a critical examination of on the origin of species-第4章

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demonstrable　that　the　structural　differences　which　separate　man　from
the　apes　are　not　greater　than　those　which　separate　some　apes　from
others。　　There　cannot　be　the　slightest　doubt　in　the　world　that　the
argument　which　applies　to　the　improvement　of　the　horse　from　an　earlier
stock；　or　of　ape　from　ape；　applies　to　the　improvement　of　man　from　some
simpler　and　lower　stock　than　man。　　There　is　not　a　single
facultyfunctional　or　structural；　moral；　intellectual；　or
instinctive；there　is　no　faculty　whatever　that　is　not　capable　of
improvement；　there　is　no　faculty　whatsoever　which　does　not　depend　upon
structure；　and　as　structure　tends　to　vary；　it　is　capable　of　being
improved。

Well；　I　have　taken　a　good　deal　of　pains　at　various　times　to　prove　this；
and　I　have　endeavoured　to　meet　the　objections　of　those　who　maintain；
that　the　structural　differences　between　man　and　the　lower　animals　are
of　so　vast　a　character　and　enormous　extent；　that　even　if　Mr。　Darwin's
views　are　correct；　you　cannot　imagine　this　particular　modification　to
take　place。　　It　is；　in　fact；　easy　matter　to　prove　that；　so　far　as
structure　is　concerned；　man　differs　to　no　greater　extent　from　the
animals　which　are　immediately　below　him　than　these　do　from　other　members
of　the　same　order。　　Upon　the　other　hand；　there　is　no　one　who　estimates
more　highly　than　I　do　the　dignity　of　human　nature；　and　the　width　of　the
gulf　in　intellectual　and　moral　matters；　which　lies　between　man　and　the
whole　of　the　lower　creation。

But　I　find　this　very　argument　brought　forward　vehemently　by　some。　　〃You
say　that　man　has　proceeded　from　a　modification　of　some　lower　animal；
and　you　take　pains　to　prove　that　the　structural　differences　which　are
said　to　exist　in　his　brain　do　not　exist　at　all；　and　you　teach　that　all
functions；　intellectual；　moral；　and　others；　are　the　expression　or　the
result；　in　the　long　run；　of　structures；　and　of　the　molecular　forces
which　they　exert。〃　　It　is　quite　true　that　I　do　so。

〃Well；　but；〃　I　am　told　at　once；　somewhat　triumphantly；　〃you　say　in　the
same　breath　that　there　is　a　great　moral　and　intellectual　chasm　between
man　and　the　lower　animals。　　How　is　this　possible　when　you　declare　that
moral　and　intellectual　characteristics　depend　on　structure；　and　yet
tell　us　that　there　is　no　such　gulf　between　the　structure　of　man　and　that
of　the　lower　animals？〃

I　think　that　objection　is　based　upon　a　misconception　of　the　real
relations　which　exist　between　structure　and　function；　between　mechanism
and　work。　　Function　is　the　expression　of　molecular　forces　and
arrangements　no　doubt；　but；　does　it　follow　from　this；　that　variation　in
function　so　depends　upon　variation　in　structure　that　the　former　is
always　exactly　proportioned　to　the　latter？　　If　there　is　no　such
relation；　if　the　variation　in　function　which　follows　on　a　variation　in
structure；　may　be　enormously　greater　than　the　variation　of　the
structure；　then；　you　see；　the　objection　falls　to　the　ground。

Take　a　couple　of　watchesmade　by　the　same　maker；　and　as　completely
alike　as　possible；　set　them　upon　the　table；　and　the　function　of
eachwhich　is　its　rate　of　goingwill　be　performed　in　the　same　manner；
and　you　shall　be　able　to　distinguish　no　difference　between　them；　but　let
me　take　a　pair　of　pincers；　and　if　my　hand　is　steady　enough　to　do　it；
let　me　just　lightly　crush　together　the　bearings　of　the　balance…wheel；
or　force　to　a　slightly　different　angle　the　teeth　of　the　escapement　of
one　of　them；　and　of　course　you　know　the　immediate　result　will　be　that
the　watch；　so　treated；　from　that　moment　will　cease　to　go。　　But　what
proportion　is　there　between　the　structural　alteration　and　the
functional　result？　　Is　it　not　perfectly　obvious　that　the　alteration　is
of　the　minutest　kind；　yet　that　slight　as　it　is；　it　has　produced　an
infinite　difference　in　the　performance　of　the　functions　of　these　two
instruments？

Well；　now；　apply　that　to　the　present　question。　　What　is　it　that
constitutes　and　makes　man　what　he　is？　　What　is　it　but　his　power　of
languagethat　language　giving　him　the　means　of　recording　his
experiencemaking　every　generation　somewhat　wiser　than　its
predecessor；more　in　accordance　with　the　established　order　of　the
universe？

What　is　it　but　this　power　of　speech；　of　recording　experience；　which
enables　men　to　be　menlooking　before　and　after　and；　in　some　dim　sense；
understanding　the　working　of　this　wondrous　universeand　which
distinguishes　man　from　the　whole　of　the　brute　world？　　I　say　that　this
functional　difference　is　vast；　unfathomable；　and　truly　infinite　in　its
consequences；　and　I　say　at　the　same　time；　that　it　may　depend　upon
structural　differences　which　shall　be　absolutely　inappreciable　to　us
with　our　present　means　of　investigation。　　What　is　this　very　speech　that
we　are　talking　about？　　I　am　speaking　to　you　at　this　moment；　but　if　you
were　to　alter；　in　the　minutest　degree；　the　proportion　of　the　nervous
forces　now　active　in　the　two　nerves　which　supply　the　muscles　of　my
glottis；　I　should　become　suddenly　dumb。　　The　voice　is　produced　only　so
long　as　the　vocal　chords　are　parallel；　and　these　are　parallel　only　so
long　as　certain　muscles　contract　with　exact　equality；　and　that　again
depends　on　the　equality　of　action　of　those　two　nerves　I　spoke　of。　　So
that　a　change　of　the　minutest　kind　in　the　structure　of　one　of　these
nerves；　or　in　the　structure　of　the　part　in　which　it　originates；　or　of
the　supply　of　blood　to　that　part；　or　of　one　of　the　muscles　to　which　it
is　distributed；　might　render　all　of　us　dumb。　　But　a　race　of　dumb　men；
deprived　of　all　communication　with　those　who　could　speak；　would　be
little　indeed　removed　from　the　brutes。　　And　the　moral　and　intellectual
difference　between　them　and　ourselves　would　be　practically　infinite；
though　the　naturalist　should　not　be　able　to　find　a　single　shadow　of
even　specific　structural　difference。

But　let　me　dismiss　this　question　now；　and；　in　conclusion；　let　me　say
that　you　may　go　away　with　it　as　my　mature　conviction；　that　Mr。　Darwin's
work　is　the　greatest　contribution　which　has　been　made　to　biological
science　since　the　publication　of　the　'Regne　Animal'　of　Cuvier；　and
since　that　of　the　'History　of　Development'　of　Von　Baer。　　I　believe　that
if　you　strip　it　of　its　theoretical　part　it　still　remains　one　of　the
greatest　encyclopaedias　of　biological　doctrine　that　any　one　man　ever
brought　forth；　and　I　believe　that；　if　you　take　it　as　the　embodiment　of
an　hypothesis；　it　is　destined　to　be　the　guide　of　biological　and
psychological　speculation　for　the　next　three　or　four　generations。







End