A　Critical　Examination　of　〃On　The　Origin　of　Species〃
  by　Thomas　H。　Huxley
  IN　the　preceding　five　lectures　I　have　endeavoured　to　give　you　an　account
  of　those　facts；　and　of　those　reasonings　from　facts；　which　form　the　data
  upon　which　all　theories　regarding　the　causes　of　the　phenomena　of
  organic　nature　must　be　based。　　And；　although　I　have　had　frequent
  occasion　to　quote　Mr。　Darwinas　all　persons　hereafter；　in　speaking　upon
  these　subjects；　will　have　occasion　to　quote　his　famous　book　on　the
  〃Origin　of　Species；〃you　must　yet　remember　that；　wherever　I　have
  quoted　him；　it　has　not　been　upon　theoretical　points；　or　for　statements
  in　any　way　connected　with　his　particular　speculations；　but　on　matters
  of　fact；　brought　forward　by　himself；　or　collected　by　himself；　and　which
  appear　incidentally　in　his　book。　　If　a　man　'will'　make　a　book；
  professing　to　discuss　a　single　question；　an　encyclopaedia；　I　cannot　help
  it。
  Now；　having　had　an　opportunity　of　considering　in　this　sort　of　way　the
  different　statements　bearing　upon　all　theories　whatsoever；　I　have　to
  lay　before　you；　as　fairly　as　I　can；　what　is　Mr。　　Darwin's　view　of　the
  matter　and　what　position　his　theories　hold；　when　judged　by　the
  principles　which　I　have　previously　laid　down；　as　deciding　our　judgments
  upon　all　theories　and　hypotheses。
  I　have　already　stated　to　you　that　the　inquiry　respecting　the　causes　of
  the　phenomena　of　organic　nature　resolves　itself　into　two　problemsthe
  first　being　the　question　of　the　origination　of　living　or　organic
  beings；　and　the　second　being　the　totally　distinct　problem　of　the
  modification　and　perpetuation　of　organic　beings　when　they　have　already
  come　into　existence。　　The　first　question　Mr。　Darwin　does　not　touch；　he
  does　not　deal　with　it　at　all；　but　he　saysgiven　the　origin　of　organic
  mattersupposing　its　creation　to　have　already　taken　place；　my　object　is
  to　show　in　consequence　of　what　laws　and　what　demonstrable　properties　of
  organic　matter；　and　of　its　environments；　such　states　of　organic　nature
  as　those　with　which　we　are　acquainted　must　have　come　about。　　This；　you
  will　observe；　is　a　perfectly　legitimate　proposition；　every　person　has　a
  right　to　define　the　limits　of　the　inquiry　which　he　sets　before　himself；
  and　yet　it　is　a　most　singular　thing　that　in　all　the　multifarious；　and；
  not　unfrequently；　ignorant　attacks　which　have　been　made　upon　the
  'Origin　of　Species'；　there　is　nothing　which　has　been　more　speciously
  criticised　than　this　particular　limitation。　　If　people　have　nothing　else
  to　urge　against　the　book；　they　say〃Well；　after　all；　you　see；　Mr。
  Darwin's　explanation　of　the　'Origin　of　Species'　is　not　good　for　much；
  because；　in　the　long　run；　he　admits　that　he　does　not　know　how　organic
  matter　began　to　exist。　　But　if　you　admit　any　special　creation　for　the
  first　particle　of　organic　matter　you　may　just　as　well　admit　it　for　all
  the　rest；　five　hundred　or　five　thousand　distinct　creations　are　just　as
  intelligible；　and　just　as　little　difficult　to　understand；　as　one。〃　　The
  answer　to　these　cavils　is　two…fold。　　In　the　first　place；　all　human
  inquiry　must　stop　somewhere；　all　our　knowledge　and　all　our
  investigation　cannot　take　us　beyond　the　limits　set　by　the　finite　and
  restricted　character　of　our　faculties；　or　destroy　the　endless　unknown；
  which　accompanies；　like　its　shadow；　the　endless　procession　of
  phenomena。　　So　far　as　I　can　venture　to　offer　an　opinion　on　such　a
  matter；　the　purpose　of　our　being　in　existence；　the　highest　object　that
  human　beings　can　set　before　themselves；　is　not　the　pursuit　of　any　such
  chimera　as　the　annihilation　of　the　unknown；　but　it　is　simply　the
  unwearied　endeavour　to　remove　its　boundaries　a　little　further　from　our
  little　sphere　of　action。
  I　wonder　if　any　historian　would　for　a　moment　admit　the　objection；　that
  it　is　preposterous　to　trouble　ourselves　about　the　history　of　the　Roman
  Empire；　because　we　do　not　know　anything　positive　about　the　origin　and
  first　building　of　the　city　of　Rome！　　Would　it　be　a　fair　objection　to
  urge；　respecting　the　sublime　discoveries　of　a　Newton；　or　a　Kepler；　those
  great　philosophers；　whose　discoveries　have　been　of　the　profoundest
  benefit　and　service　to　all　men；to　say　to　them〃After　all　that　you
  have　told　us　as　to　how　the　planets　revolve；　and　how　they　are　maintained
  in　their　orbits；　you　cannot　tell　us　what　is　the　cause　of　the　origin　of
  the　sun；　moon；　and　stars。　　So　what　is　the　use　of　what　you　have　done？〃
  Yet　these　objections　would　not　be　one　whit　more　preposterous　than　the
  objections　which　have　been　made　to　the　'Origin　of　Species。'　Mr。　Darwin；
  then；　had　a　perfect　right　to　limit　his　inquiry　as　he　pleased；　and　the
  only　question　for　usthe　inquiry　being　so　limitedis　to　ascertain
  whether　the　method　of　his　inquiry　is　sound　or　unsound；　whether　he　has
  obeyed　the　canons　which　must　guide　and　govern　all　investigation；　or
  whether　he　has　broken　them；　and　it　was　because　our　inquiry　this　evening
  is　essentially　limited　to　that　question；　that　I　spent　a　good　deal　of
  time　in　a　former　lecture　（which；　perhaps；　some　of　you　thought　might
  have　been　better　employed）；　in　endeavouring　to　illustrate　the　method
  and　nature　of　scientific　inquiry　in　general。　　We　shall　now　have　to　put
  in　practice　the　principles　that　I　then　laid　down。
  I　stated　to　you　in　substance；　if　not　in　words；　that　wherever　there　are
  complex　masses　of　phenomena　to　be　inquired　into；　whether　they　be
  phenomena　of　the　affairs　of　daily　life；　or　whether　they　belong　to　the
  more　abstruse　and　difficult　problems　laid　before　the　philosopher；　our
  course　of　proceeding　in　unravelling　that　complex　chain　of　phenomena　with
  a　view　to　get　at　its　cause；　is　always　the　same；　in　all　cases　we　must
  invent　an　hypothesis；　we　must　place　before　ourselves　some　more　or　less
  likely　supposition　respecting　that　cause；　and　then；　having　assumed　an
  hypothesis；　having　supposed　cause　for　the　phenomena　in　question；　we　must
  endeavour；　on　the　one　hand；　to　demonstrate　our　hypothesis；　or；　on　the
  other；　to　upset　and　reject　it　altogether；　by　testing　it　in　three　ways。
  We　must；　in　the　first　place；　be　prepared　to　prove　that　the　supposed
  causes　of　the　phenomena　exist　in　nature；　that　they　are　what　the
  logicians　call　'vera　causae'true　causes；in　the　next　place；　we
  should　be　prepared　to　show　that　the　assumed　causes　of　the　phenomena　are
  competent　to　produce　such　phenomena　as　those　which　we　wish　to　explain
  by　them；　and　in　the　last　place；　we　ought　to　be　able　to　show　that　no
  other　known　causes　are　competent　to　produce　those　phenomena。　　If　we　can
  succeed　in　satisfying　these　three　conditions　we　shall　have　demonstrated
  our　hypothesis；　or　rather　I　ought　to　say　we　shall　have　proved　it　as　far
  as　certainty　is　possible　for　us；　for；　after　all；　there　is　no　one　of　our
  surest　convictions　which　may　not　be　upset；　or　at　any　rate　modified　by　a
  further　accession　of　knowledge。　　It　was　because　it　satisfied　these
  conditions　that　we　accepted　the　hypothesis　as　to　the　disappearance　of
  the　tea…pot　and　spoons　in　the　case　I　supposed　in　a　previous　lecture；　we
  found　that　our　hypothesis　on　that　subject　was　tenable　and　valid；　because
  the　supposed　cause　existed　in　nature；　because　it　was　competent　to
  account　for　the　phenomena；　and　because　no　other　known　cause　was
  competent　to　account　for　them；　and　it　is　upon　similar　grounds　that　any
  hypothesis　you　choose　to　name　is　accepted　in　science　as　tenable　and
  valid。
  What　is　Mr。　Darwin's　hypothesis？　As　I　apprehend　itfor　I　have　put　it
  into　a　shape　more　convenient　for　common　purposes　than　I　could　find
  'verbatim'　in　his　bookas　I　apprehend　it；　I　say；　it　is；　that　all　the
  phenomena　of　organic　nature；　past　and　present；　result　from；　or　are
  caused　by；　the　inter…action　of　those　properties　of　organic　matter；
  which　we　have　called　ATAVISM　and　VARIABILITY；　with　the　CONDITIONS　OF
  EXISTENCE；　or；　in　other　words；given　the　existence　of　organic　matter；
  its　tendency　to　transmit　its　properties；　and　its　tendency　occasionally
  to　vary；　and；　lastly；　given　the　conditions　of　existence　by　which　organic
  matter　is　surroundedthat　these　put　together　are　the　causes　of　the
  Present　and　of　the　Past　conditions　of　ORGANIC　NATURE。
  Such　is　the　hypothesis　as　I　understand　it。　　Now　let　us　see　how　it　will
  stand　the　various　tests　which　I　laid　down　just　now。　　In　the　first
  place；　do　these　supposed　causes　of　the　phenomena　exist　in　nature？　　Is
  it　the　fact　that　in　nature　these　properties　of　organic　matteratavism
  and　variabilityand　those　phenomena　which　we　have　called　the
  conditions　of　existence；is　it　true　that　they　exist？　　Well；　of　course；
  if　they　do　not　exist；　all　that　I　have　told　you　in　the　last　three　or
  four　lectures　must　be　incorrect；　because　I　have　been　attempting　to　prove
  that　they　do　exist；　and　I　take　it　that　there　is　abundant　evidence　that
  they　do　exist；　so　far；　therefore；　the　hypothesis　does　not　break　down。
  But　in　the　next　place　comes　a　much　more　difficult　inquiry：Are　the
  causes　indicated　competent　to　give　rise　to　the　phenomena　of　organic
  nature？　　I　suspect　that　this　is　indubitable　to　a　certain　extent。　　It　is
  demonstrable；　I　think；　as　I　have　endeavoured　to　show　you；　that　they　are
  perfectly　competent　to　give　rise　to　all　the　phenomena　which　are
  exhibited　by　RACES　in　nature。　　Furthermore；　I　believe　that　they　are
  quite　competent　to　account　for　all　that　we