Paranoia and paranoid are two concepts, which have became liberated from their clinical framework and have passed into journalistic, humanistic and sociological use in recent decades. In this paper we attempt to conceptualise and define the notion of collective ’’paranoid thinking’’ and its manifestations in the form of paranoid theories or ideologies. Reviewing historical cases of paranoid ideologies (with an emphasis on Italian fascism and German nazism), we identify their common paranoid traits, genesis, structure and content. Moreover, we develop a new historiographical approach to the so–called Sonderweg question and indicate some possibilities for its application in other disciplines. A heuristic concept of paranoid thinking enables a recognition of ideologies that are most dangerous to democratic societies and indicates a possibility of effectively opposing them.
