Based on the Gifford Lectures of 1937-8 in Edinburgh, Nobel Prize winner Charles Sherrington's 1940 study addresses the nature of the mind and its relationship to life and matter. The book centres on the writings of the little-known sixteenth-century physician Jean Fernel. After setting out Fernel's views on the nature of man, Sherrington proceeds to develop his own thoughts, drawing upon a wide variety of philosophical theories. Using Fernel as a historical case study, the book demonstrates how any scientific outlook is always part of its age, and shows how views on the eternal enigmas of mankind, mind and life have changed radically over time. Sherrington's book is important in the history of ideas for its assessment of the value of advances in natural science as a framework for the development of natural theology.