Abstract

After having reconstructed a minimal biological characterisation of species, we endorse an “empirical approach” based on the idea that it is the peculiar evolutionary history of the species at issue—its peculiar origination process, its peculiar metapopulation structure and the peculiar mixture and strength of homeostatic processes vis à vis heterostatic ones—that determines species’ identity at a time and through time. We then explore the consequences of the acceptance of the empirical approach in settling the individuals versus kinds dispute. In particular, while conceptual arguments have been proposed to show that species can be equally treated as individuals and kinds because mereology’s and set-theory’s languages are inter-translatable, we advance instead a causal argument to sustain the claim that each species is both a kind and an individual.