A central question for philosophical psychology is which mental faculties form natural kinds. There is hot debate over the kind status of faculties as diverse as consciousness, seeing, concepts, emotions, constancy and the senses. In this paper, I take emotions and concepts as my main focus, and argue that questions over the kind status of these faculties are complicated by the undeservedly overlooked fact that natural kinds are indeterminate in certain ways. I will show that indeterminacy issues have led to (...) an impasse in the debates over emotions and concepts. I first consider and reject one way of resolving this impasse. I then suggest a different method, which places more emphasis on a close analysis of predictive and explanatory practices in psychology. I argue that when we apply this method, a new position emerges: that it is indeterminate whether concepts or emotions are natural kinds. They are neither determinately natural kinds, nor determinately not natural kinds. Along the way, we will see that natural kinds have been put to two completely different theoretical uses, which are often been blurred together, and that they are ill-suited to fulfil one of them. (shrink)

Hybrid and pluralist accounts of concepts agree that the class of concepts includes a multiplicity of heterogeneous representational structures, such as prototypes, sets of exemplars and theories. In this paper I argue that these accounts agree on two additional central claims related to the ways in which they articulate those structures: each type of representational structure can be used independently in psychological processes, and co-referential concepts are associated in a distinctive way as representations of the same category. Although they disagree (...) on concept individuation, they seem to agree that on a processing dimension there are multiple independent representations for a given category and on a long-term storage dimension concepts that represent the same category conform an epistemic unity. (shrink)