The Constitution of Man (or more completely, The Constitution of Man Considered in Relation to External Objects) first published in 1828 is a work by George Combe, who is credited with popularizing the pseudoscience of Phrenology.[1] Combe argues that the human mind is best understood through phrenology, and that the relative size of the various regions of the brain defined by phrenology determines a person's behavior and potential interactions with the external world. In The Constitution of Man, Combe uses phrenology to create a practical science of morality,[2] proposing that conforming to natural laws leads to happiness based on the phrenological understanding of human nature.[3] The book was an international bestseller, selling at least 100,000 copies in Britain alone[4] and over 300,000 copies worldwide by 1855, largely due to the publication of the 'people's edition,'[5] making it one of the best-sellers of the nineteenth century.[6]