Exploring the diverse modalities of medieval instruments, Mitchell’s case studies encompass techniques as seemingly distinct as time-keeping mechanisms, mathematical diagrams, logical syllogisms, and the literary devices of Geoffrey Chaucer and John Gower. A cultural and intellectual history, Mitchell’s work leads readers from three-dimensional objects (physical mechanisms) to two-dimensional inscriptions (maps and diagrams) and onward to overarching disciplinary norms in the early liberal and mechanical arts. Prying loose the subtle, adaptable, and generative concept of technical objects from limiting contemporary frameworks, he shows how these instruments are indispensable to the past-and the future-of the arts and culture at large.