Opinion: The 19th Century Roots of Modern Medical Denialism

A dubious system of herbal medicine became a blueprint for cranks peddling cures for everything from cancer to Covid-19.


Miracle cures, detox cleanses, and vaccine denial may seem to be the products of Hollywood and the social media age, but the truth is that medical pseudoscience has been a cultural touchstone in the U.S. since nearly its founding. At the dawn of the 19th century, when medical journals were still written almost entirely in Latin and only a handful of medical schools existed in the country, the populist fervor that animated the Revolutionary War came to the clinic. And while there was no shortage of cranks peddling phony medicine on a raft of dubious conspiracy theories in the early 1800s, none was more successful and celebrated than Samuel Thomson.

Portrait of Samuel Thomson

Visual: Wikimedia Commons

Portraying himself as an illiterate pig farmer (he was neither), Thomson barnstormed the Northeast telling rapt audiences things they wanted to hear: that “natural” remedies were superior to toxic “chemical” drugs; that all disease had a single cause, despite its many manifestations; that intuition and divine providence had guided him to botanical panaceas; that corrupt medical elites, blinded by class condescension and education, were persecuting him, a humble, ordinary man, because of the threat his ideas and discoveries posed to their profits.

For decades, Thomson peddled his dubious system of alternative medicine to Americans by playing to their cultural, political, and religious identities. Two centuries later, the era of Thomsonian medicine isn’t just a historical curiosity; it continues to provide a playbook for grifters and dissembling politicians peddling pseudoscientific solutions to everything from cancer to Covid-19.

An acquisitive paranoiac with the steely-eyed look of a fundamentalist preacher, Thomson lectured on the same circuit as the Second Great Awakening’s theatrical revivalists, one of countless unschooled “people’s doctors” as the esteemed orthodox physician Daniel Drake called them. In addition to his lectures, Thomson spread his gospel in his mega bestseller, “New Guide to Health,” a catalog of herbs accompanied by anecdotes testifying to their medicinal utility. Credulous readers learned that simple preparations of herbs like cayenne pepper or Lobelia inflata — also known as “puke weed” — not only relieved minor complaints like headaches and coughs but also rapidly cured progressive, terminal diseases like cancer. In breathless testimonials and self-aggrandizing anecdotes, Thomson and his followers attested to individuals being cured of dysentery, smallpox, and measles using the Thomsonian system. Between sales of the book, which went through 13 editions, and the “family rights ” to buy his patented botanical nostrums, Thomson grew fabulously wealthy.

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Though he was dismissed at the time as a dangerous fraud by mainstream physicians, Thomson was nevertheless held in high esteem by millions of Americans, who saw him as an avatar of self-reliance and entrepreneurial ambition. His followers wrote songs, poems, and prayers in homage to him. They congregated in “Friendly Botanic Societies” that more closely resembled churches than scientific seminars. His most zealous supporters, including some state legislators, hailed him alternately as the American Hippocrates or Jesus. That Thomson was regularly accused of killing patients and was even tried for murder once in Massachusetts seemed only to burnish the legend of his persecution and martyrdom.”

In retrospect it can be hard to see how Thomson garnered so much influence. None of his botanical remedies were new to medicine, nor were they very effective for treating any serious condition. Yet in some states, such as Ohio and Mississippi, between a third and half of residents were said to have eschewed orthodox medicine in favor of Thomson’s patented system. What made the Thomsonian sales pitch so successful was not just its blanket condemnation of the medical establishment, but its populist conception of healing itself. Just as Americans were free to be their own governors, lawyers, and priests, Thomson argued, so too should they be free to act as “their own physician and surgeon.” In this view, attempts to enforce state licensure laws or raise standards for medical education and practice were merely assaults on therapeutic choice and medical freedom — as anti-American as government establishment of religion.

The parallels between our “post-truth” era and the age in which Thomsonian medicine prospered are striking. Though rural Americans were highly literate by the standards of the time, they had quickly come to associate intellectualism with the hated urban ruling class. “The Thomsonians,” the sociologist Paul Starr has written, “viewed knowledge as an element in class conflict.” In other words, Americans then, as today, were deeply distrustful of an ostensibly egalitarian government led by learned patricians — or at least by those who looked and spoke the part. The simplicity of Thomson’s system and his elaborate pantomime of socioeconomic solidarity were thus vital elements of his commercial success.

Thomsonian medicine could only succeed in a nation lacking scientific medicine and sharing a “widespread belief in the superiority of inborn, intuitive, folkish wisdom over the cultivated, over-sophisticated, and self-interested knowledge of the literati and well-to-do,” as Richard Hofstadter put it in his landmark “Anti-intellectualism in American Life.” Glorification of what one Thomson biographer later called “the native practical sense of the ordinary man with direct access to truth” would later reach its zenith in national icons like Andrew Jackson and Davy Crockett. But Thomson provided a template that’s still followed today.

The parallels between today’s “post-truth” era and the age in which Thomsonian medicine prospered are striking.

Thomson and his followers also shared the conviction that access to information is not only an adequate substitute for formal education but preferable and superior to it. As steam-powered presses enabled the mass production of newspapers, early 19th century Americans were deluged with information of questionable provenance and reliability. The effect, as with the internet today, was to generate pervasive cynicism about what can actually be known; truth becomes whatever is believed most widely or fervently. Nowhere was this more evident, and to some extent warranted, than in pre-scientific medicine. In 1825, you might well have been better off seeing a pig farmer about your headaches than seeing an M.D., who probably would have recommended mercury-based purgatives and bleeding to ooze you back to humoral harmony and health.

Yet today, when medicine can claim more successes than ever and is among the most respected professions, people of all political persuasions are embracing pseudoscientific alternative therapies in truly staggering numbers. In 2012, the last year for which authoritative statistics are available, Americans spent over $30 billion out-of-pocket on so-called complementary and alternative medicine, despite a dearth of evidence suggesting any of it works. In fact, about the same proportion of Americans use such products and services today as used Thomsonian medicine in the 1830s. And despite the perception, even among some physicians, that alternative medicine is harmless, its use today is associated with significant adverse public health outcomes, such as vaccine noncompliance and a greater risk of death in cancer patients. How did we arrive at this strange place, where so many educated Americans in the 21st century reject proven, evidence-based medicine in favor of 19th century magic?

The answer is complex. Surely part of it is that we have become victims of our own success. Life expectancy is long. Infant mortality is low. Most of us get more than enough to eat and, at least prior to the ongoing coronavirus pandemic, have worried little about dying in an infectious disease outbreak, as so many of our ancestors did. Since we enjoy a relatively high standard of health, we’re free to focus on newer and harder problems like chronic diseases and developmental disorders — precisely the conditions that modern medicine lacks good treatments for. Then there are the long-term crises of knowledge and authority that have been well-chronicled by others: the glut of misinformation online, declining trust in institutions, the devaluation of expertise, and the disturbingly common belief that much if not most of what happens in our world is the result of vast, invisible conspiracies.

But Americans’ embrace of pseudomedicine is also a reaction to less abstract and more personal problems: the inaccessibility of proper care, the alienating experience many have receiving it, and its intolerably burdensome costs. Research has shown that patients in highly commodified health care systems like ours express the highest mistrust of physicians, and while the exact reasons for this are unclear, it’s reasonable to suppose that perceived conflicts of interest play a role. Enter the white-coated naturopath or chiropractor, resembling a physician in all but training, education, and experience, and eager to confirm the worst suspicions of their frustrated marks. Just as in Thomson’s time, dissatisfaction and distrust drive otherwise reasonable people into the arms of unregulated quacks who, in Hofstadter’s words, flatter their “intuitive, folkish wisdom,” provide an outlet for their political anger, and sell them an expensive illusion of empowerment and control over their health.

If we hope to limit the spread of modern medical denialism and the predatory industry feeding on and profiting from it, we must acknowledge this reality. Until we do, the neo-Thomsonians among us will continue to rake in cash and put all of us at risk with their pre-scientific, 19th century ideas.

John Charpentier is a Ph.D. candidate and immunology researcher at the University of Michigan.