John Wilkins, University of Queensland, Australia."The Unseasonable Lateness of Being, Or, Essentialism Comes After Darwin, Not Before"

Abstract: The received view of the history of the species concept is that before Darwin, naturalists held to a view of essentialism, according to which species were constituted by necessary and sufficient traits. I will argue that this is a misunderstanding based on a conflation of the Aristotelian logical and metaphysical tradition of the essence of predicates, with the use of the term "species" and the Greek term "eidos" in natural history. Instead, I will attempt to show that taxonomists (including Darwin) held to a diagnostic or taxonomic essentialism, but that nobody before Darwin, with a possible exception in Grew, argued that a species had a material or causal essence, and that the essentialism of the received view actually arose after Darwin's views, possibly as a reaction to Haeckelian evolutionary ideas in French and German speaking countries, based on the revival of Thomism in Catholic intellectual circles after 1871, between the 1890s and the 1920s. The myth of essentialism appears to be formulated around the centenary of the Origin and after, based perhaps on the early experiences of Mayr as an undergraduate.

John Wilkins is a postdoctoral research fellow at the University of Queensland Biohumanities Project. His thesis on species concepts has developed into a book, presently under review for publication as a history of the ideas of "species" through the classical, medieval, and modern eras.