a critical examination of on the origin of species-第1章

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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　may　call　purely　structural
phenomena　which　are　exhibited　by　SPECIES　in　nature。　　On　that　point　also
I　have　already　enlarged　somewhat。　　Again；　I　think　that　the　causes
assumed　are　competent　to　account　for　most　of　the　physiological
characteristics　of　species；　and　I　not　only　think　that　they　are
competent　to　account　for　them；　but　I　think　that　they　account　for　many
things　which　otherwise　remain　wholly　unaccountable　and　inexplicable；
and　I　may　say　incomprehensible。　　For　a　full　exposition　of　the　grounds
on　which　this　conviction　is　based；　I　must　refer　you　to　Mr。　　Darwin's
work；　all　that　I　can　do　now　is　to　illustrate　what　I　have　said　by　two　or
three　cases　taken　almost　at　random。

I　drew　your　attention；　on　a　previous　evening；　to　the　facts　which　are
embodied　in　our　systems　of　Classification；　which　are　the　results　of　the
examination　and　comparison　of　the　different　members　of　the　animal
kingdom　one　with　another。　　I　mentioned　that　the　whole　of　the　animal
kingdom　is　divisible　into　five　sub…kingdoms；　that　each　of　these
sub…kingdoms　is　again　divisible　into　provinces；　that　each　province　may
be　divided　into　classes；　and　the　classes　into　the　successively　smaller
groups；　orders；　families；　genera；　and　species。

Now；　in　each　of　these　groups；　the　resemblance　in　structure　among　the
members　of　the　group　is　closer　in　proportion　as　the　group　is　smaller。
Thus；　a　man　and　a　worm　are　members　of　the　animal　kingdom　in　virtue　of
certain　apparently　slight　though　really　fundamental　resemblances　which
they　present。　　But　a　man　and　a　fish　are　members　of　the　same　sub…kingdom
'Vertebrata'；　because　they　are　much　more　like　one　another　than　either
of　them　is　to　a　worm；　or　a　snail；　or　any　member　of　the　other
sub…kingdoms。　　For　similar　reasons　men　and　horses　are　arranged　as
members　of　the　same　Class；　'Mammalia'；　men　and　apes　as　members　of　the
same　Order；　'Primates'；　and　if　there　were　any　animals　more　like　men
than　they　were　like　any　of　the　apes；　and　yet　different　from　men　in
important　and　constant　particulars　of　their　organizatio