These questions are the starting point for this unprecedented, astonishing study of the role and significance of dreams, from the beginning of human history. An investigation on the grand scale, encompassing literature, anthropology, religion, and science, it articulates the essential place dreams occupy in human culture, and how they functioned as the catalyst that compelled us to transform our earthly habitat into a human world. From the earliest cave paintings  where the author finds a key to humankind's first dreams, which contributed to our capacity to perceive past and future  to cutting-edge scientific research, Ribeiro arrives at startling and revolutionary conclusions about the role of dreams in human existence and evolution. He explores the advances that contemporary neuroscience, biochemistry and psychology have made into the connections between sleep, dreams, and learning, before revealing what dreams have taught us about the neural basis of memory and the transformation of memory in recall. And he makes clear that the earliest insight into dreams as oracular has been confirmed by contemporary research.