Book excerpt: Raphael was one of the most important artists of the Italian Renaissance and one of the most important and influential in the entire history of art. His practice of 'synthetic' or 'critical' imitation became a model of creative method; his engagement with the principle of decorum revealed its deeper expressive and philosophical significance and the operation of his workshop helped to redefine the nature of the work that artists do. Robert Williams draws upon the history of literature, philosophy, and religion, as well as upon economic history, to support his detailed and illuminating accounts of Raphael's major works. His analyses serve as the foundation for a set of hypotheses about the aims and aspirations of Italian Renaissance art in general and the nature of art-historical inquiry.