This important book examines the nature of shamanism, humanity's oldest and universal expression of religiosity, from fascinating fresh perspectives. It shows consciousness to derive from a blending of bodily, neurological, social and environmental interactions, and the altered mind states of shamanism, specifically, to be adaptations of these causing ancient and modern parts of the brain to function in an integrated manner allowing nonverbal, symbolic and metaphorical mental content to be experienced directly in immersive ways, such as in "shamanic flight" - the so-called out-of-body experience. The book touches on a considerable range of related topics such as healing, the effects of music on the brain, and, most importantly, it explores how the development of shamanic rituals was a key factor in human evolution.