Michel Foucault’s History of Madness in the Age of Reason examines the 17th-century transition from viewing madness as a form of wisdom to its social exclusion through "the Great Confinement." Foucault argues that modern, institutionalized mental health care replaced physical chains with psychological observation and moral regulation to maintain social order. The work highlights that definitions of sanity are constructs used by power structures to control non-conformity.