Book excerpt: Mechanics of Motor Proteins and the Cytoskeleton provides a physical foundation for molecular mechanics. Part I explains how small particles like proteins respond to mechanical, thermal, and chemical forces, Part II focuses on cytoskeletal filaments, and Part III focuses on motor proteins. The treatments are unified in the respect that they are organized around principles rather than proteins: chapters are centred on topics such as structure, chemistry, and mechanics, and different filaments or motors are discussed together.