The Liber vaccae/Kitāb al-nawāmīs is a technical manual attributed to Plato that was compiled in the medieval Islamicate world. Although the original Arabic text does not survive in full, the work's contents are known through Latin and Hebrew translations. This dissertation challenges the claim that the Liber vaccae is a book of 'magical' procedures by examining the circumstances of its construction by an editor-compiler and its deconstruction by later transmitters and readers. For its construction, I conduct an interdisciplinary survey of Jewish, Christian, and Islamic literature from the first to the ninth centuries of the Common Era. I show that the Liber vaccae's editor-compiler navigates fraught questions about experiences that seem to be produced by divine power. By engaging with visual culture and technology, the text develops a rhetoric through which to confront the nature of prophethood. For its deconstruction, I introduce case studies of mostly late medieval Muslim, Jewish, and Christian readers who take advantage of the technical manual's malleability and reshape the Liber vaccae in some way. Such reader interventions include distinctive translation choices, acts of censorship, reattribution, and quotation. While some of these readers do engage with questions about magic, others respond to issues of textual authority, value the work as a repository of technical knowledge, or use it for entertainment purposes. My investigation of these multiple linguistic and cultural registers is supported by an extensive analysis of the Latin and Hebrew manuscripts and Arabic fragments; in the appendices I include a readable edition of the Latin text made from three major manuscripts. This philological work is the basis for a future critical edition of the Liber vaccae that will encourage further research on both its legacy and the larger genre of technical manuals.