Observers of Haitian popular religion have defined Vodou as the authentic African religion of Haitian peasants. In fact, Vodou's congregational forms and practices evolved in and around Port-au-Prince during the twentieth century as the local peasantry was being coerced into wage labor. This paper deals with the incorporation of these ritual innovations in a particular hamlet in Léogane. The agents of ritual diffusion appear to have been not only redundant peasants and neophyte proletarians circulating between the capital city and the nearby plain, but also ethnologists who moved between privileged sites of the Vodou laboratory. The scientific valorization of the heroic slave religion was a centerpiece of the Haitian ethnologists' counter-narrative to European cultural hegemony and North American colonialism. Though their approach to Vodou was part of counter-hegemonic, nationalist discourse, it nonetheless recapitulated a modern view of tradition-bound primitives.