We commonly appeal to emotions to explain human behaviour: we seek comfort out of grief, we threaten someone in anger and we hide in fear. According to the standard Humean analysis, intentional action is always explained with reference to a belief-desire pair. According to recent consensus, however, emotions have independent motivating force apart from beliefs and desires, and supplant them when explaining emotional action. In this paper I provide a systematic framework for thinking about the motivational structure of emotion and (...) show how it is consistent with the Humean analysis. On this picture, emotions are not reducible to beliefs and desires, instead their primary motivational force comes from their role as modulators of desires—they control the strength of our occurrent desires. Emotions therefore motivate actions through the belief-desire system instead of overriding it. (shrink)