The author examines phrenology by scrutinizing its central claims that mental activity resides exclusively in the brain and that each faculty corresponds to a discrete cerebral organ. The critique evaluates Gall’s evidence and methods, questions proposed anatomical correlations, and discusses distinctions between instinct and understanding as well as the role attributed to animal spirits. It surveys the positions of Spurzheim and Broussais, assessing their psychological and physiological extensions and pointing out methodological exaggerations and errors. While noting some empirical observations of value, the analysis concludes that the strict localizationist system advanced by phrenologists is unsupported by the evidence presented.