The Concept of Anxiety
All of Kierkegaard's books have either a preface, dedication, or prayer at the beginning. This book includes a lengthy introduction. "The Concept of Anxiety" was published on exactly the same date as "Prefaces", June 17, 1844. Both books deal with Hegel’s idea of mediation. Mediation is a common thread throughout Kierkegaard’s works. His work up to this point was to show that faith was being mediated by knowledge. Here he takes up the questions of sin and guilt.
Personality disorder
In 1939, psychiatrist David Henderson published a theory of 'psychopathic states' that contributed to popularly linking the term to anti-social behavior. Hervey M. Cleckley’s 1941 text, "The Mask of Sanity", based on his personal categorization of similarities he noted in some prisoners, marked the start of the modern clinical conception of psychopathy and its popularist usage.