This chapter introduces concepts that facilitate the comparison of healing roles and then applies them to the two kinds of healers: Peruvian curanderos and biomedical practitioners. Arthur Kleinman provides a classification for healing activities in plural medical systems. He first distinguishes a popular health care sector within which healing acts depend upon a general body of knowledge available to the populace as a whole. The status of Peruvian curanderos, with relatively low social authority but a solid reservoir of cultural authority, is not uncommon for folk healers in plural medical systems. Curanderos certainly recognize the tenuous position they occupy in the Peruvian medical system. Professional sector healers can attempt to discredit the practices of their competitors by calling into question the quality of the training and/or knowledge on which their claim to professional status depends. In theory, a solid foundation for the social and cultural authority of healers would be a record of successful outcomes.