The erratically fine-grained metaphysics of functional kinds in technology and biology

In this paper we present two arguments both directed against taking functional kinds as real kinds. The first argument focused on technology and aims at establishing that the technical functions of artefacts cannot be taken as their essences: this position violates on the currently available accounts of technical functions engineering intuitions about identity and persistence conditions for artefacts. Then we prove that this first argument can be transposing to biology, amounting to our second argument aimed at establishing that the biological functions of organs cannot be taken as their essences: this second position violates on the currently available accounts of biological functions intuitions in biology about identity conditions and persistence conditions for organs. The first argument poses a problem for Lynne Rudder Baker’s constitution view of artefacts, the second poses a problem for David Wiggins ’ view on kinds of biological organs. Our more general conclusion is that the problems an ontological realist is facing in technology can also surface within biology