Nicolas Guilhot in the Boston Review:
There is a widespread tendency among scholars, information watchdogs, and public officials to view conspiracy theories as theories, statements about the world that can be true or false. As they are typically false, we treat them as flawed sociological explanations, premised on logical inconsistencies or faulty evidence. The expression “conspiracy theory” was coined by a philosopher of science, Karl Popper, to designate the incapacity to understand social events as the outcome of a many interdependent processes: one saw them instead as the expression of a single and omnipotent will. The “conspiracy theory of society,” Popper wrote, was something akin to “a primitive kind of superstition.” This has remained the prevalent view ever since: in an influential article published ten years ago, two Harvard scholars—Cass Sunstein and Adrian Vermeule—called them “crippled epistemologies.”
More here.