This is a curiously conceived book. In his introduction, Mentgen begins by noting the “shocking” lack of attention the topic of astrology has received especially among German medievalist (p. 1). He also notes that the practice of astrology faced two significant obstacles throughout the medieval period—it had suffered legal condemnations since late antiquity, and certain aspects of it contradicted the Christian doctrine of human free will. Yet this book deals not at all with the long and complex history of legal or intellectual opposition to astrology. Neither does it intend to provide a complete survey of the practice of this craft in medieval times. Instead, Mentgen focuses on the issue of the public reception of astrological predictions. He notes the difficulty of defining a “public” in medieval times, with a nod to Habermas (pp. 10–12), but offers no resolution to this dilemma, and afterward treats it unproblematically. On the subject of astrological “Öffentlichkeit,” Mentgen intends to be comprehensive, covering the entire medieval period and all of Europe, but in fact he radically narrows his focus to only two issues (the second, admittedly, quite large). The book makes absolutely no attempt to unify its two entirely separate topics, and so is, in fact, really two separate books.