Mesmer's Demon: Fiction, Falsehood, and the Mechanical Imagination

In the final weeks of the year 1784, Joseph Johnson's London publishing house came out with a translation (Report) of a French treatise (Rapport des commissaires) debunking a highly popular medical treatment: animal magnetism, or "mesmerism," the science of directing an invisible fluid into the body to cure disease. The English version lagged only four months behind the original ("Classified Ads"). But news of the Rapport des commissaires's sensational contents had spread at the speed of scandal, and by December 1784, Johnson et al. had to admit that the "temporary and unfounded hypothesis" of which they proposed to offer an exposé had already been exposed several times over by the periodical press. Under those circumstances, the English edition's introduction conceded, "it may . . . be asked, why it should be thought necessary to give to the public a translation of papers" unmasking yet again this known "imposture." Johnson and the anonymous translator, William Godwin, were staunch believers in Lockean pedagogy, and so a case for the utility of falsehood stood ready to hand. The text recounted part of "the history of the errors of mankind," which was perhaps "the most instructive study in the world" (introduction xvii-xviii).¹ In other words, the house defended its reexposure of a known falsehood on pedagogical grounds, as novelists did with their fictions. The Lockean theory of education, then particularly popular in America, held that if one wanted to be able to identify lies in the wild, one had to practice on falsehoods which had already been exposed as such. Reading novels, for example, would "habituate [the] mind to remark the difference between truth and fiction," William Hill Brown ventured in The Power of Sympathy (1789), so that the reader would "never be misled . . . by the meretricious dress of a pleasing tale" (53). Perhaps the mesmeric falsehood could serve the same purpose. Some such rationale might well explain the fact that US readers pored over news of mesmerism's exposure, even though the science had never been practiced there.² Perhaps they intended to use falsehood as Johnson and Godwin exhorted them to do: as a tool for molding themselves into skeptical subjects.³

But a reader with such a project would have run into complications. The English introduction was more than a little bit at odds with the text it introduced. The Rapport des commissaires described an error of a kind that would undermine the very structures of Lockean pedagogy—one against which conscious self-training could accomplish nothing.⁴ Mesmeric treatment put patients in a state called the "crisis," in which they seized, shrieked, went into hysterics, vomited, and, allegedly, got well. Franz Anton Mesmer, the science's founder, attributed these effects to the electricity-like invisible fluid of animal magnetism he claimed to have directed into their bodies, using techniques like passes of the hand or contact with a magnet (Report 25-27).⁵ But in its Report, the commission appointed in Paris to investigate Mesmer's findings—which counted Benjamin Franklin among its members—proposed an alternate theory. Mesmer's patients, the commissioners said, had unconsciously caused their own symptoms by the workings of the "imagination": by picturing to themselves the effects they believed would occur when they were plied with animal magnetism. Such fearsome images stirred up their nervous fluids, causing the convulsions and hallucinations which patients mistook for evidence that Mesmer's mysterious substance existed (96-99). These deceptive effects happened mechanically, beyond the scope of the deliberate judgment that Johnson urged his readers to develop; they arose from an unconscious and involuntary chain reaction rippling through the body's systems. What was to prevent the imagination from committing such travesties undetected, even at the very moment when one was performing one's Lockean calisthenics?

Practicing doubt on the mesmeric falsehood, in short, entailed learning about a kind of error against which such practice would avail nothing—a kind of error one could not even recognize, let alone correct, in oneself. In opposition to Johnson's hopes, the report was to raise for its American readers the suspicion that in...