classical paranoia
as conceptualized in the 19th century by German physician Karl Ludwig Kahlbaum (1828–1899) and later refined by Emil Kraepelin, a rare disorder characterized by elaborate, fixed, and systematic delusions, usually of a persecutory, grandiose, or jealous character, that develop insidiously, cannot be accounted for by any psychiatric disorder, and exist in the context of preserved logical and orderly thinking.