ForPegg,arealbeautsheila
Preface xi
1.ResurrectingBiologicalEssentialism1 1.1Introduction1
1.2EvidenceoftheConsensus5
1.3AnArgumentfor IntrinsicBiologicalEssentialism 7
1.4RelationalSpeciesConcepts10
1.5ACrucialDistinction12
1.6SpeciesConceptsandtheCategoryProblem(2)13
1.7BSC,ENC,andtheTaxonProblem(1)15
1.8TheConspeci ficityRoutetoErrorabouttheTaxonProblem(1)19
1.9P-CCandtheTaxonProblem(1)22 1.10VariationandChange25 1.11Conclusion33
2.Defending PartlyIntrinsicTaxonEssentialism 35 2.1Introduction35
2.2Clarifications36 2.3ThreeImportantDistinctions38 2.4Variation42
2.4.1TheCommonCauseHypothesis42
2.4.2GeneticVariations44
2.4.3PhenotypicVariations45
2.4.4CausesofPhenotypicProperties46
2.4.5ComplicatedDevelopmentalPathways47
2.4.6DisjunctiveDevelopmentalPathways49
2.4.7EvolvingnotTimeless53
2.5 “TheAddedMetaphysicalClaim” 56
2.6TheIrrelevanceoftheSpeciesConcepts60
2.7TheConspeci ficityDiagnosis63
2.8TheRelationalViewofConspecificity(R-CON)68
2.9TheEssenceofImplements(“Artifacts”)72
2.10GodmanandPapineauagainst PartlyIntrinsicTaxon Essentialism 78
2.11TheHistoricalSpeciesEssentialismofGodman, Mallozzi,andPapineau80
2.11.1The “MoreFundamentalObjection” 80
2.11.2ThePositiveView82
2.12Conclusion84
3.HistoricalBiologicalEssentialism88 3.1Introduction88
3.2AnArgumentfor PartlyHistoricalTaxonEssentialism 90
3.3Hypothesis(1):DescendedfromCertainParticular ActualOrganisms93
3.4Hypothesis(2):DescendedfromaCertainKindof Organism(WhichItselfhasaWhollyRelationalEssence)96
3.5Hypothesis(3):DescendedfromaCertainKindof OrganismwithaPartlyIntrinsicEssence100
3.6Objections:TwinEarthandtheLike102
3.7Conclusion104
4.IndividualEssentialisminBiology106 4.1Introduction106
4.2IndividualEssentialism:AKripkeanView108
4.3AnArgumentfor PartlyIntrinsicIndividualEssentialism 110
4.4AnArgumentfor PartlyHistoricalIndividualEssentialism 114 4.5Haecceitism115
4.6 EssentialMembership 116
4.7Objection1:TheInterbreedingandEcological ApproachestoSpecies118
4.8Objection2:TheCladisticApproachtoSpecies119
4.9Objection3:Kitcher’ s “DumbbellAllopatry” 125
4.10Objection4:HigherTaxa127 4.11Conclusion130
5.TypeSpecimensandReference132 5.1Introduction132
5.2TheCausalTheoryofReferenceand Levine’sThesis
5.3TheFalsityof Levine’sThesis;TheCasefor C1
5.4 “ButWhatabouttheTheoryofReference?”;TheCasefor C2 141
5.5TheCausalTheoryofMultipleGrounding;TheCasefor C3
5.6PhilosophicalEvaluationsof Levine’sThesis 146
5.6.1Haber;TheCaseforC4146
5.6.2Witteveen148
5.6.3Brzozowski149
5.7Objections150
5.7.1ReviewerR1andCodesofNomenclature150
5.7.2ReviewerR2andtheLinguisticTurn153
5.8Conclusion154
6.RacialRealismandEssentialism157 6.1Introduction157
6.2APresentationoftheRacialRealismIssue158
6.3TheReality/ExistenceIssuesaboutRace159
6.4 RacialTaxonRealism 162
6.5 RacialTaxonRealism(Humans) 166
6.5.1TheCasefor RacialTaxonRealism(Humans) 166
6.5.2Objectionsto RacialTaxonRealism(Humans) 171
6.5.3Rosenbergetal.andtheEssencesofAllegedRaces177
6.6 RacialCategoryRealism(Humans):The “Worthyofthe Name” Issue179
6.7 RacialCategoryRealism(Humans):TheExplanatoryIssue184
6.7.1TheExplanatoryIssuewithOtherCategories184
6.7.2TheExplanatoryIssuewiththeCategory Race 186
6.7.3MinimalConceptsoftheHigherCategories188
6.7.4AMinimalConceptoftheCategory Race 193
6.8TooWeaktobeInteresting?197
6.9Conclusion200
Preface
AlthoughIhavemostlyworkedinthephilosophyoflanguage,Ihavealwaysbeen interestedinthephilosophyofbiology.Iwouldtendtogototalksonthesubject whenatphilosophyconferences.Someofmybestfriendsarephilosophersof biology.Butitwasnotuntil2003thatIstartedworkingonthesubject.Iwas prompteddosoinwritingapaperdefendingthelinguisticthesisthatthe Kripkeannotionof “rigidity” weneedforkindtermsisoneof rigidapplication notoneof rigiddesignation (2005).¹Thepromptcamebecausethisthesis,when appliedtothelikesof ‘tiger’,raisedissuesofbiologicalessentialism.Thatledmeto readaveryinstructivepaperbySamirOkasha(2002)inwhichhesetoutthe receivedviewsaboutessentialisminthephilosophyofbiology.Theseviewsstruck measquitewrong.For,theydenyanyintrinsicgeneticcomponenttotheessence ofaspeciesorotherbiologicaltaxon.Andtheyimplicitlydenythatanymember ofaspeciesisessentiallyamember.
So,withoutmoreado,Iwroteaneight-pagepieceIcalled, “SomeHeretical ThoughtsonBiologicalEssentialism”.Isentthistoeveryphilosopherofbiology Iknew,andmanyIdidnot.Thishadtwosurprisingconsequences.First,the volumeofresponsewasastounding:initialresponsestogetherwithfollow-up discussionsamountedto100pages.Second,giventheconsensus,Iexpectedthe expertstoidentifydeep flawsinthese “hereticalthoughts”.Yetthisdidnot happen.Iwascorrected,informed,andguidedonmanymatters,alwaysina wonderfullyhelpfulway,andyetmybasicargumentforbiologicalessentialism seemedtometosurvivefairlyintact.Thatargumentwas,inbrief,thatbiological explanationdemandedintrinsicessences.So,tothehorrorofsomefriends,Iwent seriouslytoworkontheseissues.Thisledtoseveralpublications,startingwith “ResurrectingBiologicalEssentialism” (2008),and finallytothisbook.
Whilewritingthebookin2020,someotherrelated,andrather “hot”,issues pressedinonme:issuesofbiologicalrace “realism” andessentialism.Idecidedto includethoseissuesinthebook.
So,whataretheissuesthatconcernthebook?Settingasideraceforamoment, theissuesareasfollows:
1.Whatisit tobe amemberofaparticularbiologicaltaxon? Invirtueofwhat is anorganism,say,a Canislupus?What makes itone?Thesearevariouswaystoask
¹I firstpresentedthislinguisticthesisinDevittandSterelny(1999:85),largelystimulatedbymy anonymousreviewingofwhatwastobecomeLaPorte(2000).
aboutthe ‘ essence ’ , ‘nature’ , ‘identity’ ,even ‘definition’,ofaparticulartaxon.They raisetheissueof taxonessentialism.
2.Whatitis tobe aparticularindividualorganism? Invirtueofwhat isan organism,say,theQueen?What makes ither?Thesearevariouswaystoaskabout the “ essence ” , “nature” ,or “identity” ofaparticularindividual.Theyraisetheissue of individualessentialism.
3.Ifanindividualorganismbelongstoataxondoesitdosoessentially?Thisis theissueof essentialmembership.Clearly,ifwehadanswerstoboth taxon essentialism and individualessentialism wewouldhaveananswerto essential membership:anorganism O isessentiallyamemberofataxon T iffanorganism havingtheessenceof O entailsitshavingtheessenceof T. Theseessentialismissueshavebeenmuchdiscussedbymetaphysicians.Thus, on taxonessentialism ,SaulKripke(1980),HilaryPutnam(1975),andDavid Wiggins(1980)haveproposedviewsthataresimilartomine.Myviewisthat theessenceofataxon,particularlyaspecies,is(atleastpartly)an intrinsic, underlying,probablylargelygeneticproperty.Thisviewaccordswithcommon senseandhasbeenwidelyacceptedinphilosophy.Theseauthorsalsoembraced essentialmembership.And,talkingabouttheQueeninparticular,Kripkehas urgedaviewon individualessentialism:heroriginincertaingametesfromcertain parentsisessentialtoher.This “originessentialism” hasstirredcontroversy amongmetaphysicians.
Themethodologyofthemetaphysiciansistoappealtointuitions. Whathavephilosophersofbiologyhadtosayontheseissues?Thecontrast withmetaphysicianscouldhardlybemorestark.First,philosophersofbiology (andbiologists)aredismissiveofthepopularKripkeanviewon taxonessentialism. Theideathataspecieshasanunderlyingintrinsicessenceisthoughttosmackof “Aristotelianessentialism ” andreflectanaiveanduninformedviewofbiologythat isincompatiblewithDarwinism.Clearly,iftheessenceofaspeciesisnotintrinsic itmustberelational(assumingthatithasanessenceatall).Theconsensusis indeedthattheessenceisrelational:foranorganismtobeamemberofacertain species,itmusthaveacertain history.Second,untilrecently,theissueof essential membership hadbeenlargelyignoredinphilosophyofbiology.Insofarasithas beenaddressedithasbeenrejected.Third,theissueof individualessentialism has beentotallyignoredinphilosophyofbiology.
Themethodologyofphilosophersofbiologyistoappealtobiologicaltheory. In “Resurrecting”,Iwentalongwiththeconsensusinaccepting,without argument,thatthereisanhistorical component totheessenceofataxon. However,Iwentsharplyagainsttheconsensus,particularlyoverspecies,in arguingthatthereis also anunderlyingintrinsiccomponent.SoIsidedwith Kripkeandthefolkagainstthephilosophersofbiology.ButIdidsofollowingthe methodologyofphilosophersofbiology:Iappealedtobiologicalexplanationsnot intuitions.Thisbookstartswithareprintof “Resurrecting” inChapter1.
ErnstMayrmadeanimportantdistinctionbetweentwoproblemsabout species:the “taxon” problemandthe “category” problem.Invirtueofwhatis anorganisminthetaxon lion andnot tiger?Thatisanexampleofthetaxon problem.Invirtueofwhatisthetaxon lion aspeciesandnotasubspecies orgenus?Thatisanexampleofthecategoryproblem.Thisdistinctionis widelyacceptedbutitssignificanceisoftenoverlookedindiscussionsof biologicalessentialismandracialrealism.Thedistinctioniscrucialtomycase forintrinsicessentialismin “Resurrecting”,andtothediscussionsthatfollowin thisbook.
“Resurrecting” receiveddetailedandinterestingcriticismsfromseveralphilosophersofbiology:RobertWilsonetal.(2007),MatthewBarker(2010),Marc Ereshefsky(2010),RichardRichards(2010),TimLewens(2012),Sarah-JaneLeslie (2013),MatthewSlater(2013),andMarionGodman,AntonellaMallozzi,and DavidPapineau(GodmanandPapineau2020;Godmanetal.2020).Chapter2 defendsmyintrinsicessentialismfromthesecriticisms.InsodoingIhopeto strengthenthecaseforthatessentialism.
Theconsensusviewthattheessenceofataxoniswhollyrelationalraisestwo questions.(A)Whybelieveit?(B)What precisely isthiswhollyrelationalessence? Theliteratureprovidessurprisinglylittleinthewayofplausibleanswers,particularlyto(B).Concerning(A),Chapter3presentsanargumentthatthereisatleast anhistorical component totheessence.Thechapterarguesagainstsuchanswersas Ihavebeenableto findto(B).Iturgesinsteadthattherelevanthistoryofataxon isoforganisms ofacertainintrinsickind evolvingintoorganismsof acertain otherintrinsickind,untilwereachthetaxoninquestion.So,thehistorical componenttotheessencerequiresanintrinsiccomponent.So,thisviewis anotherchallengetotheconsensusinthephilosophyofbiology.
Sofar,theconcernhasbeenallwithtaxa.InChapter4,thebookturnsto individuals.Whereas essentialmembership hasbeenatopicofinterestinmetaphysicsithasbeenlargelyignoredinphilosophyofbiologyuntilquiterecently,as LaPorte(1997)pointedout.Hesetaboutremedyingthissituation.Whereas,he charges, “essentialistshavetendedtoberathernaïveonscientificmatters”,he aimstoapproachtheissue “inthelightofbiologicalsystematics” (p.97).This approachleadshimtoreject essentialmembership.Someotherphilosophersof biologyhavesincejoinedhiminthis;forexample,Griffiths(1999),Okasha (2002),andLeslie(2013).
So,thesephilosophersofbiologyurge,fromabiologicalbasis,aviewofwhatis not essentialtoanindividualorganism.Butneithertheynor,sofarasIcan discover,anyotherphilosopherofbiologyoranybiologist,seriouslyaddressthe broaderissueof individualessentialism ,theissueofwhat is essentialtothe organism.Itseemsthatthisissue,muchdiscussedbymetaphysicians,has entirely escapedtheattentionofphilosophersofbiology.Chapter4arguesthatitdeserves attention.
Chapter4presentsanargumentfromtheexplanatoryconcernsofbiologyfor theKripkeanviewthatanorganism,likeataxon,hasapartlyintrinsic,partly historical,essence.Thistogetherwiththebook’sviewon taxonessentialism yield anargumentfor essentialmembership.Theconsensusiswrongagain.
Essentialmembership hasbecometopicalbecauseofaseriesofpapers,mostly in BiologyandPhilosophy,beginningwiththeonebyAlexLevine(2001).Levine rejects essentialmembership andsoholdsthatthatanyorganismisonlycontingentlyamemberofitsspecies.He findsthiscontingencyinconflictwiththe commonthesisinbiologythatanyorganismselectedasthe “typespecimen” fora speciesisnecessarilyamemberofthatspecies.Levineexpressestheconflictneatly: “quaorganism ,thetypespecimenbelongstoitsrespectivespeciescontingently, while quatypespecimen,itbelongsnecessarily” (p.334).Inembracing essential membership inChapter4,IrejectLevine’ s qua-organism thesis.InChapter5, Iargueagainsthis qua-type-specimen thesis.
Finally,Iturntothelively fieldofthephilosophyofrace,a fieldthatengages philosopherswithbackgroundsfrombiologytosocialtheory.Amajorconcernof the fieldiswhetherraceisbiologically “real”,whetherrace “exists”.Arelated concerniswithwhatracesareor,asIputit,withtheiressencesornatures.In Chapter6,Iconsidertheseissuesfromtheperspectivedevelopedearlierinthis bookandinanarticle, “NaturalKindsandBiologicalRealisms” (2011c).I findthe issueof “racialrealism” unclearinitsblurringoftheearlier-emphasizedcrucial distinctionbetweentaxonandcategoryissues;inthiscase,betweentheissueof allegedracesandtheissueofthecategory Race.Armedwiththisdistinction, Iarguethatthereareracialkinds,insomesense,thatareindeed “intherealmof thebiological”.Thesekinds,likethosethoughttobepartoftheLinnaean hierarchy,haveessencesthatarepartlyhistoricalandpartlyunderlyingintrinsic properties.Thisracialrealismdoesnot,ofcourse,endorseanytheoryofraces, particularlynotracistonesthathavebeenusedasinstrumentsofdiscrimination andoppression.
Myworkonalltheseissueshasledtoseveralpapersthathavebeendeliveredin talksandsometimespublished.Ihavealreadymentioned “ResurrectingBiological Essentialism” (2008).Itwasdeliveredatmanyplacesaroundtheworld,starting withsomeuniversitiesinAustraliainNovember2005.Sincethispublicationhas beenthesubjectofthecriticismsdiscussedinChapter2,Ithoughtitbestto reprintitasChapter1,withoutanychangesexceptafewadditionalfootnotes. Apreliminaryversionofthepublication “DefendingIntrinsicBiological Essentialism” (2021a)wasdeliveredataworkshopinhonorofKimSterelny’ s 60thbirthdayatMysteryBay(NSW,Australia)inNovember2010.ThepublicationdrewonamuchlongerversionthatwasdeliveredattheUniversityofRijeka aspartofaseriesoflecturesinApril2017.Chapter2isamodifiedandfurther expandedversionofthatpublication,includingalsoaversionofanotherpublication,myresponse(2020:441–9)toMarionGodmanandDavidPapineau
(2020). “HistoricalBiologicalEssentialism” (2018a)was firstdeliveredatthe UniversityofSydneyinApril2017.Chapter3isamodifiedversionofthe publication. “IndividualEssentialisminBiology” (2018b),was firstdeliveredat MacquarieUniversity,Sydney,inNovember2015.Chapter4isamodi fiedand expandedversionofthepublication.AversionofChapter5, “TypeSpecimensand Reference”,wasrejectedbytwojournals.Butthiscloudhadasilverlining:itgave mesomehelpfulinsightintolikelyobjections,whichIaddress.Chapter6, “Racial RealismandEssentialism ” wasthebasisfortwolecturesattheUniversityofRijeka inOctober2021andseverallatertalkselsewhere.Workingonitinspiredapaper, “TheMinimalRoleoftheHigherCategoriesinBiology” (2023).
IhavereceivedcommentsandadvicefrommanyovertheyearssinceIaired “SomeHereticalThoughts”,includingfromthosewhocommentedonthepapers thatthebookdrawson.Hereismybest,butprobablyinadequate,attempttolist thosewhohavehelpedinonewayoranother:MatthewBarker,AlbertoCordero, MichaelDickson,JohnDupré,MarcEreshefsky,PeterGodfrey-Smith,Paul Griffiths,AdamHochman,TimJuvshik,PhilipKitcher,JosephLaPorte,Michael Levin,AntonellaMallozzi,RajNanavati,KarenNeander,SamirOkasha, MakmillerPedroso,GeorgesRey,StephenSchwartz,StephenStich,Iakovos Vasiliou,JoelVelasco,DenisWalsh,JohnWilkins,AndreaWoody.Finally,thanks tothemembersofmyclasseson “BiologicalEssentialism” attheGraduateCenter.
MichaelDevitt Hudson,NY October,2022
ResurrectingBiologicalEssentialism
“Essentialismaboutspeciesistodayadeadissue” (Sober1980:249)
“Folkessentialismisbothfalseandfundamentallyinconsistentwith theDarwinianviewofspecies” (Grif fiths2002:72)
1.1Introduction
Theideathatbiologicalnaturalkinds,particularlyaspecieslikedogs,have intrinsicunderlyingnaturesisintuitivelyappealing.¹Ithasbeenshowntobe widespreadevenamongchildren(Keil1989).Itwasendorsedbyagreatphilosopher,Aristotle.Undertheinfluenceofthelogicalpositivists,Popper(1950),Quine (1960),andothers,itfellfromphilosophicalfavorinthetwentiethcenturyuntil revivedbySaulKripke(1980),HilaryPutnam(1975),andDavidWiggins(1980). Manyphilosophersprobablynowtaketheviewforgranted.Ifso,theyareright outoftouchwithbiologistsand,especially,philosophersofbiology.For,the consensusamongphilosophersofbiology,andawidespreadviewamongbiologists,isthatthissortof “Aristotelianessentialism” isdeeplywrong,reflecting “typological” thinkinginsteadoftherecommended “population” thinking(Sober 1980:247–8).Thisessentialismisthoughttoarisefromanaiveanduninformed viewofbiology,indeedtobeincompatiblewithDarwinism.²Thisviewisnicely presentedandarguedforinapaperbySamirOkasha(2002).Ishalltakethatas mymaintext.Ishalldefendintrinsicbiologicalessentialism.Ithinkthatthe childrenarerightandthephilosophersofbiology,wrong.³
¹Firstpublishedinthe PhilosophyofScience,75(Devitt2008).Reprintedin PuttingMetaphysics First:EssaysonMetaphysicsandEpistemology (Devitt2010)withsomeadditionalmaterialinfootnotes, identifiedby “[2009addition]”.Manyoftheseadditionsremaininthepresentversion.Someothers havebeenadded,identifiedas “[2022addition]”
²MichaelRuseplacesKripke,Putnam,andWiggins “somewheretotherightofAristotle” andtalks ofthemshowing “analmostproudignoranceoftheorganicworld” (1987:358n).JohnDupréargues thattheviewsofPutnamandKripkearefatallydivergentfrom “someactualbiologicalfactsand theories” (1981:66).[2009addition]Thestandardstoryisthatbiologywasinthegripofclassical essentialismuntilsavedbyDarwin.PollyWinsor(2006)arguespersuasivelythatthisstoryisa fabricationofErnstMayr’ s.
³Thispaperwaspromptedbywritinganotheronedefendingthethesisthatthenotionofrigiditywe needforkindtermsisoneof rigidapplication notoneof rigiddesignation (Devitt2005).Theviewthat naturalkindtermsarerigidappliershasthemetaphysicalconsequencethatamemberofanaturalkind
BiologicalEssentialism.MichaelDevitt,OxfordUniversityPress.©MichaelDevitt2023. DOI:10.1093/oso/9780198840282.003.0001
Istartbysayingsomethingaboutessentialismingeneralandaboutthe essentialismIshalldefendinparticular.
Aproperty P is anessentialproperty ofbeingan F iffanythingisan F partlyin virtueofhaving P.Aproperty P is theessence ofbeingan F iffanythingisan F in virtueofhaving P.Theessenceofbeing F isthesumofitsessentialproperties. Essencescanbefullyintrinsic;forexample,theessenceofbeinggoldishaving atomicnumber79.Essencescanbepartlyintrinsicandpartlyextrinsicand relational;⁴ forexample,theessenceofbeingapencilispartlybeinganinstrument forwriting,whichanobjecthasinvirtueofitsrelationtohumanintentions,and partlyhavingthesortofphysicalconstitutionthatdistinguishesitfromapen, whichanobjecthasintrinsically.Finally,essencescanbefullyrelationaland extrinsic;beingAustralianisprobablyanexamplebecauseitseemsthat anything RupertMurdock,PharLap(ahorse),theSydneyOperaHouse,a bottleofPenfolds’ Grange,theexpression “noworriesmate”,andsoon can havethepropertyprovideditstandsintherightrelationtoAustralia. ⁵
ThedoctrineIwanttodefend,whichIshallcall “IntrinsicBiological Essentialism”,abbreviatedsometimesto “Essentialism”,isthatLinnaeantaxa haveessencesthatarepartlyintrinsicunderlyingproperties.Thiscallsforsome clarificationandcomment.
(i)By “Linnaeantaxa” Imeankindsthatarethoughttofallunderthebiological categoriesintheLinnaeanhierarchy:kingdoms,phyla,classes,orders,families, genera,species,andevensubspecies(varieties).⁶ Idonotmeankindslikethoseof predatorsorparasites.AndIdonotmeanthecategoriesthemselves. Essentialism isathesisaboutwhatitisforanorganismtobe,say,adognotacat,notabout whatitisfor,say,dogstobeaspeciesnotagenus.(Thisdistinctionwillloomlarge insections1.5to1.9.)Thefocusofmydiscussionwillbeonspeciesbut, Iemphasize, Essentialism coverskindsthatfallunderallthecategories. isessentiallyamember.Thissortof “individualessentialism” needstobedistinguishedfromthe “kind essentialism” thatistheconcernofthepresentpaper.[2022addition]Individualessentialismis discussedinChapter4.
⁴ Biologicalessentialismisusuallytakentobeconcerned only withwhatisintrinsic(e.g.,Mayr1963: 16;Sober1993:146;Wilson1999b:188).ThisreflectstheinfluenceofAristotle.Ithinkitmorehelpful todefineessentialisminamoregeneralwaysothatissuescomedowntothe sort ofessencethata kindhas.
⁵ Lockecalledanunderlyingintrinsicessencethatiscausallyresponsiblefortheobservable propertiesofitskinda “realessence”.Thisiscontrastedwitha “nominalessence” whichispicked outbyreference-determiningdescriptionsassociatedwithakindterm.So,havingatomicnumber79is therealessenceofgoldandtheessenceofbeingAustralian,whateveritmaybe,ismerelynominal. KripkeandPutnamshowedthatnaturalkindtermslike ‘gold’ arenotassociatedwithreferencedeterminingdescriptionsandsodonotpickoutnominalessences;theypickoutrealessenceswithout describingthem.Thisisnottosaythataterm couldnot pickoutanominalessencethatisalsoreal; indeed, ‘havingatomicnumber79’ issuchaterm(cf.Boyd1999:146).
⁶ Isay “thoughttofall” becauseIsympathizewiththedoubtsofsomeaboutthishierarchy; seeEreshefsky(1999;2001);Mishler(1999).[2022addition]Thereisadiscussionofthesedoubts later(6.7).
(ii)Iincludethequali fication “atleastpartly” becauseIshallnottakeissuewith theconsensusthataspeciesispartlyanhistoricalentity.⁷
(iii)Insexualorganismstheintrinsicunderlyingpropertiesinquestionareto befoundamongthepropertiesofzygotes;inasexualones,amongthoseof propagulesandthelike.⁸ Formostorganismstheessentialintrinsicproperties areprobablylargely,althoughnotentirely,genetic.Sometimesthoseproperties maynotbegeneticatallbutin “thearchitectureofchromosomes” , “developmentalprograms” orwhatever(Kitcher1984:123).⁹ Forconvenience,Ishalloften writeasiftheessentialintrinsicpropertiesweresimplygeneticbutIemphasize thatmy Essentialism isnotcommittedtothis.
(iv) IntrinsicBiologicalEssentialism wouldcertainlybeopposedbytheconsensusbecauseofitscommitmentto intrinsic essences.Buttheconsensusshouldnot beopposedtobiologicalessentialismingeneralbecause,asIamunderstanding essentialism,theconsensusisthatspecieshaveessencesbuttheseare extrinsicor relational.AndKimSterelnyandPaulGriffiths,intheirexcellentintroductionto thephilosophyofbiology, SexandDeath,areexplicitlynotopposedtothissort ofessentialism: “theessentialpropertiesthatmakeaparticularorganisma platypus...arehistoricalorrelational” (1999:186).Ofcourse,theveryterm ‘essentialism ’ hasbecomesodistastefultobiologistsbecauseofitsassociation withAristotelianmetaphysicsthatabiologistwoulddoubtlessbereluctantto admittoanysortofessentialism.ButtheessentialismIhavede finedneednot comewiththoseAristoteliantrappings.Manyphilosopherswouldbesimilarly reluctantbecausetheterm ‘essentialism’ strikesthemasquaintlyold-fashioned, scholastic,evenunscientific.Butsuchreluctancewouldbeamerelyverbalmatter. Theissueofessentialismwouldremaineveniftheterm ‘essentialism ’ were dropped.Itistheissueofinvirtueofwhatanorganismisamemberofacertain Linnaeantaxon;theissueofwhatmakesanorganismamemberofthattaxon;the issueoftheverynatureofthetaxon.Istickwith ‘essentialism ’ becauseitisthe
⁷ However,Isaythattheessencesare “atleast,partly” intrinsicratherthansimply “partly” because Idowonderwhether all speciesare,orshouldbe,partlyhistorical.Citingthepossibilityofregularly producedhybridslikethelizard Cnemidophorustesselatus,PhilipKitcherclaimsthat “itisnot necessary,anditmaynotevenbetrue,thatallspeciesarehistoricallyconnected” (1984:117).[2022 addition]HistoricalessentialismisdiscussedinChapter3.
⁸ WhatIwouldlikeisatermforasexualorganismsthatislike ‘zygote’ forsexualonesinreferringto thebeginningofanorganism.JohnWilkinsinformsmethatthereisnoonetermforthis.Othershe mentionsinclude ‘bud’ and ‘gemmule’.Hehasalsodrawnmyattentiontootherusesof ‘propagule’ . Thus,considerthefollowingdefinition:
Inanimals,theminimumnumberofindividualsofaspeciescapableofcolonizinganew area.Thismaybefertilizedeggs,amatedfemale,asinglemaleandasinglefemale,ora wholegroupoforganismsdependinguponthebiologicalandbehavioralrequirementsof thespecies.Inplants,apropaguleiswhateverstructurefunctionstoreproducethespecies:a seed,spore,stemorrootcutting,etc.http://www.radford.edu/~swoodwar%20/CLASSES/ GEOG235/glossary.html
⁹ WebsterandGoodwin(1996)promotetheideaof “morphogenetic fields” .
termthatphilosophersofbiologyuseforthedoctrinethattheywanttorejectand Iwanttopromote.Thosewhoareoffendedbythetermshouldreplaceitwithone oftheotherwaysofcharacterizingtheissue.
(v)Thereissomecontroversyoverwhetherspeciesarenaturalkindsor individuals.MichaelGhiselin(1974)andDavidHull(1978)seemtoseeindividualismasanantidotetoessentialism.¹⁰ But,asOkashapointsout, “theissuesabout essentialism ...donot dependonwhichviewoftheontologicalstatusofspecies wefavour” (2002:193–4;seealsoKitcher2003:137–40).¹¹Thus,ifaspeciesisan individualratherthanakind,ouressentialismissueforspeciesbecomesthatof sayinginvirtueofwhatorganismsare partsof acertainspecies,forexample,the species Canisfamiliaris.Andtheconsensusanswershouldbethatitisentirelyin virtueoftheorganisms’ historicalorrelationalproperties,entirely “becausethey arepartofthegenealogicalnexus” (Hull1978:309),whereasmy Essentialism’ s answerwouldbethatitispartlyinvirtueoftheorganisms’ intrinsicunderlying properties.¹²Indeedtheessentialismissuecanbeposed “nominalistically” ina waythatisnoncommittalontheontologicalstatusofspecies:Invirtueofwhatis anorganism,say,a Canisfamiliaris?AndthatishowI do posetheissueinsection 1.5.Imeantobeneutralontheontologicalissuebutforconveniencewillmostly talkofspeciesasiftheywerekinds.
(vi) Essentialism isprimarilyconcernedwiththenaturesofthe actual groups identifiedbythefolkandbiologistsforexplanatorypurposes.This “descriptive” issueneedstobedistinguishedfromthe “normative” issueofthenaturesofthe groupsthatwe should identifyforexplanatorypurposes.Clearly,wemightnotbe doingwhatweshouldbedoing.However,Ishallwriteasifweare.Ifwearenot, thenmy Essentialism shouldbetakentocoverthegroupsthatweshouldbe identifyingforexplanatorypurposesaswell.
Insection1.2,Igiveevidencethattheconsensusreallyisopposedto Intrinsic BiologicalEssentialism.Insection1.3,Iargueforthedoctrine:explanationsin biologydemandthattherebeessentialintrinsicunderlyingproperties.Iturnthen toobjections.Insection1.4,Idescribethestandardrelationalviewsofspecies which,accordingtotheconsensus,make Essentialism untenable.Insection1.5, Iemphasizeadistinctionwhichiscrucialtoshowingthattheconsensusiswrong aboutthis.Thedistinctionisbetweentwoquestions.(1)Whatisittobeamember ofanygroupthathappenstobeaspecies?(2)Whatisitforagrouptobea
¹⁰“Individualism aboutspeciesisanideawithcloselinkstoantiessentialism,bothconceptuallyand historically” (Griffiths1999:211).
¹¹RichardBoydgoessofarastosaythatthedistinctionbetweenspeciesbeingindividualsorkinds “isalmostjustoneofsyntax” (1999:164).
¹²Also,weshouldnote,if Canisfamiliaris isanindividual,wecanaskaboutits individual essence justaswecanaboutthatofanyindividual(n.3).Andtheconsensusanswershouldbethatitsessenceis itsbeingconstitutedbyorganismsthatsharehistoricalorrelationalpropertieswhereasmy Essentialism’sanswerwouldbethatthoseorganismsmustalsosharecertainintrinsicunderlying properties.[2022addition]IndividualessentialismisdiscussedinChapter4.
species?Insections1.6to1.9,Iarguethattherelationalviewsofspeciesare, primarilyatleast,answerstoquestion(2). Essentialism,incontrast,isananswer to(1).Indeed,theserelationalviewscan,mostly,behappilyweddedto Essentialism.Eventheinfluentialphylogenetic-cladisticviewcanbeweddedifit losessomeimplausiblefeatures.¹³Howhastheconsensusgotitsowrong?My tentativediagnosisisthattheerrorhasarisenfromconflatingquestions(1)and (2),aconflationencouragedbysomemistakenthoughtsaboutconspeci ficity. Finally,insection1.10,IaccommodatesomegeneralfeaturesofDarwinianism, associatedwithvariationandchange,featuresthatarethoughttoundermine Essentialism.Theaccommodationrequiresacceptanceofsomeindeterminacyin whatconstitutesabiologicalkind.Butwemustallacceptthat,whateverourviews of Essentialism
Iftheargumentsinsections1.4to1.10areright,thestatedobjectionstoan essentialistdoctrinelike IntrinsicBiologicalEssentialism fail.Perhapsthereare someunstatedobjectionsthatwouldsucceed.Andperhapsthesecouldprovide thebasisforshowingthattheargumentsinsection1.3infavorof Essentialism are inadequate.Giventhestrengthandlongevityoftheconsensusinbiologyagainst intrinsicessentialism,itseemsreasonabletopredictthis.Still,itremainstobeseen whetheritisso.AttheveryleastIhopetoshowthatthecasefortheconsensus needstobemadealotbetterthanithasbeen.
Ihaveclaimedthattheconsensusamongphilosophersofbiologyisthatdoctrines like IntrinsicBiologicalEssentialism arewrong.Amongthosephilosophers,the claimhardlyneedssupportbecausetheconsensusissoestablished.Still,among philosophersingeneral,theclaimdoesneedsupportbecause,influencedby KripkeandPutnam,many findtheclaimincredibleandsothinkImustbe strugglingwithastrawman.Theepigraphstothispaper,drawnfromtheworks ofElliottSoberandPaulGrif fiths,twoleadingphilosophersofbiology,aresome evidencethatIamnot.Hereissomemore.
Theconsensusstartsbydenyingthatmembersofaspeciesshareadistinctive setofgeneticproperties.Thus,accordingtoOkasha,
virtuallyallphilosophersofbiologyagreethat...itsimplyisnottruethatthe groupsoforganismsthatworkingbiologiststreatascon-specificshareasetof commonmorphological,physiologicalorgenetictraitswhichsetthemofffrom otherspecies.(2002:196)
¹³[2009addition]Notso:theweddingispossibleevenwiththeimplausiblefeatures;see nn.43and44.
1.2EvidenceoftheConsensus
Clearly,ifthemembersofaspeciesdonotshareadistinctivesetofgenetic propertiesthenthosepropertiescouldnotbeessentialpropertiesofthatspecies. Indeed,Okashaclaimsthat “biologistsandphilosophersofbiologytypically regardessentialismaboutspeciesasincompatiblewithmodernDarwiniantheory” (2002:191).AndJohnDupréclaimsthat “itiswidelyrecognizedthatDarwin’ s theoryofevolutionrendereduntenabletheclassicalessentialistconceptionof species” (1999:3).AlexRosenbergsays: “Theproponentsofcontemporaryspecies definitionsareallagreedthatspecieshavenoessence” (1985:203).Mohan Matthenclaimsthat “species ...areassociatedwithnononrelationalrealessence” (1998:115).Soberexpressesthisconsensusasfollows: “biologistsdonotthink thatspeciesarede finedintermsofphenotypicorgeneticsimilarities”;tigersare “not defined byasetoftraits” (1993:148).SterelnyandGriffithsputthepoint bluntly: “nointrinsicgenotypicorphenotypicpropertyisessentialtobeinga memberofaspecies” (1999:186).Ghiselinputsitevenmorebluntly: “ThatJohn Doehasaparticularsetofgenesisaboutasrelevanttohisbeingaspecimenof Homosapiens L.asitistohisworkingforthemanufacturersofBrandX” (1974:283).
Finally,iftheessenceofaspeciesisnotintheleastintrinsicthenitmustbe entirelyrelational.IhavealreadyquotedSterelnyandGriffiths’ claimtothiseffect abouttheplatypus.Andtheythinkthatnearlyeveryoneagreeswiththem:thereis “closetoaconsensusinthinkingthatspeciesareidentifiedbytheirhistories” (1999:8).TheirviewisendorsedbyOkasha(2002:202).Soberdeclaresthattigers are “historicalentities” (1993:148). “Twoorganismsareconspecificinvirtueof theirhistoricalconnectiontoeachother,notinvirtueoftheirsimilarity ” (1993: 150).Similarly,MarcEreshefsky,speakingfor “Darwin,thefoundersofthe ModernSynthesis,andmostcladists” (2001:209).Finally,Hullclaims: “Ifspecies areinterpretedashistoricalentities,thenparticularorganismsbelonginaparticularspeciesbecausetheyarepartofthatgenealogicalnexus,notbecausethey possessanyessentialtraits.Nospecieshasanessenceinthissense ” (1978:313). RuthMillikansaysmuchthesame(2000:19).
Theconsensusisbroadbutsomearenotpartofit.ThusDavidB.Kittsand DavidJ.Kitts(1979)urgeanintrinsicessentialismlikemine.Accordingto RichardBoyd(1999)andRobertWilson(1999b),speciesare “homeostaticcluster kinds” andItakeitthattheythinkthattheyhaveatleastpartlyintrinsic essences.¹⁴ AndPhilipKitcherhasthistosay: “Iwanttoremainagnosticonthe issueofwhetheranyspeciestaxonhasanontrivialessence” (1984:132,n.16).
¹⁴ HilaryKornblithfavorstheviewthatspeciesarehomeostaticclusterkinds,notesthatthe membersoftheclusterneednotbeintrinsic,butdoesnottakeastandonwhetheranyofthemare (1993:111,n.10).Griffithswritesapprovinglyofthehomeostaticclusterviewbutarguesthatspecies havepurelyhistoricalessences(1999:217–22).[2022addition]Wilsonetal.includethepropertyof havingacertaingenotype inthecluster(2007:199).MyEssentialismisclearlynotahomeostatic clusterview.
Itaketheoppositionto IntrinsicBiologicalEssentialism tobeestablished.Itis nowtimetoargueforthedoctrine.
1.3AnArgumentfor IntrinsicBiologicalEssentialism
Ishalloffertworeasonsforbelieving Essentialism.The firstissuperficialbutstill, itseemstome,indicativeofwherethetruthlies.Suchessentialpropertiesseemto bepartofwhat “genomeprojects” arediscovering.Theprojectsseemtobe throwinglightontheverynatureofcertainspecies.Thusthe NewYorkTimes recentlyreportedthatresearchershope “todiscover,fromathree-waycomparison ofchimp,humanandNeanderthalDNA,whichgeneshavemadehumans human ” (Wade2006:A14).¹⁵ Philosophersofbiologydisparagethiscommon view(SterelnyandGrif fiths1999:7;Okasha2002:197)buttheviewiscertainly appealing.
Thesecondreasonisdeepandshowswhytheviewisappealing.Wegroup organismstogetherunderwhatseem,atleast,tobethenamesofspeciesorother taxaandmakegeneralizationsaboutthemorphology,physiology,andbehaviorof themembersofthesegroups:aboutwhattheylooklike,aboutwhattheyeat,about wheretheylive,aboutwhattheypreyonandarepreyto,abouttheirsignals,about theirmatinghabits,andsoon.Thesegeneralizationsarethestuffofpopular natureprogramsandaretobefoundthroughoutthewritingsofbiologistsand philosophersofbiology.Forexample,wearetoldthativyplantsgrowtowardthe sunlight(Sober1993:6);thatpolarbearshavewhitefur;thatIndianrhinoceri haveonehornandAfricanrhinoceri¹⁶ havetwo(p.21);thatHawaiian Drosophila “routinelyforminterspeci fichybridsinthewild” (p.156);thattheAustralasian bitternissuperblycamouflaged(SterelnyandGriffiths1999:32);that “Major Mitchellcockatoosoccasionallyhybridizewithgalahs” (p.189);that “Australian trees...arenotjustdrought-proof;theyare fireproofaswell” (p.203);that “magnetotacticbacteria...comeequippedwithlittlecompassescalledmagnetosomes,whichtheyusetonavigateawayfromoxygen-richsurfacewaterbecause oxygenistoxictothem” (p.209).
Generalizationsofthiskinddemandanexplanation. Whyaretheyso? Why,for example,istherethisdifferencebetweentheIndianandAfricanrhinos?Such questionscould,ofcourse,beseekinganexplanationoftheevolutionaryhistory that ledto thegeneralizationbeingtrue.Setthatasideforamoment.The questionscouldalsobeseekinganexplanationof whatmakes thegeneralization
¹⁵ Consideralsothisrecentnewsreportinthe ScientificAmerican online: “‘DNAbarcodesare givingusadirectsignalofwherespeciesboundarieslie,’ saysPaulHerbert,anevolutionarybiologistat theUniversityofGuelphinOntarioandaprogenitorofthegeneticbarcodeeffort” (Biello2007).
¹⁶ [2022addition]Africanrhinosaremadeupoftwospecies, Cereaotheriumsimum (“White”)and Dicerosbicornis (“Black”)andsoarenotstrictlyaLinnaeantaxon.
true.Regardlessofthehistoryofitscomingtobetrue,invirtueofwhatisitnow true?Whatarethemechanisms?Thetruthofthesegeneralizationscannotbe brutefactsabouttheworldandsomustbeexplained.Explanationswillmake someappealtotheenvironment¹⁷ buttheycannotappealonlytothat.Therehas tobesomethingabouttheverynatureofthegroup agroupthatappearstobea speciesortaxonofsomeothersort that,givenitsenvironment,determinesthe truthofthegeneralization.Thatsomethingisanintrinsicunderlying,probably largelygenetic,propertythatispartoftheessenceofthegroup.Indeed,whatelse coulditbe?¹⁸ SomeintrinsicunderlyingpropertyofeachIndianrhinocausesit,in itsenvironment,togrowjustonehorn.AdifferentsuchpropertyofeachAfrican rhinocausesit,initsenvironment,togrowtwohorns.Theintrinsicdifference explainsthephysiologicaldifference.Ifweputtogethereachintrinsicunderlying propertythatsimilarlyexplainsasimilargeneralizationaboutaspecies,thenwe havetheintrinsicpartofitsessence.¹⁹
Thegeneralizationswehavebeendiscussingreflectthefactthatitis informative toknowthatanorganismisamemberofacertainspeciesorothertaxon:these classi ficationsare “informationstores” (SterelnyandGriffiths1999:195).But beingamemberofacertaintaxonismorethaninformative,itis explanatory Matthenpointsoutthat “manybiologistsseemcommittedtotheideathat somethingisstriped because itisatiger” (1998:115).Andsotheyshouldbe: thefactthatanindividualorganismisatiger,anIndianrhino,anivyplant,or whatever,explainsawholelotaboutitsmorphology,physiology,andbehavior.At firstsight,theexplanationoftheanimal’sstripesmayseemrathersuperficial,but itisnotreally.For,whenbiologistsgrouporganismstogetherundersomename onthebasisofobservedsimilarities,theydosopartly ontheassumptionthatthose similaritiesaretobeexplainedbysomeintrinsicunderlyingnatureofthegroup.It seemstomeclearthatthisistheirpractice,whatevertheysayaboutessentialism.²⁰ Sotheapparentlysuperficialexplanationpointstothedeepfactthatthereis somethingintrinsic,probablyunknown,partlyinvirtueofwhichtheanimalisa tigerandwhichcausesittobestriped.Thatsomethingisanessentialintrinsic property.Thesumofthoseproperties,togetherperhapswithsomehistoricalones, constitutetheessenceofatiger.Soberrightlyinsiststhattheessenceofaspecies
¹
⁷ Theroleoftheenvironmentisveryobviouswithplants.Thustheheightofcornina fielddepends onthetemperature,thesoil,andsoon.
¹
⁸ Thepointisnot,ofcourse,thattheexplanationofanygeneralization,evenanybiologicalone, demandsanintrinsicproperty,justthattheexplanationofageneralizationofthekindillustrated demandsone.
¹
⁹ Sothisintrinsicpartisa real essence,inLockeanterms;seen.5.
²⁰ ThefollowingcommentofSterelnyisinterestinginthisrespect: “Some,perhapsmost,evolutionarybiologiststakespeciationtooccuronlywhentherehavebeenintrinsicchanges”.He findsthis “puzzlingfortheviewthatspeciesarehistoricallydefinedentitiesisclosetotheconsensusviewin evolutionarybiology”.Heisinclinedtoblametheinfluenceofthefolkwho,aswenoted(1.1),tendto beintrinsicessentialists(1999:130).Ithinkthatthebiologistsandthefolkare,deepdown,tunedinto thedemandsofexplanation.
mustexplainwhyitsmembersarethewaytheyare.Itmustbe “acausal mechanismthatactsoneachmemberofthespecies,makingitthekindofthing thatitis” (1980:250).²¹Thatisexactlywhatthis(partly)intrinsicessenceis. Idistinguishedtwosortsofexplanationthatmightbesoughtinaskingwhy membersofaspecieshaveacertainproperty.InsodoingIamfollowinginthe footstepsofErnstMayr(1961).Heregardsanexplanationofthemechanisms withinmembersofaspeciesthatmakeageneralizationtrue(regardlessof thehistory)asconcernedwith “proximate” causationandpartof “functional biology”.Incontrastanexplanationoftheevolutionaryhistorythatledto themechanismbeingpresentinthemembersofaspeciesisconcernedwith “ultimate” causationandispartof “evolutionarybiology”.Theuseof “ultimate” todescribethelatterexplanationseemslikeagratuitousput-downoftheformer.
Kitcher’seven-handeddescriptioninresponsetoMayr’sis primafacie more appropriate: “thereareindeedtwokindsofbiologicalinvestigationthatcanbe carriedoutrelativelyindependentlyofoneanother,neitherofwhichhaspriority overtheother” (1984:121).AdoptingKitcher’sterminology,Ishallcalltheformer sortofexplanation “structural” andthelatter “historical”.Structuralexplanations, ashesays,seekto “explainthepropertiesoforganismsbymeansofunderlying structuresandmechanisms”.Hegivesaniceexample:
Abiologistmaybeconcernedtounderstandhow,inaparticulargroupofbivalve mollusks,thehingealwayscomestoaparticularform.Theexplanationthatis soughtwilldescribethedevelopmentalprocessofhingeformation,tracingthe finalmorphologytoasequenceoftissueorcellularinteractions,perhapseven identifyingthestagesinontogenyatwhichdifferentgenesareexpressed.(p.121)
Hegoesontoclaimthat “explanationsofthistypeaboundinbiology:thinkofthe mechanicalaccountsofnormal(andabnormal)meiosis,ofrespirationand digestion,ofdetailsofphysiologicalfunctioninginallkindsofplantsandanimals” (p.121).Andmypointisthat,atbottom,structuralexplanationswilladvertto essentialintrinsic,probablylargelygenetic,properties.²²Itisbecausethebivalve molluskshaveacertainintrinsicunderlyingnaturethatthehingetakesthatform. Thatisthedeepexplanation.²³
Thisdiscussiongeneratesanumberofquestions.Herearetwo:(I) “Surelyany ofthegeneralizationswehavebeendiscussingcouldhaveexceptions:asmall mutationmayleadtoanorganismthatseemstobeamemberofaspeciesand
²¹[2022addition]Ilatercallthis “theSoberdemand” (2.5).
²²Griffithsthinksnotbuthisargumentconflatesstructuralexplanationswithhistoricalexplanations(1999:210–11,219–21).
²³Hullunfavorablycontrasts “classificationists” seeking “theunitofidentification” with “phylogeneticists” seeking “theunitofevolution” (1965:204).Ithinkthattheclassificationistsshouldbeseen asseekingunitsof structuralexplanation,averyworthwhilepursuit.
yetlacksthepropertyattributedtothespeciesbyageneralization.Sothe generalizationsdonotseemtobelaw-like.Howdoes IntrinsicBiological Essentialism dealwiththat?”²⁴ (II) “Itisofcoursethecasethatthetruthofany suchgeneralizationmustbeexplainedbyanintrinsic,probablylargelygenetic, property,butwhydoesthatpropertyhavetobean essential propertyofthekind inquestion?”²⁵ Ishallconsiderthesequestionsinsection1.10,alongwithothers arisingfromDarwinianviewsofvariationandchange.Ishallarguethat Essentialism hasanadequateanswertoallthesequestions.
Soberclaimsthat “evolutionarytheoryhasremoved theneed forproviding specieswithconstituentdefinitions” andhencewithintrinsicessences(1980:255).
Isuspectthatthissortoffocusonevolution,henceonhistoricalratherthan structuralexplanations,hasmisledbiologistsandphilosophersofbiologyabout essentialism.²⁶ Thishavingbeensaid,Isuspectthatevenhistoricalexplanations demandapartlyintrinsicessence;that,forexample,theexplanationofhowpolar bearscametobewhitewillultimatelydependonessentialintrinsicpropertiesof polarbearsandoftheirgrizzlyancestors.ButIshallnotattempttoarguethis.
Ihavepresentedapositiveargumentfor IntrinsicBiologicalEssentialism.We mightsumitup: structural explanationsinbiologydemandthatkindshave essentialintrinsicproperties.Thatismy first mainpointindefenseof Essentialism.IntherestofthepaperIwilldevelopthecasefor Essentialism in thecourseofrespondingtoobjections.
1.4RelationalSpeciesConcepts
Istartwithwhatisallegedtobethecentralobjectionto IntrinsicBiological Essentialism:accordingtonearlyallcurrent “speciesconcepts”—theoriesabout thenatureofspecies speciesare relational.Okashaexpressesthisconsensusas follows: “Onallmodernspeciesconcepts(exceptthephenetic),thepropertyin virtueofwhichaparticularorganismbelongstoonespeciesratherthananotheris arelationalratherthananintrinsicpropertyoftheorganism” (2002:201).
Despitetheconsensusthatthesespeciesconceptsmake Essentialism untenable, thenatureofbiologicalspeciesis,andalwayshasbeen,anextremelycontroversial issue: “Thespeciesproblemisoneoftheoldestcontroversiesinnaturalhistory” (O’Hara1993:231);itis “oneofthethorniestissuesintheoreticalbiology” (Kitcher2003:xii).²⁷ Therearearoundtwodozenspeciesconceptsand “atleast
²⁴“Philosophersofbiologyhaveoftennotedthatthereseemtobenolawswhichapplytoalland onlymembersofaspeciestaxon(Hull1978;Rosenberg1985)” (Okasha2002:209).
²⁵ IamindebtedtoPeterGodfrey-Smithforraisingthisquestion.
²⁶ See,forexample,Matthen(1998:117–21),Griffiths(1999:219–22),andMillikan(2000:18–20).
²⁷ Although,interestinglyenough,anissuethatDarwinhimselfwasskepticalabout:hetalksof “the vainsearchfortheundiscoveredandundiscoverableessenceofthetermspecies” (1859:381).
sevenwell-acceptedones” (Ereshefsky1998:103).IshallfollowOkashainplacing themin “fourbroadcategories”.InthissectionIshallbrieflydescribethese concepts.Inthenext,Ishalldrawadistinctionwhichiscrucialtoshowing,in sections1.6to1.9,thattheconsensusiswrong.
1. Phenetic concepts.Onthissortofview,organismsaregroupedintospecies onthebasisofoverallsimilarityofphenotypictraits.Thisisthoughtbyits proponentstohavetheadvantageofbeingfully “operational”.Okashasaysthat pheneticconceptsare “theleastpopular” (2002:199)andthisishardlysurprising becausetheyarisefromthe “philosophicalattitude...ofempiricism” (Sokaland Crovello1970:29). “Phenetictaxonomistshaveoftenwantedtosegregatetaxonomyfromtheory” (SterelnyandGriffiths1999:196).²⁸ Thiscategoryofspecies conceptistheonlyoneofthefourthatis not intheleasthistoricalandrelational. Ishallsetitaside.
2. BiologicalSpecies concepts(“BSC”).ThemostfamousexampleofBSCisdue toMayr.Hedefinedspeciesas “groupsofinterbreedingnaturalpopulationsthat arereproductivelyisolatedfromothersuchgroups” (Mayr1969:26).Sterelnyand Griffithsremarkthat “Ifthereceivedviewhasareceivedspeciesconcept” itisBSC (1999:188).²⁹
3. EcologicalNiche concepts(“ENC”).AccordingtoENC,aspeciesoccupiesa certainecologicalniche. “Aspeciesisalineage...whichoccupiesanadaptivezone minimallydifferentfromthatofanyotherlineageinitsrangeandevolves separatelyfromalllineagesoutsideitsrange” (vanValen1976:70).Okashaputs theviewsuccinctly:species “exploitthesamesetofenvironmentalresourcesand habitats” (2002:200).³⁰
4. Phylogenetic-Cladistic concepts(“P-CC”).Onthisviewwe “identifyspecies intermsofevolutionaryhistory...[with]particularchunksofthegenealogical nexus....Speciescomeintoexistencewhenanexistinglineagesplitsintotwo... andgoextinctwhenthelineagedivides,orwhenallmembersofthespeciesdie” (Okasha2002:200).SterelnyandGriffithsclaimthat “somethinglikeaconsensus hasemergedinfavorofa cladistic conceptionofsystematics” (1999:194). Nonetheless,ithassomesurprisingfeatures,asweshallsee(1.9).
ButperhapsthemostimportantfeatureoftheP-CCconceptforthepurposes ofthispaperisthatitis,aseveryoneagrees, incomplete.Itneedstobesupplementedbyatheoryofspeciation,atheorythatexplainswhenalineage has
²⁸ SterelnyandGriffithsincludeunderpheneticconceptsthosethatdefinespeciesintermsof genetic similarly(1999:184).Iclearlydonotincludethese.Itakethephenotypeofanorganismtobe observablepropertiesofitdistinctfrom,butcausedby,itsgenotype(alongwiththeenvironment).
²⁹ Popularasitis,BSChasbeenthesubjectofextensivecriticism;see,forexample,Sokaland Crovello(1970);vanValen(1976);Cracraft(1983);Sober(1993:155–6);Kitcher(1984:118–20;2003: 141–5);Mallet(1995);Dupré(1999);SterelnyandGriffiths(1999:186–90).Malletclaimsprovocatively thattheBSCconcept “owesnothingeithertogeneticsortoDarwinism” (p.295).
³⁰ Ghiselin(1987:374–8)hassomeseverecriticismsofENC.
splitintwo.Forthis,asOkashasays,P-CC “willhavetorelyonaconceptofoneof theothertypes” (2002:201).
1.5ACrucialDistinction
Itisallegedthat,accordingtoeachofthesespeciesconcepts,exceptthephenetic whichwearesettingaside,speciesarerelational.Theseconceptsarethought, therefore,toshowthatthenatureofaspeciescouldnotbepartlyintrinsicand hencethatdoctrineslike IntrinsicBiologicalEssentialism arefalse.Inassessingthis thoughtitisveryimportanttodistinguishthequestionthat Essentialism is supposedtoanswerfromanotherwhichitisn’t.
Let Fsbesomegroupthathasbeenclassi fiedforbiologicalpurposesunderone ofthetaxa;forexample,agroupofpoodles,dogsor Canis.Thequestionthat Essentialism answershasmanyforms,asalreadyindicated(1.1,(iv)):
(1)Invirtueofwhatisanorganisman F?
Whatmakesanorganisman F?
Whatisthenatureofbeing F?
Whatistheessenceofbeing F?
Thisisaquestionaboutthe propertiesoforganisms.Whenitconcerns Fsthatform aspecies,Mayrcallsitthespecies “taxon” problem(1982:253–4).Soletus generalizethisas “thetaxonproblem”.Itneedstobedistinguishedfromthe verydifferent, “higherlevel”,problemaboutthe propertiesofthoseproperties:
(2)Invirtueofwhatare Fsasubspecies,aspecies,agenusoretc.?
Whatmakesagroupof Fsasubspecies,aspecies,agenusoretc.?
Whatisthenatureofbeingasubspecies,aspecies,agenusoretc.?
Whatistheessenceofbeingasubspecies,species,genusoretc.?
Whenitconcernsspecies,Mayrcallsitthespecies “category” problem(1982: 253–4).Soletusgeneralizethisas “thecategoryproblem” . “Whatisittobeapoodlenotabulldog?” isaninstanceofthetaxonproblem (1), “Whatisitforpoodlestobeasubspeciesnotaspecies?” isaninstanceofthe categoryproblem(2).Thedistinctionbetweenthetwoproblemsmayseem obviousandyetitiseasilyconflatedbycertainformsofwords.Inparticular, considerthequestion, “Whatisaspecies? ” or “Whatisthenature/definitionofa species? ” Thesequestionsareambiguous.Theycouldbeaskingwhatsortofa natureanygrouphasthathappenstobeaspecies,aninstanceofthetaxon problem(1).Buttheyaremorelikelytobeaskingwhatisitforanygrouptobe aspecies,aninstanceofthecategoryproblem(2).
Thedistinctionbetweenthetwoproblemsisabsolutelycrucialtothispaper. Whichproblemarethespeciesconceptssupposedtoanswer?Accordingto Okasha,speakingfortheconsensus,theyareatleastsupposedtoanswerproblem (1)forspecies:theyaresupposedtoshow,aswenoted,that “thepropertyinvirtue ofwhichaparticularorganismbelongstoonespeciesratherthananotherisa relationalratherthananintrinsicpropertyoftheorganism” (2002:201).Yet Ereshefksy,inhisintroductiontoacollectionthatincludesmanyclassicpaperson speciesconcepts(1992a),saysthat “ourconcerniswithadefinitionofthespecies category” ratherthanofthespeciestaxon(1992b:xiv;seealsoKitcher1984:120). AndaccordingtoSterelnyandGriffiths(1999:211)andWilson(1999b:191–2), thespeciesconceptsprovideanswersto both taxonandcategoryproblems.Ishall arguethat,onthecontrary,thespeciesconceptsareprimarilyconcernedwith(2) andthrowlittlelighton(1).³¹Yet IntrinsicBiologicalEssentialism isconcerned with(1).So,thecentralobjectionto Essentialism,basedonthespeciesconcepts, fails.Thisismy second mainpointindefenseof Essentialism. Insection1.6Ishallshowhowmuchthespeciesconceptsbearonthecategory problem(2).Insections1.7and1.8,Ishallshowhowlittletheybearonthetaxon problem(1).
1.6SpeciesConceptsandtheCategoryProblem(2)
Thespeciesconceptsstraightforwardlyanswerproblem(2)forspecies:theytellus about “thespeciescategory” (SterelnyandGriffiths1999:184).³²Thusthepopular biologicalspeciesconcept(BSC)tellsusthatagroupisaspeciesinvirtueofbeing aninterbreedingnaturalpopulationthatisreproductivelyisolatedfromother suchgroups.Andtheecologicalnicheconcept(ENC)tellsusthatagroupisa speciesinvirtueofbeingalineagewhichoccupiesanadaptivezoneminimally differentfromthatofanyotherlineageinitsrangeandevolvingseparatelyfrom alllineagesoutsideitsrange.Andboththeseanswersdoindeedentailthatbeinga speciesis relational:agroupisaspeciesinvirtueofitsbreedingornicherelations toothergroups.
Thestoryfortheinfluentialphylogenetic-cladisticconcept(P-CC)isabitmore complicated.Aswehavenoted,theP-CCaccountofspeciesadvertstothe splittingofalineageandsoneedstobesupplementedwithatheoryofsplitting, atheoryofspeciation.Thus,accordingtoP-CC,agroupoforganismsconstitute
³¹Notethatthisis not thegeneralclaimthatanswersto(2)willthrowlittlelighton(1);indeed,see n.33.Itisaclaimthat therelationalspeciesconcepts throwlittlelighton(1).
³²Wearesettingasidethepheneticconceptbutitisinterestingtonotethatitisnotobviousthatthis concept does answer(2).Afterall,subspecieslikepoodlesandgeneralike canis couldequallybe identifiedbyanoverallsimilarityofphenotypictraits.Whatsortofsimilaritymarksoutspeciesin particular?
