From Michel de Certeau’s The Possession at Loudun (pg.43-44):
Fragile, unstable, contested, the words ascribed to the diabolical transcendence flew out of sight. They were compensated for by increased exhibitionism. Soon they were to be replaced by the themes of preaching: the preaching devils would represent the last of diabolical discourse, but a discourse nonetheless useful. Already, with the secondary and facetious malice to which Jeanne des Anges alluded in her autobiography, the possessed women themselves would deny the exorcists those proper words that they expected:
When asked: Quis es tu, mendax, pater mendacii? Quod est nomen tuum [Who are you, liar, father of lies? What is your name?] the demon said, after a long silence: “I forgot my name. I can’t find it … ”
And commanded once more to say his name, he said: “I lost my name in the wash.”
The intervention of royal justice will strike a blow against this linguistic esoterism from which it will not recover. The devil will be either the witnesses or the accused, and they will speak French like everybody else.
I wish I had the French edition to check but I’m assuming – because the text always indicates and translates Latin – that the final reply is in French and captures the frustrated breakdown of the possessed’s pretense to Latin.
From Michel de Certeau’s The Possession at Loudun (pg. 3):
Possession became a great public confrontation between science and religion, a debate on what is certain and what uncertain, on reason, the supernatural, authority. This was orchestrated by an entire erudite literature and the popular press. It was a “theater” that attracted the curious from all of France and practically all of Europe, a circus “for the satisfaction of these gentlemen,” according to the wording of many official transcripts of the day.
The show was staged in Loudun for almost ten years, and soon provided a center for edification, apologetics, pilgrimages, and pious or philanthropic associations. The diabolical was becoming commonplace. It was gradually becoming profitable. It was reintroduced in the language of a society, while at the same time continuing to perturb that society. In this story, the diabolical played the role set out for it by the rules of the already traditional commedia dell’arte. An evolution took place The Devil, violent at first, was slowly becoming civilized. He would lead disputations. He was discussed. He would end up repeating himself monotonously. The horror was transformed into a spectacle, the spectacle into a sermon. True, there was still weeping and wailing during the exorcisms that continued to be carried out after the execution of “the sorcerer,” Urbain Grandier, but that did not prevent the serving of snacks to the spectators who filled the churches