De umbris idearum (encyclical)

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You may be looking for the short story or the book.

De umbris idearum, or "On the Shadows of Ideas", was an encyclical written by Pope Beatrix II in 2649 authorising the Catholic Church to brainwash the Remote to serve in the Beatrician Crusade. Some historians believed that the fact that the encyclical shared its name with a 16th century book by Giordano Bruno to be a coincidence. (PROSE: De Umbris Idearum)