Mesmerism is not best known by its originator’s intent. If you say you have been “mesmerized” you do not usually mean that you have been successfully treated for a nervous complaint by having iron rods waved over your body. You mean that you have fallen under a spell, ceded your rational agency in some way, whether to a professional hypnotist, a virtuosic performance pianist, or a distractingly handsome boy in your 9 a.m. class. The curious transformation of mesmerism into its own mirror image lies at the heart of Ogden’s question.
The story goes roughly like this. First, you have the good doctor claiming to have made a scientific discovery, by which he will use detailed procedures and specialized metal tools for the advancement of human wellbeing — all thoroughly scientific-sounding. The practice ostensibly produces effects such as hypnosis, convulsions, and trances for medical benefit. The doctor has his followers. Later you have a thorough debunking of the supposed new science, after which a second generation of mesmerists appears. Precisely because the debunking had attributed the marvelous effects of mesmerism to unruly imagination, the second crop of mesmerists proposes the practice as a way to harness and manage human belief in the supernatural and the outlandish.
Ogden is not perfectly clear about the degree to which second-generation mesmerists straightforwardly believed in animal magnetism, but there appears to have been some variety. For example, she writes about Mesmer’s student Charles Deslon that he
prefigured the nimble about-face that practitioners would soon make en masse: he said that magnetism, rather than being a deplorable example of credulity, was actually the science of governing it. As [astronomer Jean-Sylvain] Bailly sardonically recorded, Deslon “declared in our session held at the house of Dr. Franklin ... that he thought he might lay it down as a fact, that the imagination had the greatest share in the effects of animal magnetism; he said that this new agent might be no other than the imagination itself, whose power is as extensive as it is little known.”
On the other hand, another influential mesmerist, J. P. F. Deleuze, believed that the fluid really existed, but had been misinterpreted throughout history because of “false physical theories or ... superstition.” In the cases of both Deslon and Deleuze, this reworked mesmerism was meant as a technique for manipulating credulity. Either the suggestibility of patients to performed technique produced the effects, or their pre-existing beliefs in magical thrall made them receptive to the hypnosis or clairvoyance that magnetic fluid could really induce.
Whatever beliefs the mesmerist professed, on the mesmeric stage his craft depended on performing the technique of mesmerism with seriousness and intent. With subjects selected for their predisposition to belief, mesmerist and subject constituted what Daniel O’Keefe, in Stolen Lightning: The Social Theory of Magic (1982), calls an “act-as-if group”: a social interaction that temporarily redraws the accepted borders of reality by mutual agreement.
O’Keefe believes that the act-as-if groups are the basis for magic. Mutual agreement overvalues a temporary subjective state, giving it new meaning, creating a framework around it. The agreement then allows the subjective state to be sustained. So, by Ogden’s account, you have an odd tension. By one light, the mesmerists who identified imagination as the active agent stand for greater enlightenment than those who believed in the non-existent magnetic fluid. And yet their attempts to control imagination in others hinged on encouraging and ritualizing false beliefs — exactly what some sociologists say magicians do.