Who makes a book, the author or the publisher? Joseph Skloot studies a classic of medieval Jewish literature, Sefer Hasidim, to answer this old question in a new way. He takes the reader into two printing houses, one Jewish and one Christian, and shows how each of them framed and transformed the book, giving it an author and sometimes rewriting its text, in their editions. A classic of medieval spirituality that remained labile in manuscript, Sefer Hasidim took on the form it would retain for centuries in the inky hands of correctors. This lively and learned book is a tour de force of book history, rich in textual and human detail.