Butagentleandpeacefulanimalwhichlivesamongotheranimalsofthesamedispositionandofgentlenurture，willbeanenemyofbloodandcarnage；itwillblushinternallyathavingshedblood。Thereisperhapsthisdifference，thatsinceamonganimalseverythingissacrificedtotheirneeds，totheirpleasures，tothenecessitiesoflife，whichtheyenjoymorethanwe，theirremorseapparentlyshouldnotbeaskeenasours，becausewearenotinthesamestateofnecessityasthey。Customperhapsdullsandperhapsstiflesremorseaswellaspleasures。
ButIwillforamomentsupposethatIamutterlymistakeninconcludingthatalmostalltheworldholdsawrongopiniononthissubject，whileIaloneamright。Iwillgrantthatanimals，eventhebestofthem，donotknowthedifferencebetweenmoralgoodandevil，thattheyhavenorecollectionofthetroubletakenforthem，ofthekindnessdonethem，norealizationoftheirownvirtues。[Iwillsuppose]，forinstance，thatthislion，towhichI，likesomanyothers，havereferred，doesnotrememberatallthatitrefusedtokilltheman，abandonedtoitsfury，inacombatmoreinhumanthanonecouldfindamonglions，tigersandbears，puttogether。Forourcompatriotsfight，SwissagainstSwiss，brotheragainstbrother，recognizeeachother，andyetcaptureandkilleachotherwithoutremorse，becauseaprincepaysforthemurder。
Isupposeinshotthatthenaturallawhasnotbeengiventoanimals。Whatwillbetheconsequencesofthissupposition？Manisnotmouldedfromacostlierclay；naturehasusedbutonedough，andhasmerelyvariedtheleaven。ThereforeifanimalsdonotrepentforhavingviolatedthisinmostfeelingwhichI
amdiscussing，orratheriftheyabsolutelylackit，manmustnecessarilybeinthesamecondition。Farewellthentothenaturallawandallthefinetreatisespublishedaboutit！Thewholeanimalkingdomingeneralwouldbedeprivedofit。But，conversely，ifmancannotdispensewiththebeliefthatwhenhealthpermitshimtobehimself，healwaysdistinguishestheupright，humane，andvirtuous，fromthosewhoarenothuman，virtuous，norhonorable：
thatitiseasytotellvicefromvirtue，bytheuniquepleasureandthepeculiarrepugnancethatseemstobetheirnaturaleffects，itfollowsthatanimals，composedofthesamematter，lackingperhapsonlyonedegreeoffermentationtomakeitexactlylikeman’s，mustsharethesameprerogativesofanimalnature，andthatthusthereexistsnosoulorsensitivesubstancewithoutremorse。Thefollowingconsiderationswillreinforcetheseobservations。
Itisimpossibletodestroythenaturallaw。Theimpressofitonallanimalsissostrong，thatIhavenodoubtthatthewildestandmostsavagehavesomemomentsofrepentance。IbelievethatthatcruelmaidofChalonsinChampagnemusthavesorrowedforhercrime，ifshereallyatehersister。Ithinkthatthesamthingistrueofallthosewhocommitcrimes，eveninvoluntaryortemperamentalcrimes：trueofGastonofOrleanswhocouldnothelpstealing；ofacertainwomanwhowassubjecttothesamecrimewhenpregnant，andwhosechildreninheritedit；ofthewomanwho，inthesamecondition，ateherhusband；ofthatotherwomenwhokilledherchildren，saltedtheirbodies，andateapieceofthemeveryday，asalittlerelish；ofthatdaughterofathiefandcannibalwhoattwelveyearsfollowedinhissteps，althoughshehadbeenorphanedwhenshewasayearold，andhadbeenbroughtupbyhonestpeople；tosaynothingofmanyotherexamplesofwhichtherecordsofourobserversarefull，allofthemprovingthatthereareathousandhereditaryvicesandvirtueswhicharetransmittedfromparentstochildrenasthoseofthefostermotherpasstothechildrenshenurses。Now，Ibelieveandadmitthatthesewretchesdonotforthemostpartfeelatthetimetheenormityoftheiractions。Bulimia，orcaninehunger，forexample，canstifleallfeeling；itisamaniaofthestomachthatoneiscompelledtosatisfy，butwhatremorsemustbeinstoreforthosewomen，whenthecometothemselvesandgrowsober，andrememberthecrimestheyhavecommittedagainstthosetheyheldmostdear！Whatapunishmentforaninvoluntarycrimewhichtheycouldnotresist，ofwhichtheyhadnoconsciousnesswhatever！However，thisisapparentlynotenoughforthejudges。Forofthesewomen，ofwhomItell，onewascruellybeatenandburned，andanotherwasburiedalive。Irealizethatallthisisdemandedbytheinterestofsociety。Butdoubtlessitismuchtobewishedthatexcellentphysiciansmightbetheonlyjudges。Theyalonecouldtelltheinnocentcriminalfromtheguilty。
Ifreasonistheslaveofadepravedormaddesire，howcanitcontrolthedesire？
Butifcrimecarrieswithititsownmoreorlesscruelpunishment，ifthemostcontinuedandmostbarbaroushabitcannotentirelyblotoutrepentanceinthecruelesthearts，ifcriminalsarelaceratedbytheverymemoryoftheirdeeds，whyshouldwefrightentheimaginationofweakminds，byahell，byspecters，andbyprecipicesoffireevenlessrealthanthoseofPascal？Whymustwehaverecoursetofables，asanhonestpopeoncesaidhimself，totormenteventheunhappywretcheswhoareexecuted，becausewedonotthinkthattheyaresufficientlypunishedbytheirownconscience，theirfirstexecutioner？Idonotmeantosaythatallcriminalsareunjustlypunished；Ionlymaintainthatthosewhosewillisdepraved，andwhoseconscienceisextinguished，arepunishedenoughbytheirremorsewhentheycometothemselves，aremorse，Iventuretoassert，fromwhichnatureshouldinthiscasehavedeliveredunhappysoulsdraggedonbyafatalnecessity。
Criminals，scoundrels，ingrates，thoseinshortwithoutnaturalfeelings，unhappytyrantswhoareunworthyoflife，invaintakeacruelpleasureintheirbarbarity，fortherearecalmmomentsofreflectioninwhichtheavengingconsciencearises，testifiesagainstthem，andcondemnsthemtobealmostceaselesslytorntopiecesattheirownhands。Whoevertormentsmenistormentedbyhimself；andthesufferingsthathewillexperiencewillbethejustmeasureofthosethathehasinflicted。
Ontheotherhand，thereissomuchpleasureindoinggood，inrecognizingandappreciatingwhatonereceives，somuchsatisfactioninpractisingvirtue，inbeinggentle，humane，kind，charitable，compassionateandgenerous（forthisonewordincludesallthevirtues），thatIconsiderassufficientlypunishedanyonewhoisunfortunateenoughnottohavebeenbornvirtuous。
Wewerenotoriginallymadetobelearned；wehavebecomesoperhapsbyasortofabuseofourorganicfaculties，andattheexpenseoftheStatewhichnourishesahostofsluggardswhomvanityhasadornedwiththenameofphilosophers。Naturehascreatedusallsolelytobehappy-yes，allofusfromthecrawlingwormtotheeaglelostintheclouds。Forthiscauseshehasgivenallanimalssomeshareofnaturallaw，asharegreaterorlessaccordingtotheneedsofeachanimal’sorganswheninnormalcondition。
Nowhowshallwedefinenaturallaw？Itisafeelingthatteachesuswhatweshouldnotdo，becausewewouldnotwishittobedonetous。ShouldIdareaddtothiscommonidea，thatthisfeelingseemstomebutakindoffearordread，assalutarytotheraceastotheindividual；formayitnotbetruethatwerespectthepurseandlifeofothers，onlytosaveourownpossessions，ourhonor，andourselves；likethoseIxionsofChristianitywholoveGodandembracesomanyfantasticvirtues，merelybecausetheyareafraidofhell！
Youseethatnaturallawisbutanintimatefeelingthat，likeallotherfeelings（thoughtincluded）belongsalsotoimagination。
Evidently，therefore，naturallawdoesnotpresupposeeducation，revelation，norlegislator，-providedonedoesnotproposetoconfusenaturallawwithcivillaws，intheridiculousfashionofthetheologians。
Thearmsoffanaticismmaydestroythosewhosupportthesetruths，buttheywillneverdestroythetruthsthemselves。
Idonotmeantocallinquestiontheexistenceofasupremebeing；
onthecontraryitseemstomethatthegreatestdegreeofprobabilityisinfavorofthisbelief。Butsincetheexistenceofthisbeinggoesnofurtherthanthatofanyothertowardprovingtheneedofworship，itisatheoretictruthwithverylittlepracticalvalue。Therefore，sincewemaysay，aftersuchlongexperience，thatreligiondoesnotimplyexacthonesty，weareauthorizedbythesamereasonstothinkthatatheismdoesnotexcludeit。
Furthermore，whocanbesurethatthereasonforman’sexistenceisnotsimplythefactthatheexists？Perhapshewasthrownbychanceonsomespotontheearth’ssurface，nobodyknowshownorwhy，butsimplythathemustliveanddie，likethemushroomswhichappearfromdaytoday，orlikethoseflowerswhichbordertheditchesandcoverthewalls。
Letusnotloseourselvesintheinfinite，forwearenotmadetohavetheleastideathereof，andareabsolutelyunabletogetbacktotheoriginofthings。Besidesitdoesnotmatterforourpeaceofmind，whethermatterbeeternalorhavebeencreated，whethertherebeorbenotaGod。Howfoolishtotormentourselvessomuchaboutthingswhichwecannotknow，andwhichwouldnotmakeusanyhappierevenwerewetogainknowledgeaboutthem！
But，somewillsay，readallsuchworksasthoseofFé；nelon，ofNieuwentyt，ofAbadie，ofBerham，ofRais，andtherest。Well！
whatwilltheyteachmeorratherwhathavetheytaughtme？Theyareonlytiresomerepetitionsofzealouswriters，oneofwhomaddstotheotheronlyverbiage，morelikelytostrengthenthantounderminethefoundationsofatheism。Thenumberofevidencesdrawnfromthespectacleofnaturedoesnotgivetheseevidencesanymoreforce。Eitherthemerestructureofafinger，ofanear，ofaneye，asingleobservationofMalpighiprovesall，anddoubtlessmuchbetterthanDescartesandMalebrancheprovedit，oralltheotherevidencesprovenothing。Deists，andevenChristians，shouldthereforebecontenttopointoutthatthroughouttheanimalkingdomthesameaimsarepursuedandaccomplishedbyaninfinitenumberofdifferentmechanisms，allofthemhoweverexactlygeometrical。Forwhatstrongerweaponscouldtherebewithwhichtooverthrowatheists？Itistruethatifmyreasondoesnotdeceiveme，manandthewholeuniverseseemtohavebeendesignedforthisunityofaim。Thesun，air，water，theorganism，theshapeofbodies，-everythingisbroughttoafocusintheeyeasinamirrorthatfaithfullypresentstotheimaginationalltheobjectsreflectedinit，inaccordancewiththelawsrequiredbytheinfinitevarietyofbodieswhichtakepartinvision。Inearswefindeverywhereastrikingvariety，andyetthedifferenceofstructureinmen，animals，birds，andfishes，doesnotproducedifferentuses。Allearsaresomathematicallymade，thattheytendequallytooneandthesameend，namelyhearing。ButwouldChance，thedeistasks，beagreatenoughgeometriciantovarythus，atpleasure，theworksofwhichsheissupposedtobetheauthor，withoutbeinghinderedbysogreatadiversityfromgainingthesameend？
Again，thedeistwillbringforwardasadifficultythosepartsoftheanimalthatareclearlycontainedinitforfutureuse，thebutterflyinthecaterpillar，maninthesperm，awholepolypineachofitsparts，thevalvuleintheovalorifice，thelungsinthefoetus，theteethintheirsockets，thebonesinthefluidfromwhichtheydetachthemselvesand（inanincomprehensiblemanner）
harden。Andsincethepartisansofthistheory，farfromneglectinganythingthatwouldstrengthenproof，nevertireofpilingupproofuponproof，theyarewillingtoavailthemselvesofeverything，evenoftheweaknessofthemindincertaincases。Look，theysay，atmenlikeSpinoza，Vanini，Desbarreau，andBoindin，apostleswhohonordeismmorethantheyharmit。Thedurationoftheirhealthwasthemeasureoftheirunbelief，andonerarelyfails，theyadd，torenounceatheismwhenthepassions，withtheirinstrument，thebody，havegrownweak。
ThatiscertainlythemostthatcanbesaidinfavoroftheexistenceofGod：althoughthelastargumentisfrivolousinthattheseconversionsareshort，andthemindalmostalwaysregainsitsformeropinionsandactsaccordingly，assoonasithasregainedorratherrediscovereditsstrengthinthatofthebody。Thatis，atleast，muchmorethanwassaidbythephysicianDiderot，inhisPensé；esPhilosophiques，asublimeworkthatwillnotconvinceasingleatheist。Whatreplycan，intruth，bemadetoamanwhosays，``Wedonotknownature；causeshiddeninherbreastmighthaveproducedeverything。Inyourturn，observethepolypofTrembley：doesitnotcontaininitselfthecauseswhichbringaboutregeneration？Whythenwoulditbeabsurdtothinkthattherearephysicalcausesbyreasonofwhicheverythinghasbeenmade，andtowhichthewholechainofthisvastuniverseissonecessarilyboundandheldthatnothingwhichhappens，couldhavefailedtohappen，-causes，ofwhichwearesoinvinciblyignorantthatwehavehadrecoursetoaGod，who，assomeaver，isnotsomuchasalogicalentity？Thustodestroychanceisnottoprovetheexistenceofasupremebeing，sincetheremaybesomeotherthingwhichisneitherchancenorGod-
Imean，nature。Itfollowsthatthestudyofnaturecanonlymakeunbelievers；
andthewayofthinkingofallitsmoresuccessfulinvestigatorsprovesthis。’’
Theweightoftheuniversethereforefarfromcrushingarealatheistdoesnotevenshakehim。Alltheseevidencesofacreator，repeatedthousandsandthousandsoftimes，evidencethatareplacedfarabovethecomprehensionofmenlikeus，areself-evident（howeverfaronepushtheargument）onlytotheanti-Pyrrhonians，ortothosewhohaveenoughconfidenceintheirreasontopbelievethemselvescapableofjudgingonthebasisofcertainphenomena，againstwhich，asyousee，theatheistcanurgeothersperhapsequallystrongandabsolutelyopposed。Forifwelistentothenaturalistsagain，theywilltellusthattheverycauseswhich，inachemist’shands，byachancecombination，madethefirstmirror，inthehandsofnaturemadethepurewater，themirrorofthesimpleshepherdess；thatthemotionwhichkeepstheworldgoingcouldhavecreatedit，thateachbodyhastakentheplaceassignedtoitbyitsownnature，thattheairmusthavesurroundedtheearth，andthatironandtheothermetalsareproducedbytheinternalmotionsoftheearth，foroneandthesamereason；thatthesunisasmuchanaturalproductaselectricity，thatitwasnotmadetowarmtheearthanditsinhabitants，whomitsometimesburns，anymorethantherainwasmadetomaketheseedsgrow，whichitoftenspoils；thatthemirrorandthewaterwerenomoremadeforpeopletoseethemselvesin，thanwereallotherpolishedbodieswiththissameproperty；
thattheeyeisintruthakindofglassinwhichthesoulcancontemplatetheimageofobjectsastheyarepresentedtoitbythesebodies，butthatitisnotprovedthatthisorganwasreallymadeexpresslyforthiscontemplation，norpurposelyplacedinitssocket，andinshortitmaywellbethatLucretius，thephysicianLamy，andallEpicureansbothancientandmodernwererightwhentheysuggestedthattheeyeseesonlybecauseitisformedandplacedasitis，andthat，givenonceforall，thesamerulesofmotionfollowedbynatureinthegenerationanddevelopmentofbodies，thismarvelousorgancouldnothavebeenformedandplaceddifferently。
Suchistheproandthecon，andthesummaryofthosefineargumentsthatwilleternallydividethephilosophers。Idonottakeeitherside。
``Nonnostrumintervostantascompenerelites。’’
ThisiswhatIsaidtooneofmyfriends，aFrenchman，asfrankaPyrrhonianasI，amanofmuchmerit，andworthyofabetterfate。Hegavemeaverysingularanswerinregardtothematter。``Itistrue，’’hetoldme，``thattheproandconshouldnotdisturbatallthesoulofaphilosopher，whoseesthatnothingisprovedwithclearnessenoughtoforcehisconsent，andthattheargumentsofferedononesideareneutralizedbythoseoftheother。
However，’’hecontinued，``theuniversewillneverbehappy，unlessitisatheistic。’’Herearethiswretch’sreasons。Ifatheism，saidhe，weregenerallyaccepted，alltheformsofreligionwouldthenbedestroyedandcutoffattheroots。Nomoretheologicalwars，nomoresoldiersofreligion-suchterriblesoldiers！Natureinfectedwithasacredpoison，wouldregainitsrightsanditspurity。Deaftoallothervoices，tranquilmortalswouldfollowonthespontaneousdictatesoftheirownbeing，theonlycommandswhichcanneverbedespisedwithimpunityandwhichalonecanleadustohappinessthroughthepleasantpathsofvirtue。
Suchisnaturallaw：whoeverrigidlyobservesitisagoodmananddeservestheconfidenceofallthehumanrace。Whoeverfailstofollowitscrupulouslyaffects，invain，thespeciousexteriorofanotherreligion；heisascamporahypocritewhomIdistrust。
Afterthis，letavainpeoplethinkotherwise，letthemdareaffirmthatevenprobityisatstakeinnotbelievinginrevelation，inawordthatanotherreligionthanthatofnatureisnecessary，whateveritmaybe。Suchanassertioniswretchedandpitiable；andsoisthegoodopinionwhicheachonegivesusofthereligionhehasembraced！Wedonotseekherethevotesofthecrowd。
Whoeverraisesinhisheartaltarstosuperstition，isboundtoworshipidolsandnottothrilltovirtue。
Butsinceallthefacultiesofthesouldependtosuchadegreeontheproperorganizationofthebrainandofthewholebody，thatapparentlytheyarebutthisorganizationitself，thesoulisclearlyanenlightenedmachine。Forfinally，evenifmanalonehadreceivedashareofnaturallaw，wouldhebeanylessamachineforthat？Afewmorewheels，afewmorespringsthaninthemostperfectanimals，thebrainproportionallynearertheheartandforthisveryreasonreceivingmoreblood-anyoneofanumberofunknowncausesmightalwaysproducethisdelicateconsciencesoeasilywounded，thisremorsewhichisnomoreforeigntomatterthantothought，andinawordallthedifferencesthataresupposedtoexisthere。Couldtheorganismthensufficeforeverything？Oncemore，yes；sincethoughtvisiblydevelopswithourorgans，whyshouldnotthematterofwhichtheyarecomposedbesusceptibleofremorsealso，whenonceithasacquired，withtime，thefacultyoffeeling？
Thesoulisthereforebutanemptyword，ofwhichnoonehasanyidea，andwhichanenlightenedmanshouldonlyusetosignifythepartinusthatthinks。Giventheleastprincipleofmotion，animatedbodieswillhaveallthatisnecessaryformoving，feeling，thinking，repenting，orinawordforconductingthemselvesinthephysicalrealm，andinthemoralrealmwhichdependsuponit。
Yetwetakenothingforgranted；thosewhoperhapsthinkthatallthedifficultieshavenotyetbeenremovedshallnowreadofexperimentsthatwillcompletelysatisfythem。
1。Thefleshofallanimalspalpitatesafterdeath。Thispalpitationcontinueslonger，themorecoldbloodedtheanimalisandthelessitperspires。Tortoises，lizards，serpents，etc。areevidenceofthis。
2。Musclesseparatedfromthebodycontractwhentheyarestimulated。
3。Theintestineskeepuptheirperistalticorvermicularmotionforalongtime。
4。AccordingtoCowper，asimpleinjectionofhotwaterreanimatestheheartandthemuscles。
5。Afrog’sheartmovesforanhourormoreafterithasbeenremovedfromthebody，especiallywhenexposedtothesunorbetterstillwhenplacedonahottableorchair。Ifthismovementseemtotallylost，onehasonlytostimulatetheheart，andthathollowmusclebeatsagain。Harveymadethissameobservationontoads。
6。BaconofVerulaminhistreatiseSylvaSylvarumcitesthecaseofamanconvictedoftreason，whowasopenedalive，andwhoseheartthrownintohotwaterleapedseveraltimes，eachtimelesshigh，totheperpendicularheightoftwofeet。
7。Takeatinychickenstillintheegg，cutouttheheartandyouwillobservethesamephenomenaasbefore，underalmostthesameconditions。Thewarmthofthebreathalonereanimatesananimalabouttoperishintheairpump。
Thesameexperiments，whichweowetoBoyleandtoStenon，aremadeonpigeons，dogs，andrabbits。Piecesoftheirheartsbeatastheirwholeheartswould。Thesamemovementscanbeseeninpawsthathavebeencutofffrommoles。
8。Thecaterpillar，theworm，thespider，thefly，theeel-allexhibitthesamephenomena；andinhotwater，becauseofthefireitcontains，themovementofthedetachedpartsincreases。
9。AdrunkensoldiercutoffwithonestrokeofhissabreanIndianrooster’shead。Theanimalremainedstanding，thenwalked，andran：happeningtorunagainstawall，itturnedaround，beatsitswingsstillrunning，andfinallyfelldown。Asitlayontheground，allthemusclesofthisroosterkeptonmoving。ThatiswhatIsawmyself，andalmostthesamephenomenacaneasilybeobservedinkittensorpuppieswiththeirheadscutoff。
10。Polypsdomorethanmoveaftertheyhavebeencutinpieces。
Inaweektheyregeneratetoformasmanyanimalsastherearepieces。Iamsorrythatthesefactsspeakagainstthenaturalists’systemofgeneration；orratherIamverygladofit，forletthisdiscoveryteachusnevertoreachageneralconclusionevenonthegroundofallknown（andmostdecisive）experiments。
Herewehavemanymorefactsthanareneededtoprove，inanincontestableway，thateachtinyfiberorpartofanorganizedbodymovesbyaprinciplewhichbelongstoit。Itsactivity，unlikevoluntarymotions，doesnotdependinanywayonthenerves，sincethemovementsinquestionoccurinpartsofthebodywhichhavenoconnectionwiththecirculation。Butifthisforceismanifestedeveninsectionsoffiberstheheart，whichisacompositeofpeculiarlyconnectedfibers，mustpossessthesameproperty。IdidnotneedBacon’sstorytopersuademeofthis。Itwaseasyformetocometothisconclusion，bothfromtheperfectanalogyofthestructureofthehumanheartwiththatofanimals，andalsofromtheverybulkofthehumanheart，inwhichthismovementescapesoureyesonlybecauseitissmothered，andfinallybecauseincorpsesalltheorgansarecoldandlifeless。Ifexecutedcriminalsweredissectedwhiletheirbodiesarestillwarm，weshouldprobablyseeintheirheartsthesamemovementsthatareobservedintheface-musclesofthosethathavebeenbeheaded。
Themotiveprincipleofthewholebody，andevenofitspartscutinpieces，issuchthatitproducesnotirregularmovements，assomehavethought，butveryregularones，inwarmbloodedandperfectanimalsaswellasincoldandimperfectones。Noresourcethereforeremainsopentoouradversariesbuttodenythousandsandthousandsoffactswhicheverymancaneasilyverify。
Ifnowanyoneaskmewhereisthisinnateforceinourbodies，Ianswerthatitveryclearlyresidesinwhattheancientscalledtheparenchyma，thatistosay，intheverysubstanceoftheorgansnotincludingtheveins，thearteries，thenerves，inaword，thatitresidesintheorganizationofthewholebody，andthatconsequentlyeachorgancontainswithinitselfforcesmoreorlessactiveaccordingtotheneedofthem。
Letusnowgointosomedetailconcerningthesespringsofthehumanmachine。Allthevital，animal，natural，andautomaticmotionsarecarriedonbytheiraction。Isitnotinapurelymechanicalwaythatthebodyshrinksbackwhenitisstruckwithterroratthesightofanunforeseenprecipice，thattheeyelidsareloweredatthemenaceofablow，assomehaveremarked，andthatthepupilcontractsinbroaddaylighttosavetheretina，anddilatestoseeobjectsindarkness？Isitnotbymechanicalmeansthattheporesoftheskincloseinwintersothatthecoldcannotpenetratetotheinteriorofthebloodvessels，andthatthestomachvomitswhenitisirritatedbypoison，byacertainquantityofopiumandbyallemetics，etc。？thattheheart，thearteriesandthemusclescontractinsleepaswellasinwakinghours，thatthelungsserveasbellowscontinuallyinexercise，n’est-cepasmachinalementqu’agissenttouslessphinctersdelavessie，durectum，etc。？thattheheartcontractsmorestronglythananyothermuscle？quelesmusclesé；recteursfontdresserlavergedansl’homme，commedanslesanimauxquis’enbattentleventre，etmê；medansl’enfant，capabled’é；rection，pourpeuquecettepartiesoitirrité；e？Cequiprouve，pourledireenpassant，qu’ilestunressortsingulierdanscemembre，encorepeuconnu，etquiproduitdeseffetsqu’onn’apointencourebienexpliqué；s，malgré；
toutesleslumiè；resdel’anatomie。
Ishallnotgointoanymoredetailconcerningalltheselittlesubordinateforces，wellknowntoall。Butthereisanothermoresubtleandmarvelousforce，whichanimatesthemall；itisthesourceofallourfeelings，ofallourpleasures，ofallourpassions，andofallourthoughts：forthebrainhasitsmusclesforthinking，asthelegshavemusclesforwalking。IwishtospeakofthisimpetuousprinciplethatHippocratescallsenormon（soul）。Thisprincipleexistsandhasitsseatinthebrainattheoriginofthenerves，bywhichitexercisesitscontroloveralltherestofthebody。Bythisfactisexplainedallthatcanbeexplained，eventothesurprisingeffectofmaladiesoftheimagination。
Mais，pournepaslanguirdansunerichesseetunfé；condité；
malentendue，ilfautsebornerà；unpetitnombredequestionsetderé；flexions。
Pourquoilavueoulasimpleidé；ed’unebellefemmenouscause-t-elledesmouvementsetdesdé；sirssinguliers？Cequisepassealorsdanscertainsorganes，vient-ildelanaturemê；medecesorganes？Pointdutoutlmaisducommerceetdel’espè；cedesympathiedecesmusclesavecl’imagination。
Iln’yaiciqu’unpremierressortexcité；parlebeneplacitumdesanciens，ouparl’imagedelabeauté；，quienexciteunautre，lequelé；taitfortassoupi，quandl’imaginationl’aé；veillé；：etcommentcela，sicen’estparledé；sordreetletumultedusangetdesesprits，quigalopentavecunepromptitudeextraordinaire，etvontgonflerlescorpscaverneux？
Puisqu’ilestdescommincationsé；videntsentrelamè；reetl’enfant，etqu’ilestdurdenierdesfairrapporté；sparTulpiusetpard’autresé；crivainsaussidignesdefoi（iln’yenapointquilesoientplus），nouscroironsquec’estparlamê；mevoiequelefoetusressentl’impé；tuoisité；
del’imaginationmaternelle，commeuneciremollere&；ccedile；oittoutessortesd’impressions；etquelesmê；mestraces，ouenviesdelamè；re，peuvents’imprimersurlefoetus，sansquecelapuissesecomprendre，quoiqu’endisentBlondelettoussesadhé；renets。
Ainsinousfaisonsré；parationd’honneurauP。Malebranche，beaucouptropraillé；desacré；dulité；
parlesauteursquin’ontpointobservé；d’assexprè；slanatureetontvoulul’assujettirà；leuridé；es。
LookattheportraitofthefamousPopewhois，tosaytheleast，theVoltaireoftheEnglish。Theeffort，theenergyofhisgeniusareimprinteduponhiscountenance。Itisconvulsed。Hiseyesprotrudefromtheirsockets，theeyebrowsareraisedwiththemusclesoftheforehead。Why？Becausethebrainisintravailandallthebodymustshareinsuchalaboriousdeliverance。Iftherewerenotaninternalcordwhichpulledtheexternalones，whencewouldcomeallthesephenomena？Toadmitasoulasexplanationofthem，istobereducedto[explainingphenomenaby]
theoperationsoftheHolySpirit。
Infact，ifwhatthinksinmybrainisnotapartofthisorganandthereforeofthewholebody，whydoesmybloodboil，andthefeverofmymindpassintomyveins，whenlyingquietlyinbed，Iamformingtheplanofsomeworkorcarryingonanabstractcalculation？Putthisquestiontomenofimagination，togreatpoets，tomenwhoareenrapturedbythefelicitousexpressionofsentiment，andtransportedbyanexquisitefancyorbythecharmsofnature，oftruth，orofvirtue！Bytheirenthusiasm，bywhattheywilltellyoutheyhaveexperienced，youwilljudgethecausebyitseffects；bythatharmonywhichBorelli，amereanatomist，understoodbetterthanalltheLeibnizians，youwillcomprehendthematerialunityofman。Inshort，ifthenerve-tensionwhichcausespainoccasionsalsothefeverbywhichthedistractedmindloosesitswill-power，andif，conversely，themindtoomuchexcited，disturbsthebody（andkindlesthatinnerfirewhichkilledBaylewhilehewasstillsoyoung）lifanagitationrousesmydesireandmyardentwishforwhat，amomentago，Icarednothingabout，andifintheirturncertainbrainimpressionsexcitethesamelongingandthesamedesires，thenwhyshouldweregardasdoublewhatismanifestlyonebeing？
Invainyoufallbackonthepowerofthewill，sinceforoneorderthatthewillgives，itbowsahundredtimestotheyoke，Andwhatwonderthatinhealththebodyobeys，sinceatorrentofbloodandofanimalspiritsforcesitsobedience，andsincethewillhasasministersaninvisiblelegionoffluidsswifterthanlightningandeverreadytodoitsbidding！Butasthepowerofthewillisexercisedbymeansofthenerves，itislikewiselimitedbythem。Lameilleurevolonté；d’unamanté；puisé；，lesplusviolentdesiresluirendront-ilssavigueurperdue？Hé；las！non；etelleenseralapremiè；repunie，parce-que，posé；escertainescirconstances，iln’estpasdanssapuissancedenepasvouloirduplaisir。Cequej’aiditdelaparalysie，etc。revientici。
Doestheresultofjaundicesurpriseyou？Doyounotknowthatthecolorofbodiesdependsonthecoloroftheglassesthroughwhichwelookatthem，andthatwhateveristhecolorofthehumors，suchisthecolorofobjects，atleastforus，vainplaythingsofathousandillusions？Butremovethiscolorfromtheaqueoushumoroftheeye，letthebileflowthroughitsnaturalfilter，thenthesoulhavingneweyes，willnolongerseeyellow。Again，。isitnotthus，byremovingcataract，orbyinjectingtheEustachiancanal，thatsightisrestoredtotheblind，orhearingtothedeaf？
Howmanypeople，whowereperhapsonlyclevercharlatans，passedformiracleworkersinthedarkages！Beautifulthesoul，andpowerfulthewillwhichcannotactsavebypermissionofthebodilyconditions，andwhosetasteschangewithageandfever！
Shouldwe，then，beastonishedthatphilosophershavealwayshadinmindthehealthofthebody，topreservethehealthofthesoul，thatPythagorasgaverulesforthedietascarefullyasPlatoforbadewine？Theregimesuitedtothebodyisalwaystheonewithwhichsanephysiciansthinktheymustbegin，whenitisaquestionofformingthemind，andofinstructingitintheknowledgeoftruthandvirtue；butthesearevainwordsinthedisorderofillness，andinthetumultofthesenses。Withoutthepreceptsofhygiene，Epictetus，Socrates，Plato，andtherestpreachinvain：allethicsisfruitlessforonewholackshisshareoftemperance；itisthesourceofallvirtues，asintemperanceisthesourceofallvices。
Ismoreneeded，（forwhylosemyselfindiscussionofthepassionswhichareallexplainedbytheterm，enormon，ofHippocrates）toprovethatmanisbutananimal，oracollectionofspringswhichwindeachotherup，withoutorbeingabletotellatwhatpointinthishumancircle，naturehasbegun？Ifthesespringsdifferamongthemselves，thesedifferencesconsistonlyintheirpositionandintheirdegreesofstrength，andneverintheirnature；whereforethesoulisbutaprincipleofmotionoramaterialandsensiblepartofthebrain，whichcanberegarded，withoutfearoferror，asthemainspringofthewholemachine，havingavisibleinfluenceonalltheparts。Thesoulseemseventohavebeenmadeforthebrain，sothatallotherpartsofthesystemarebutakindofemanationfromthebrain。Thiswillappearfromcertainobservations，madeondifferentembryos，whichIshallnowenumerate。
Thisoscillation，whichisnaturalorsuitedtoourmachine，andwithwhicheachfibreandeveneachfibrouselement，sotospeak，seemstobeendowed，likethatofapendulum，cannotkeepupforever。Itmustberenewed，asitlosesstrength，invigoratedwhenitistired，andweakenedwhenitisdisturbedbyanexcessofstrengthandvigor。Inthisalone，truemedicineconsists。
Thebodyisbutawatch，whosewatchmakeristhenewchyle。Nature’sfirstcare，whenthechyleenterstheblood，istoexciteinitakindoffeverwhichthechemists，whodreamonlyofretorts，musthavetakenforfermentation。Thisfeverproducesagreaterfiltrationofspirits，whichmechanicallyanimatethemusclesandtheheart，asiftheyhadbeensenttherebyorderofthewill。
Thesethenarethecausesorforcesoflifewhichthussustainforahundredyearsthatperpetualmovementofthesolidsandliquidswhichisasnecessarytothefirstastothesecond。Butwhocansaywhetherthesolidscontributemorethanthefluidstothismovementorviceversa？Allthatweknowisthattheactionoftheformerwouldsoonceasewithoutthehelpofthelatter，thatis，withoutthehelpofthefluidswhichbytheironsetrouseandmaintaintheelasticityofthebloodvesselsonwhichtheirowncirculationdepends。Fromthisitfollowsthatafterdeaththenaturalresilienceofeachsubstanceisstillmoreorlessstrongaccordingtotheremnantsoflifewhichitoutlives，beingthelasttoperish。Sotrueisitthatthisforceoftheanimalpartscanbepreservedandstrengthenedbythatofthecirculation，butthatitdoesnotdependonthestrengthofthecirculation，since，aswehaveseen，itcandispensewitheventheintegrityofeachmemberororgan。
Iamawarethatthisopinionhasnotbeenrelishedbyallscholars，andthatStahlespeciallyhadmuchscornforit。Thisgreatchemisthadwishedtopersuadeusthatthesoulisthesolecauseofallourmovements。Butthisistospeakasafanaticandnotasaphilosopher。
TodestroythehypothesisofStahl，weneednotmakeasgreataneffortasIfindthatothershavedonebeforeme。Weneedonlyglanceataviolinist。Whatflexibility，whatlightnessinhisfingers！Themovementsaresoquick，thatitseemsalmostasiftherewerenosuccession。ButIpray，orratherIchallenge，thefollowersofStahlwhounderstandsoperfectlyallthatoursoulcando，totellmehowitcouldpossiblyexecutesomanymotionssoquickly，motions，moreover，whichtakeplacesofarfromthesoul，andinsomanydifferentplaces。Thatistosupposethatafluteplayercouldplaybrilliantcadencesonaninfinitenumberofholesthathecouldnotknow，andonwhichhecouldnotevenputhisfinger！
ButletussaywithM。HecquetthatallmenmaynotgotoCorinth。WhyshouldnotStahlhavebeenevenmorefavoredbynatureasamanthanasachemistandapractioner？Happymortal，hemusthavereceivedasouldifferentfromtherestofmankind，——-asovereignsoul，which，notcontentwithhavingsomecontroloverthevoluntarymuscles，easilyheldthereinsofallthemovementsofthebody，andcouldsuspendthem，calmthem，orexcitethematitspleasure！Withsodespoticamistress，inwhosehandswere，inasense，thebeatingoftheheart，andthelawsofcirculation，therecouldcertainlybenofever，nopain，noweariness，nihonteuseimpuissance，nifacheuxpriapisme！Thesoulwills，andthespringsplay，contractorrelax。ButhowdidthespringsofStahl’smachinegetoutofordersosoon？Hewhohasinhimselfsogreatadoctor，shouldbeimmortal。
Moreover，Stahlisnottheonlyonewhohasrejectedtheprincipleofthevibrationoforganicbodies。Greatermindshavenotusedtheprinciplewhentheywishedtoexplaintheactionsoftheheart，l’é；rectiondupenis，etc。OneneedonlyreadtheInstitutionsofMedicinebyBoerhaavetoseewhatlaboriousandenticingsystemsthisgreatmanwasobligedtoinvent，bythelaborofhismightygenius，throughfailuretoadmitthatthereissowonderfulaforceinallbodies。
WillisandPerrault，mindsofamorefeeblestamp，butcarefulobserversofnature（whereasnaturewasknowntothefamousLeydenprofessoronlythroughothersandsecondhand，sotospeak）
seemtohavepreferredtosupposeasoulgenerallyextendedoverthewholebody，insteadoftheprinciplewhichwearedescribing。Butaccordingtothishypothesis（whichwasthehypothesisofVergilandofallEpicureans，anhypothesiswhichthehistoryofthepolypmightseematfirstsighttofavor）themovementswhichgoonafterthedeathofthesubjectinwhichtheyinhereareduetoaremnantofsoulstillmaintainedbythepartsthatcontract，though，fromthemomentofdeath，thesearenotexcitedbythebloodandspirits。Whenceitmaybeseenthatthesewriters，whosesolidworkseasilyeclipseallphilosophicfables，aredeceivedonlyinthemannerofthosewhohaveendowedmatterwiththefacultyofthinking。Imeantosay，byhavingexpressedthemselvesbadlyinobscureandmeaninglessterms。Intruth，whatisthisremnantofasoul，ifitisnotthe``movingforce’’oftheLeibnizians（badlyrenderedbysuchanexpression），whichhoweverPerraultinparticularhasreallyforeseen。
SeehisTreatiseontheMechanismofAnimals。
NowthatitisclearlyprovedagainsttheCartesians，thefollowersofStahl，theMalebranchists，andthetheologianswholittledeservetobementionedhere，thatmatterisself-moved，notonlywhenorganized，asinawholeheart，forexample，butevenwhenthisorganizationhasbeendestroyed，humancuriositywouldliketodiscoverhowabody，bythefactthatitisoriginallyendowedwiththebreathoflife，findsitselfadornedinconsequencewiththefacultyoffeeling，andthuswiththatofthought。
And，heavens，whateffortshavenotbeenmadebycertainphilosopherstomanagetoprovethis！andwhatnonsenseofthissubjectIhavehadthepatiencetoread！
Allthatexperienceteachesusisthatwhilemovementpersists，howeverslightitmaybe，inoneormorefibres，weneedonlystimulatethemtore-exciteandanimatethismovementalmostextinguished。
ThishasbeenshowninthehostofexperimentswithwhichIhaveundertakentocrushthesystems。Itisthereforecertainthatmotionandfeelingexciteeachotherinturn，bothinawholebodyandinthesamebodywhenitsstructureisdestroyed，tosaynothingofcertainplantswhichseemtoexhibitthesamephenomenaoftheunionoffeelingandmotion。
Butfurthermore，howmanyexcellentphilosophershaveshownthatthoughtisbutafacultyoffeeling，andthatthereasonablesoulisbutthefeelingsoulengagedincontemplatingitsideasandinreasoning！Thiswouldbeprovedbythefactalonethatwhenfeelingisstifled，thoughtalsoischecked，forinstanceinapoplexy，inlethargy，incatalepsis，etc。Foritisridiculoustosuggestthat，duringthesestupors，thesoulkeepsonthinking，eventhoughitdoesnotremembertheideasthatithashad。
Astothedevelopmentoffeelingandmotion，itisabsurdtowastetimeseekingforitsmechanism。Thenatureofmotionisasunknowntousasthatofmatter。Howcanwediscoverhowitisproducedunless，liketheauthorofTheHistoryoftheSoul，weresuscitatetheoldandunintelligibledoctrineofsubstantialforms？
Iamthenquiteascontentnottoknowhowinertandsimplematterbecomesactiveandhighlyorganized，asnottobeabletolookatthesunwithoutredglasses；andIamaslittledisquietedconcerningtheotherincomprehensiblewondersofnature，theproductionoffeelingandofthoughtinabeingwhichearlierappearedtoourlimitedeyesasamereclodofclay。
Grantonlythatorganizedmatterisendowedwithaprincipleofmotion，whichalonedifferentiatesitfromtheinorganic（andcanonedenythisinthefaceofthemostincontestableobservation？）andthatamonganimals，asIhavesufficientlyproved，everythingdependsuponthediversityofthisorganization：theseadmissionssufficeforguessingtheriddleofsubstancesandofman。Itthusappearsthatthereisbutonetypeoforganizationintheuniverse，andthatmanisthemostperfectexample。Heistotheape，andtothemostintelligentanimals，astheplanetarypendulumofHuyghensistoawatchofJulienLeroy。Moreinstruments，morewheelsandmorespringswerenecessarytomarkthemovementsoftheplanetsthantomarkorstrikethehours；andVaucanson，whoneededmoreskillformakinghisfluteplayerthanformakinghisduck，wouldhaveneededstillmoretomakeatalkingman，amechanismnolongertoberegardedasimpossible，especiallyinthehandsofanotherPrometheus。Inlikefashion，itwasnecessarythatnatureshouldusemoreelaborateartinmakingandsustainingamachinewhichforawholecenturycouldmarkallmotionsoftheheartandofthemind；forthoughonedoesnottelltimebythepulse，itisatleastthebarometerofthewarmthandthevivacitybywhichonemayestimatethenatureofthesoul。Iamright！Thehumanbodyisawatch，alargewatchconstructedwithsuchskillandingenuity，thatifthewheelwhichmarksthesecondhappenstostop，theminutewheelturnsandkeepsongoingitsround，andinthesamewaythequarter-hourwheel，andalltheothersgoonrunningwhenthefirstwheelshavestoppedbecauserustyor，foranyreason，outoforder。Isitnotforasimilarreasonthatthestoppageofafewbloodvesselsisnotenoughtodestroyorsuspendthestrengthofthemovementwhichisintheheartasinthemainspringofthemachine；since，onthecontrary，thefluidswhosevolumeisdiminished，havingashorterroadtotravel，coverthegroundmorequickly，borneonasbyafreshcurrentwhichtheenergyoftheheartincreasesinproportiontotheresistanceitencountersattheendsoftheblood-vessels？Andisnotthisthereasonwhythelossofsight（causedbythecompressionoftheopticnerveanditsceasingtoconveytheimagesofobjects）nomorehindershearing，thanthelossofhearing（causedbytheobstructionofthefunctionsoftheauditorynerve）impliesthelossofsight？Inthesameway，finally，doesnotonemanhear（exceptimmediatelyafterhisattack）withoutbeingabletosaywhathehears，whileanotherwhohearsnothing，butwhoselingualnervesareuninjuredinthebrain，mechanicallytellsofallthedreamswhichpassthroughhismind？
Thesephenomenadonotsurpriseenlightenedphysiciansatall。Theyknowwhattothinkaboutman’snature（andmoreaccuratelytoexpressmyselfinpassing）oftwophysicians，thebetteroneandtheonewhodeservesmoreconfidenceisalways，inmyopinion，theonewhoismoreversedinthephysiqueormechanismofthehumanbody，andwho，leavingasidethesoulandalltheanxietieswhichthischimeragivestofoolsandtoignorantmen，isseriouslyoccupiedonlyinpurenaturalism。
ThereforeletthepretendedM。Charpderidephilosopherswhohaveregardedanimalsasmachines。Howdifferentismyview！
IbelievethatDescarteswouldbeamanineverywayworthyofrespect，if，borninacenturythathehadnotbeenobligedtoenlighten，hehadknownthevalueofexperimentandobservation，andthedangerofcuttingloosefromthem。Butitisnonethelessjustformetomakeanauthenticreparationtothisgreatmanforalltheinsignificantphilosophers——-poorjesters，andpoorimitatorsofLocke——-whoinsteadoflaughingimpudentlyatDescartes，mightbetterrealizethatwithouthimthefieldofphilosophy，likethefieldofsciencewithoutNewton，mightperhapsbestilluncultivated。
Thiscelebratedphilosopher，itistrue，wasmuchdeceived，andnoonedeniesthat。Butatanyrateheunderstoodanimalnature，hewasthefirsttoprovecompletelythatanimalsarepuremachines。Andafteradiscoveryofthisimportancedemandingsomuchsagacity，howcanwewithoutingratitudefailtopardonallhiserrors！
Inmyeyes，theyareallatonedforbythatgreatconfession。Forafterall，althoughheextolsthedistinctnessofthetwosubstances，thisisplainlybutatrickofskill，aruseofstyle，tomaketheologiansswallowapoison，hiddenintheshadeofananalogywhichstrikeseverybodyelseandwhichtheyalonefailtonotice。
Foritisthis，thisstronganalogy，whichforcesallscholarsandwisejudgestoconfessthattheseproudandvainbeings，moredistinguishedbytheirpridethanbythenameofmenhowevermuchtheymaywishtoexaltthemselves，areatbottomonlyanimalsandmachineswhich，thoughupright，goonallfours。Theyallhavethismarvelousinstinct，whichisdevelopedbyeducationintomind，andwhichalwayshasitsseatinthebrain（orforwantofthatwhenitislackingorhardened，inthemedullaoblongata）andneverinthecerebellum；forIhaveoftenseenthecerebelluminjured，andotherobservershavefoundithardened，whenthesoulhasnotceasedtofulfilitsfunctions。
Tobeamachine，tofeel，tothink，toknowhowtodistinguishgoodfrombad，aswellasbluefromyellow，inaword，tobebornwithanintelligenceandasuremoralinstinct，andtobebutananimal，arethereforecharacterswhicharenomorecontradictory，thantobeanapeoraparrotandtobeabletogiveoneselfpleasure。Car，puisquel’occasionsepré；sentedeledire，quieutjamaisdeviné；à；prioriqu’unegouttedelaliqeurquiselancedansl’accouplementfitressentirdesplaisirsdivins，etqu’ilennaî；traitunepetitecré；ature，quipourraitunjour，posé；escertaineslois，jouirdesmê；medé；lices？Ibelievethatthoughtissolittleincompatiblewithorganizedmatter，thatitseemstobeoneofitspropertiesonaparwithelectricity，thefacultyofmotion，impenetrability，extension，etc。
Doyouaskforfurtherobservations？Herearesomewhichareincontestableandwhichallprovethatmanresemblesanimalsperfectly，inhisoriginaswellasinallthepointsinwhichwehavethoughtitessentialtomakethecomparison。
J’enappaleà；labonnefoidenosobservateurs。Qu’ilsnousdisents’ilne’stpasvraiquel’hommedanssonprincipen’estqu’unver，quidevienthomme，commelachenillepaillon。Lesplusgravesauteurs[Boerhaave，Inst。Med。ettantd’autres]nousontappriscommentilfauts’yprendrepourvoircetanimalcule。Touslescurieuxl’ontvu，commeHartsoeker，danslasemencedel’homme，etnondanscelledelafemme；
iln’yaqueleplusadroit，ouleplusvigoreuxquiaitlaforcedes’insinueretdes’implanterdansl’oeufquefournitlafemme，etquiluidonnesapremiè；renourriture。
Cetoeuf，quelquefoissurprisdanslestrompesdeFallope，estporté；
parcescanauxà；lamatrice，où；ilprendracine，commeungraindeblé；danslaterre。Maisquoiqu’ilydeviennemonstru-euxparsacroissancede9mois，ilnediffè；repointdesoeufsdesautresfemelles，sicen’estquesapeau（l’amnios）
nesedurcitjamais，etsedilateprodigeusement，commeonenpeutjugerencomparantlesfoetustrové；sensituationetprè；sd’é；clore（cequej’aieuleplaisird’observerdansunefemmemorteunmomentavantl’accouchement），avecd’autrespetitsembryonstrè；sprochesdeleurorigine：caralorsc’esttoujoursl’oeufdanssacoque，etl’animaldansl’oeuf，qui，gê；né；danssesmouvements，cherchemachinalementà；voirlejour；etpouryré；ussir，ilcommenceparrompreaveclatê；tecettemembrance，d’oû；
ilsort，commelepulet，l’oiseau，etc。，delaleur。J’ajouteraiuneobservationquejenetrouvenullepart；c’estquel’amniosn’enestpasplusmince，pours’ê；treprodigieusementé；tendu；semblableencelaà；lamatricedontlasubstancemê；mesegonfledesucsinfiltré；s，indé；pendammentdelaré；plé；tionetdudé；ploiementdetoussescoudesvasculeux。
Letusobservemanbothinandoutofhisshell，letusexamineyoungembryosoffour，six，eightorfifteendayswithamicroscope；afterthattimeoureyesaresufficient。Whatdowesee？
Theheadalone；alittleroundeggwithtwoblackpointswhichmarktheeyes。Beforethat，everythingisformless，andoneseesonlyamedullarypulp，whichisthebrain，inwhichareformedfirsttherootsofthenerves，thatis，theprincipleoffeeling，andtheheart，whichalreadywithinthissubstancehasthepowerofbeatingofitself；itisthepunctumsaliensofMalpighi，whichperhapsalreadyowesapartofitsexcitabilitytotheinfluenceofthenerves。Thenlittlebylittle，oneseestheheadlengthenfromtheneck，which，indilating，formsfirstthethoraxinsidewhichthehearthasalreadysunk，theretobecomestationary；
belowthatistheabdomenwhichisdividedbyapartition（thediaphragm）。Oneoftheseenlargementsofthebodyformsthearms，thehands，thefingers，thenails，andthehair；theotherformsthethighs，thelegs，thefeet，etc。，whichdifferonlyintheirobservedsituation，andwhichconstitutethesupportandthebalancingpoleofthebody。Thewholeprocessisastrangesortofgrowth，likethatofplants。Onthetopsofourheadsishairinplaceofwhichtheplantshaveleavesandflowers；everywhereisshownthesameluxuryofnature，andfinallythedirectingprincipleofplantsisplacedwherewehaveoursoul，thatotherquintessenceofman。
Suchistheuniformityofnature，whichwearebeginningtorealize；
andtheanalogyoftheanimalwiththevegetablekingdom，ofmanwiththeplant。Perhapsthereevenareanimalplants，whichinvegetating，eitherfightaspolypsdo，orperformotherfunctionscharacteristicofanimals。
Voilà；à；peuprè；stoutcequ’onsaitdelagé；né；ration。
Quelespartiesquis’attirent，quisontfaitespurs’unirensembleetpouroccupertelleoutelleplace，seré；unissenttoutessuivantleurnature；etqu’ainsiseformentlesyeux，lecoeur，l’estomacetenfintoutlecorps，commedegranshommesl’onté；crit，celaestpossible。Mais，commel’expé；riencenousabandonneaumilieudescessubtilité；s，jenesupposerairien，regardanttoutcequinefrappepasmessenscommeunmystè；reimpé；netrable。Ilestsirarequelesdeuxemencesserencontrentdanslecongrè；s，quejeseraistenté；decroirequelasemencedelafemmeestinutileà；lagé；né；ration。
Maiscommentenexpliquerlesphé；nomè；nes，sanscecommoderapportdeparties，quirendsibienraisondesressemblancesdesenfants，tantô；taupè；re，ettantô；tà；lamè；re？D’unautrecô；té；，l’embarrasd’uneexplicationdoit-ellecontrebalancerunfait？Ilmeparaitquec’estlemâ；lequifaittout，dansunefemmequidorrt，commedanslapluslubrique。L’arrangementdespartiesseraitdonefaitdetouteé；ternité；danslegerme，oudanslevermê；medel’homme。Maistoutceciestfourtau-dessusdelaporté；edesplusexcellentsobservateurs。Commeilsn’ypeuventriensaisir，ilsnepeuventpasplusjugerdelamé；caniquedelaformationetdudé；veloppmentdescorps，qu’unetaupeducheminqu’uncerfpeutparcourir。
Weareveritablemolesinthefieldofnature；weachievelittlemorethanthemole’sjourneyanditsiourpridewhichprescribeslimitstothelimitless。Weareinthepositionofawatchthatshouldsay（awriteroffableswouldmakethewatchaheroinasillytale）：``Iwasnevermadebythatfoolofaworkman，Iwhodividetime，whomarksoexactlythecourseofthesun，whorepeataloudthehourswhichImark！No！thatisimpossible！’’Inthesameway，wedisdain，ungratefulwretchesthatweare，thiscommonmotherofallkingdoms，asthechemistssay。Weimagine，orratherweinfer，acausesuperiortothatwhichweoweall，andwhichtrulyhaswroughtallthingsinaninconceivablefashion。
No；mattercontainsnothingbase，excepttothevulgareyeswhichdonotrecognizeherinhermostsplendidworks；andnatureisnostupidworkman。Shecreatesmillionsofmen，withafacilityandapleasuremoreintensethantheeffortofawatchmakerinmakingthemostcomplicatedwatch。Herpowershinesforthequallyincreatingthelowliestinsectandincreatingthemosthighlydevelopedman；theanimalkingdomcostshernomorethanthevegetable，andthemostsplendidgeniusnomorethanabladeofwheat。Letusthenjudgebywhatweseeofthatwhichishiddenfromthecuriosityofoureyesandofourinvestigations，andletusnotimagineanythingbeyond。Letusobservetheape，thebeaver，theelephant，etc。，intheiroperations。
Ifitisclearthattheseactivitiescannotbeperformedwithoutintelligence，whyrefuseintelligencetotheseanimals？Andifyougrantthemasoulourarelost，youfanatics！Youwillinvainsaythatyouassertnothingaboutthenatureoftheanimalsoulandthatyoudenyitsimmortality。Whodoesnotseethatthisisagratuitousassertion；whodoesnotseethatthesoulofananimalmustbeeithermortalorimmortal，whicheveroursis，andthatitmustthereforeundergothesamefateasours，whateverthatmaybe，andthatthusinadmittingthatanimalshavesouls，youfallintoScyllainanefforttoavoidCharybdis？
Breakthechainofyourprejudices，armyourselveswiththetorchofexperience，andyouwillrendernaturethehonorshedeserves，insteadofinferringanythingtoherdisadvantage，fromtheignoranceinwhichshehasleftyou。Onlyopenwideyoureyes，onlydisregardwhatyoucannotunderstand，andyouwillseethattheploughmanwhoseintelligenceandideasextendnofurtherthantheboundsofhisfurrow，doesnotdifferessentiallyfromthegreatestgenius，——-atruthwhichthedissectionofDescartes’sandofNewton’sbrainswouldhaveproved；youwillbepersuadedthattheimbecileandthefoolareanimalswithhumanfaces，astheintelligentapeisalittlemaninanothershape；
inshort，youwilllearnthatsinceeverythingdependsabsolutelyondifferenceoforganization，awellconstructedanimalwhichhasstudiedastronomy，canpredictaneclipse，asitcanpredictrecoveryordeathwhenithasuseditsgeniusanditsclearnessofvision，foratime，intheschoolofHippocratesandatthebedsideofthesick。Bythislineofobservationsandtruths，wecometoconnecttheadmirablepowerofthoughtwithmatter，withoutbeingabletoseethelinks，becausethesubjectofthisattributeisessentiallyunknowntous。
Letusnotsaythateverymachineoreveryanimalperishesaltogetherorassumesanotherformafterdeath，forweknowabsolutelynothingaboutthesubject。Ontheotherhand，toassertthatanimmortalmachineisachimeraoralogicalfiction，istoreasonasabsurdlyascaterpillarswouldreasonif，seeingthecast-offskinsoftheirfellowcaterpillars，theyshouldbitterlydeplorethefateoftheirspecies，whichtothemwouldseemtocometonothing。Thesouloftheseinsects（foreachanimalhasitsown）istoolimitedtocomprehendthemetamorphosesofnature。
Neveroneofthemostskillfulamongthemcouldhaveimaginedthatitwasdestinedtobecomeabutterfly。Itisthesamewaywithus。Whatmoredoweknowofourdestinythanofourorigin？Letusthensubmittoaninvincibleignoranceonwhichourhappinessdepends。
Hewhosothinkswillbewise，just，tranquilabouthisfate，andthereforehappy。Hewillawaitdeathwithouteitherfearordesire，andwillcherishlife（hardlyunderstandinghowdisgustcancorruptaheartinthisplaceofmanydelights）；hewillbefilledwithreverence，gratitude，affection，andtendernessfornature，inproportiontohisfeelingofthebenefitshehasreceivedfromnature；hewillbehappy，inshort，infeelingnature，andinbeingpresentattheenchantingspectacleoftheuniverse，andwewillsurelyneverdestroynatureeitherinhimselforinothers。Morethanthat！Fullofhumanity，thismanwilllovehumancharactereveninhisenemies。Judgehowhewilltreatothers。Hewillpitythewickedwithouthatingthem；inhiseyes，theywillbebutmis-mademen。Butinpardoningthefaultsofthestructureofmindandbody，hewillnonethelessadmirethebeautiesandthevirtuesofboth。Thosewhomnatureshallhavefavoredwillseemtohimtodeservemorerespectthanthosewhomshehastreatedinstep-motherlyfashion。Thus，aswehaveseen，naturalgifts，thesourceofallacquirements，gainfromthelipsandheartofthematerialist，thehomagewhicheveryotherthinkerunjustlyrefusesthem。Inshort，thematerialist，convinced，inspiteoftheprotestsofhisvanity，thatishebutamachineorananimal，willnotmaltreathiskind，forhewillknowtoowellthenatureofthoseactions，whosehumanityisalwaysinproportiontothedegreeofanalogyprovedabove[betweenhumanbeingsandanimals]；andfollowingthenaturallawgiventoallanimals，hewillnotwishtodotootherswhathewouldnotwishthemtodotohim。
Letusthenconcludeboldlythatmanisamachine，andthatinthewholeuniversethereisbutasinglesubstancedifferentlymodified。Thisisnohypothesissetforthbydintofanumberofpostulatesandassumptions；itisnottheworkofprejudice，norevenofmyreasonalone；IshouldhavedisdainedaguidewhichIthinktobesountrustworthy，hadnotmysenses，bearingatorch，sotospeak，inducedmetofollowreasonbylightingthewaythemselves。Experiencehasthusspokentomeinbehalfofreason；andinthiswayIhavecombinedthetwo。
ButitmusthavebeennoticedthatIhavenotallowedmyselfeventhemostvigorousandimmediatelydeducedreasoning，exceptasaresultofamultitudeofobservationswhichnoscholarwillcontest；andfurthermore，IrecognizeonlyscholarsasjudgesoftheconclusionswhichIdrawfromtheobservations；andI
herebychallengeeveryprejudicedmanwhoisneitheranatomist，noracquaintedwiththeonlyphilosophywhichcanherebeconsidered，thatofthehumanbody。Againstsostrongandsolidanoak，whatcouldtheweakreedsoftheology，ofmetaphysics，andoftheschools，avail，————childisharms，likeourparlorfoils，thatmaywellaffordthepleasureoffencing，butcanneverwoundanadversary。NeedIsaythatIrefertotheemptyandtrivialnotions，tothepitiableandtriteargumentsthatwillbeurged（aslongastheshadowofprejudiceorofsuperstitionremainsonearthforthesupposeincompatibilityoftwosubstanceswhichmeetandmoveeachotherunceasingly？
Suchismysystem，orratherthetruth，unlessIammuchdeceived。
Itisshortandsimple。Disputeitnowwhowill。