Hume’s “impressions of reflection” is a category made up of all our non-sensory feelings, including “the passions and other emotions.” These two terms for affective mental states, ‘passion’ and ‘emotion’, are both used frequently in Hume’s work, and often treated by scholars as synonymous. I argue that Hume’s use of both ‘passion’ and ‘emotion’ in his discussions of affectivity reflects a conceptual distinction implicit in his work between what I label ‘attending emotions’ and ‘fully established passions.’ The former are the (...) transient, changeable, valenced feelings that flow between perceptions and constitute their felt nature and impulse. The latter are the particular passions fully realized, with characteristic valence, and analyzed by Hume in terms of their particular belief structures and relations between ideas and impressions understood to be constituent of particular passions. The term ‘emotion’ for Hume generally denotes either the attending feeling, sometimes distinct from the passion (particularly as ‘passion’ is being used to include the associated beliefs, causes and objects), or as a synonym for a particular passion, typically when Hume is primarily referring to the felt nature of the passion. Generally speaking, ‘passion’ is a more cognitive category of affective mental state, while ‘emotion’ is more sensationalist. I will further argue that when we grant Hume the emotion/passion distinction, he can accommodate both highly sensationalist and highly cognitivist understandings of affective mental states. I finish with the application of my distinction to two key topics in Hume studies: his sympathy mechanism, and his theory of belief and motivation. (shrink)