Published online by Cambridge University Press: 28 February 2022
Taxonomy is not destiny. In the context of scientific theories, it is explanation rather than taxonomy which should play the leading role. (The domain of any theory consists not of mere items—as in philately or genealogy—but of phenomena.) Unless biological taxonomy is guided by underlying theory—presumably, evolutionary theory, genetics, and molecular biology—systematics risks degenerating into mere genealogy.
David Hull believes that certain taxa employed in history of science should be conceived on the model of biological species. He first discusses the nature of species, indicating (in 1.) what they are not— they are not “natural kinds“—and then (in 2.) what they are—i.e., they are “historical entities”, “chunks of the genealogical nexus” which are individuated in relation to some arbitrarily selected and quite often atypical “type specimen”. The connection between the two points, the negative and the positive, is that conspecificity is determined by actual spatiotemporal contacts of the sort required by descent, rather than by any putative similarities among conspecific organisms.