Witches, ghosts, fairies. Premodern Europe was filled with strange creatures, with the devil lurking behind them all. But were his powers real? Did his powers have limits? Or were tales of the demonic all one grand illusion? Physicians, lawyers, and theologians at different times and places answered these questions differently and disagreed bitterly. The demonic took many forms in medieval and early modern Europe. By examining individual authors from across the continent, this book reveals the many purposes to which the devil could be put, both during the late medieval fight against heresy and during the age of Reformations. It explores what it was like to live with demons, and how careers and identities were constructed out of battles against them – or against those who granted them too much power. Together, contributors chart the history of the devil from his emergence during the 1300s as a threatening figure – who made pacts with human allies and appeared bodily – through to the comprehensive but controversial demonologies of the turn of the seventeenth century, when European witch-hunting entered its deadliest phase. This book is essential reading for all students and researchers of the history of the supernatural in medieval and early modern Europe.

How scientists through the ages have conducted thought experiments using imaginary entities—demons—to test the laws of nature and push the frontiers of what is possible Science may be known for banishing the demons of superstition from the modern world. Yet just as the demon-haunted world was being exorcized by the enlightening power of reason, a new kind of demon mischievously materialized in the scientific imagination itself. Scientists began to employ hypothetical beings to perform certain roles in thought experiments—experiments that can only be done in the imagination—and these impish assistants helped scientists achieve major breakthroughs that pushed forward the frontiers of science and technology. Spanning four centuries of discovery—from René Descartes, whose demon could hijack sensorial reality, to James Clerk Maxwell, whose molecular-sized demon deftly broke the second law of thermodynamics, to Darwin, Einstein, Feynman, and beyond—Jimena Canales tells a shadow history of science and the demons that bedevil it. She reveals how the greatest scientific thinkers used demons to explore problems, test the limits of what is possible, and better understand nature. Their imaginary familiars helped unlock the secrets of entropy, heredity, relativity, quantum mechanics, and other scientific wonders—and continue to inspire breakthroughs in the realms of computer science, artificial intelligence, and economics today. The world may no longer be haunted as it once was, but the demons of the scientific imagination are alive and well, continuing to play a vital role in scientists' efforts to explore the unknown and make the impossible real.

A prescient warning of a future we now inhabit, where fake news stories and Internet conspiracy theories play to a disaffected American populace “A glorious book . . . A spirited defense of science . . . From the first page to the last, this book is a manifesto for clear thought.”—Los Angeles Times How can we make intelligent decisions about our increasingly technology-driven lives if we don’t understand the difference between the myths of pseudoscience and the testable hypotheses of science? Pulitzer Prize-winning author and distinguished astronomer Carl Sagan argues that scientific thinking is critical not only to the pursuit of truth but to the very well-being of our democratic institutions. Casting a wide net through history and culture, Sagan examines and authoritatively debunks such celebrated fallacies of the past as witchcraft, faith healing, demons, and UFOs. And yet, disturbingly, in today's so-called information age, pseudoscience is burgeoning with stories of alien abduction, channeling past lives, and communal hallucinations commanding growing attention and respect. As Sagan demonstrates with lucid eloquence, the siren song of unreason is not just a cultural wrong turn but a dangerous plunge into darkness that threatens our most basic freedoms. Praise for The Demon-Haunted World “Powerful . . . A stirring defense of informed rationality. . . Rich in surprising information and beautiful writing.”—The Washington Post Book World “Compelling.”—USA Today “A clear vision of what good science means and why it makes a difference. . . . A testimonial to the power of science and a warning of the dangers of unrestrained credulity.”—The Sciences “Passionate.”—San Francisco Examiner-Chronicle

'A gripping new drama in science ... if you want to understand how the concept of life is changing, read this' Professor Andrew Briggs, University of Oxford When Darwin set out to explain the origin of species, he made no attempt to answer the deeper question: what is life? For generations, scientists have struggled to make sense of this fundamental question. Life really does look like magic: even a humble bacterium accomplishes things so dazzling that no human engineer can match it. And yet, huge advances in molecular biology over the past few decades have served only to deepen the mystery. So can life be explained by known physics and chemistry, or do we need something fundamentally new? In this penetrating and wide-ranging new analysis, world-renowned physicist and science communicator Paul Davies searches for answers in a field so new and fast-moving that it lacks a name, a domain where computing, chemistry, quantum physics and nanotechnology intersect. At the heart of these diverse fields, Davies explains, is the concept of information: a quantity with the power to unify biology with physics, transform technology and medicine, and even to illuminate the age-old question of whether we are alone in the universe. From life's murky origins to the microscopic engines that run the cells of our bodies, The Demon in the Machine is a breath-taking journey across the landscape of physics, biology, logic and computing. Weaving together cancer and consciousness, two-headed worms and bird navigation, Davies reveals how biological organisms garner and process information to conjure order out of chaos, opening a window on the secret of life itself.

This book is the first all-encompassing exploration of the role of demons in philosophical and scientific thought experiments. In Part I, the author explains the importance of thought experiments in science and philosophy. Part II considers Laplace’s Demon, whose claim is that the world is completely deterministic. Part III introduces Maxwell’s Demon, who - by contrast - experiences a world that is probabilistic and indeterministic. Part IV explores Nietzsche’s thesis of the cyclic and eternal recurrence of events. In each case a number of philosophical consequences regarding determinism and indeterminism, the arrows of time, the nature of the mind and free will are said to follow from the Demons’s worldviews. The book investigates what these Demons - and others - can and cannot tell us about our world.

NEW YORK TIMES BESTSELLER • In the final book of his astonishing career, Carl Sagan brilliantly examines the burning questions of our lives, our world, and the universe around us. These luminous, entertaining essays travel both the vastness of the cosmos and the intimacy of the human mind, posing such fascinating questions as how did the universe originate and how will it end, and how can we meld science and compassion to meet the challenges of the coming century? Here, too, is a rare, private glimpse of Sagan’s thoughts about love, death, and God as he struggled with fatal disease. Ever forward-looking and vibrant with the sparkle of his unquenchable curiosity, Billions & Billions is a testament to one of the great scientific minds of our day. Praise for Billions & Billions “[Sagan’s] writing brims with optimism, clarity and compassion.”—Ft. Lauderdale Sun-Sentinel “Sagan used the spotlight of his fame to illuminate the abyss into which stupidity, greed, and the lust for power may yet dump us. All of those interests and causes are handsomely represented in Billions & Billions.”—The Washington Post Book World “Astronomer Carl Sagan didn’t live to see the millennium, but he probably has done more than any other popular scientist to prepare us for its arrival.”—Atlanta Journal & Constitution “Billions & Billions can be interpreted as the Silent Spring for the current generation. . . . Human history includes a number of leaders with great minds who gave us theories about our universe and origins that ran contrary to religious dogma. Galileo determined that the Earth revolved around the Sun, not the other way around. Darwin challenged Creationism with his Evolution of Species. And now, Sagan has given the world its latest challenge: Billions & Billions.”—San Antonio Express-News “[Sagan’s] inspiration and boundless curiosity live on in the gift of his work.”—Seattle Times & Post-Intelligencer “Couldn’t stay awake in your high school science classes? This book can help fill in the holes. Acclaimed scientist Carl Sagan combines his logic and knowledge with wit and humor to make a potentially dry subject enjoyable to read.”—The Dallas Morning News

This major work offers a new interpretation of the witchcraft beliefs of European intellectuals between the fifteenth and eighteenth centuries, showing how these beliefs fitted rationally with other beliefs of the period and how far the nature of rationality is dependent on its historical context.