What is a dream? Why do we dream? 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. Ribeiro 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. Accessible, authoritative, and fascinating from first to last, The Oracle of Night gives us a wholly new way to understand this most basic of human experiences.