Is There Still Hope for a Scholastic Ontology of Biological Species?

371 The Thomist 76 (2012): 371-95 IS THERE STILL HOPE FOR A SCHOLASTIC ONTOLOGY OF BIOLOGICAL SPECIES? TRAVIS DUMSDAY Concordia University College of Alberta Edmonton, Alberta, Canada T HOMISTIC AND OTHER SCHOLASTIC philosophies of nature are committed to hylomorphism, and thus to a thoroughgoing essentialism. That is, they are committed to the view that the world is divided up into objects belonging to various natural kinds, the essences of which—or substantial forms of which, prescinding from common matter—ground the properties associated with the kinds and determine the range of behaviors of their individual members. The standard Scholastic view maintains that this essentialist picture obtains universally in nature; from fundamental physics right up through biology, all substances are partly constituted by substantial forms. However, this view has become more difficult to uphold in the biological realm. The large majority of contemporary philosophers of biology and theoretical biologists are decidedly antiessentialist when it comes to biological taxa, with the predominant view being that the identity conditions of taxa are wholly relational. The species taxon Felis catus is the species taxon it is because of its lineal relations, its occupation of a certain slot on the tree of life. Felis catus descended from a certain ancestor species, and that descent determines its identity. Correspondingly, for a particular organism to be a cat is not to have a certain genetic code, or certain morphological features, or indeed any sort of intrinsic nature or essence. Instead, to be a cat TRAVIS DUMSDAY 372 1 It should be clarified at the outset that although most contemporary philosophers of biology are antiessentialist with respect to species taxa, this does not entail that they are antiessentialists with respect to other biological entities. For instance, T. Reydon (“Gene Names as Proper Names of Individuals: An Assessment,” British Journal for the Philosophy of Science 60 [2009]: 409-32), while rejecting the idea that species have essences, takes a fairly essentialist line when it comes to genes. 2 D. Oderberg, Real Essentialism (London: Routledge, 2007). 3 L. Elders, The Philosophy of Nature of St. Thomas Aquinas (New York: Peter Lang, 1997). 4 M. Adler, Problems for Thomists: The Problem of Species (New York: Sheed and Ward, 1940). 5 John Deely, “The Philosophical Dimension of the Origin of Species, Part I,” The Thomist 33 (1969): 75-149; idem, “The Philosophical Dimension of the Origin of Species, Part II,” The Thomist 33 (1969): 251-341. 6 E. Gilson, From Aristotle to Darwin and Back Again: A Journey in Final Causality, Species, and Evolution, trans. J. Lyon (Notre Dame: University of Notre Dame Press, 1984). is to have cats as parents.1 This is a far cry from the idea that all cats are cats because they are all partly constituted by the same kind of substantial form. The arguments in support of this broad consensus against intrinsic biological essentialism constitute an important challenge to a Scholastic philosophy of nature. No Scholastic thinker would wish to concede that hylomorphism is inapplicable to biological taxa. Moreover, it is not clear how standard natural-law theories of ethics would play out in a nonessentialist view of biological kinds—in an ontology in which living things, including humans, lack intrinsic natures. Indeed, the lack of engagement between contemporary natural-law theory and contemporary philosophy of biology could end up being seriously detrimental to the former. Yet despite the importance of the issue there have been few exchanges between recent Scholastic thought and the antiessentialist majority in analytic philosophy of biology. With the notable exception of David Oderberg,2 recent work in the Scholastic philosophy of nature tends to pass it by (e.g., the work of Leo Elders),3 while older studies by such well-known figures as Mortimer Adler,4 John Deely,5 and Etienne Gilson6 remain valuable but are in need of supplementation and further development in the face of new challenges. A SCHOLASTIC ONTOLOGY OF BIOLOGICAL SPECIES 373 7 See T. Dumsday, “A New Argument for Intrinsic Biological Essentialism,” Philosophical Quarterly 62 (2012): 486-504. My goal here is to lay the foundations of an updated defense of Scholastic biological essentialism. Specifically I will defend the core idea that biological species...