How should we go about developing emotion taxonomies suitable for a science of emotion? Scientific categories are supposed to be “projectable”: They must support generalizations required for the scientific practices of induction and explanation. Attempts to provide projectable emotion categories typically classify emotions in terms of a limited set of modules, but such taxonomies have had limited uptake because they arguably misrepresent the diversity of our emotional repertoire. However, more inclusive, non-modular, taxonomies also prove problematic, for they struggle to meet (...) the projectability constraint. In this paper, I explain how a developmental approach to emotion, one that utilizes the notion of progressive modularization, can help us approach emotion categorization in a more inclusive and projectable manner. (shrink)