Human interaction with the living world, in science and beyond, always involves classification. While it has been a long-standing scientific goal to produce a single, all-purpose taxonomy of life to cater for this need, classificatory practice is often subject to confusion and disagreement, and many philosophers have advocated forms of classificatory pluralism. This entails that multiple classifications should be allowed to coexist, and that whichever classification is best, is context-dependent. In this paper, we discuss some practical consequences of classificatory pluralism, in particular concerning how one is supposed to find the best classification for a given context. We do so by means of a case study concerning oaks, in particular the pedunculate oak (Quercus robur L.) and the sessile oak (Q. petraea (Matt.) Liebl.), two widely used putative species that present several classificatory challenges; and by applying one recent philosophical framework conceptualizing classification, the so-called Grounded Functionality Account of (natural) kinds. We show how the GFA elucidates several issues related to oak classification and gives directions to optimize classificatory practices, and discuss its implications for scientific taxonomy
