It is only recently that I had the pleasure, through Andrew Cuthbertson's translation, of being able to read Duchenne's book with ease. Because of my rusty college French, my initial introduction to Duchenne was selective. My access to Duchenne had been aided by Harriet Oster, a postdoctoral fellow working with me in the early 1970s. With her background in French literature, and an interest in measuring facial behavior, Harriet carefully checked Duchenne's description of the muscles responsible for particular changes in facial appearance. I was then, with my colleague Waly Friesen, deeply immersed in constructing a tool for measuring facial behavior based on the anatomy of facial movement. Duchenne's book was an invaluable resource. His identification of the particular muscles producing specific changes in facial appearance provided the groundwork for those who measure facial behavior today. Duchenne's study of the mechanics of facial movement and the objective assessment of facial activity are, therefore, of great historical importance.

Most recently I have become fascinated by Duchenne's ideas on the nature of facial expression of emotion, having been quite unfamiliar with some of them until reading the translation in full.