The traditional medical practitioner occupies a unique role in African societies. He or she is not only a doctor but also a visionary, a seer, and often a priest. One can acquire the specialized skills of a healer by three methods: first, by training and a long period of apprenticeship; second, by divine selection and in answer to a call by a powerful spirit to be his chief priest or messenger; and third, as a family inheritance. In any case, the magical powers are acquired through ritual offerings and living in a prescribed manner, but the knowledge of efficacious herbs comes mainly from training and sometimes from revelation in dreams and trances.