INTRODUCTION Psychologists and philosophers have been debating about the nature of categories, kinds, and the role of language in concept representation and concept acquisition for decades if not centuries. When studying the nature of kind representations, much of the literature in cognitive and developmental psychology has focused on the important process of categorization (see the many chapters in this volume). In this chapter, I focus on a less studied aspect of kind representations, namely the process of individuation. I suggest that a theory of kind representations should account for both categorization and individuation.