Chi è l’impostore? Ciarlatanesimo, immaginazione e la condanna del mesmerismo

The famous controversy about animal magnetism and its condemnation, in 1784, by a commission led by Benjamin Franklin directly engage the categories of imposture and quackery and their relations with imagination. On a first level, the commissioners, by refusing the existence of the fluid assumed by Mesmer as the agent of his prodigious healings, and rather considering them as the effect of imitation and imagination, identified the latter with imposture. At the same time, however, denouncing the physical and moral risks of magnetism, they implicitly recognized its real effects. Things are more complex if we consider Mesmer’s reply, which points out the refusal by the commissioners of the empirical evidences produced by animal magnetism, thus returning against them the same accusation of deception. Moreover, the commission had chosen not to examine Mesmer’s treatments, but those of his former pupil Deslon, which Mesmer accused in turn to be an impostor who pretended having been introduced to his secret doctrines. This affair, which excited French public opinion on the eve of the Revolution, has been thoroughly examined both from historical and epistemological perspectives but still deserves further analysis also returning on old and new sources. The same charge of imposture was to be appointed to the somnambulists put in magnetic trance by Mesmer’s epigones, thus questioning the role of the irrational aspects of human mind and the Enlightenment’s category of identity.