Fantastical conspiracy theories tend to imagine secret plots of colossal scale, duration, and power. Beliefs in American conspiracies in the 1800s, the Yale historian David Brion Davis has written, usually consisted of hard grains of truth connected with a mucilage of exaggeration and fantasy. But the central theme, which is so central to the paranoid style, is the conviction that an exclusive monolithic structure has imposed a purposeful pattern on otherwise unpredictable events.
