Key figures: Franz Anton Mesmer (1734–1815), Charles d’Eslon (physician and advocate), Benjamin Franklin (future commissioner), Antoine Lavoisier (future commissioner), Mozart (early acquaintance)
Summary
Franz Anton Mesmer arrived in Paris in late February 1778 after a forced departure from Vienna the previous year, establishing a medical clinic at the Place Vendôme, one of Paris’s most prestigious addresses. Mesmer—born on May 23, 1734, in Iznang, Swabia—had earned a medical degree from the University of Vienna in 1766 with a dissertation on the influence of the planets on the human body (De Planetarum Influxu), an early signal of his heterodox theoretical orientation.
Mesmer introduced his theory of animal magnetism (magnétisme animal)—an invisible, universal force or “fluid” that he believed pervaded all bodies and could be directed by a trained practitioner’s will. According to his doctrine, obstructions of this magnetic fluid caused disease, and restoration of its equilibrium would bring cure. He had experimented with these ideas in Vienna from around 1774, using magnetized metal rods to treat patients, but repeated clashes with Vienna’s medical establishment and a scandal involving a blind pianist patient, Maria Theresia Paradis, forced his departure from Austria in 1777.
In Paris, Mesmer refined his methods around a device called the baquet: a large oak tub filled with iron filings, bottles of magnetized water, and iron rods protruding through the lid. Patients sat around the baquet, grasped the rods, and linked hands to form a “magnetic circuit.” Mesmer would move among them, touching affected areas with an iron wand, gazing intensely, and making “magnetic passes”—slow gestures over the body at close range. Many patients experienced convulsions, sobbing, laughter, or trance-like states that Mesmer called the crise magnétique, which he considered the curative mechanism. His treatment rooms were carefully staged: dim lighting, mirrors, soft music, and burning incense heightened the atmosphere of mysterious power.
Charles d’Eslon and Medical Legitimacy
Within weeks of his arrival, Mesmer attracted wealthy and fashionable Parisian clientele. A pivotal development occurred when Charles d’Eslon (1739–1786), a member of the Faculty of Medicine and first physician to the Comte d’Artois (the king’s youngest brother), became a convert and public advocate. D’Eslon submitted Mesmer’s doctrines to the Faculty of Medicine in the autumn of 1778, requesting formal recognition. The Faculty rejected the request—a pattern of institutional resistance that would recur—but d’Eslon’s sponsorship granted Mesmer entrée to aristocratic circles and substantial paying patients. By the end of 1778, Mesmer was reportedly charging high fees (estimates range from 10 to 100 livres per session) and treating several hundred patients annually.
The social composition of Mesmer’s practice illustrates mesmerism’s class dynamics: wealthy noble and bourgeois patients dominated, but Mesmer occasionally offered free group sessions for the poor in the baquet collectif, generating further publicity. His clinic was said to gross tens of thousands of livres per year by the early 1780s—an extraordinary sum.
Mozart and Earlier Encounters
Mesmer’s name had already crossed paths with a future icon of the arts. A decade before the Paris clinic opened, Wolfgang Amadeus Mozart had staged his first opera, Bastien und Bastienne (1768), in the private garden theater of Mesmer’s Vienna home. The Mesmer household was a center of musical and intellectual sociability, and young Mozart’s family maintained cordial relations with the doctor. Mozart’s later opera Così fan tutte (1790) would include a playful reference to the mesmerist laying on of hands. In Paris in 1778, Mozart himself was present—working through the same social circuits of aristocratic patronage in the spring and summer—though no direct encounter between the two in Paris that year is documented.
Scientific and Medical Controversy
The French medical establishment viewed mesmerism with deep suspicion. The Société Royale de Médecine, founded in 1776, saw animal magnetism as quackery threatening the professionalization of medicine. Critiques focused on the lack of any verifiable mechanism for the putative universal fluid: no instrument could detect it, no independent means of verification existed. Advocates responded that the consistent clinical effects—the crises, the apparent cures—constituted sufficient empirical evidence.
The controversy intersected with broader Enlightenment debates about the nature of invisible forces. Lavoisier, then transforming chemistry with his oxygen theory, operated from assumptions of quantifiable, reproducible phenomena—the antithesis of Mesmer’s unverifiable fluid. The tension between these worldviews would come to a head in the 1784 investigation.
The 1778 Setting: Paris as Stage
Mesmerism’s emergence in Paris coincided with several overlapping cultural currents in 1778. Voltaire, whose death in May 1778 set Paris in mourning, had embodied the Enlightenment’s confident rationalism; yet mesmerism demonstrated that the era’s appetite for new philosophies and secret knowledge was far from sated. Benjamin Franklin, resident in Paris as an American commissioner since December 1776, was moving in the same elite Parisian circles that patronized Mesmer. Franklin’s friendship with d’Eslon, and his own interest in electrical phenomena, would eventually make him the natural choice to lead the commission that investigated Mesmer’s claims.
Paris in 1778 was also gripped by the excitement of the Franco-American Alliance, signed in February. The city’s intellectual and aristocratic classes were electrified by political events, and mesmerism fitted neatly into an atmosphere where hidden forces—diplomatic, military, philosophical—seemed to be reshaping the world.
Significance
Mesmerism’s emergence in 1778 marked a pivotal moment in the history of therapeutic practice and the psychology of suggestion. Though Mesmer’s animal magnetism theory was ultimately discredited, several outcomes proved durable:
Hypnosis: Mesmer’s induction of trance-like states through ritual, suggestion, and focused attention was the direct predecessor of what James Braid would later name “hypnosis” (1843). The dissociation of patients from ordinary consciousness, and their heightened suggestibility, were real phenomena—even if the mechanism was psychological rather than physical.
Placebo research: The 1784 Royal Commission—comprising Franklin, Lavoisier, Joseph-Ignace Guillotin, and four others—designed what historians recognize as a landmark early controlled experiment. To test whether animal magnetism had an independent physical effect, commissioners blindfolded patients and falsely told them they were or were not being magnetized. Patients responded to the suggestion, not the actual presence of the wand—an early empirical demonstration of the placebo effect.
The Franklin Commission precedent: The commission’s report, published in August 1784, employed systematic blinding and controls in a manner that anticipates modern clinical trial methodology. Though its conclusion—that animal magnetism had no physical reality—devastated Mesmer’s reputation, the method it used became a template for evaluating therapeutic claims.
Social psychology: The mesmerist movement showed how a charismatic practitioner, an elaborate ritual setting, collective emotional experience, and elite social endorsement could sustain belief in a theory without verifiable mechanism. This pattern—the charismatic healer, the social epidemic of credulous enthusiasm, the eventual regulatory intervention—would recur throughout the history of fringe medicine.
Mesmer spent his later years in relative obscurity in Switzerland, where he died in 1815, reportedly still believing in his theory. Animal magnetism outlived him for decades: its practitioners gave way to hypnotists, who in turn contributed to the development of psychoanalysis. The word “mesmerize,” meaning to hold in rapt attention or induce a trance, preserves his name in everyday language.
See Also
- Benjamin Franklin (1706–1790) — the American commissioner who would chair the 1784 royal commission investigating animal magnetism
- Antoine Lavoisier — Chemical Experiments and the Oxygen Theory of 1778 — the quantitative science that stood opposed to Mesmer’s unverifiable fluid, and a fellow 1784 commissioner
- Mozart’s Symphony No. 31 in D Major, ‘Paris’ (K. 297) — the young composer, an early Vienna acquaintance of Mesmer, at work in the same 1778 Paris
- Treaty of Alliance (France–United States) — the February 1778 event that electrified the Parisian circles into which mesmerism arrived
Sources
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[Franz Anton Mesmer Wikipedia](https://en.wikipedia.org/wiki/Franz_Mesmer) -
[Franz Anton Mesmer Encyclopædia Britannica](https://www.britannica.com/biography/Franz-Anton-Mesmer) -
[Mesmerising Science: The Franklin Commission and the Modern Clinical Trial The Public Domain Review](https://publicdomainreview.org/essay/mesmerising-science-the-franklin-commission-and-the-modern-clinical-trial) -
[Animal magnetism Encyclopædia Britannica](https://www.britannica.com/topic/animal-magnetism)