Ulrich Missberger - Conceptual frames as an analytical tool for problems in biological taxonomy and theory dynamics

Application to taxonomical questions: Biologists face problems in distinguishing natural kinds from unnatural ones. The most prominent case is that of a biological species (D. Stamos: The Species Problem. 2003). It is directly linked to the question what the units of evolution are. Since the 1970ies semantic externalism and its causal theory of reference (utnam and Kripke) has been proposing chromosome structure as the binding link for the members of a species. But practising biologists do not delimit taxa based on the internal microstructure of individuals. J. LaPorte (Natural Kinds and Conceptual Change. 2004; OUP) proposes to delimit natural kinds by their explanatory value: The concept ‘polar bear’ explains why it has an extremely dense fur, why it raises cubs as it does etc. (LaPorte 2004:19) As a consequence naturalness of a biological kind becomes a gradual property (M. Mahner / M. Bunge: Foundations of Biophilosophy 1997:221) linked to methodological and epistemic practices, since ‘explanatory value’ is an epistemic notion , not an ontological one. But what does decide about the greater or smaller explanatory value of a concept? The analytical tool of frames allows to examine LaPorte’s claim and its competitors by scrutinizing the attribute list of frames for natural kind terms: Do the relevant features represent intrinsic properties or relational properties? Can essentialism (and nominalism respectively) concerning biological taxa be pinned down to concept constitution by a frame? Should an attribute like ‘warm-bloodedness’ be formally reconstructed as a property in the set theoretic sense or as a predicate, because the same predicate refers to two properties? The physiological mechanisms bringing about homoiothermy are diffeent in birds and in mammals (M.Mahner/M. Bunge: Foundations of Biophilosophy 1997:221).
   Application to theory dynamics: Philosophers of science like Th. Kuhn and P. Feyerabend postulated theoretic incommensurability undermining longterm scientific progress across paradigm shift and scientific revolutions. But their analyses are sketchy. They did not differentiate between linguistic versus conceptual change and they often ran together reference change and meaning change. An example offered by Kuhn is that of the term ‘mammal’: ‘Mammal’ changed meaning after taxonomists had discovered monotremes (= Kloakentiere = Gabeltiere) in Australia. They are the only mammals laying eggs instead of giving birth to live young. So they exhibit both reptilian and mammalian features. The only two living families are platypus (= ornithorrhynchus anatinus = Schnabeltier) and echidna (= spiny anteater = Ameisenigel = Schnabeligel). Kuhn concluded that after the discovery of monotremes ‘to be a mammal is not what is was before’ (Kuhn 1990:307). Further examples are ‘reptile’ and ‘lizard’ (according to cladistic taxonomy no longer clades,but artificial groups), ‘tiger’,’rodent’ and ‘dinosaur’. The tool of conceptual frames allows to scrutinize whether there is in facta subject change involved in changes in use of a natural kind term in examples like these. A more neutral starting point is talking of linguistic instability leaving open whether we are confronted with real incommensurability or with a case of meaning refinement even favouring scientific progress.