This book deals with Balinese psycho-social experiences in trance-possession states during traditional healing, religious ceremonials, dance, drama and gamelan performances, as well as in several mental disorders. It concludes that trance-possession in Bali is the same, phenomenologically, as multiple personality disorder (MPD) in the West. It also presents criteria for the diagnosis of possession in any culture, a new theory of possession, and multifold comparisons of trance-possession in Bali with MPD in the West.