This book discusses the cultural importance of spirits, what spirits want, and how humans interact with them, using examples from around the world and through time. Examples range from the vengeful spirits of the Zulu that cast lightning bolts from clear skies to punish wrongdoers, to the benevolent Puebloan Kachina that encourage prosperity, safety, and rain in the arid American Southwest. The case studies illustrate how humans seek to cooperate (or counteract) spirits to heal the physical and spiritual ailments of their people, to divine the truth, or to gain resources. Building from their cross-cultural analyses, the authors further discuss how our physiology and psychology impact our interaction with the spirits. Readers will come away with an appreciation of the beauty and power of the spirits that continue to shape the lives of people around the world.