This is a landmark in science writing that resurrects from the vaults of neglect the polymath Jerome Cardano, a Milanese of the sixteenth century. Who is he? A gambler and blasphemer, inventor and chancer, plagued by demons and anxieties, astrologer to kings, emperors, and popes, and the unacknowledged discoverer of the mathematical foundations of quantum physics. The Quantum Astrologer's Handbook, like Jerome, has multiple occupations: it is at once a biography, a history of science, an explanation of quantum theory, and an engrossing story that reads like the best kind of novel. It is a science book like no other about a scientist like no other.