Henry Charles Lea (1825-1909) was an American publisher, civic activist, philanthropist and historian from Philadelphia, Pennsylvania. As a historian of medieval Europe, he wrote extensively on the institutional and legal history of the Catholic Church. His active writing career on historical subjects spannedmore than fifty years, during which he published ten books and numerous articles. He wrote a series of books on the Inquisition, beginning with A History of the Inquisition of the Middle Ages (1888) and continuing with A History of the Inquisition of Spain (1906-1907) and The Inquisition in the Spanish Dependencies (1908). He also collected materials related to witchcraft beliefs, the prosecution of witches by the Inquisition, and contemporary reports of witchcraft.
Henry Charles Lea's essay The Spanish Inquisition as an Alienist was published in the magazine Popular Science Monthly in July 1893.