This volume presents new research in medieval conceptions of magic, science, and the natural world, bringing not only medicine but also meteorology and navigation into the discussion. Ground-breaking theoretical chapters on theology, natural sciences, and the writing of history are presented by established experts in their fields. These are accompanied by case studies of interactions between magic, science, and natural philosophy. Each chapter offers new findings while contributing to a comprehensive survey of the shifting boundaries between natural and supernatural across both space and time. Emerging areas, such as the study of prognostics, are represented by challenging new work. This collection will prove fascinating to everyone engaging with this expanding field.