In early modern Europe there was a small group of books on the art of physiognomy which claimed to provide self-knowledge through an interpretation of external features. The authors of these books explained how the eyes, the face, and all of nature's natural bodies became windows of the soul. Along with the spreading influence of the 'Egyptian', the natural magic of the language of physiognomy became a way of looking and listening that some thought capable of recapturing the original divine characters of the natural, hieroglyphic language of man. In the experimental imagination of the English Renaissance magus Robert Fludd, the art of physiognomy was combined with the arts of memory and astrology. Under the impact of the religious turmoils of the Reformation, and the gradual establishment of a new understanding of the physics of the world by the seventeenth century's new natural philosophers, the hermetic physiognomy that was seen by some as a self-transformative form of praying in which one's soul resonated with the soul of the world became, in the eyes of many others, nothing more than an amusing game. Dr Porter uses remnants of the highly illustrated and graffitied texts on physiognomy to interpret the way that these books were read and viewed, and trace the changes that took place between the end of the Middle Ages and the beginning of Romanticism.