The Aristotelian Tradition of Natural Kinds and Its Demise by Stewart Umphrey

Abstract

Reviewed by: The Aristotelian Tradition of Natural Kinds and Its Demise by Stewart Umphrey Christopher A. Decaen The Aristotelian Tradition of Natural Kinds and Its Demise. By Stewart Umphrey. Washington, D.C.: The Catholic University of America Press, 2018. Pp. ix + 260. $75.00 (cloth). ISBN: 978-0-8132-3041-2. There are "two great waves of natural-kinds realism," according to Umphrey: the more recent beginning in Mill and others in the nineteenth century, whereas the original, premodern wave spanned Aristotle through the medievals (1). This book is an erudite philosophical history of that original wave and its demise, the latter beginning with Galileo and ending with Darwin. Although a central current in the history of philosophy, the question about [End Page 503] whether the species that we instinctively pick out of the natural world are really there or something we concoct and then project has never before received a book-length study. This should be all the more concerning, given the assumption among Thomists that Darwin has not really dealt the deathblow to our philosophy of nature. Fortunately, Umphrey fills this lacuna and thereby offers a good assessment of "what happened" among philosophers of nature toward the elimination of the everyday view that dogs really are one kind of thing—and by the way, ants are another, and elms and planets a third and fourth. Umphrey's work is a historical companion to his more topical treatment of the same subject, Natural Kinds and Genesis: The Classification of Material Entities (Lanham, Md.: Lexington Books, 2016). There, he argues that although contemporary science seems to eliminate the idea that any species of organism is a natural kind, it "does not make it easy to decide that there are, or are not, natural kinds" altogether, leaving open the possibility that molecular compounds could be an example (13). Although, for a student of St. Thomas, this conclusion sacrifices too much—particularly when Umphrey simply grants that there are no species of organisms that "form disjoint classes in virtue of their intrinsic natures" (11)—the aim in both books is to "pave the way for … a renewal" of natural philosophy in the face of both "protometaphysical antirealism" and "philosophical naturalism" about natural kinds (17), an aim the perennial philosophy would support. In spite of being a companion to the 2016 volume, this newer volume can easily be read on its own, in part thanks to Umphrey's substantial review of the earlier work in his prologue. His language for describing natural kinds, especially in the prologue, may be a bit foreign to a student of Aristotle and the medievals—indicating an analytic influence and perhaps rooted in Umphrey's inclination to view old natural-kinds realism in light of the new—but his frequent references to "continuants," "dividuals," "grades of worldly involvement," "singleton," "disjoint," and "s-resemblance classes" are usually explained without residual obscurity. The book is divided into seven chapters, the first two on the precursors to Aristotle's natural kinds (the pre-Socratics and Plato), the second two on Aristotle's theory and the Christian and Scholastic incorporation of it that also began its unraveling, and the last three on its demise in modern philosophy of nature (especially Galileo, Bacon, Descartes, Locke, Newton, Kant, and Darwin). In the first chapter, Umphrey concludes that, although the earliest Greek poets and pre-Socratics had a notion of nature and "have some idea of kinds … they seem unaware of natural kinds as such" (24). The later pre-Socratics were less uniform: Anaxagoras allowed "no individual continuants and no natural kinds in the primary sense" (39), whereas the atomists "were the first natural philosophers to admit individual continuants" (40), the atoms, but were ambiguous about natural kinds for these atoms, and Empedocles offered "the first evidence of philosophical reflection on natural kinds" (43). One of Umphrey's points in the first chapter is that although Aristotle's view of natural kinds "has its native home in everyday thought" (2), his "bio-centric" (15) [End Page 504] replacement of the pre-Socratic views, all of which in one way or another rejected natural kinds, was itself revolutionary, equal in gravity only to the...