The author explores the question of the nature of emotion by critically examining three theoretical approaches - the somatic or peripheralist, the cerebrocentric, and the cognitive. In finding the somatic approach superior to the others, the author explicitly challenges current conceptions regarding the nature of emotion. Giving particular emphasis to the works of William James, the author recasts the somatic theory in detail and demonstrates how it best fits the available clinical experimental data. Written in jargon-free language, the book presents to specialists and non-specialists alike an overview of this topic.