Abstract

In this paper I distinguish three kinds of kinds: traditional philosophical kinds such as truth, knowledge, and causation; natural science kinds such as spin, charge and mass; and social kinds such as class, poverty, and marriage. The three-fold taxonomy I work with represents an idealised abstraction from the wide variety of kinds that there are and the messy phenomena that underlie them. However, the kinds I identify are discrete, and the three-fold taxonomy is useful when it comes to understanding claims about the normativity, scope, and implementation of conceptual engineering. In particular it reveals: first, that conceptual engineering in a broad sense is not distinctively normative; but second, that there is a distinctive normativity present in conceptual engineering in the narrow sense of amelioration; third, that conceptual engineering in the narrow sense of amelioration is only possible for terms that refer to kinds whose grounds we can change; and fourth, that the amelioration of such kind terms can be brought about as a result of changing the grounds of those kinds. The overall aim is to draw attention to the differences between kinds of kinds to make sense of the diverse and often conflicting claims in the conceptual engineering literature, both from its proponents and from its detractors. The hope is that paying attention to the differences between kinds of kinds will provide a better understanding of the landscape.