Originally published in Brazil as O oráculo da noite : A história e a ciência do sonho by Companhia das Letras, São Paulo, in 2019.

Includes bibliographical references and index.

"What is a dream? Why do we dream? How do our bodies and minds use dreams? These questions are the starting point for this unprecedented, astonishing study of the role and significance of dreams, from the beginning of human history. It is an investigation on the grand scale, encompassing literature, anthropology, religion, and science, one that 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 and how they contributed to our capacity to perceive past and future, and to conceive the existence of "souls" and "spirits"--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. He explains 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"-- Provided by publisher.