Biological Kinds as Moving Targets: Toward a Practice-Based Account of Biological Classification

Thomas Reydon

So far most philosophical work on scientific classification focused on kinds and classifications as end products, rather than on the processes by which these are produced by scientists. While this has resulted in a number of accounts of classifications and kinds, none of these accounts have been found satisfactory. As an alternative approach to the issue, I want to suggest that philosophers interested in classification and kinds should focus on the diverse aspects of classificatory practices rather than on the products of these practices (i.e., classifications and kinds as described in the literature). I will develop this suggestion by starting from Ian Hacking’s dichotomy between “interactive kinds” and “indifferent kinds”. While I think Hacking pointed to an important aspect of how classification works, I want to argue that instead of adopting a strict dichotomy between two kinds of kinds, or between two kinds of classificatory practices, classificatory practices in the sciences are better understood in terms of a continuum involving different degrees of interactivity and indifference. In particular the biological sciences seem to constitute a domain in which partly indifferent / partly interactive kinds are widely found. Examining the causes of interactivity in biological classificatory practices can tell us much about the nature of classifications and kinds that is overlooked in available accounts, or so I will argue.