Kinds and Essences: Rescuing the New Biological Essentialism

Abstract

After the rise of Darwin’s theory of evolution it seemed that the much-feared ghost of traditional essentialism had disappeared from biology. However, developments of the last century in analytic metaphysics (Kripke, Putnam, Wiggins) appear to have resurrected the Aristotelian monster in various forms. The aim of this paper is to investigate the revival of the essentialist doctrine as applied to biological species, namely the thesis that organisms belong to a particular natural kind in virtue of possessing certain essential properties, and examine to what extent these new biological essentialisms are sustainable. For this purpose, I intend to analyze these proposals in both their forms, relational essentialism (Okasha, LaPorte) and intrinsic essentialism (Devitt), and confront them with their main anti-essentialist criticisms. The answer, I advance, is that natural kind essentialism as applied to biological taxa is, not only tenable, but theoretically adequate. Yet not in its typical variants. I contend that understood as HPC kinds (Boyd, Wilson), organisms possess clusters of co-occurring properties that are caused by various mechanisms which in turn determine the shared similarities that define membership to species. Such an approach encompasses both the intrinsic and relational mechanisms that make species members be what they are. However, this theory faces criticisms regarding circularity and the problem of polymorphism (Ereshefsky & Matthen). I suggest that reinterpreting the HPC theory as informationally-connected property clusters (Martínez) solves the objection posing an improved version of the HPC theory and providing what I believe is a theoretically adequate and explanatorily robust version of biological essentialism.