evolution and ethics and other essays-第3部分

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except　for　the　intervention　of　man。

Reckoned　by　our　customary　standards　of　duration；　the　native　vegetation；
like　the　〃everlasting　hills〃　which　it　clothes；　seems　a　type　of
permanence。　The　little　Amarella　Gentians；　which　abound　in　some　places
to…day；　are　the　descendants　of　those　that　were　trodden　underfoot；　by
the　prehistoric　savages　who　have　left　their　flint　tools；　about；　here
and　there；　and　they　followed　ancestors　which；　in　the　climate　of　the
glacial　epoch；　probably　flourished　better　than　they　do　now。　Compared
with　the　long　past　of　this　humble　plant；　all　the　history　of　civilized
men　is　but　an　episode。

Yet　nothing　is　more　certain　than　that；　measured　by　the　liberal　scale
of　time…keeping　of　the　universe；　this　present　state　of　nature；　however
it　may　seem　to　have　gone　and　to　go　on　for　ever；　is　＇3＇　but　a　fleeting
phase　of　her　infinite　variety；　merely　the　last　of　the　series　of
changes　which　the　earth's　surface　has　undergone　in　the　course　of　the
millions　of　years　of　its　existence。　Turn　back　a　square　foot　of　the
thin　turf；　and　the　solid　foundation　of　the　land；　exposed　in　cliffs　of
chalk　five　hundred　feet　high　on　the　adjacent　shore；　yields　full
assurance　of　a　time　when　the　sea　covered　the　site　of　the　〃everlasting
hills〃；　and　when　the　vegetation　of　what　land　lay　nearest；　was　as
different　from　the　present　Flora　of　the　Sussex　downs；　as　that　of
Central　Africa　now　is。*　No　less　certain　is　it　that；　between　the　time
during　which　the　chalk　was　formed　and　that　at　which　the　original　turf
came　into　existence；　thousands　of　centuries　elapsed；　in　the　course　of
which；　the　state　of　nature　of　the　ages　during　which　the　chalk　was
deposited；　passed　into　that　which　now　is；　by　changes　so　slow　that；　in
the　coming　and　going　of　the　generations　of　men；　had　such　witnessed
them；　the　contemporary；　conditions　would　have　seemed　to　be　unchanging
and　unchangeable。

　　　　*　See　〃On　a　piece　of　Chalk〃　in　the　preceding　volume　of　these
　　　　Essays　（vol。　　viii。　p。　1）。

But　it　is　also　certain　that；　before　the　deposition　of　the　chalk；　a
vastly　longer　period　had　elapsed；　throughout　which　it　is　easy　to
follow　the　traces　of　the　same　process　of　ceaseless　modification　and　of
the　internecine　struggle　for　existence　of　living　things；　and　that　even
when　we　can　get　no　further　＇4＇　back；　it　is　not　because　there　is　any
reason　to　think　we　have　reached　the　beginning；　but　because　the　trail
of　the　most　ancient　life　remains　hidden；　or　has　become　obliterated。

Thus　that　state　of　nature　of　the　world　of　plants　which　we　began　by
considering；　is　far　from　possessing　the　attribute　of　permanence。　Rather
its　very　essence　is　impermanence。　It　may　have　lasted　twenty　or　thirty
thousand　years；　it　may　last　for　twenty　or　thirty　thousand　years　more；
without　obvious　change；　but；　as　surely　as　it　has　followed　upon　a　very
different　state；　so　it　will　be　followed　by　an　equally　different
condition。　That　which　endures　is　not　one　or　another　association　of
living　forms；　but　the　process　of　which　the　cosmos　is　the　product；　and
of　which　these　are　among　the　transitory　expressions。　And　in　the　living
world；　one　of　the　most　characteristic　features　of　this　cosmic　process
is　the　struggle　for　existence；　the　competition　of　each　with　all；　the
result　of　which　is　the　selection；　that　is　to　say；　the　survival　of
those　forms　which；　on　the　whole；　are　best　adapted；　to　the　conditions
which　at　any　period　obtain；　and　which　are；　therefore；　in　that　respect；
and　only　in　that　respect；　the　fittest。*　The　acme　reached　by　the　cosmic
＇5＇　process　in　the　vegetation　of　the　downs　is　seen　in　the　turf；　with
its　weeds　and　gorse。　Under　the　conditions；　they　have　come　out　of　the
struggle　victorious；　and；　by　surviving；　have　proved　that　they　are　the
fittest　to　survive。

　　　　*　That　every　theory　of　evolution　must　be　consistent　not　merely
　　　　with　progressive　development；　but　with　indefinite　persistence
　　　　in　the　same　condition　and　with　retrogressive　modification；　is　a
　　　　point　which　I　have　insisted　upon　repeatedly　from　the　year　1862
　　　　till　now。　See　Collected　Essays；　vol。　ii。　pp。　461…89；　vol。　iii。
　　　　p。　33；　vol。　viii。　p。　304。　In　the　address　on　〃Geological
　　　　Contemporaneity　and　Persistent　Types〃　（1862）；　the
　　　　paleontological　proofs　of　this　proposition　were；　I　believe；
　　　　first　set　forth。

That　the　state　of　nature；　at　any　time；　is　a　temporary　phase　of　a
process　of　incessant　change；　which　has　been　going　on　for　innumerable
ages；　appears　to　me　to　be　a　proposition　as　well　established　as　any　in
modern　history。

Paleontology　assures　us；　in　addition；　that　the　ancient　philosophers
who；　with　less　reason；　held　the　same　doctrine；　erred　in　supposing　that
the　phases　formed　a　cycle；　exactly　repeating　the　past；　exactly
foreshadowing　the　future；　in　their　rotations。　On　the　contrary；　it
furnishes　us　with　conclusive　reasons　for　thinking　that；　if　every　link
in　the　ancestry　of　these　humble　indigenous　plants　had　been　preserved
and　were　accessible　to　us；　the　whole　would　present　a　converging　series
of　forms　of　gradually　diminishing　complexity；　until；　at　some　period　in
the　history　of　the　earth；　far　more　remote　than　any　of　which　organic
remains　have　yet　been　discovered；　they　would　merge　in　those　low　groups
among　which　the　Boundaries　between　animal　and　vegetable　life　become
effaced。*

　　　　*　〃On　the　Border　Territory　between　the　Animal　and　the　Vegetable
　　　　Kingdoms；〃　Essays；　vol。　viii。　p。　162

＇6＇　The　word　〃evolution；〃　now　generally　applied　to　the　cosmic　process；
has　had　a　singular　history；　and　is　used　in　various　senses。*　Taken　in
its　popular　signification　it　means　progressive　development；　that　is；
gradual　change　from　a　condition　of　relative　uniformity　to　one　of
relative　complexity；　but　its　connotation　has　been　widened　to　include
the　phenomena　of　retrogressive　metamorphosis；　that　is；　of　progress
from　a　condition　of　relative　complexity　to　one　of　relative　uniformity。

As　a　natural　process；　of　the　same　character　as　the　development　of　a
tree　from　its　seed；　or　of　a　fowl　from　its　egg；　evolution　excludes
creation　and　all　other　kinds　of　supernatural　intervention。　As　the
expression　of　a　fixed　order；　every　stage　of　which　is　the　effect　of
causes　operating　according　to　definite　rules；　the　conception　of
evolution　no　less　excludes　that　of　chance。　　It　is　very　desirable　to
remember　that　evolution　is　not　an　explanation　of　the　cosmic　process；
but　merely　a　generalized　statement　of　the　method　and　results　of　that
process。　And；　further；　that；　if　there　is　proof　that　the　cosmic　process
was　set　going　by　any　agent；　then　that　agent　will　be；　the　creator　of　it
and　of　all　its　products；　although　supernatural　intervention　may　remain
strictly　excluded　from　its　further　course。

So　far　as　that　limited　revelation　of　the　nature　of　things；　which　we
call　scientific　knowledge；　has　＇7＇　yet　gone；　it　tends；　with　constantly
increasing　emphasis；　to　the　belief　that；　not　merely　the　world　of
plants；　but　that　of　animals；　not　merely　living　things；　but　the　whole
fabric　of　the　earth；　not　merely　our　planet；　but　the　whole　solar
system；　not　merely　our　star　and　its　satellites；　but　the　millions　of
similar　bodies　which　bear　witness　to　the　order　which　pervades
boundless　space；　and　has　endured　through　boundless　time；　are　all
worki