The nature of emotion is an important question in several philosophical domains, but little attention has so far been paid to identifying the general ontological category to which emotions belong. Given that they are short-lived, are they events? Since they often have components or stages, are they processes? Or does their close link with behaviour mean they are dispositions? In this volume, leading scholars investigate these basic ontological issues, contributing to current discussions about emotions and paving the way for new research into an underexplored area of philosophy. With chapters addressing issues including the temporal profile of emotions, the distinction between emotions and other affective states, and the epistemology of emotion, this highly original book will be valuable for students and specialists of philosophy, and particularly for those working in the metaphysics of mind and emotions.