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The term "pseudoscience," which literally means "false science," is sometimes contrasted unambiguously with "true science," as if we can make an easy distinction between the two terms or as if only a fraud or ignoramus would put forward as scientific something that is not. Once in a while that clear-cut distinction is warranted. Albert Abrams (1863–1924), a medical doctor, is a case in point. For his quack medicine the American Medical Association later dubbed him the "dean of twentieth-century charlatans." Abrams devised all sorts of diagnostic machines, including the Dynamizer, the Biodynamometer, and the Reflexophone. Another diagnostic machine, the Omnipotent Oscilloclast, could determine from one drop of blood, Abrams claimed, not only a person's disease but also his or her religious affiliation.

Although some pseudoscience of the late nineteenth century and early twentieth century can be traced to the ingenuities of con artists like Abrams, most pseudoscience of the period arose under much more complex circumstances. Among those circumstances were unprecedented scientific discoveries, a burgeoning popular interest in science, a widening gap between general literacy and scientific literacy, and a great deal of uncertainty about the implications of new scientific discoveries. With the uncertainties came a hunger for mystery as well as for some assurance that an understanding of the material world would not undermine a spiritual and ethical sensibility. Perhaps traces of these hungers exist in all cultures, but the late nineteenth century and early twentieth century had a particularly acute longing for them. These hungers and uncertainties provided rich material for contemporary writers. Mark Twain and other American writers responded both to the conditions that invited pseudoscience and to specific pseudoscientific fads, including mesmerism, physiognomy, phrenology, electrotherapy, wonder medicines, water therapy, and occultism—as well as to new archaeological "discoveries."

As already suggested, some definitions of "pseudoscience" imply that "false science" can be distinguished unambiguously from "true science." For example, in The Skeptic's Dictionary (2003), Robert Todd defines "pseudoscience" as a "set of ideas based on theories put forth as scientific when they are not scientific." Todd implies that the distinction between science and nonscience is clear-cut; he elsewhere implies that a good skeptic would spot dubious evidence and would not fall prey to the claims of pseudoscientists such as Abrams. However, for the purposes of this article, the most useful definitions of pseudoscience will be those that allow for some ambiguity, such as the definition in the American Heritage Dictionary. There "pseudoscience" is defined as "an unscientific or trivial scientific theory, methodology, or activity that appears to be or is presented as scientific." This definition permits one to consider pseudoscience from a number of perspectives, including its presentation (at one extreme, by charlatans), its reception (at one extreme, by the scientifically illiterate), and tensions in science itself between appearance and reality, between the intuitive and the counterintuitive.


"There's a sucker born every minute." This insight, first quipped in 1869, was not lost on charlatans such as George Hull, Stub Newell, Charles Dawson, and Smith Woodward. Hull created a sensation when in 1868 he and his brother-in-law, Stub Newell, manufactured a fossil later dubbed the "Cardiff Giant." Hull was an atheist who had argued with an evangelical Christian about a line from Genesis: "There were giants in the earth in those days" (Gen. 6:4). Hull schemed with his brother-in-law to add one more "fossil" to the many already discovered in a region near Cardiff, New York. After ordering three thousand pounds of gypsum and hiring a stonecutter to make a "petrified giant," Hull and Newell buried the fake giant in a marsh, where it was "discovered" in 1869 by well diggers. For the next year, thousands of curiosity seekers flocked to Cardiff, undeterred by the skepticism of scientists who declared that the giant was either a statue or a hoax. Hull and Newell's fortunes grew as each tourist dropped fifty cents for a look at the fossilized giant. However, Hull and Newell were P. T. Barnum's ultimate "suckers." Barnum attempted to buy interests in the Cardiff Giant, and when he was turned down he made a fake of the fake and claimed that Hull had sold him the original and was now displaying the fake. Not only did Barnum's fake fake giant allegedly draw larger crowds, the "sucker" quote is misattributed to Barnum when in fact it was uttered by Hull's banker, David Hannum.

The line between pseudoscience and science, between dogma and theory, is often clearer in hindsight than it is in the present. Nonetheless, the conditions under which pseudoscience has thrived in the past include those conditions noted by Mark Twain: situations in which individuals stop asking questions and seekers reach too readily for answers.

I have seen several entirely sincere people who . . . believed that without doubt or question they had found the Truth. That was the end of the search. The man spent the rest of his life hunting up shingles wherewith to protect his Truth from the weather.

Twain, What Is Man? and Other Essays, p. 15.

If Barnum, Hull, and Newell were able to prey on gullible nonscientists, Dawson and Woodward in 1912 and again in 1915 showed that paleontologists could be equally gullible. In the gravel pits of Piltdown, England, Dawson "found" several parts of a prehistoric man hailed as a "missing link" between apes and humans. Presumably Dawson and his companion Woodward were the ones who buried the fake "missing link," which was later determined to be a human skull wired together with an apish jaw. Although the American paleontologist Henry Fairfield Osborn was skeptical upon Dawson's first "discovery," he became an enthusiastic believer when Dawson "found" the second skull fragment. Unlike the Cardiff Giant, which was exposed as a hoax within a year, the Piltdown fragments were accepted as authentic for nearly fifty years.

In the half-century between the fake discoveries of the Cardiff Giant and the Piltdown Man, pseudoscientific fads thrived on both sides of the Atlantic. Among con artists of the period were some who allegedly hoped to teach a lesson. In 1908 Douglas Blackburn admitted that he and G. A. Smith had never communicated telepathically, as they had been claiming for the last quarter of a century. In trying to justify their chicanery, Blackburn claimed that their hoax "originated in the honest desire of two youths to show how easily men of scientific mind and training could be deceived when seeking evidence in support of a theory they were wishful to establish" (Kurtz, p. 235).

Whether or not most pseudoscientists were clever enough to recognize the vulnerabilities of "men of scientific mind," they were certainly clever enough to recognize the vulnerabilities of those who lacked scientific training. It was the heyday of unqualified capitalism and of ways to make a fast buck at the expense of others' gullibility. Practitioners of phrenology, physiognomy, mesmerism, theosophy, and spiritualism thrived. Frequently the fakers who carried on these trades pandered to prevailing prejudices—racism, for example, in the case of phrenologists and physiognomists—as well as to prevailing desires—for marvels, miracles, and spiritual connections.

In the wake of Darwin's evolutionary theory, many people feared that science would undermine religion, which perhaps fueled interest in the occult and spiritualism. Spirit mediums, as used here, refers to charlatans who claimed that they could summon spirits and ghosts and communicate with them, sometimes with the aid of devices such as a heart-shaped pointer called a planchette, which would spell out answers on a Ouija board, sometimes during séances, sessions held in semidarkened rooms, where the medium would seem to go into a trance to summon her spirits. Among the best-known spirit mediums were Helena Petrovna Blavatsky (1831–1891), a piano teacher turned circus bareback rider who became world famous for her psychic claims; Eva C. (1886–?), born Marthe Béraud, who "materialized spirit faces" by presenting crumpled pictures in darkened rooms; and Edgar Cayce (1877–1945), a photographer who believed that he had clairvoyant powers. Blavatsky, Cayce, and another medium, Rudolf Steiner (1861–1925), all claimed that they could consult the Akashic records, records supposed to contain data on everything future, present, and past, in order to contact spirits. In 1875 Max Auzinger developed a "black art principle," a conjuring trick of covering scaffolds and supports when featuring such objects as "floating" trumpets and tambourines during séances.

Some pseudoscientific fads simply appealed to a common appetite for amazing and awesome events. Among the most skillful conjurers was Harry Houdini (1874–1926), world famous as an escape artist and magician. The "mentalists" Washington Irving Bishop (1856–1889), Joseph Dunninger (1892–1975), and Erik Jan Hanussen (1889–1933) claimed that they had paranormal powers enabling them to accomplish superhuman feats such as the "blindfold drive" (navigating a carriage while blindfolded), mind reading, and psychokinesis (making objects move, allegedly by mind power). In 1882 F. W. Myers coined the term "telepathy" to describe the ability of humans or animals to perceive others' thoughts without depending on the senses. Not only people but animals were featured for their marvelous talents. Clever Hans, a horse, attracted crowds throughout the 1890s because of his "ability" to do mathematical calculations. Perhaps the most amazing theory of the period was the "hollow earth" theory, first suggested by the astronomer Edmond Halley and "improved" upon in 1870 by Cyrus Reed Teed, who believed that the world is hollow and people live on the inside of it.

Perhaps the richest sampling of the pseudoscience craze of the late nineteenth century is found in the fiction of Mark Twain, where one finds references to bloodletting ("A Majestic Literary Fossil"), fraudulent patent medicines (The Gilded Age), electrotherapy (A Connecticut Yankee), water treatments (The Adventures of Tom Sawyer), and mesmerism (his autobiography), among many others. Much of the humor in The Innocents Abroad depends on his readers' familiarity with current scientific and pseudoscientific topics.

At one point in The Innocents Abroad, Twain lampoons a human tendency to project motivations when no evidence exists for them and to dream up theories with no foundation. His American innocents discover a cut in a hillside exposing several veins not of gold, copper, or any other mineral but of oyster shells mixed with crockery. The innocents wonder how those oysters got up the hill and, after rejecting several natural and biblical explanations, theorize that the oysters climbed up there to look at the scenery. This theory, though, is rejected because oysters, with their retiring dispositions, actually scorn beautiful scenery.

Later his innocents arrive in a Greek church, only to discover that one unusually short column marks the center of the earth, a reference to the Flat Earth Society, a group that flourished on both sides of the Atlantic after Samuel Birley Rowbotham calculated in 1849 that the North Pole is at the center of the earth and that the earth is indeed flat. (Interestingly, Rowbotham's pseudoscientific theory, fueled by discrepancies between biblical and scientific versions of geography, is based on data about lighthouses and the point at which mariners sight them. Using numbers available in Lighthouses of the World, Rowbotham's calculations actually stand up to scrutiny, but his sampling procedures do not.) Twain's fictional believers conclude that the column in the Greek chapel exists as a "withering rebuke to those philosophers who would make us believe that it is not possible," while Twain's skeptic climbs the dome of the church to see if he can see his shadow. The skeptic concludes that the church must be the center of the earth since he sees no shadow, even though it is a cloudy day.

Twain's fictional innocents then discover under the roof of the Greek church a sign identifying Adam's tomb in an episode reminiscent of the Cardiff Giant and pseudoscientific spoofs on biblical authority. Twain's innocent narrator is ecstatic to find Adam's tomb in this land of strangers, for it is the tomb of one of his blood relatives. "True," he acknowledges, "a distant one, but still a relation" ( p. 211). Whether Twain humorously jabs at science or pseudoscience, his writing reflects the era's preoccupation with both.


The word "scientist" did not exist until William Whewell coined it in 1822 to describe the people who attended the British Association for the Advancement of Science (BAAS). By mid-century science had become a marker of national status; by the turn of the century the Nobel Prize was established as one of the most prestigious international prizes ever to have existed. Scientists were held in high regard, and many Americans wanted to know more about them and their discoveries. Most Americans, however, lacked the scientific training to distinguish between science and pseudoscience.

The popular interest in science was not due to the amount of information the new sciences produced. Nineteenth-century science was not yet "big science," a term coined by Alvin Weinberg in 1961 to describe the multibillion-dollar network of corporate- and government-funded research that pumps out massive amounts of information. What was unprecedented, however—and what fascinated and troubled ordinary nineteenth-century newspaper readers—was the degree to which scientific assumptions challenged many of the prevailing religious and social "ways of knowing." If scientists were stirring an epistemological pot, ordinary men and women were left wondering what the basis could be for answering life's most basic questions, what the basis could be for seeking truth. The discomfort some people felt left them vulnerable to the "quick fixes" offered by con men such as Abrams. The longing for a lost, less-material world left others hungering for the pseudoscience of various occultists and spiritualists. The mere novelty of unprecedented scientific changes whetted the appetites of those who sought the sensational and who subsequently sought any wondrous or miraculous device. Whether or not ordinary Americans liked what science might be showing them, they could not help reacting to the issues that science put before them.

More and more Americans were able to read in the nineteenth century. The agrarian and Industrial revolutions in the early part of the century led to falling mortality rates and a huge spike in population. Paralleling the spike in population was a spike in literacy, partly due to the early-nineteenth-century self-help movements and Jacksonian "we can do it ourselves" democracy. The nineteenth century also witnessed a huge increase in publications, including many unrefereed magazines that would allow their authors to raise controversial—and perhaps pseudoscientific—issues unchecked. The sizable literate public and its freedom of expression in the nineteenth century may have been double-sided: on one hand, more people had the potential to read about scientific issues; on the other hand, there were more venues for out-right fraud and deliberate pseudoscience.

While ordinary readers of novels and newspapers were frequently interested in scientific issues, few were prepared to critique what they might be reading. By what standards would one judge the merits of a scientific claim? These standards were just being established within newly emerging scientific subdisciplines, and they were often lost on the average reader.

Part of the gap between the general reader and the scientist was due to changes in professionalization. Earlier in the century scholars were respected for being Renaissance men, for being generalists who knew a little bit about a lot of different things; by the end of the century scholars had specialized, and the Renaissance ideal was largely forgotten. According to Mary Jo Nye, the scientific changes that took place during the nineteenth century outstripped changes before and since. It was during this period that scientific training and research practices that had in many ways remained unchanged since medieval times shifted to the modern model of government-funded universities outfitted with research labs, where faculty members are expected to produce and publish original research.

It was during this century too that the peer-reviewed journals that publish original research became established within disciplinary norms, together with an increase in specialized societies that served as gateways. The number of scientists and scientific papers had doubled approximately every fifteen years since the beginning of the seventeenth century; by the mid-nineteenth century publication in the sciences had become specialized, often coinciding with the legitimization of new subdisciplines. Representative of the shift from general to specialized literacy is the shift in Nature, first published in 1869. David Roos argues that the editors of Nature initially aimed to "create a higher-level but still general and accessible forum for the discussion of scientific matters" (p. 162) but that specialization shortly eclipsed accessibility.

The average American reader, then, was likely to be interested in scientific issues but was unlikely to find accessible the papers published in peer-reviewed scientific journals. Whatever this average American read was likely to be mediated by a nonscientist, often in novels, periodicals, and poetry. Thus the nineteenth-century "Age of Science" was populated largely by nonscientists who learned about science in texts penned by nonscientists.

By 1870 periodicals such as Galaxy, Atlantic Monthly, Appleton's Journal, North American Review, and Harper's New Monthly had begun to accommodate their readers' interest in science even though their "science columns" may not have been reviewed by practicing scientists. It was 1920 before journalists established professional standards for science reporting, and then only under pressure from the American Medical Association, which objected to lurid tales in popular publications such as William Randolph Hearst's American Weekly. As Martin Gardner notes, this weekly would publish stories about "men who could hear radio broadcasts through gold inlays in their teeth" and "frogs found alive in the cornerstones of ancient buildings" (p. 4).

As suggested earlier, some pseudoscientific theories may have thrived in this period because of fears about the difficulty of reconciling religious doctrine with evolutionary theory. Another fear, concern about the future of race relations after Reconstruction, may have fueled pseudoscientific theories of white supremacy, ranging from Samuel George Morton's and Paul Broca's work with craniometry to Joseph Le Conte's biological justification for the "race line," which, he maintained, resulted from a "necessary instinct" to preserve the blood purity of the "higher race." Further stimulating pseudoscientific arguments about race were Herbert Spencer's Social Darwinism and widespread interest in physiognomy, the art of reading character and fate from the features of the face, whereby white features were equated with good character and black features with bad. For some writers, both physiognomy and phrenology could be tools for suggesting so-called natural relationships between physical features and character.

One finds in the literature of Thomas Dixon, Mark Twain, William Dean Howells, Charles Chesnutt, and James Weldon Johnson, among others, widespread response to pseudoscientific theories of race, ranging from Dixon's white supremacist The Leopard's Spots (1902) to Johnson's critique of representations of race in The Autobiography of an Ex-Colored Man (1912). Pudd'nhead Wilson (1894), Twain's most direct treatment of slavery, resists easy interpretation, while William Dean Howells's An Imperative Duty (1892) and Charles Chesnutt's The House behind the Cedars (1900) represent the relationship between race and character ironically.

With the emergence of science fiction came narratives that for the most part critically reflected upon real issues in science and society through the medium of fantastic scientific schemes. For example, Edward Bulwer-Lytton's 1871 utopian fantasy The Coming Race features an engineer who stumbles into a mine and finds there a whole civilization of mystics who have at their disposal the powerful force of Vril, an electricity-like force that is both more creative and destructive than anything known to ordinary humans. While the Vril-yas are depicted as proscience and the novel suggests that Bulwer-Lytton was well versed in scientific issues, the novel also addresses pseudoscientific subjects such as Social Darwinism, eugenics, and clairvoyance. Arguably, this novel responds to the same public ambivalence about evolutionary theory and technological progress that prompted public interest in many of the pseudoscientific issues of the day. By the end of the century science fiction as a self-conscious genre was well established with the publication of H. G. Wells's "The Man of the Year Million," The Time Machine, and War of the Worlds. While these texts include "false science" in the sense of imaginary schemes, Wells expected his readers to know that they were imaginary. Even when the reader knows a novel is fiction, though, some elements from the fiction may live on in pseudoscientific lore, as was the case with Vril, the cosmic energy described in The Coming Race, which captured the imagination of the occultist Madame Blavatsky and the "inventor" John Keely.

Also ambiguous is the "pseudoscience" in Ignatius Donnelly's wildly successful novel Ragnarok, published in 1883. Was Donnelly a pseudoscientist? He was a lawyer, a U.S. congressman, and a dabbler in science. He was obsessed by the existence of Atlantis and the belief that a visiting comet would have catastrophic effects. His novel Ragnarok describes a comet colliding with Earth. Was he using fiction to perpetuate ideas that he really believed?


By the mid-nineteenth century science was no longer primarily an avocation for gentlemen amateurs but a vocation for professionals. However, scientists too could make mistakes and pseudoscientific claims. Sometimes the same individual was spectacularly wrong about one thing and brilliantly right about another. While nonscientists lacked the training to be able to distinguish science from pseudoscience, scientists had training but often could not distinguish absolutely between pseudoscience and science except in hindsight.

Among famous physicists who generalized from the physical to the metaphysical were Rudolf Clausius, who in 1865 coined the term "entropy," and William Thomson (Lord Kelvin), who in 1854 coined the term "thermodynamics." In 1875 Lord Kelvin coauthored a book, The Unseen Universe, that argued that energy moves between visible and invisible worlds. These physicists' metaphysical claims would be considered pseudoscientific by most physicists in the twenty-first century. Psychologists as well as physicists sought a unified theory of spirit and material forces. William James, who contributed much to nineteenth-century psychology, believed in the mediumship of the spiritualist Leonora Piper (1857–1950), a Boston housewife who conducted pseudoscientific séances. Again, some of the brightest individuals of the period also accepted as factual things that were not.

Moreover, some fields that one thinks of as "sciences" in the early twenty-first century were really closer to "arts" in the nineteenth century, including medicine. Between the limited understanding of bacteriology, infection, and disease on the one hand and the rise in advertising and unlabeled patent medicines on the other, sincere medical practitioners could make nearly as many mistakes as their quack counterparts, something Mark Twain will not let one forget. While snake-oil salesmen may have represented quackery at its worst, the sincere medical doctor may not have been much more help until the Pure Food and Drug Act of 1906 forced labeling of medicines and until penicillin and other antibiotics were discovered two decades later.

Within scientific institutions, little happened in the last half of the nineteenth century in the absence of intense debate, whether about mental capacities, the periodic table, probabilistic interpretations of thermodynamics, the electron, X-rays, or general relativity. In the heat of these debates, weak and pseudoscientific theories competed with those eventually accepted as scientific. Generally it is only in hindsight, after the debates have been settled, that one can determine what is "true science" and what is "false science." Furthermore, on occasion "false science" serves as a placeholder for a subsequent "true" theory.

James Clerk Maxwell, the Scottish physicist who died in 1879, claimed that "it is a good thing to have two ways of looking at a subject and to admit there are two ways of looking at it. I hold that the chief merit of a temporary theory is that it shall guide the experiment without impeding the progress of the true theory when it appears" (quoted in Nye, p. 72).

While Maxwell understood that his scientific claims were tentative at best and would not be confirmed until some time in the future, some scientists were less critical and made claims that edge closer to "false science," to pseudoscience. Even so, the boundary between "true" and "false" is not always clear. Franz Josef Gall (1758–1828), a medical doctor and the father of phrenology, paved the way for legions of quacks who bilked nineteenth-century curiosity seekers with fatuous character analyses and the reading of head bumps. Yet while phrenology was a thriving pseudoscientific industry for much of the nineteenth century, one cannot say that Gall was a simple pseudoscientist. His assumption that bumps on the head correlate to certain character traits is false, but his idea that different sites of the brain may be responsible for different functions is not entirely mistaken.

One can perhaps empathize with the plight of ordinary victims of pseudoscience when one looks at the experiences of scientists who, although trained to be skeptical, suspended their critical faculties in the face of some overwhelming desire. For instance, in 1903, shortly after the discovery of X-rays, the French physicist René Blondlot believed that he had discovered a new form of radiation, which he named N-rays after his university in Nancy, France. The American physicist Robert Wood secretly removed Blondlot's "radioactive" object during one of Blondlot's demonstrations, but Blondlot proceeded to count N-rays. There is no reason to doubt his sincerity, although there is every reason to think his will to believe led him to imagine specks of light when there were none.

About the same time, Gustav Geley looked into the pseudoscientific spiritualism of Eva C., even though he was an established physicist. Similarly Charles Richet, the 1913 Nobel laureate for physiology and medicine, endorsed the claims of spirit mediums such as Eva C. and William Eglinton. In the early twentieth century Sir Oliver Joseph Lodge, a scientist who did pioneer work in early radio and research on lightning, believed that he had contact with his son Raymond, killed in World War I. Peter Demianovich Ouspensk, a Russian mathematician and mystic, tried to reconcile Western rationalism and Eastern mysticism, and Sir William Matthew Flinders Petrie, a talented archaeologist, believed that the Great Pyramid of Egypt was constructed in the form of a prophetic message. In all of these instances one might speculate that the scientists' overwhelming desires led them to believe in the existence of something for which there is no evidence. If such highly trained individuals as these could have lapses in scientific skepticism, one can surely understand the enthusiasms of the scientifically illiterate majority in the nineteenth century.

See alsoCircuses; Darwinism; Health and Medicine; Museums; Science and Technology; Spiritualism


Primary Works

Bulwer-Lytton, Edward. The Coming Race. 1871. Peterborough, Ontario: Broadview Press, 2002.

Chesnutt, Charles. The House behind the Cedars. 1900. New York: Penguin, 1993.

Dixon, Thomas. The Leopard's Spots. 1902. Chicago: University of Chicago Press, 1982.

Donnelly, Ignatius. Ragnarok. 1883 Kila, Mo.: Kessinger, 1997.

Howells, William Dean. An Imperative Duty. New York: Harper, 1892.

Johnson, James Weldon. The Autobiography of an Ex-Colored Man. 1912. New York: Dover, 1995.

Twain, Mark. The Adventures of Tom Sawyer. 1876. New York: World, 1946.

Twain, Mark. A Connecticut Yankee at King Arthur's Court. 1889. New York: Harper, 1917.

Twain, Mark. The Innocents Abroad; or, The New Pilgrims' Progress. 1869. New York: Oxford University Press, 1996.

Twain, Mark. The Tragedy of Pudd'nhead Wilson. 1894. Avon, Conn.: Limited Editions Club, 1974.

Twain, Mark. What Is Man? and Other Essays. New York and London: Harper & Brothers, 1917.

Twain, Mark, and C. D. Warner. The Gilded Age. 1873. New York: Oxford University Press, 1996.

Wells, H. G. "The Man of the Year Million." 1893. In Apeman, Spaceman, edited by Leon E. Stover and Harry Harrison. London: Penguin, 1968.

Wells, H. G. The Time Machine. 1893. New York: Limited Editions Club, 1964.

Wells, H. G. War of the Worlds. 1898. London: Heinemann, 1951.

Secondary Works

Boeckmann, Cathy. A Question of Character: Scientific Racism and the Genres of American Fiction, 1892–1912. Tuscaloosa: University of Alabama Press, 2000.

Gardner, Martin. Fads and Fallacies in the Name of Science. New York: Dover, 1957.

Gould, Stephen Jay. The Mismeasure of Man. Rev. ed. New York: Norton, 1996.

Gould, Stephen Jay. "Piltdown Revisited." In his The Panda's Thumb: More Reflections in Natural History. New York: Norton, 1980.

Jastrow, Joseph, ed. The Story of Human Error. New York: Appleton-Century, 1936.

Jay, Ricky. Learned Pigs and Fireproof Women. New York: Villard, 1986.

Kerr, Howard. Mediums, and Spirit-Rappers, and Roaring Radicals: Spiritualism in American Literature, 1850–1900. Chicago: University of Illinois Press, 1972.

Kurtz, Paul, ed. A Skeptic's Handbook of Parapsychology. Buffalo, N.Y.: Prometheus, 1985.

Langmuir, Irving. "Pathological Science." Transcribed and edited by Robert N. Hall. Physics Today 42 (October 1989): 36–48.

Nye, Mary Jo. Before Big Science: The Pursuit of Modern Chemistry and Physics. Cambridge, Mass.: Harvard University Press, 1996.

Randi, James. An Encyclopedia of Claims, Frauds, and Hoaxes of the Occult and Supernatural. New York: St. Martin's Griffin, 1995.

Roos, David. "The Aims and Intentions of Nature." In Victorian Science and Victorian Values, edited by James Paradis and Thomas Postelwait. New Brunswick, N.J.: Rutgers University Press, 1985.

Martha D. Patton