This is a reissue of a book published by the Clarendon Press in 1970 with a new introduction to take account of recent developments in the history of 19th century neuroscience. The author examines ideas of the nature and localization of the functions of the brain in the light of the philosophical constraints at work in the sciences of mind and brain in the 19th century. Particular attention is paid to phrenology, sensory--motor physiology, associationist psychology, and the theory of evolution as applied to the study of psychology. The author argues that the methods and assumptions of modern science achieved apparent success in this domain at the expense of the biological approach which justified the integration of formerly disparate traditions. The method of historical case study is used to illuminate the assumptions of current research. Read Less