Margaret Murray argued that the people executed in the European witch trials were practitioners of a surviving pagan fertility religion, organised in covens of thirteen, worshipping a horned god whom Christian interrogators recorded as the Devil. The thesis had scholarly manners, footnotes to trial records and a Clarendon Press imprint, and through her 1929 article on witchcraft for the Encyclopaedia Britannica, which stood for decades, it reached a whole reading public as settled fact. The evidence problem was visible early and fatal in the end. Reviewers of the 1921 book, and later critics in detail, showed that Murray quoted confessions selectively, splicing fragments so that fantastic material, night flight, shape changing, feasting with the dead, vanished and left an apparently sober record of meetings; that her covens of thirteen dissolved on inspection of the sources; and that the continuous organised cult she posited had left no trace in the abundant records of medieval church discipline.
Norman Cohn's Europe's Inner Demons in 1975 demonstrated the circularity of building a real religion out of statements produced under torture within a demonological script, and Jacqueline Simpson's 1994 survey in Folklore explained how completely professional folklorists had rejected the case even while the public embraced it. No specialist historian of the trials now defends the thesis, and the study's status is debunked, in the strict sense: tested against its own cited sources and found to have been made of them rather than from them.