Throughout his pontificate, John XXII exhibited a marked concern over matters of sorcery, divination, and demonic invocation. The pope feared magical assaults and assassination attempts on his own person, and he used charges of heresy, sorcery, and idolatry as political weapons against his enemies. He also promoted the more general persecution of sorcery by ordering papal inquisitors to take action against sorcerers and by issuing a sentence of automatic excommunication against all those who practiced any form of demonic invocation that entailed the supplication or worship of demons. His bull on this matter, Super illius specula (Upon His Watchtower), remained an important part of the legal apparatus against practitioners of sorcery for the remainder of the Middle Ages.