 We can use answers to these questions to articulate the metaphysical commitment of a theory of natural kinds (Bird 2018). At one extreme the out-and-out conventionalist may claim that there is no natural sameness and difference in nature (or at least that our human classifications do not capture any such natural sameness and difference). Afortiori, there are no classifications into natural kinds, no entities that are natural kinds, and no natural kinds essences. At the other extreme, one might hold that there are natural distinctions between things, some of these distinctions are distinctions of kinds, that the natural kinds are a certain species of entity, that these entities are irreducible, and that they have essences. Intermediate views tend to be more popular. For example, a common view is that there are natural classifications by kinds, but there are no entities that are the natural kinds. Some hold that view and accept essentialism about natural kinds, while others hold that view and reject essentialism.