Ranging from alchemy to necromancy, "books of secrets" offered medieval readers an affordable and accessible collection of knowledge about the natural world. Allison Kavey's study traces the cultural relevance of these books and also charts their influence on the people who read them. Citing the importance of printers in choosing the books' contents, she points out how these books legitimized manipulating nature, thereby expanding cultural categories, such as masculinity, femininity, gentleman, lady, and midwife, to include the willful command of the natural world.