Marià Aguiló, like other 19th century folklorists, collected written materials and oral testimonies ¿still unpublished¿ about folk beliefs, superstitions and customs, particularly in relation to witchcraft and demonology. In this paper I use some examples to reflect on the boundaries of folktale and legend and on the complex relationships they maintain with other ethnopoetic genres such as superstitions, customs, sayings or memorates. Both these relationships and the various degrees of narrative development that popular beliefs can have are conditioned by the validity of the belief among the small group members and the degree to which the informant emotionally identifies with the content that he relates or reports. I also consider the hypothesis that carnivalesque contrafacta of some stories should not be understood as having resulted from the loss of the belief or superstition on which they are based, but rather as an alternative way of managing the fears that provoke supernatural forces and worlds.