　electrical　phenomenon；　for　example；　and　we　ask　for　its　ground　（or　reason）：　we　are　told
  that　electricity　is　the　ground　of　this　phenomenon。　What　is　this　but　the　same　content　as　we　had
  immediately　before　us；　only　translated　into　the　form　of　inwardness？
  The　ground　however　is　not　merely　simple　self…identity；　but　also　different：　hence　various　grounds
  may　be　alleged　for　the　same　sum　of　fact。　。。。
  A　content　thus　objectively　and　intrinsically　determined；　and　hence　self…acting；　will　hereafter　come
  before　us　as　the　notion：　and　it　is　the　notion　which　Leibnitz　had　in　his　eye　when　he　spoke　of
  sufficient　ground；　and　urged　the　study　of　things　under　its　point　of　view。　His　remarks　were　originally
  directed　against　that　merely　mechanical　method　of　conceiving　things　so　much　in　vogue　even　now；　a
  method　which　he　justly　pronounces　insufficient。　We　may　see　an　instance　of　this　mechanical　theory
  of　investigation　when　the　organic　process　of　the　circulation　of　the　blood　is　traced　back　merely　to
  the　contraction　of　the　heart　。。。
  It　is　unfair　to　Leibnitz　to　suppose　that　he　was　content　with　anything　so　poor　as　this　formal　law　of
  the　ground。　The　method　of　investigation　which　he　inaugurated　is　the　very　reverse　of　a　formalism
  which　acquiesces　in　mere　grounds；　where　a　full　and　concrete　knowledge　is　sought。　Considerations