Diversification and Professionalization in Psychology offers readers a multicentric perspective on the history of social science and compares the developments in psychology in relation to the developments made in the other social and natural sciences. This is the second volume about the formation of modern psychology and provides a comprehensive look into the origins and developments of modern psychology. With a large geographical coverage, European developments are put into their own context in their own time. In doing this, the book explores different early schools, from social reductionists like Durkheim, Charles Blondel, and Maurice Halbwachs, to the social debates about relativism in Lévy-Bruhl, early Piaget, the beginnings of ethology, and the semiotic approach of Karl Bühler. These thinkers are placed in relation to the recent upsurge of different social and biological theories of the mind. Throughout, the author develops a detailed presentation of the thematic development of psychology and links the history of psychology to an outline of contemporary psychology. This is an invaluable introductory text for undergraduate students of the history of psychology and will also appeal to postgraduates, academics, and anyone interested in psychology or the history of science. It will also be of interest to graduate students of psychology, biology, sociology, and anthropology with a theoretical interest in the history of the field.