For some years, the first author and our colleague April Fallon have been investigating the emotion of disgust (Rozin & Fallon, 1987). We consider this emotion to be food-related at its core, and define it, in accordance with Angyal (1941) as “revulsion at the prospect of oral incorporation of an offensive substance.” In our investigations with subjects in the University of Pennsylvania community we noted that offensive objects that elicit disgust, such as cockroaches, worms, or human body excretions, have potent contaminating properties. When they contact an otherwise edible food, they tend to render it inedible, even though there is no sensory trace of this contact. Furthermore, replicas of disgusting substances, even when known to be made of edible materials (e.g., a realistic fly made of candy), are often rejected as food. Our puzzlement about these expressions of the potency of disgust objects was resolved, in a sense, with the discovery that they were prototypical instances of the laws of sympathetic magic, as described in Frazer's The Golden Bough ([1890] 1959). Engaged by the fact that these widespread disgust responses in American culture fit with “beliefs” supposedly common only in traditional cultures, we began an investigation of the operation of the laws of sympathetic magic in everyday life, in disgust and other domains (Rozin, Millman, & Nemeroff, 1986). This research prompted us to think through the meaning and significance of the laws of sympathetic magic. This chapter presents some of the first fruits of this work.