part17- 第3部分

distribute　them　into　masses；　throwing　into　each　of　these　all　the

individuals　which　have　a　certain　degree　of　resemblance；　to　subdivide

these　again　into　smaller　groups；　according　to　certain　points　of

dissimilitude　observable　in　them；　and　so　on　until　we　have　formed　what

we　call　a　system　of　classes；　orders；　genera　and　species。　　In　doing

this；　we　fix　arbitrarily　on　such　characteristic　resemblances　and

differences　as　seem　to　us　most　prominent　and　invariable　in　the

several　subjects；　and　most　likely　to　take　a　strong　hold　in　our

memories。　　Thus　Ray　formed　one　classification　on　such　lines　of

division　as　struck　him　most　favorably；　Klein　adopted　another；　Brisson

a　third；　and　other　naturalists　other　designations；　till　Linnaeus

appeared。　　Fortunately　for　science；　he　conceived　in　the　three

kingdoms　of　nature；　modes　of　classification　which　obtained　the

approbation　of　the　learned　of　all　nations。　　His　system　was

accordingly　adopted　by　all；　and　united　all　in　a　general　language。　　It

offered　the　three　great　desiderata：　First；　of　aiding　the　memory　to

retain　a　knowledge　of　the　productions　of　nature。　　Secondly；　of

rallying　all　to　the　same　names　for　the　same　objects；　so　that　they

could　communicate　understandingly　on　them。　　And　Thirdly；　of　enabling

them；　when　a　subject　was　first　presented；　to　trace　it　by　its

character　up　to　the　conventional　name　by　which　it　was　agreed　to　be

called。　　This　classification　was　indeed　liable　to　the　imperfection　of

bringing　into　the　same　group　individuals　which；　though　resembling　in

the　characteristics　adopted　by　the　author　for　his　classification；　yet

have　strong　marks　of　dissimilitude　in　other　respects。　　But　to　this

objection　every　mode　of　classification　must　be　liable；　because　the

plan　of　creation　is　inscrutable　to　our　limited　faculties。　　Nature　has

not　arranged　her　productions　on　a　single　and　direct　line。　　They

branch　at　every　step；　and　in　every　direction；　and　he　who　attempts　to

reduce　them　into　departments；　is　left　to　do　it　by　the　lines　of　his

own　fancy。　　The　objection　of　bringing　together　what　are　disparata　in

nature；　lies　against　the　classifications　of　Blumenbach　and　of　Cuvier；

as　well　as　that　of　Linnaeus；　and　must　forever　lie　against　all。

Perhaps　not　in　equal　degree；　on　this　I　do　not　pronounce。　　But　neither

is　this　so　important　a　consideration　as　that　of　uniting　all　nations

under　one　language　in　Natural　History。　　This　had　been　happily

effected　by　Linnaeus；　and　can　scarcely　be　hoped　for　a　second　time。

Nothing　indeed　is　so　desperate　as　to　make　all　mankind　agree　in　giving

up　a　language　they　possess；　for　one　which　they　have　to　learn。　　The

attempt　leads　directly　to　the　confusion　of　the　tongues　of　Babel。

Disciples　of　Linnaeus；　of　Blumenbach；　and　of　Cuvier；　exclusively

possessing　their　own　nomenclatures；　can　no　longer　communicate

intelligibly　with　one　another。　　However　much；　therefore；　we　are

indebted　to　both　these　naturalists；　and　to　Cuvier　especially；　for　the

valuable　additions　they　have　made　to　the　sciences　of　nature；　I　cannot

say　they　have　rendered　her　a　service　in　this　attempt　to　innovate　in

the　settled　nomenclature　of　her　productions；　on　the　contrary；　I　think

it　will　be　a　check　on　the　progress　of　science；　greater　or　less；　in

proportion　as　their　schemes　shall　more　or　less　prevail。　　They　would

have　rendered　greater　service　by　holding　fast　to　the　system　on　which

we　had　once　all　agreed；　and　by　inserting　into　that　such　new　genera；

orders；　or　even　classes；　as　new　discoveries　should　call　for。　　Their

systems；　too；　and　especially　that　of　Blumenbach；　are　liable　to　the

objection　of　giving　too　much　into　the　province　of　anatomy。　　It　may　be

said；　indeed；　that　anatomy　is　a　part　of　natural　history。　　In　the

broad　sense　of　the　word；　it　certainly　is。　　In　that　sense；　however；　it

would　comprehend　all　the　natural　sciences；　every　created　thing　being

a　subject　of　natural　history　in　extenso。　　But　in　the　subdivisions　of

general　science；　as　has　been　observed　in　the　particular　one　of

natural　history；　it　has　been　necessary　to　draw　arbitrary　lines；　in

order　to　accommodate　our　limited　views。　　According　to　these；　as　soon

as　the　structure　of　any　natural　production　is　destroyed　by　art；　it

ceases　to　be　a　subject　of　natural　history；　and　enters　into　the　domain

ascribed　to　chemistry；　to　pharmacy；　to　anatomy；　&c。　　Linnaeus'　method

was　liable　to　this　objection　so　far　as　it　required　the　aid　of

anatomical　dissection；　as　of　the　heart；　for　instance；　to　ascertain

the　place　of　any　animal；　or　of　a　chemical　process　for　that　of　a

mineral　substance。　　It　would　certainly　be　better　to　adopt　as　much　as

possible　such　exterior　and　visible　characteristics　as　every　traveller

is　competent　to　observe；　to　ascertain　and　to　relate。　　But　with　this

objection；　lying　but　in　a　small　degree；　Linnaeus'　method　was

received；　understood；　and　conventionally　settled　among　the　learned；

and　was　even　getting　into　common　use。　　To　disturb　it　then　was

unfortunate。　　The　new　system　attempted　in　botany；　by　Jussieu；　in

mineralogy；　by　Hauiy；　are　subjects　of　the　same　regret；　and　so　also

the　no…system　of　Buffon；　the　great　advocate　of　individualism　in

opposition　to　classification。　　He　would　carry　us　back　to　the　days　and

to　the　confusion　of　Aristotle　and　Pliny；　give　up　the　improvements　of

twenty　centuries；　and　co…operate　with　the　neologists　in　rendering　the

science　of　one　generation　useless　to　the　next　by　perpetual　changes　of

its　language。　　In　botany；　Wildenow　and　Persoon　have　incorporated　into

Linnaeus　the　new　discovered　plants。　　I　do　not　know　whether　any　one

has　rendered　us　the　same　service　as　to　his　natural　history。　　It　would

be　a　very　acceptable　one。　　The　materials　furnished　by　Humboldt；　and

those　from　New　Holland　particularly；　require　to　be　digested　into　the

Catholic　system。　　Among　these；　the　Ornithorhyncus　mentioned　by　you；

is　an　amusing　example　of　the　anomalies　by　which　nature　sports　with

our　schemes　of　classification。　　Although　with　out　mammae；　naturalists

are　obliged　to　place　it　in　the　class　of　mammiferae；　and　Blumenbach；

particularly；　arranges　it　in　his　order　of　Palmipeds　and　toothless

genus；　with　the　walrus　and　manatie。　　In　Linnaeus'　system　it　might　be

inserted　as　a　new　genus　between　the　anteater　and　manis；　in　the　order

of　Bruta。　　It　seems；　in　truth；　to　have　stronger　relations　with　that

class　than　any　other　in　the　construction　of　the　heart；　its　red　and

warm　blood；　hairy　integuments；　in　being　quadruped　and　viviparous；　and

may　we　not　say；　in　its　_tout　ensemble_；　which　Buffon　makes　his　sole

principle　of　arrangement？　　The　mandible；　as　you　observe；　would　draw

it　towards　the　birds；　were　not　this　characteristic　overbalanced　by

the　weightier　ones　before　mentioned。　　That　of　the　Cloaca　is

equivocal；　because　although　a　character　of　birds；　yet　some　mammalia；

as　the　beaver　and　sloth；　have　the　rectum　and　urinary　passage

terminating　at　a　common　opening。　　Its　ribs　also；　by　their　number　and

structure；　are　nearer　those　of　the　bird　than　of　the　mammalia。　　It　is

possible　that　further　opportunities　of　examination　may　discover　the

mammae。　　Those　of　the　Opossum　are　asserted；　by　the　Chevalier

d'Aboville；　from　his　own　observations　on　that　animal；　made　while　here

with　the　French　army；　to　be　not　discoverable　until　pregnancy；　and　to

disappear　as　soon　as　the　young　are　weaned。　　The　Duckbill　has　many

additional　particularities　which　liken　it　to　other　genera；　and　some

entirely　peculiar。　　Its　description　and　history　needs　yet　further

information。




　　　　　　　　In　what　I　have　said　on　the　method　of　classing；　I　have　not　at

all　meant　to　insinuate　that　that　of　Linnaeus　is　intrinsically

preferable　to　those　of　Blumenbach　and　Cuvier。　　I　adhere　to　the

Linnean　because　it　is　sufficient　as　a　ground…work；　admits　of

supplementary　insertions　as　new　productions　are　discovered；　and

mainly　because　it　has　got　into　so　general　use　that　it　will　not　be

easy　to　displace　it；　and　still　less　to　find　another　which　shall　have

the　same　singular　fortune　of　obtaining　the　general　consent。　　During

the　attempt　we　shall　become　unintelligible　to　one　another；　and

science　will　be　really　retarded　by　efforts　to　advance　it　made　by　its

most　favorite　sons。　　I　am　not　myself　apt　to　be　alarmed　at　innovations

recommended　by　reason。　　That　dread　belongs　to　those　whose　interests

or　prejudices　shrink　from　the　advance　of　truth　and　science。　　My

reluctance　is　to　give　up　an　universal　language　of　which　we　are　in

possession；　without　an　assurnace　of　general　consent　to　receive

another。　　And　the　higher　the　character　of　the　authors　recommending

it；　and　the　more　excellent　what　they　offer；　the　greater　the　danger　of

producing　schism。




　　　　　　　　I　should　seem　to　need　apology　for　these　long　remarks　to　you　who

are　so　much　more　recent　in　these　studies；　but　I　find　it　in　your

particular　request　and　my　own　respect　for　it；　and　with　that　be

pleased　to　accept　the　assurance　of　my　esteem　and　consideration。







　　　　　　　　THE　CENSORSHIP　OF　BOOKS




　　　　　　　　_To　N。　G。　Dufief_

　　　　　　　　_Monticello；　April　19；　1814_




　　　　　　　　DEAR　SIR；　　Your　favor　of　the　6th　instant　is　just　received；

and　I　shall　with　equal　willingness　and　truth；　state　the　degree　of

agency　you　had；　respecting　the　copy　of　M。　de　Becourt's　book；　which

came　to　my　hands。　　That　gentleman　informed　me；　by　letter；　that　he　was

about　to　publish　a　volume　in　French；　〃Sur　la　Creation　du　Monde；　un

Systeme　d'Organisation　Primitive；〃　which；　its　title　promised　to　be；

either　a　geological　or　astronomical　work。　　I　subscribed；　and；　when

published；　he　sent　me　a　copy；　and　as　you　were　my　correspondent　in　the

book　line　in　Philadelphia；　I　took　the　liberty　of　desiring　him　to　call

on　you　for　the　price；　which；　he　afterwards　informed　me；　you　were　so

kind　as　to　pay　him　for　me；　being；　I　believe；　two　dollars。　　But　the

sole　copy　which　came　to　me　was　from　himself　directly；　and；　as　far　as

I　know；　was　never　seen　by　you。




　　　　　　　　I　am　really　mortified　to　be　told　that；　_in　the　United　States　of

America_；　a　fact　like　this　can　become　a　subje