High Quality Content by WIKIPEDIA articles! The Mask of Sanity is a book written by Hervey Cleckley, M.D., first published in 1941, describing Cleckley`s clinical interviews with incarcerated psychopaths. It is considered a seminal work and the most influential clinical description of psychopathy in the 20th century. The basic elements of psychopathy outlined by Cleckley are still relevant today. The title refers to the normal "mask" that conceals the mental disorder of the psychopathic person in Cleckley`s conceptualization.