Nearly twenty years ago I agreed to team-teach a course in the history of psychology with a female colleague who was pregnant at the time and was not be able to complete the course alone. At the end of the course she confided that she did not really enjoy teaching history of psychology, and I told her that I had fallen in love with it. By mutual agreement I took over the course, and have been hooked on the subject ever since. Shortly after, I gave my first conference paper in the history of psychology, published the first of a series of papers on the history of psychology, and finally a book (for this press) on the history of social psychology. Having a professional background in philosophy and psychology, I felt like a graduate student again. Then I set myself the most daunting task of all, to write a complete history of psychology from the time of the ancient Greeks to the “cognitive revolution” in psychology. The present work is the product of many years of scholarly labor and multiple transformations of the original draft.

This work advances a conceptual history of psychology, which traces the continuities and discontinuities in our theoretical conceptions of human psychology and behavior from the speculations of the ancient Greeks to the institutionalized scientific psychology of the twentieth century. I highlight some of the remarkable continuities that reach across centuries and millennia, such as those between Aristotle's psychology and contemporary cognitive psychology, as well as fundamental discontinuities between superficially similar theoretical positions, such as those between Darwinism and the forms of functionalist and behaviorist psychology commonly supposed to be based upon it. I also try to tease apart historically associated positions that have no essential connection, such as the common association between materialism and the view that human psychology is continuous with animal psychology.

I have made a serious attempt to illustrate the contingency of many of the conceptual principles and associations that have informed the historical development of psychology and that today continue to shape our conception of the contemporary discipline.