Conclusion

Abstract

The theoretical core of this book has been to identify natural kinds as those categories which are indispensable for successful science in some specified domain. I have formulated this as two distinct requirements: the success clause requires that the category support successful science, and the restriction clause requires that it be indispensable. The latter allows us to distinguish the real features of the world from the categories which are introduced merely for scientific bookkeeping; that is, it separates the natural kinds from the merely conventional or fungible kinds. The overall account recognizes natural kinds as categories that support induction and scientific enquiry, categories which arise in and are genuine features of specific domains of objects and phenomena. Scientists themselves are typically only concerned with the first aspect of natural kinds: success. After all, their goal is to do science — not to do metaphysics. (I articulated the core account in Chapter 2, on the basis of desiderata discussed in Chapter 1.)