An introduction to biological essentialism

1 An introduction tobiological essentialismJohn WilkinsBiohumanities ProjectUniversity of QueenslandAn ambiguous term Meaning of essence - what-it-is-to-be Originally tied to substance-formontology of Aristotle Prescientific theory of knowledge basedon defining ordinary terms (Man is arational animal) Separate from other features orproperties (accidents) Invariance of tokens of a typeThe ReceivedView in biology Before Darwin, biological kinds wereessentialist Darwin introduced population thinking The Modern Synthesis showed thatspecies were polytypic (or polymorphic ) Hence, biological essentialism is falseThe history of the ReceivedView Plato fingered by Simpson and Mayr Aristotle by A.

2 J. Cain in 1958 (Cain was astudent of Mayr s) Popper s opposition to essentialism dates tohisOpen Society(1945), also fingers Plato as theculprit David Hull in 1965 publishes The effects ofessentialism on taxonomy: two thousand yearsof stasis from a graduate seminar with Popper Mayr s revision fingered Revisionist History No essentialism of biological species untilafterDarwin Type Essence Aristotle did not establish essentialisminbiology Idealists before Darwin not anti-transmutation Species were always defined by thegenerativeproduction of form(The Generative Conceptionof Species )Four kinds of essentialisms Cognitive essentialism Sociological essentialism Semantic or formal essentialism Material or causal essentialismCognitive essentialism Piaget, Carey, Keil,Atran and Gelman Focuses on a native inference ofsomething common to all tokens of atype Atran claims that species in folktaxonomy have cognitive essences Problem: No straight mapping tobiological kinds (Why the Cassowary isnot a Bird)Sociological essentialism Human nature as essence Racial essences Ethnic essences Gender essences Problem.

3 Human diversity fails to trackthe standard essential kinds ( , racesor gender) and contributes to racism or formal essentialism Essence of terms, words or natural kinds Traditional version: necessary and sufficientconditions for inclusion in a kind term (Putnamand Kripke) More recent versions: Family resemblance predicates Homeostatic property clusters (Boyd) Population structure kinds (Ereshefsky and Matthen) Vague kindsSemantic essentialism 2 Problems: Ordinary kind terms fail to track scientifickinds (elms and lilies) Appears to not match scientific practice Does not do what it is thought to do underthe ReceivedView (diagnosis and definition)Material or causal essentialism Traditional: microstructural constitution Some aspects of the type are causallyeffective in making tokens instances ofthe type The distinction between formal andmaterial essence is old goes back atleast to AquinasAquinas on the material/formaldistinctionThese [species infimaeorspecialissimae]are called individuals, in so far as they arenot further divisible formally.

4 Individualshowever are called particulars in so far asthey are not further divisible neithermaterially nor lib. XMet. Lect10, 21-23 Aquinas distinguishes the material fromthe formal. Later writers continue s biology Did not tend to use the logic of division of theCategoriesorMetaphysics He and Theophrastus (his student and founderof botany) used genos (genus) and eidos (species) interchangeably in biology This was the case until the 16thC (Fuchs inbotany and Gesner in zoology) So the wordsgenusandspecieshad no specialbiological meaning until thenLogic and biology Always held to be distinct Cain, Mayr, Simpson, Hull and othersmisled by reading logical ideas as referringto biology But thelogiciansknew they weredistinct.

5 In 1826,Whatley explicitly said asmuch in hisElements of Logic, a widelyused textWhatley on species if anyone utters such a proposition as .. Arguswas a mastiff, to what head of Predicables wouldsuch a Predicate be referred? Surely our logicalprinciples would lead us to answer, that it is theSpecies; since it could hardly be called an Accident,and is manifestly no other yetevery Naturalist would at once pronounce thatMastiff, is no distinct Species, but is only avarietyof the Species Dog..Whatley the solution of the difficulty is to be found in thepeculiar technical sense .. of the word Species whenapplied toorganized Beings: in which case it is alwaysapplied (when we are speaking strictly, as naturalists) toindividuals as are supposed to bedescended from acommon stock, or whichmighthave so descended; resemble one another (to use M.)

6 Cuvier sexpression) as much as those of the same stock do..[The fact of two organisms being the same species] being onewhich can seldom bedirectlyknown, the consequence is,that themarksby which any Species of Animal or Plant isknown, are not the of ( biological ) essentialism Arises in the periodafterDarwin (1870s 1920s) Largely in Germany and France Contemporary with the rise of neo-scholasticism afterVatican I, and the later neo-Thomist movement of theearly 20thC Often directed against Haeckel and his Monism Usually Catholic (but not the official RCC position) A conjecture: Mayr was an undergraduate in Germanyduring the height of the neo-Thomist revival (1922 28):a connection?The phylogenetic perspective Species as individuals thesis (SAI) Historical individuals with proper names Clades versus grades/natural kinds versusnatural (evolutionary) groups Basal groups are constructs if they fail toinclude descendents Hence species are not natural kindsCould there be a biological essence forsome kinds?

7 If a population has a completely shared traitthat Causes or contributes causally to the populationbeing what it is Is modally necessary to being that kindthen yes. But most kinds will not be essentially defined(species will, typically, not be essential kinds)Relational biological essences Essences might be relations: Genealogical relations (interbreeding) Historical relations (shared ancestry) Similarity relations (phenetics) Which relations matter, and which don t?Summary Essencein biology is an ambiguous term Usually means invariance of properties oftokens of a type Notthe default view before Darwin Comes informalandmaterialvarieties, or inmodern terms,semanticandcausalvarieties Semantic essentialism is harmless.

8 Causalessentialism is contrary to biological facts (it isargued by population thinkers )