I criticize the treatment of natural kinds as some sort of object, advocated in a recent paper by Alexander Bird. The arguments he gives for regimenting an illustrative statement featuring chemical kinds in his preferred manner are not conclusive, and his criticisms of an alternative strategy involving universally quantified sentences fail. This is important because of the widespread but poorly supported assumption that expressions of natural kinds should be treated as singular referring terms.

This paper maps the landscape for a range of views concerning the metaphysics of natural kinds. I consider a range of increasingly ontologically committed views concerning natural kinds and the possible arguments for them. I then ask how these relate to natural kind essentialism, arguing that essentialism requires commitment to kinds as entities. I conclude by examining the homeostatic property cluster view of kinds in the light of the general understanding of kinds developed.