Once there was a boy who feared to sleep, beset as he was by troubled dreams. His night terrors contained muddy alleys and dark streets gray with rain. He traveled with companions and knew that one of them would be sacrificed to the appetite of witches. He dreamed, too, of a dangerous criminal, invisible but lurking, hanging like a bat far above his head. And he dreamed of tigers that attacked in deep jungles, and of falling into the blue-black sea teeming with sharks. How, asks the Brazilian neuroscientist Sidarta Ribeiro, are we to make sense of “such a wealth of detail”? How can we explain the nature, recurrence and meaning of dreams? In “The Oracle of Night: The History and Science of Dreams,” Mr. Ribeiro seeks to answer these questions with a sweeping account as tangled and chaotic—and fascinating— as the dreams themselves. Paradoxically familiar yet still mysterious, the “curious state of internal life that we call dreaming,” as Mr. Ribeiro describes it, allows persons and places to be exchanged or transformed “with incredible fluidity.” We build up our nightly narratives as “a simulacrum of reality constructed out of fragments of memories.” As a result, to interpret a dream requires “a deep understanding of the cognitive and emotional context of the dreamer.” “The Oracle of Night” is not, however, an attempt to demystify the act of dreaming. Instead, it reinfuses the dreamscape with beauty, mystery and significance. And it begins with Mr. Ribeiro’s own story; he was that dreaming boy.
Months before his first nightmare, young Sidarta’s father died of a violent heart attack. His mother, now a widow with small children, fell into a depression, and Sidarta found himself old enough to understand the loss and pain but too young to be of any material support. He began dreaming of death and orphanhood. As the dreams went on, however, they began to change. A friend appeared, often resembling his father. Sidarta still faced each successive danger—the criminal, the tiger, the sea, the sharks—alone, but once he understood that the sharks would not hurt him, the dreams stopped. “The understanding that our journey is a solitary one,” Mr. Ribeiro explains, was “recorded in the memory in orange, red, and purple”—the same colors of the sunset sky the day he lost his father.
For thousands of years, humankind read the future in dreams. Later, Freudian psychoanalysis and Jungian archetypes turned the dream into a window to our unconscious past. “The Oracle of Night” means to wed these two notions, weaving past and future together and theorizing dream function “as a crucial tool for surviving in the present.” Mr. Ribeiro writes: “In the last three hundred thousand years, humanity’s biological hardware has changed very little, but the cultural software has evolved apace.” Prehistoric dreams were “mostly made of stone,” but also of hunger, pursuit, rage, fear, desire—and those yearnings are still with us.
Dreaming offers “imagination with no brakes, and no control, set free to fear, to create, to lose and find.” But what is dreaming, and what is it for? In an attempt to find an answer, “The Oracle of Night” takes a breakneck journey through history, from cave paintings and the ancient Greeks to Celtic myths, Egyptian pharaohs, Gilgamesh and Julius Caesar. The text, translated from the Portuguese by Daniel Hahn, moves fluidly from systemic historiography to guesswork and lighthearted extrapolation. (What did dinosaurs dream about?) These leaps in the timeline resemble dreamwork and are perhaps intentional, asking us to surrender to stream-of-conscious ideas as they ramble past us. Zinging between time periods and fields of sometimes jargon-laden study, the book also provides self-conscious sign-posted summaries. (“Let’s do a quick recap. Hundreds of millions of years ago . . . ”) The result is a curiously hybridized book, at times playful, at times intensely scientific.
Mr. Ribeiro, the founder and vice director of the Brain Institute at Universidade Federal do Rio Grande do Norte in Brazil, demonstrates an impressive understanding of dream function. Presiding over “The Oracle of Night” like a patron saint is Sigmund Freud, who showed that dreaming and desire are one, intimately related to our dopamine centers of reward and action. We are still, only now, beginning to understand how we dream: It is more than a fragment of memory; it has a language of its own, valuable to learning, to remembering, to the communication of our humanity to others and to ourselves.
Dreaming offers imagination with no brakes and no control. One is set free to create, to fear, to lose and find—and then interpret.
Despite its well-sourced scientific discussions and the collective weight of its historical case studies, the strength of “The Oracle of Night” lies in its poetic and visceral retelling of dreams. Mr. Ribeiro describes the dream of his pregnant wife, where her grandmother embodies a hammock to rock her, petting her hair and telling her she will be a good mother. He describes Giuseppe Tartini pining after an ungraspable dream in the violinist’s “Devil’s Trill Sonata.” And he tells of his own nightmares, where “the boy advanced, rifle in hand, and started his crossing of the causeway, keeping his balance several yards above a tempestuous, foamy, lead-green sea.” In these moments, the author demonstrates the most provocative argument of all: Because we all dream, the retellings provide us with a common experience of humanity. We feel the same strange slippage of time and being, of reality and sense, and nod in our agreement that these are not mere fragments of memory but pieces of ourselves.
Daunting in its breadth and encyclopedic in structure, “The Oracle of Night” contains a narrative thread that leads the reader from its inception to close. Mr. Ribeiro reminds us to push back against a culture of insomnia, to prioritize sleep, and to actively control, recall and learn from our dreams. “Similar circadian rhythms are found in almost all living beings,” he tells us. Perhaps dreams may even be a hallmark of life itself.
Ms. Schillace is editor in chief of the journal Medical Humanities and the author, most recently, of “Mr. Humble and Dr. Butcher.”