¡¶essays on life, art and science¡·

ÏÂÔر¾Êé

Ìí¼ÓÊéÇ©

essays on life, art and science- µÚ29²¿·Ö


°´¼üÅÌÉÏ·½Ïò¼ü ¡û »ò ¡ú ¿É¿ìËÙÉÏÏ·­Ò³£¬°´¼üÅÌÉ쵀 Enter ¼ü¿É»Øµ½±¾ÊéĿ¼ҳ£¬°´¼üÅÌÉÏ·½Ïò¼ü ¡ü ¿É»Øµ½±¾Ò³¶¥²¿£¡
tells¡¡us£»¡¡on¡¡the¡¡first¡¡page¡¡of¡¡his¡¡preface£»¡¡that¡¡he¡¡has¡¡no¡¡intention
of¡¡dealing¡¡even¡¡in¡¡outline¡¡with¡¡the¡¡vast¡¡subject¡¡of¡¡evolution¡¡in
general£»¡¡and¡¡has¡¡only¡¡tried¡¡to¡¡give¡¡such¡¡an¡¡account¡¡of¡¡the¡¡theory¡¡of
natural¡¡selection¡¡as¡¡may¡¡facilitate¡¡a¡¡clear¡¡conception¡¡of¡¡Darwin's
work¡£¡¡¡¡How¡¡far¡¡he¡¡has¡¡succeeded¡¡is¡¡a¡¡point¡¡on¡¡which¡¡opinion¡¡will
probably¡¡be¡¡divided¡£¡¡¡¡Those¡¡who¡¡find¡¡Mr¡£¡¡Darwin's¡¡works¡¡clear¡¡will
also¡¡find¡¡no¡¡difficulty¡¡in¡¡understanding¡¡Mr¡£¡¡Wallace£»¡¡those£»¡¡on¡¡the
other¡¡hand£»¡¡who¡¡find¡¡Mr¡£¡¡Darwin¡¡puzzling¡¡are¡¡little¡¡likely¡¡to¡¡be
less¡¡puzzled¡¡by¡¡Mr¡£¡¡Wallace¡£¡¡¡¡He¡¡continues£º¡­

¡¨The¡¡objections¡¡now¡¡made¡¡to¡¡Darwin's¡¡theory¡¡apply¡¡solely¡¡to¡¡the
particular¡¡means¡¡by¡¡which¡¡the¡¡change¡¡of¡¡species¡¡has¡¡been¡¡brought
about£»¡¡not¡¡to¡¡the¡¡fact¡¡of¡¡that¡¡change¡£¡¨

But¡¡¡¨Darwin's¡¡theory¡¨as¡¡Mr¡£¡¡Wallace¡¡has¡¡elsewhere¡¡proved¡¡that¡¡he
understandshas¡¡no¡¡reference¡¡¡¨to¡¡the¡¡fact¡¡of¡¡that¡¡change¡¨that¡¡is
to¡¡say£»¡¡to¡¡the¡¡fact¡¡that¡¡species¡¡have¡¡been¡¡modified¡¡in¡¡course¡¡of
descent¡¡from¡¡other¡¡species¡£¡¡¡¡This¡¡is¡¡no¡¡more¡¡Mr¡£¡¡Darwin's¡¡theory
than¡¡it¡¡is¡¡the¡¡reader's¡¡or¡¡my¡¡own¡£¡¡¡¡Darwin's¡¡theory¡¡is¡¡concerned
only¡¡with¡¡¡¨the¡¡particular¡¡means¡¡by¡¡which¡¡the¡¡change¡¡of¡¡species¡¡has
been¡¡brought¡¡about¡¨£»¡¡his¡¡contention¡¡being¡¡that¡¡this¡¡is¡¡mainly¡¡due¡¡to
the¡¡natural¡¡survival¡¡of¡¡those¡¡individuals¡¡that¡¡have¡¡happened¡¡by¡¡some
accident¡¡to¡¡be¡¡born¡¡most¡¡favourably¡¡adapted¡¡to¡¡their¡¡surroundings£»
or£»¡¡in¡¡other¡¡words£»¡¡through¡¡accumulation¡¡in¡¡the¡¡common¡¡course¡¡of
nature¡¡of¡¡the¡¡more¡¡lucky¡¡variations¡¡that¡¡chance¡¡occasionally
purveys¡£¡¡¡¡Mr¡£¡¡Wallace's¡¡words£»¡¡then£»¡¡in¡¡reality¡¡amount¡¡to¡¡this£»¡¡that
the¡¡objections¡¡now¡¡made¡¡to¡¡Darwin's¡¡theory¡¡apply¡¡solely¡¡to¡¡Darwin's
theory£»¡¡which¡¡is¡¡all¡¡very¡¡well¡¡as¡¡far¡¡as¡¡it¡¡goes£»¡¡but¡¡might¡¡have
been¡¡more¡¡easily¡¡apprehended¡¡if¡¡he¡¡had¡¡simply¡¡said£»¡¡¡¨There¡¡are
several¡¡objections¡¡now¡¡made¡¡to¡¡Mr¡£¡¡Darwin's¡¡theory¡£¡¨

It¡¡must¡¡be¡¡remembered¡¡that¡¡the¡¡passage¡¡quoted¡¡above¡¡occurs¡¡on¡¡the
first¡¡page¡¡of¡¡a¡¡preface¡¡dated¡¡March¡¡1889£»¡¡when¡¡the¡¡writer¡¡had
completed¡¡his¡¡task£»¡¡and¡¡was¡¡most¡¡fully¡¡conversant¡¡with¡¡his¡¡subject¡£
Nevertheless£»¡¡it¡¡seems¡¡indisputable¡¡either¡¡that¡¡he¡¡is¡¡still
confusing¡¡evolution¡¡with¡¡Mr¡£¡¡Darwin's¡¡theory£»¡¡or¡¡that¡¡he¡¡does¡¡not
know¡¡when¡¡his¡¡sentences¡¡have¡¡point¡¡and¡¡when¡¡they¡¡have¡¡none¡£

I¡¡should¡¡perhaps¡¡explain¡¡to¡¡some¡¡readers¡¡that¡¡Mr¡£¡¡Darwin¡¡did¡¡not
modify¡¡the¡¡main¡¡theory¡¡put¡¡forward£»¡¡first¡¡by¡¡Buffon£»¡¡to¡¡whom¡¡it
indisputably¡¡belongs£»¡¡and¡¡adopted¡¡from¡¡him¡¡by¡¡Erasmus¡¡Darwin£»
Lamarck£»¡¡and¡¡many¡¡other¡¡writers¡¡in¡¡the¡¡latter¡¡half¡¡of¡¡the¡¡last
century¡¡and¡¡the¡¡earlier¡¡years¡¡of¡¡the¡¡present¡£¡¡¡¡The¡¡early
evolutionists¡¡maintained¡¡that¡¡all¡¡existing¡¡forms¡¡of¡¡animal¡¡and
vegetable¡¡life£»¡¡including¡¡man£»¡¡were¡¡derived¡¡in¡¡course¡¡of¡¡descent
with¡¡modification¡¡from¡¡forms¡¡resembling¡¡the¡¡lowest¡¡now¡¡known¡£

Mr¡£¡¡Darwin¡¡went¡¡as¡¡far¡¡as¡¡this£»¡¡and¡¡farther¡¡no¡¡one¡¡can¡¡go¡£¡¡¡¡The
point¡¡at¡¡issue¡¡between¡¡him¡¡and¡¡his¡¡predecessors¡¡involves¡¡neither¡¡the
main¡¡fact¡¡of¡¡evolution£»¡¡nor¡¡yet¡¡the¡¡geometrical¡¡ratio¡¡of¡¡increase£»
and¡¡the¡¡struggle¡¡for¡¡existence¡¡consequent¡¡thereon¡£¡¡¡¡Messrs¡£¡¡Darwin
and¡¡Wallace¡¡have¡¡each¡¡thrown¡¡invaluable¡¡light¡¡upon¡¡these¡¡last¡¡two
points£»¡¡but¡¡Buffon£»¡¡as¡¡early¡¡as¡¡1756£»¡¡had¡¡made¡¡them¡¡the¡¡keystone¡¡of
his¡¡system¡£¡¡¡¡¡¨The¡¡movement¡¡of¡¡nature£»¡¨¡¡he¡¡then¡¡wrote£»¡¡¡¨turns¡¡on¡¡two
immovable¡¡pivots£º¡¡¡¡one£»¡¡the¡¡illimitable¡¡fecundity¡¡which¡¡she¡¡has
given¡¡to¡¡all¡¡species£º¡¡¡¡the¡¡other£»¡¡the¡¡innumerable¡¡difficulties¡¡which
reduce¡¡the¡¡results¡¡of¡¡that¡¡fecundity¡£¡¨¡¡¡¡Erasmus¡¡Darwin¡¡and¡¡Lamarck
followed¡¡in¡¡the¡¡same¡¡sense¡£¡¡¡¡They¡¡thus¡¡admit¡¡the¡¡survival¡¡of¡¡the
fittest¡¡as¡¡fully¡¡as¡¡Mr¡£¡¡Darwin¡¡himself£»¡¡though¡¡they¡¡do¡¡not¡¡make¡¡use
of¡¡this¡¡particular¡¡expression¡£¡¡¡¡The¡¡dispute¡¡turns¡¡not¡¡upon¡¡natural
selection£»¡¡which¡¡is¡¡common¡¡to¡¡all¡¡writers¡¡on¡¡evolution£»¡¡but¡¡upon¡¡the
nature¡¡and¡¡causes¡¡of¡¡the¡¡variations¡¡that¡¡are¡¡supposed¡¡to¡¡be¡¡selected
from¡¡and¡¡thus¡¡accumulated¡£¡¡¡¡Are¡¡these¡¡mainly¡¡attributable¡¡to¡¡the
inherited¡¡effects¡¡of¡¡use¡¡and¡¡disuse£»¡¡supplemented¡¡by¡¡occasional
sports¡¡and¡¡happy¡¡accidents£¿¡¡¡¡Or¡¡are¡¡they¡¡mainly¡¡due¡¡to¡¡sports¡¡and
happy¡¡accidents£»¡¡supplemented¡¡by¡¡occasional¡¡inherited¡¡effects¡¡of¡¡use
and¡¡disuse£¿

The¡¡Lamarckian¡¡system¡¡has¡¡all¡¡along¡¡been¡¡maintained¡¡by¡¡Mr¡£¡¡Herbert
Spencer£»¡¡who£»¡¡in¡¡his¡¡¡¨Principles¡¡of¡¡Biology£»¡¨¡¡published¡¡in¡¡1865£»
showed¡¡how¡¡impossible¡¡it¡¡was¡¡that¡¡accidental¡¡variations¡¡should
accumulate¡¡at¡¡all¡£¡¡¡¡I¡¡am¡¡not¡¡sure¡¡how¡¡far¡¡Mr¡£¡¡Spencer¡¡would¡¡consent
to¡¡being¡¡called¡¡a¡¡Lamarckian¡¡pure¡¡and¡¡simple£»¡¡nor¡¡yet¡¡how¡¡far¡¡it¡¡is
strictly¡¡accurate¡¡to¡¡call¡¡him¡¡one£»¡¡nevertheless£»¡¡I¡¡can¡¡see¡¡no
important¡¡difference¡¡in¡¡the¡¡main¡¡positions¡¡taken¡¡by¡¡him¡¡and¡¡by
Lamarck¡£

The¡¡question¡¡at¡¡issue¡¡between¡¡the¡¡Lamarckians£»¡¡supported¡¡by¡¡Mr¡£
Spencer¡¡and¡¡a¡¡growing¡¡band¡¡of¡¡those¡¡who¡¡have¡¡risen¡¡in¡¡rebellion
against¡¡the¡¡Charles¡­Darwinian¡¡system¡¡on¡¡the¡¡one¡¡hand£»¡¡and¡¡Messrs¡£
Darwin¡¡and¡¡Wallace¡¡with¡¡the¡¡greater¡¡number¡¡of¡¡our¡¡more¡¡prominent
biologists¡¡on¡¡the¡¡other£»¡¡involves¡¡the¡¡very¡¡existence¡¡of¡¡evolution¡¡as
a¡¡workable¡¡theory¡£¡¡¡¡For¡¡it¡¡is¡¡plain¡¡that¡¡what¡¡Nature¡¡can¡¡be¡¡supposed
able¡¡to¡¡do¡¡by¡¡way¡¡of¡¡choice¡¡must¡¡depend¡¡on¡¡the¡¡supply¡¡of¡¡the
variations¡¡from¡¡which¡¡she¡¡is¡¡supposed¡¡to¡¡choose¡£¡¡¡¡She¡¡cannot¡¡take
what¡¡is¡¡not¡¡offered¡¡to¡¡her£»¡¡and¡¡so¡¡again¡¡she¡¡cannot¡¡be¡¡supposed¡¡able
to¡¡accumulate¡¡unless¡¡what¡¡is¡¡gained¡¡in¡¡one¡¡direction¡¡in¡¡one
generation£»¡¡or¡¡series¡¡of¡¡generations£»¡¡is¡¡little¡¡likely¡¡to¡¡be¡¡lost¡¡in
those¡¡that¡¡presently¡¡succeed¡£¡¡¡¡Now¡¡variations¡¡ascribed¡¡mainly¡¡to¡¡use
and¡¡disuse¡¡can¡¡be¡¡supposed¡¡capable¡¡of¡¡being¡¡accumulated£»¡¡for¡¡use¡¡and
disuse¡¡are¡¡fairly¡¡constant¡¡for¡¡long¡¡periods¡¡among¡¡the¡¡individuals¡¡of
the¡¡same¡¡species£»¡¡and¡¡often¡¡over¡¡large¡¡areas£»¡¡moreover£»¡¡conditions
of¡¡existence¡¡involving¡¡changes¡¡of¡¡habit£»¡¡and¡¡thus¡¡of¡¡organisation£»
come¡¡for¡¡the¡¡most¡¡part¡¡gradually£»¡¡so¡¡that¡¡time¡¡is¡¡given¡¡during¡¡which
the¡¡organism¡¡can¡¡endeavour¡¡to¡¡adapt¡¡itself¡¡in¡¡the¡¡requisite
respects£»¡¡instead¡¡of¡¡being¡¡shocked¡¡out¡¡of¡¡existence¡¡by¡¡too¡¡sudden
change¡£¡¡¡¡Variations£»¡¡on¡¡the¡¡other¡¡hand£»¡¡that¡¡are¡¡ascribed¡¡to¡¡mere
chance¡¡cannot¡¡be¡¡supposed¡¡as¡¡likely¡¡to¡¡be¡¡accumulated£»¡¡for¡¡chance¡¡is
notoriously¡¡inconstant£»¡¡and¡¡would¡¡not¡¡purvey¡¡the¡¡variations¡¡in
sufficiently¡¡unbroken¡¡succession£»¡¡or¡¡in¡¡a¡¡sufficient¡¡number¡¡of
individuals£»¡¡modified¡¡similarly¡¡in¡¡all¡¡the¡¡necessary¡¡correlations¡¡at
the¡¡same¡¡time¡¡and¡¡place¡¡to¡¡admit¡¡of¡¡their¡¡being¡¡accumulated¡£¡¡¡¡It¡¡is
vital¡¡therefore¡¡to¡¡the¡¡theory¡¡of¡¡evolution£»¡¡as¡¡was¡¡early¡¡pointed¡¡out
by¡¡the¡¡late¡¡Professor¡¡Fleeming¡¡Jenkin¡¡and¡¡by¡¡Mr¡£¡¡Herbert¡¡Spencer£»
that¡¡variations¡¡should¡¡be¡¡supposed¡¡to¡¡have¡¡a¡¡definite¡¡and¡¡persistent
principle¡¡underlying¡¡them£»¡¡which¡¡shall¡¡tend¡¡to¡¡engender¡¡similar¡¡and
simultaneous¡¡modification£»¡¡however¡¡small£»¡¡in¡¡the¡¡vast¡¡majority¡¡of
individuals¡¡composing¡¡any¡¡species¡£¡¡¡¡The¡¡existence¡¡of¡¡such¡¡a
principle¡¡and¡¡its¡¡permanence¡¡is¡¡the¡¡only¡¡thing¡¡that¡¡can¡¡be¡¡supposed
capable¡¡of¡¡acting¡¡as¡¡rudder¡¡and¡¡compass¡¡to¡¡the¡¡accumulation¡¡of
variations£»¡¡and¡¡of¡¡making¡¡it¡¡hold¡¡steadily¡¡on¡¡one¡¡course¡¡for¡¡each
species£»¡¡till¡¡eventually¡¡many¡¡havens£»¡¡far¡¡remote¡¡from¡¡one¡¡another£»
are¡¡safely¡¡reached¡£

It¡¡is¡¡obvious¡¡that¡¡the¡¡having¡¡fatally¡¡impaired¡¡the¡¡theory¡¡of¡¡his
predecessors¡¡could¡¡not¡¡warrant¡¡Mr¡£¡¡Darwin¡¡in¡¡claiming£»¡¡as¡¡he¡¡most
fatuously¡¡did£»¡¡the¡¡theory¡¡of¡¡evolution¡£¡¡¡¡That¡¡he¡¡is¡¡still¡¡generally
believed¡¡to¡¡have¡¡been¡¡the¡¡originator¡¡of¡¡this¡¡theory¡¡is¡¡due¡¡to¡¡the
fact¡¡that¡¡he¡¡claimed¡¡it£»¡¡and¡¡that¡¡a¡¡powerful¡¡literary¡¡backing¡¡at
once¡¡came¡¡forward¡¡to¡¡support¡¡him¡£¡¡¡¡It¡¡seems¡¡at¡¡first¡¡sight
improbable¡¡that¡¡those¡¡who¡¡too¡¡zealously¡¡urged¡¡his¡¡claims¡¡were
unaware¡¡that¡¡so¡¡much¡¡had¡¡been¡¡written¡¡on¡¡the¡¡subject£»¡¡but¡¡when¡¡we
find¡¡even¡¡Mr¡£¡¡Wallace¡¡himself¡¡as¡¡profoundly¡¡ignorant¡¡on¡¡this¡¡subject
as¡¡he¡¡still¡¡either¡¡is£»¡¡or¡¡affects¡¡to¡¡be£»¡¡there¡¡is¡¡no¡¡limit
assignable¡¡to¡¡the¡¡ignorance¡¡or¡¡affected¡¡ignorance¡¡of¡¡the¡¡kind¡¡of
biologists¡¡who¡¡would¡¡write¡¡reviews¡¡in¡¡leading¡¡journals¡¡thirty¡¡years
ago¡£¡¡¡¡Mr¡£¡¡Wallace¡¡writes£º¡­

¡¨A¡¡few¡¡great¡¡naturalists£»¡¡struck¡¡by¡¡the¡¡very¡¡slight¡¡difference
between¡¡many¡¡of¡¡these¡¡species£»¡¡and¡¡the¡¡numerous¡¡links¡¡that¡¡exist
between¡¡the¡¡most¡¡different¡¡forms¡¡of¡¡animals¡¡and¡¡plants£»¡¡and¡¡also
observing¡¡that¡¡a¡¡great¡¡many¡¡species¡¡do¡¡vary¡¡considerably¡¡in¡¡their
forms£»¡¡colours¡¡and¡¡habits£»¡¡conceived¡¡the¡¡idea¡¡that¡¡they¡¡might¡¡be¡¡all
produced¡¡one¡¡from¡¡the¡¡other¡£¡¡¡¡The¡¡most¡¡eminent¡¡of¡¡these¡¡writers¡¡was
a¡¡great¡¡French¡¡naturalist£»¡¡Lamarck£»¡¡who¡¡published¡¡an¡¡elaborate¡¡work£»
the¡¡Philosophie¡¡Zoologique£»¡¡in¡¡which¡¡he¡¡endeavoured¡¡to¡¡prove¡¡that
all¡¡animals¡¡whatever¡¡are¡¡descended¡¡from¡¡other¡¡species¡¡of¡¡animals¡£
He¡¡attributed¡¡the¡¡change¡¡of¡¡species¡¡chiefly¡¡to¡¡the¡¡effect¡¡of¡¡changes
in¡¡the¡¡conditions¡¡of¡¡lifesuch¡¡as¡¡climate£»¡¡food£»¡¡&c¡££»¡¡and
especially¡¡to¡¡the¡¡desires¡¡and¡¡efforts¡¡of¡¡the¡¡animals¡¡themselves¡¡to
improve¡¡their¡¡condition£»¡¡leading¡¡to¡¡a¡¡modification¡¡of¡¡form¡¡or¡¡size
in¡¡certain¡¡parts£»¡¡owing¡¡to¡¡the¡¡well¡­known¡¡physiological¡¡law¡¡that¡¡all
organs¡¡are¡¡strengthened¡¡by¡¡constant¡¡use£»¡¡while¡¡they¡¡are¡¡weakened¡¡or
even¡¡completely¡¡lost¡¡by¡¡disuse¡¡¡£¡¡¡£¡¡¡£

¡¨The¡¡only¡¡other¡¡important¡¡work¡¡dealing¡¡with¡¡the¡¡question¡¡was¡¡the
celebrated¡¡'Vestiges¡¡of¡¡Creation£»'¡¡published¡¡anonymously£»¡¡but¡¡now
acknowledged¡¡to¡¡have¡¡been¡¡written¡¡by¡¡the¡¡late¡¡Robert¡¡Chambers¡£¡¨

None¡¡are¡¡so¡¡blind¡¡as¡¡those¡¡who¡¡will¡¡not¡¡see£»¡¡and¡¡it¡¡would¡¡be¡¡waste
of¡¡time¡¡to¡¡argue¡¡with¡¡the¡¡invincible¡¡ignorance¡¡of¡¡one¡¡who¡¡thinks
Lamarck¡¡and¡¡Buffon¡¡conceived¡¡that¡¡all¡¡species¡¡were¡¡produced¡¡from¡¡one
another£»¡¡more¡¡especially¡¡as¡¡I¡¡have¡¡already¡¡dealt¡¡at¡¡some¡¡length¡¡with
the¡¡early¡¡evolutionists¡¡in¡¡my¡¡work£»¡¡¡¨Evolution£»¡¡Old¡¡and¡¡New£»¡¨¡¡first
published¡¡ten¡¡years¡¡ago£»
СÌáʾ£º°´ »Ø³µ [Enter] ¼ü ·µ»ØÊéÄ¿£¬°´ ¡û ¼ü ·µ»ØÉÏÒ»Ò³£¬ °´ ¡ú ¼ü ½øÈëÏÂÒ»Ò³¡£ ÔÞһϠÌí¼ÓÊéÇ©¼ÓÈëÊé¼Ü