The impetus for this book came when I was delivering a series of undergraduate lectures on emotion to psychology students at the University of Oxford. I was unable to find what I considered a suitable basic text for the course. The available books consisted almost entirely of presentations of particular theories of emotion. It struck me as strange that any field of science should have such a multiplicity of theories – except for the fact that in many cases different theorists were addressing different data bases. What seemed to me to be lacking, therefore, was a general pretheoretical framework into which all of the relevant data could be fitted.

This book is an attempt to provide such a framework. It does not present a specific theory of emotion, although it might bias one in favour of some theories rather than others. The central idea of the book is that biology and particularly evolution provide the best starting point for the study of emotion. This idea is neither novel, since it is the basis for Darwin's work, nor is it unrepresented in current theorising (see particularly Plutchik's various works). However, I do not think its implications have ever been considered outside the bounds of specific theorising. In particular, I have tried to show that all of the conventional properties of emotion such as expression, feeling, and motivation can be considered in a scientific manner and useful conclusions drawn therefrom.