Purity and purification – All cultures make some division between what they consider “normal” and what they consider “abnormal”; some also categorize certain things, events, and acts as either “sacred” or “profane” and have procedures for keeping them apart or dealing with contact between them. Anthropologist Mary Douglas has written important works about these issues. Shamans are often required to mediate between people, or between humans and otherthanhuman persons (e.g., animals, ancestors, or spirits), because someone has offended someone else. This central part of their function as ritualists reestablishes “purity” in the relationships. Also, significant portions of many shamanic rituals involve purification, especially those utilizing purgatives (which may also result in visions) and those initiating altered styles of communication between shamans and their helpers. Maria Sabina talked about the importance of purificatory purgatives in the healing process, both for the curandera and for the patient.
SOURCE:
Historical Dictionary of Shamanism by Graham Harvey and Robert J. Wallis 2007