Hume describes “mental geography” as the endeavor to know “the different operations of the mind, to separate them from each other, to class them under their proper heads, and to correct all that seeming disorder, in which they lie involved, when made the object of reflection and enquiry.” While much has been written about his geography of thought in Treatise Book 1, relatively little has been written about his geography of feeling in Books 2 and 3, with the result that (...) there has been considerable puzzlement and disagreement about the meaning and grounds of many of his central theses about the passions, action, and morals. My endeavor in this chapter is to remove some common sources of perplexity about his classification of the operations of feeling “under their proper heads” in that work. I begin by explaining his three highest-level distinctions bearing on this terrain: that between impressions and ideas; that between original impressions and secondary impressions; and that between the passions and the other emotions. In order to understand this third distinction, I explain his three different senses of the term ‘emotion’ and the relations among them. I ill then examine five different kinds of secondary impressions that he recognizes. These are: (1) sensible agitations; (2) feelings of or from mental operations; (3) volitions; (4) the passions (including motives); and (5) sentiments of taste. The broad outlines of the resulting geography are mapped out in a chart at the end. (shrink)