Phrenology was a theory of brain function developed by Franz Joseph Gall in the 1790s. It maintained that mental faculties and character traits were localized in specific brain areas, whose development determined the shape of the skull. Phrenologists believed they could “read” people’s character and abilities by examining the bumps and depressions on their skulls. Despite its worldwide popularity, phrenology quickly became controversial. Critics discredited it as materialistic, deterministic, and quack science; supporters viewed it as a science and a profession, with clients being offered guidance for self-knowledge and improvement, as well as advice in areas like education, social reform, and criminology. Phrenology reflected and reinforced nineteenth-century ideas about race, gender, and class. Yet, paradoxically, while employed to support discrimination and even genocide, it could also empower marginalized groups. Though discredited by later physiology, phrenology’s cultural legacy endures, illustrating early efforts to connect the brain with mind, personality, and morality.