Chester Clinic

 

Scientific myth-conceptions

Stephen Norris, Section Editor DOUGLAS ALLCHINMinnesota Center for the Philosophy of Science and Program in History of Scienceand Technology, University of Minnesota, Minneapolis, MN 55455, USA Received 9 August 2001; revised 2 April 2002; accepted 26 April 2002 ABSTRACT: Using several familiar examples—Gregor Mendel, H. B. D. Kettlewell,
Alexander Fleming, Ignaz Semmelweis, and William Harvey—I analyze how educators
currently frame historical stories to portray the process of science. They share a rhetori-
cal architecture of myth, which misleads students about how science derives its authority.
Narratives of error and recovery from error, alternatively, may importantly illustrate the
nature of science, especially its limits. Contrary to recent claims for reform, we do not need
more history in science education. Rather, we need different types of history that convey
the nature of science more effectively.
 2003 Wiley Periodicals, Inc. Sci Ed 87:329 – 351,
2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.10055 Even nonscientists know about Charles Darwin and the voyage of the Beagle, Gregor Mendel and inheritance in pea plants, and James Watson and the double helix of DNA.
Stories of scientific discovery permeate our culture and science curricula. So one may won-der why recent calls for science education reform (e.g., National Research Council, 1995;Rutherford & Ahlgren, 1990) advocate further history in science teaching. The problem,I contend, is not deficit of history. Rather, the concern should be what type of history isused. I refer, in particular, to popular histories of science that romanticize scientists, inflatethe drama of their discoveries, and cast scientists and the process of science in monumen-tal proportion. They distort history and foster unwarranted stereotypes about the natureof science—all for the sake of "telling a good story" (Shaffer, 1990). While based on au-thentic events, these histories are deeply misleading. They subvert the goal of teaching the"history and nature of science" central to those reforms. Here, I focus specifically on therhetorical architecture: How are the mischaracterizations embodied in rhetorical devices This paper was presented as the keynote address at the Fourth International Seminar for History of Science and Science Education, Winnipeg, Manitoba, July 23, 2001.
Correspondence to: Douglas Allchin; e-mail: [email protected]  2003 Wiley Periodicals, Inc.
and shaped by the narrative format? Many errors result, I claim, from rendering science ina mythic form, in a literary sense. These are not just ordinary misconceptions of science.
They are myth-conceptions.1 Science educators especially, I fear, tend to perpetuate suchmyth-conceptions. But educators are also ideally positioned to remedy them. Here, I profilethe problem and some prospective solutions.
I explore this topic by, first, surveying five familiar historical cases: Gregor Mendel and genetics, H. B. D. Kettlewell and the peppered moth, Alexander Fleming and penicillin,Ignaz Semmelweis and handwashing, and William Harvey and circulation of the blood.
While the errors in recent accounts may themselves be informative, my chief concern isanalyzing the source of the errors. By highlighting the rhetorical strategies and devicesin the context of deeper history, I hope to show just how such stories "lie" or misleadabout the nature of science. Ultimately, the suite of cases exhibits a syndrome, not fullyvisible in any one case. These historical narratives of science exhibit conventional literaryfeatures of myth. (Readers interested in my thematic conclusions here may proceed di-rectly to the section on "The Architecture of Scientific Myths" any time, returning to the data(Cases 1 – 5) as occasion demands.) Finally, I consider the role of scientific error in teachingnature of science, among other guidelines for educators and teaching strategies.
Critiquing deficits in histories and stories of science is almost commonplace now in our postmodern era. Indeed, such critiques are not difficult once one recognizes that any narrativeof science is inherently limited. Every account must be selective in some respect and hencecan be portrayed as biased (Turnbull, 1993). Several perspectives significant to the scienceclassroom are now widely documented. Among the familiar potential distortions, one maycite hagiography, Whiggism (or inevitabilism; Butterfield, 1959), gender bias (Rossiter,1982), and accounts imbued with political ideology or culture (Foucault, 1972; Haraway,1989); all these may concern the science educator. However, in my analysis the storyteller'sperspective and/or "interests" are peripheral. The authors seem to try "honestly" to conveythe nature of science. Yet one may still find their accounts significantly misleading forstudents. The problem is not truncation itself. Selectivity does not inherently yield myths.
I focus specifically on the narrative elements as problematic. How can the very act oftelling a story shape content or foster flawed renderings? Once again, I want to interpret thefundamental myth-conceptions, not merely (more) historical misconceptions.
Recently, rhetorical analysis has turned to scientific texts and discourse (for example, Gilbert & Mulkay, 1984; Gross, 1990; Halliday & Martin, 1993; Myers, 1990; Selzer, 1 Here, I may clarify my meaning of the term "myth". In the popular mind myth is false belief, often opposed to science (as true belief ). When applied to science or science education ("the myth of the scientificmethod" or "the myth of scientific objectivity"), critics use myth to refer especially to widespread andunquestioned false beliefs (Bauer, 1992; MacCormac, 1976; McComas, 1998; Savan, 1988; Sismondo,1996). In these cases, the term "myth" serves primarily as a rhetorical device for casting the author as anauthority rescuing readers from credulity. I am not using myth in these common senses. Others construemyth in science as a foundational religious metaphor (MacCormac, 1976; Midgely, 1992). They equatemyth with a cultural perspective or cognitive meta-structure (sometimes critiquing it, sometimes endorsingit). While much can be (and has been) said about scientism, I do not mean scientific myth in this senseeither.
In Greek, mythos means "telling" or "story". In my use, therefore, a myth is always a narrative, a literary form, style or genre. (I do not adopt the adjunct meanings used theoretically by anthropologists orpsychologists.) Like parables, myths function primarily as explanations and/or justifications (Bauer, 1992;Milne, 1998). Thus they generally contain superhuman elements and/or natural phenomena, whence they,in part, draw their persuasive power. In many cases, myths embody a worldview by providing formulae orarchetypes for appropriate or sanctioned behavior, hence their narrative format. In construing myth in thisway, my analysis does not focus on false belief itself. Rather, I examine how errors symptomatically revealthe structure of the narratives and how they function as myths. The elements noted here are profiled furtherbelow ("The Architecture of Scientific Myths") as they apply to stories and histories of science.
1993). Such work has delved into the craft of persuasion, concepts of evidence, the "con-struction" of knowledge, and the contrasting narratives of science and nature. While thiswork focuses chiefly on professional communication, it offers tools for considering scientifictexts in educational contexts. For example, one may be alert for literary devices, persuasiveconstructs, or recurring plot patterns. Parallel work has focused on public understandingof science, especially on its role in public decision-making (for example, Martin, 1991;Toumey, 1996). How might the often simplistic conceptions be rooted in historical treat-ments in science education and elsewhere? Is there any potential remedy? Further resourcesmay be found in analyses of narratives and historical explanation (for example, Munz, 1997;White, 1987). Finally, one may consider how the psychological context of storytelling af-fects the nature of stories in the science classroom. For example, the relationship betweenstoryteller and hearer/reader may affect how the story is told. Gilovich (1991) identifies atleast two major social functions in telling stories: information and entertainment. Contenttends to be selected and sometimes altered to meet these two functions. Again, one may bealert to how cognitive factors shape educators' histories of science. Ultimately, how can allthese analytical tools inform practicing teachers who approach histories of science as partof an effort to teach nature of science? What simple themes and tools can be distilled forsomeone with perhaps limited expertise in history, philosophy, sociology, and rhetoric ofscience?2 CASE 1: GREGOR MENDEL
Consider first an icon of science: Gregor Mendel. Few biology textbooks fail to mention Mendel and his work on pea plants. He is, as historian – biologist Jan Sapp (1990) notes,"an ideal type of scientist wrapped in monastic and vocational virtues." That is, he isan exemplary scientist. Stories about him implicitly contain morals about the nature ofscience. For example, Mendel worked alone in an Austrian monastery. Lesson: Scientistsmodestly seek the truth, not ambition. Mendel used peas. Moral: Scientists design studiesusing appropriate materials. He counted his peas: Scientists are quantitative. He counted hispeas for many generations over many years: Scientists are patient. He counted thousandsand thousands of peas: Scientists are hard-working. After all this, Mendel was neglectedby his peers, who failed to appreciate the significance of his work, but he was later andjustly "rediscovered": Scientific truth triumphs over social prejudice. Above all, Mendelwas right: Scientists do not err. His figures, in fact, were too good to be true, statisticallyspeaking. But he was ultimately correct. Any hint of fraud should only confirm the depthof his theoretical insight. The common story about Mendel is a lesson in the nature ofscience. And it is mythic in proportion. Although he has not been canonized by the Church,biologists certainly honor and revere him so.
Visual images echo this lesson. Texts sometimes use photos to illustrate scientists from history, and Mendel is no exception. Some texts, however, use illustrations instead. Forexample, one popular biology text (Campbell, Reece, & Mitchell, 1999, p. 249) abandonsthe stuffy posed photo in favor of a painting of the scientist "at work." Mendel is portrayedobserving: That's how we know he's a scientist. He wears his eyeglasses and a whiteapron, features naive students often include when asked to "draw-a-scientist." Moreover, a 2 Readers curious about the author's rhetoric will find the case studies exhibiting the style of Greek tragedy on a small scale: dramatizing the consequences of historical hubris (forsaking humility in professingknowledge of history of science). The analyses are rich in irony, where inconsistencies, formed by shifts incontext, tend to discredit apparently simple statements. Substantial metaphorical/analogical work followsto link the various ironies. Features of the five cases are treated as a synecdoche of certain narratives ofscience, characterized as mythic.
soft-edged medium and pastel color palette epitomizes the idealized, romantic tone of thestandard narrative. Such illustrations, too—even with no caption—convey a lesson aboutthe nature of science.3 On the surface, nothing seems flawed with the conventional story of Mendel. But histori- ans' interpretations differ remarkably (Brannigan, 1981; Corcos & Monaghan, 1993; Hartl& Orel, 1992; Monaghan & Corcos, 1990; Olby, 1985, 1997; Sapp, 1990). First, textbookstypically elucidate "Mendel's" two laws. Paradoxically, though, in his classic 1865 paper,Mendel did not explicitly formulate a "Second Law," the principle of independent assort-ment. While he did perform dihybrid crosses and reported 9:3:3:1 results, there was noformal recognition of the "independent" behavior of the two character states. In fact, ge-neticists did not distinguish "Mendel's" 1st and 2nd laws until several years after the revivalof his work, when they encountered anomalous ratios in offspring. Bateson, for example,found a 12:1:1:3 ratio in sweet peas for flower color and pollen shape: alleles segregated,but the genes did not assort. Ironically, then, while Mendel's 2nd law bears Mendel's name,he himself did not state it. Accounts credit Mendel with more than he did.
Second, Mendel worked at the level of observable characters. He did not distinguish clearly between traits and material units of heredity—today's phenotype/genotype distinc-tion, at the heart of Mendelian genetics. Nor did Mendel see his "elementes" (today's genes)as occurring in pairs in each organism. Mendel's notation clearly shows, that an A × Across yielded A + 2Aa + a: the homozygous form was "A" and not a diploid "AA" (Olby,1985). Mendel, it seems, was not quite "Mendelian." Again, Mendel gets undue credit.
Everyone knows how Mendel examined seven character pairs in peas: tall – dwarf, smooth – wrinkled, green – yellow, etc. Mendel actually investigated 22 (Di Trocchio, 1991).
He set aside the ones whose results were too confusing. Yet stories have long paraded the im-age of a perfect a priori experimental design. Textbooks seemed eager to boast of Mendel'sinsight, even when no evidence supported it.
Mendel referred to his traits as dominant and recessive. This strikes us as Mendel's discovery. But the notion of prepotency—that one parental trait determines the trait ofthe offspring—was common among breeders. Mendel followed a few earlier biologists inmerely attributing it to the trait, rather than the parent. Texts also present dominance asfoundational, its exceptions as "non-Mendelian." Mendel himself, however, seemed awarethat dominance was not the norm. Just before introducing dominant traits he noted that(Mendel, 1866, Section 4) with some of the more striking characters, those, for instance, which relate to the formand size of the leaves, the pubescence of the several parts, etc., the intermediate, indeed, isnearly always to be seen.
He noted other exceptions: stem length (the hybrids were actually longer; Section 4), seedcoat color (hybrids were more frequently spotted; Section 4), flowering time and pedunclelength (Section 8). For Mendel, his law applied only to "those differentiating characters,which admit of easy and certain recognition" (Section 8). Other characters followed another,different rule or law. Mendel's concept of dominance, initially a linguistic convention forlabeling traits, has been universalized. In some cases it is a "law." The notion has beenaggrandized and, simultaneously, credited to one person (Allchin, 2000).
Textbooks widely dub Mendel as the founder of modern genetics. Yet Mendel did not study abstract principles of inheritance. The clarity of Mendel's original 1865 paper to 3 I do not intend to single out this text for criticism. Rather, I hope that comments about a popular text can reflect a widespread problem.
modern readers—even high school students—is deceptive. Rather, he focused narrowlyon a problem related to trying to create pure-breeding hybrids and to characterize theidentity of species. His paper presents a "law of hybridization" and a mathematical for-malism that describes it (Hartl & Orel, 1992). His sequel work (1869) on hawkweedshowed that he could not easily generalize his results on peas. Not all things Mendelianare Mendel's. Through the attribution, his achievement, once again, becomes inflated(Brannigan, 1981).
The aura of Mendel and his achievement is further evidenced in how biologists and historians present Mendel as supporting contradictory claims. Despite their disagreement,Sapp (1990) notes, all nevertheless appeal to Mendel's monumental authority to bolstertheir own claims. Indeed, their goal of securing Mendel's mantle seems to explain theircontrary interpretations of his work. His monumentality seems more important than whathe wrote. Sapp's observations should alert educators to dissect the architecture of howtextbooks, likewise, portray Mendel. The problem is not just telltale elisions. In manyinstances, Mendel has been recreated historically to fill a monumental, heroic image.
CASE 2: H. B. D. KETTLEWELL
Another favorite textbook icon is the peppered moth, which evolved during Britain's industrial revolution. The popular images of the moths against different backgrounds epito-mizes the classic study by Bernard Kettlewell, contrasting survival in polluted versus ruralforests. Many biology texts describe—and typically celebrate—the elegant design of theseexperiments. Recent accounts have sought to update the science (Majerus, 1998; Rudge,2000). Here, I am concerned primarily with how the story is told.
Again, the history contrasts sharply with the canonical classroom image (Allchin, 2001a).
First, Kettlewell's monograph, The Evolution of Melanism, plainly shows that in addition tothe familiar dark and "peppered" forms, there is a series of intermediates, known as insularia(1973, plate 9.1). The range of coloration in insularia indicates greater complexity. Oneeasily finds such specimens, Kettlewell noted, in museum collections, and he includedthem in his own field studies. Having recruited observers from around Britain, Kettlewellcatalogued the relative frequency of the three forms in various locations. The incidence ofinsularia was sometimes as high as 40% or more (Kettlewell, 1973, pp. 134 – 136). Insulariawas no trivial exception. Still, while Kettlewell documented insularia in his research, itbecame eclipsed in subsequent renditions of his work. For example, his 1973 book coversported the now canonical images, omitting insularia. Kettlewell himself seemed to promotethe streamlined story publicly. Pursuing the ideal of conveying the process of science, sometextbooks include the original published data of the contrasting Birmingham and Dorsetenvironments. But while Kettlewell tallied survival rates for all three forms (Kettlewell,1955, 1956), the texts omit insularia (e.g., Hagen, Allchin, & Singer, 1996, p. 7). Althoughthe essential conclusions do not differ, the implicit lesson about science does. That is, in thesimplified image, science sorts things crisply into black and white, true and false, withoutany "shades of grey," partial conclusions or residual uncertainties. Science is black andwhite—like the moth images.
Like Mendel's work, Kettlewell's research has become rendered conceptually. The idea of a well conceived controlled experiment yielding solid evidence contrasts with the his-tory, however. Hagen (1993, 1999) observed that at first, Kettlewell presented data onlyfrom the polluted Birmingham woods. He made no reference whatsoever to Dorset, nowconsidered a critical complement in the study's design. Nor did he give any hint that hisstudy was incomplete or preliminary or partial. Why? One hidden task of Kettlewell'sstudies was collecting enough organisms to mark, release, and then recapture. Kettlewell was apparently limited by sheer logistics in managing moth pupae (Rudge, 2001). Yethe also proceeded anyway, publishing only "half" the study. Perhaps Kettlewell did notsee the "control" as important initially, at least as texts portray it today (Hagen, 1993).
There were numerous other controls, generally overlooked today (Rudge, 1999, pp. 19 –20). Ultimately, Kettlewell's first study was heavily criticized. Ornithologists claimed thatbirds did not prey on the moths at all. In his follow-up study, Kettlewell enlisted etholo-gist Niko Tinbergen to document the predation on film (Rudge, 2001). He also added datafrom the unpolluted Dorset woods. Kettlewell, then, patched together several separate stud-ies. The history belies the stereotypical image of great scientists. There was no "Eureka!"Rather, conclusions flowed from a series of less extraordinary modes of thinking and work-ing. Again, the process of science seems not so "black-and-white" as the textbook storyimplies.
The potential danger in habitual simplification is that teachers can convey a false image of the nature of science. In a sense, they condition students to expect simplicity. When studentsencounter complexity, they may feel betrayed or "simply" lack the requisite interpretiveskills. Consider, for example, Wells' recent criticism of the peppered moth case as a "myth,"in the sense of "not an account of objective reality" (Wells, 2000, p. 1) and "no betterthan alchemy" (p. 155). That is, he denies that it provides evidence for evolution. Why?In his arguments, Wells points disparagingly to every uncertainty and discrepancy in theevidence. For Wells, if the evidence does not match the story as told in the textbook,then the scientific conclusions are wrong. Uncertainties, doubts and lack of unambiguousevidence mean, simply, that the evidence is "impeached" (p. 151). Discrepancies count asoutright flaws. No qualifications are allowed. No nuances in interpreting the evidence orconsidering multiple causal factors. This approach seems to take seriously the "discipline"of science (p. 2). There is no room for ambiguity or resolving complex evidence. Scienceeducators may recoil in horror. But in the preface to his creationist tract, Wells admits thateven through graduate school he believed almost everything he read in his textbooks astrue, plain and simple (p. xi). For Wells, science seems black and white. And the result,in his case, appears to be rejection of evolution, because the real science does not matchexactly the textbook ideal. The Kettlewell case may thus alert educators to the potentialconsequences of casting the process of science as black-and-white—like the peppered mothsone sees in the textbooks.
CASE 3: ALEXANDER FLEMING
My third case is perhaps the most celebrated example of chance, or accident, in science: the discovery of penicillin by Alexander Fleming. In the conventional story (e.g., Ho, 1999;WGBH, 1998), a stray mold spore borne through an open window landed on an exposedbacterial culture. Then, as Time reports in its 100 Persons of the Century (Ho, 1999): Staphylococcus bacteria grew like a lawn, covering the entire plate—except for the areasurrounding the moldy contaminant. Seeing that halo was Fleming's "Eureka" moment,an instant of great personal insight and deductive reasoning . . It was a discovery thatwould change the course of history. The active ingredient in that mold, which Flemingnamed penicillin, turned out to be an infection-fighting agent of enormous potency. Whenit was finally recognized for what it was—the most efficacious life-saving drug in theworld—penicillin would alter forever the treatment of bacterial infections. By the middleof the century, Fleming's discovery had spawned a huge pharmaceutical industry, churningout synthetic penicillins that would conquer some of mankind's most ancient scourges,including syphilis, gangrene, and tuberculosis.
Fleming himself often underscored the role of chance in his work. In receiving numeroushonors, he was fond of reminding others, "I did not invent penicillin. Nature did that. I onlydiscovered it by accident." Fleming, as hero, is a role model: Someone who had the insightto capitalize on a chance observation, consequently giving health, even lives, to millions.
This story is deeply misleading, even where not demonstrably false. It excludes relevantdetails, mischaracterizes others and arranges the narrative suggestively (Macfarlane, 1985).
"Undoing" the rhetoric, I hope, shows how it creates its lesson about nature of science,especially about the roles of context and contingency.
First, consider the phrase, "when it was finally recognized for what it was." Because originally, in 1928, Fleming hardly envisioned penicillin as the great drug it later became.
He did not strongly advocate treating humans with it until 1940. What happened in those 12years? Initially, Fleming had indeed been searching for antibacterial agents. But he was notimpressed with penicillin's therapeutic potential. It was not absorbed if taken orally. Takenby injection instead, it was excreted in a matter of hours. For Fleming penicillin was limited,perhaps to topical antisepsis. Hardly momentous. In the ensuing years Fleming used peni-cillin, but as a bacteriological tool. It suppressed the growth of certain bacterial species andallowed him to culture certain others. That became valuable for manufacturing vaccines—amajor task Fleming managed at St. Mary's Hospital in the 1930s. Meanwhile, Fleming'sresearch had turned to another group of chemicals, the sulphonamides. Without furtherwork, Fleming's discovery would have languished, another relatively mundane scientificfinding (Figure 1). Chance is reserved for Fleming's first observation, not its subsequentdevelopment. It sparks the plot, but does not let it wander without direction.
The ultimate pursuit of penicillin in treating human infections was due entirely to an- other lab, led by Howard Florey in Oxford. In 1938 Ernst Chain, Florey's associate, begansearching for natural antibacterial agents, endeavoring to elucidate their mechanisms morefully. He chose three to study, penicillin just one among them. Chain used Fleming's 1929paper, but with his own, quite different, purpose (Figure 1). By early 1939 Chain and Floreybegan to suspect the medical potential of penicillin. But because of the war effort, Floreyhad problems securing funds for testing. They also faced several technical challenges. Theyneeded to improve production and purification methods, refine an assay to determine thestrength of their extracts, and scale up production. After 5 months of work, all with noguarantee of success, they had enough brown powder to test on a few mice, which yieldedpromising results. While this work reflects the bulk of the scientific process, the traditionalstory consolidates it as uninteresting drudgery.
Figure 1. Alternative histories in the discovery of penicillin: history as a web, rather than a timeline.
Now, the popular story sometimes notes, "As the world took notice, they swiftly demon- strated that injections of penicillin caused miraculous recoveries in patients with a varietyof infections" (Ho, 1999). But the work was hardly minimal. Or swift. For tests on humans,they needed substantially more penicillin. The Oxford labs culturing the mold scaled upfrom flasks and biscuit tins to hundreds of bedpan-like vessels stored on bookshelves. Pu-rification turned from the laboratory to dairy equipment. After the first test they had to findways to remove impurities that caused side effects. The tests eventually went quite well,but it had required two professors, five graduate students, and 10 assistants working almostevery day of the week for several months to produce enough penicillin to treat six patients.
While a narrative of science might well celebrate hard work, here the "swift" pace linkinginsight to triumph seems primary. Also, emphasis on the downstream work would reducethe dramatic role of the chance event as central.
Fleming noticed Florey and Chain's striking results. Yet he did not disturb his research agenda. He knew that penicillin's value still lay in economical mass production. Thus,the research—and, in a sense, the discovery—was still not complete, and certainly notFleming's alone. One can now imagine the details of 3 more years of work before the U.S.
could produce enough penicillin to treat a quarter-million patients per month. The ultimateachievement was indeed monumental and worth celebrating in the classroom. However, thestory exaggerates the scale of Fleming's role, thereby creating a distorted image of genius inscience (as true also for Mendel, Case 1). Fleming, Florey, and Chain all shared the NobelPrize in 1945. If Fleming "changed the course of history" (Ho, 1999), it was not withoutthe help of Florey, Chain and dozens, even hundreds, of technicians. An aura surroundsFleming, like an inspiring tale of a scientist winning the lottery: vicariously, we thrill in hisgood fortune. But the story inflates the role of one scientist at the expense of representinghow science happened.
While this episode exemplifies the role of "chance," popularizers nevertheless credit Fleming, as hero, with noticing the antibacterial properties: the "‘Eureka' moment" that Ho(1999) described. Others, however, besides Fleming had noticed the antibacterial propertiesof Penicillium, including Joseph Lister, John Tyndall, Ernest Duschene, Louis Pasteur, andJules Joubert (Figure 1).4 Fleming was not as uniquely perceptive nor as singularly lucky asthe popular story suggests. Moments of mythic insight may involve large doses of opportu-nity, context, and contingency, not just intellectual prowess. Given other circumstances, thehistory might not have included Fleming at all. But this history is harder to package into acompelling narrative.
Classroom histories tend to follow only a single linear plot. The narrative connects Fleming directly to the status of penicillin today. Other plot lines and scientists become invis-ible. The outcome thus seems inevitable. But to understand the process of science as it movesforward, the alternative futures and potential alternative discoveries are essential (Figure 1).
Educators must portray "science-in-the-making," advancing blindly, not "science-made"unfolding predictably (Latour, 1987). Contingency does not define just the moment in 1928 4 In 1871, Joseph Lister (noted for introducing antiseptic practice into surgery) found that a mold in a sample of urine seemed to be inhibiting bacterial growth. In 1875 John Tyndall reported to the RoyalSociety in London that a species of Penicillium had caused some of his bacteria to burst. In 1877 LouisPasteur and Jules Joubert observed that airborne microorganisms could inhibit the growth of anthrax bacilliin urine that had been previously sterilized. Most dramatically, Ernest Duchesne had completed a doctoraldissertation in 1897 on the evolutionary competition among microorganisms, focusing on the interactionbetween E. coli and Penicillium glaucum. Duchesne reported how the mold had eliminated the bacteria inculture. He had also inoculated animals with both the mold and a lethal dose of typhoid bacilli, showing thatthe mold prevented the animals from contracting typhoid. He urged more research. Following his degreehe went into the army and died of tuberculosis before pursuing that research. Chance, here, worked againsthis discovery bearing fruit (Judson, 1981).
when Fleming turned his attention to the discarded, now a famous culture in the tray oflysol. It permeates the whole process. It may not fit a standard plot trajectory conveniently.
In celebrating Fleming, therefore, one might focus instead on his habits: the context that fostered the moment so often depicted as critical. Fleming was not known for running a"tidy" lab. Abandoned cultures heaped unattended in a basin would not have been at allunusual—less "chance" than the story suggests. Such "messy" circumstances invite theunexpected. For molecular biologist Max Delbr¨uck, this promotes discovery. He labeled itthe "principle of limited sloppiness" (Fisher & Lipson, 1988, p. 184; Judson, 1981, p. 71).
In addition, Fleming was accustomed to play and pursue "idle" curiosities. At first, hesimply found the halo of inhibited bacterial growth interesting. Later in the day he touredthe building trying to interest his colleagues—who were largely unimpressed: no promiseof miracle cures yet. There was no "instant of great personal insight and deductive reasoning"(Ho, 1999), as dictated by the heroic plot template. Rather, personal amusement. Later,Fleming drew pictures with Penicillium on culture plates and watched them "develop" overseveral days as the bacteria grew in the negative spaces. A teacher might have pined thatFleming was frequently not "on task." A very different image of science emerges when onesees sloppiness and play as contributing significantly to Fleming's "chance" moment. Theplot becomes less algorithmic.
In the traditional history, science appears to rely on an exceptional individual and a rare moment of insight to propel it forward. The fuller story reminds us, dramatically, how itmight have been otherwise. The conventional story is narratively cozy. It celebrates modestyand good luck. Science appears formulaic and sure, even where the critical event is portrayedas chance. A more authentic history, however, reveals the many contingencies and contextualfactors that shape the scientific enterprise through multitude potential pathways (Figure 1).
CASE 4: IGNAZ SEMMELWEIS
My fourth case concerns tragic death from childbed fever in Vienna in the mid-1800s and the discovery of the importance of handwashing by Ignaz Semmelweis (Carter, 1983).
Here is how the case appeared recently in the Journal of College Science Teaching (Colyer,2000) and on a major website of case studies5: Ignaz Semmelweis, a young Hungarian doctor working in the obstetrical ward of ViennaGeneral Hospital in the late 1840s, was dismayed . . that nearly 20% of the women under hisand his colleagues' care . . died shortly after childbirth. [Students pause here to hypothesizecauses.] One day, Semmelweis and some of his colleagues were . . performing autopsies . . Oneof Semmelweis' friends . . punctured his finger with the scalpel. Days later, [he] becamequite sick, showing symptoms not unlike those of childbed fever. [Students are again askedwhat to do next.] In an effort to curtail the deaths in his ward due to childbed fever, Semmelweis instituteda strict handwashing policy amongst his male medical students and physician colleaguesin "Division I" of the ward . . Mortality rates immediately dropped from 18.3% to 1.3% . . [Students interpret.] 5 For economy, I have edited the content heavily, while hoping to preserve the sense of the original.
Colyer's approach is certainly not unique. See, for example, Episode 622 from the radio series "Engines ofOur Ingenuity" (also on the web). The romanticism of popular historical narratives, especially among med-ical professionals, is evident in such sensational labels as "conquest," "tribute," "pioneer" and "prophet,"allfound in titles of articles on Semmelweis in medical journals from the last two decades.
Despite the dramatic reduction in the mortality rate in Semmelweis' ward, his colleaguesand the greater medical community greeted his findings with hostility or dismissal . .
Semmelweis was not able to secure the teaching post he desired . . In 1860, [he] finallypublished his principal work on the subject of puerperal sepsis but this, too, was dismissed. . the years of controversy and repeated rejection of his work by the medical commu-nity caused him to suffer a mental breakdown. Semmelweis died in 1865 in an Austrianmental institution. Some believe that his own death was ironically caused by puerperalsepsis.
Semmelweis is the quintessential scientific hero, defending scientific truth in the face ofadversity. The predominant tone is tragic. But the lessons about science are essentiallythe same, albeit often inverted. The exercise above aims appropriately at reviving science-in-the-making (Case 3) by engaging students in situated decision-making. Still, a sense ofdrama is crucial. Making the story compelling largely depends on suppressing relevant factsand perspectives. It is worth considering how the history is traded for drama.
First, authors sometimes portray Semmelweis as the person who noticed the problem of childbed fever, although the reputation of the Division I ward was notorious, even amongpatients. This creates a stronger protagonist. But it also inflates his genius.
Second, in this case we hear how Semmelweis noticed his colleague's wound during an autopsy, implying his subsequent insight about his illness was immediate and clear. In fact,he would have noticed the illness first, without context, and had to puzzle in reconstructingits cause. Why would he have even suspected the cadaveric material? Perhaps he alreadyhad an inkling. Gradual realization, however, does not drive a plot quite as well as an "aha!"insight.
In this episode, a key element is the rejection of Semmelweis's conclusions. Thus, in conventional stories, the critics were wrong. All wrong. Anything less would diminishSemmelweis's stature. In a sharp dichotomy, the evidence favors Semmelweis exclusively,while "unscientific" factors (must?) bias his critics. Authors cast the negative response aspermeated with personal prejudice and social ideology. Some commentators note that Sem-melweis was Hungarian and portray him as a victim of Austrian xenophobia. They disregardthe contemporary intellectual context, however. Vienna was then viewed as "the Mecca ofMedicine." Therapeutic caution had emerged, correcting earlier excesses of bloodletting,purgatives, etc. (Johnston, 1972). Our modern practices of diagnostics and loose bandagingof wounds began here. Many thus found Semmelweis's results empty. He did not identifywhat caused the disease, for example. Without knowing the cause, one could easily err—andbe diverted from searching for the real cause. With no concept of germ theory (still decadesaway), Semmelweis's peers may thus have responded to his conclusions cautiously forgood reasons. But this does not contribute to either building sympathy for the protagonistor portraying science as methodologically transparent.
Few stories mention Semmelweis's polemical, sometimes offensive, tone in discourse.
Instead, his critics receive all the blame. Their attributes are all negative: xenophobia,hubris, pettiness, and hostility. The asymmetry sharpens the sense of conflict. It encouragesthe reader to sympathize with the main character's struggle.
Now, had Semmelweis been wrong, stories would likely hail the role of the scientific community in catching error. They would extol the social system of checks and balancesin science (because it led, in retrospect, to the right answer). When the same system leadsto skepticism about ideas we now consider right, one tends to find only conservatism andcondemn it. What seems to matter is not profiling the process of peer review—for betteror worse—but matching the outcome with a method that justifies it. Right answer?: rightmethod. Wrong answer?: wrong method. It fits an easy narrative formula.
In this episode, the rejection of Semmelweis is typically overstated. In fact, hospitals across Europe widely (although not universally) instituted handwashing. Semmelweis wasnot as neglected as the typical story suggests. But suppressing this heightens the dramaof vindication. The story can trumpet the triumph of science and truth, contrasted againstsocial prejudice (inscribed also in the Mendel case).
Now, why did Semmelweis lose his position at the hospital? It may seem natural to extend the pattern of his science being rejected and it gives a sharper edge to his heroism.
But documents suggest Semmelweis was caught in larger institutional power struggles.
Furthermore, he was obsessed with childbed fever. Neglect of his other duties likely servedas adequate excuse for dismissal. Here, the narrative tends to interpret his whole life narrowlythrough science, even where it may not be irrelevant.
Finally, the irony that Semmelweis succumbed to the very disease he sought to cure seems too poignant not to mention. Some narratives say he was driven to suicide, amplifying thesense of tragedy. Our best evidence indicates that guards beat him while he was tryingto escape an insane asylum, leaving lethal injuries and infected wounds. But this endingis not very powerful rhetorically. Ideally, a story ends in uplifting triumph or cathartictragedy.
Thus, many elements of popular narratives heighten the drama, even if not well informed historically. When the history misleads, of course, so too does the portrayal of science.
CASE 5: WILLIAM HARVEY
Finally, consider the case of William Harvey and the circulation of the blood (Pagel, 1967, 1976). Harvey, physician to royalty, claimed that the blood did not move on its ownto its "natural place," but was propelled by the action of the heart. Moreover, blood is notmerely used up in the extremities. Rather, it continues to flow as in a natural cycle. Harvey'sconceptual achievement was certainly recognized by his peers, although, one might note,not without some particular disputes. He also epitomized the emergence of experimentalinvestigation in the early 1600s.
Here I focus on an account by Lawson (2000), which uses history explicitly to promote a particular view of the process of science. Harvey is presented as an example of thecentrality of hypothetico – deductive reasoning in science. But why history? Here, historyis a critical persuasive tactic. By inscribing the philosophical perspective into the work ofa renowned scientist, an author gives it the semblance of "naturalness" or authority (recallSapp's comments on Mendel, Case 1). An imaginary example simply does not carry thesame cachet. In this case, Harvey is first established as the desired authority by dramatizinghis discovery (Lawson, 2000, p. 482): Galen's theory of blood flow was virtually unquestioned for nearly 1500 years until 1628when the English physician William Harvey . . published a book." 6 Here, the monumental time scale (over a millennium!) functions to impress us with thescale and singularity of the achievement. Yet this apparently modest statement collapsescontributions from several physicians over a century into just one person: William Harvey.
Michael Servetus in 1553, Realdus Columbus 6 years later, and Andreas Cesalpius in 1603each claimed that blood follows the "pulmonary transit," although each for a different 6 Harvey's discoveries were actually mostly complete by 1616, when he started lecturing about them.
Publication followed years later. Misdating seems like a minor quibble, but it confuses the publication withthe research itself, a point echoed below.
reason.7 All questioned Galen's authority. And each introduced new ideas about circulatingblood flow. Moreover, with wider scope, one finds that Ibn al-Nafis discussed pulmonaryblood flow in the 1200s, during the Golden Age of Arabic science. Cultural slight andhistorical details aside, the magnitude of Harvey's achievement has been grossly exagger-ated. Here, a reader can see more clearly how the inflated genius (Cases 1, 3, 4) is part ofa persuasive strategy. The implicit lesson for the reader?: Harvey possessed some specialform of reasoning, which his peers did not, that is critical to success in science.
Lawson's account emphasizes especially Harvey's reasoning against Galen. Galen be- lieved that blood must flow from the heart to the lungs, and that some blood flowed back tothe other side of the heart, but he also reasoned that blood might permeate the septum of theheart directly. This is treated as somewhat astonishing, even outlandish. Harvey, we are told,put the mistake right with hypothetico – deductive reasoning. (Never mind that Vesalius hadcriticized Galen on this very point based on his observations decades earlier.) The unin-formed reader never learns that Galen was a pioneer in dissection. He hardly would haveadvanced such a claim foolishly, in absence of any observation whatsoever. Here, Galen, asstraw man, fills the narrative role of adversary, or villain. We never learn how Galen mighthave reasoned, nor why his ideas were respected for so long. Indeed, the question does noteven arise, although this presentation purports to illustrate scientific reasoning historically.
Later, the reader learns of what was supposedly Harvey's greatest triumph: the prediction of capillaries (e.g., Asimov, 1964, pp. 24, 29; Baumel & Berber, 1973, pp. 12 – 13; Lewis,1988). Though no one could observe them at the time, Harvey apparently saw the boldimplications of his theory: If . . the blood flows away from the heart in the arteries, andIf . . the bloods flows towards the heart in the veins,Then . . the arteries and the veins must be connected.
Harvey's impressive "if – then" reasoning, we are told, was vindicated in 1661, 14 yearsafter his death. Here, the drama is framed to demonstrate the power of deductive—that is,"scientific" —reasoning (Lawson, 2000, pp. 483, 484). Well, this is how one might recon-struct the reasoning knowing that capillaries exist. When I began teaching, I encounteredthis story about Harvey's prediction and I believed it. I had not yet read Harvey's originalwork. In his classic De motu cordis, Harvey describes how blood percolates in the lungsand is collected as though from a sponge (Ch. 7). Blood permeates the pores of the flesh,he said (Ch. 10, 14). It is absorbed and imbibed from every part by the veins, he echoed in alater publication (A Second Disquisition to John Riolan). Harvey did not reason blindly. Hehad dissected many "lesser" animals that have hearts but no blood vessels ("open circulatorysystems," in our terminology). He had observed directly that connections were not needed.
Harvey did not predict capillaries. That misattribution eclipses the 17th-century perspectivein which he reasoned. Yet it fits the narrative goal of framing Harvey as a scientific herowho champions a certain style of reasoning.
Harvey supposedly further exercised if – then reasoning to frame numerous tests, as de- scribed in his landmark book. But this means reading Harvey as plainly describing theinvestigative process, rather than trying to persuade his readers. Indeed, it is not too difficultto discern Harvey's own rhetorical strategy. He offers numerous demonstrations, such as 7 Servetus gave new importance to the air in vitalizing the blood and hence to the blood's passage through the lungs. Columbus inferred the direction of blood flow from the structure of the blood vessels. Cesalpiuslinked the pulmonary circuit to thinking about cycles in nature and chemical distillation (resonating withFludd's interpretation, see later).
the one portrayed in the renowned figure of ligatured arms. These are not "tests" in thesense of inquiry or epistemic probes. They take the form: If . . you don't believe me,then . . do X to prove it to yourself by direct observation.
This underlies much of Harvey's if – then language. Here, the publication is mistaken forthe science itself, with misleading results. Narratively, however, a method is only justifiedby showing how it leads to discovery.
Consider, finally, the treatment of one of Harvey's central ideas: Harvey's guiding analogy was . . circular planetary orbits and the belief that large-scaleplanetary patterns should be echoed in smaller-scale physiological systems (p. 482).
This is the microcosm – macrocosm concept of the chemical philosophy, shared by RobertFludd, a close friend of Harvey's. The analogy also extended to chemical reactions, strength-ening the analogical resonance. Harvey used this image throughout his book, sometimesexplicitly as an argument. He described the heart as the sun of the microcosm, givingwarmth and life to the body. That seems very strange to us today – and decidedly "un-scientific." Yet historians document that this analogy was integral to Harvey's very rea-soning. Some may want to discount that this microcosm worldview could lead Harveyto "discover" something we now regard as true. No doubt because the analogy is falseby today's standards. Attributing it to Harvey appears to lessen his status as a scien-tist. But it is coupled with Harvey's achievement. It is essential if we want to under-stand scientific reasoning, and portray it faithfully to students. But in Lawson's article,the analogy is only curtly acknowledged, then abandoned as peripheral. The historicalfacts, even about reasoning, seems secondary to the persuasive aims of the "historical"narrative.
Errors pervade Lawson's brief two-page treatment of history. But the errors themselves are not as important as the source of the errors. Harvey is repeatedly shoehorned into aparticular method of scientific reasoning for rhetorical purposes. When one delves intohistory to prove a point, rather than to "listen" to what it has to say, one can easily err.
Historians talk about respecting history—that is, regarding history (ethically) as an end, notan instrumental means towards some other goal. Historians ideally endeavor (intellectually)to find and decipher the details and complexities of historical context, and not just remaptheir own views onto the past. In Lawson's account one finds the persuasive elements of themonumentalized Harvey and the historical errors intimately coupled. Mythic grandeur andmisconception arise together. That is what constitutes a myth-conception.
THE ARCHITECTURE OF SCIENTIFIC MYTHS
Ultimately, historical reconstructions of scientific discovery—whether of Mendel, Fleming, Kettlewell, Semmelweis, or Harvey—designed to fit certain narrative patternsare the source of myth-conceptions in science. While the cases I've recounted are all bi-ological, I trust that they are so familiar that even nonbiologists can recognize them andappreciate the analysis. One can equally find these trends in stories of Antoine Lavoisierand oxygen, Alfred Wegener and continental drift, Galileo and his advocacy of Copernican-ism, or Isaac Newton and his optics. All narratives of science and of scientists risk driftinginto myth. Teachers need to be mindful to respect history. In the spirit of recent reforms in science education, educators need to jettison mythic history if they want to portray thenature of science faithfully.8 In profiling the historical misperceptions in the five case-myths above, I do not mean to imply that every science teacher should be a professional historian. My primary concernhere is not historical accuracy per se, but the mythic style.9 The lesson is not in the detailsof each history, but in their common narrative elements. Namely, what transforms plainstories into myths? Particulars aside, what features characterize this type of history? Canone generalize its internal structure? Teachers who understand the rhetorical dimension ofstories, I hope, will be better able to regulate how their own storytelling affects students.
Here, then, my emphasis shifts from historical to literary, or rhetorical, analysis. What isthe architecture of scientific myths? (See Footnote 1.) First, all the scientists, as literary characters, are larger than life. They are heroic (Milne, 1998). Their personality exudes virtue. They exhibit no character flaws. For example, asscientists, they do not err. Also, as I have noted repeatedly, their achievements are inflated.
Discoveries that, historically, were gradual and distributed over several persons are concen-trated in one person, and often in one momentous insight. Historians have long criticizedhagiographies, idolizing biographies that willfully omit any trait deemed negative. Butthe cases here go beyond merely "sanitizing" history. They introduce historical error andtransform human scientists into superhuman characters. The scientists thus share with theirwholly fictional literary counterparts the traits of heroes, legends, and sometimes even gods.
Their monumental features serve a major function: to engage the reader.
For some, these mythic, superhuman characters function as role models that inspire students. Paradoxically, this seems to subvert the current goal of portraying science "as ahuman endeavor" (National Research Council, 1995, pp. 200 – 201, emphasis added; seealso Rutherford & Ahlgren, 1990, pp. 9 – 13). The situation is certainly more complex thanwhen Brush (1974) famously suggested that history of science be rated "X" in the classroom.
Brush was concerned that students exposed to real, non-mythic scientists might not want tobecome scientists themselves. More recently, Brush (2002) has partly "recanted" and nowconsiders some scientists, at least, to be good role models. But Brush has focused primarilyon recruitment, and he has not addressed directly the topic of misrepresenting scientists orexaggerating their achievements. In any event, educational goals now address science forall students. Moreover, they incorporate history of science in roles other than as a vehiclefor recruitment (National Research Council, 1995, pp. 2, 200 – 204; see also Rutherford &Ahlgren, 1990, pp. v – xi, 9 – 13, 135 – 153). Still, the role of history—or mythic history—inproviding role models may need to be addressed.
First, the assumption that role models must be universally positive has yet to be fully studied. Certainly, some anecdotal evidence suggests that some scientists have been inspiredby such myths. But we do not know whether the mythic image alone was causally significant 8 The phrase "nature of science" is ambiguous. It may be either descriptive or normative. That is, the educational objective may be to teach science as an idealized process or as it is practiced. There is a tensionbecause, historically, science has not always realized the ideal. For my part, professional ethics seemsto mandate that teachers portray (without endorsing) science as it is practiced in a real, human—even ifimperfect—world. Teachers should also articulate the ideal "nature of science" and discuss how and whyit may vary from the real.
9 Of course, I certainly hope that teachers endeavor to respect historical facts as much as scientific facts.
For example, many favorite classroom anecdotes of scientists are apocryphal. Here, I focus on what mightcue the inexperienced teacher when to question such stories.
(such individuals may already have been oriented towards science for other reasons). Wedo not know if great, but less hyperbolic figures may serve the same role. Nor do weknow whether the myths are significant across the entire population of scientists. Many, oreven most, scientists may well be inspired by other factors. For example, other historicalevidence (also anecdotal) indicates the importance of simple encouragement, even whereno role model existed (for example, in the cases of some women and minorities). At thevery least, educators need substantially better research on the causal relationship betweenmythic characters as role models and recruitment in science before asserting its importance.
Further, we do not know how many potential scientists are alienated by such myths. In what ways (that may now go unnoticed) do these mythic figures discourage students frompursuing science? They may be negative role models. That is, a student with a keen interestin science (but perhaps unproven ability) may infer that she or he cannot make a meaningfulcontribution, so why try? I have certainly encountered students who complain that "scienceis only for geniuses." Research results on attitudes towards science and recruitment shouldcertainly be interpreted in terms of different types of history (e.g., Martin & Brouwer, 1991).
Further, the assumption that heroes must be perfect to be role models may well be questioned.
Indeed, they are much more human and real—and more accessible to students, I contend—ifeducators acknowledge their flaws and limits as well as their triumphs (Milne, 1988, p. 184).
In addition, focusing exclusively on recruitment upstages questions of establishing "role models" in other contexts. That is, these mythic figures also generate expectations forhow scientists should perform in society. They are role models of a very different kind.
How much is public sentiment towards science shaped by failure of scientists to meet thestandards of the myth? How do the superhuman images of scientists shape public discourseon issues that are informed by science? Again, more research would be helpful. In any event,teachers ought not to confuse mere engagement with larger-than-life characters as personalinspiration. In summary, the importance of mythic scientists as role models in education isnot clear.
One may, nonetheless, interpret their role within the mythic narratives themselves. Be- cause it is not just the characters that are monumental. Everything is grand in scale. Forexample, Fleming did not just discover the antibacterial properties of some fungus. No, he"conquered some of mankind's most ancient scourges" (Ho, 1999). Harvey did not discovercirculation merely. Rather, he rescued us from a mistake that had persisted for 1500 years.
Kettlewell, by his own popular account (1959), discovered "Darwin's missing evidence."He thus apparently secured evolutionary theory from a century-long vulnerability. A singlescientific study seems to have immense significance. All this has strong implications for therelationship between the storyteller and the hearer/reader. The storyteller feels more valued(and more powerful) by telling an important story. Likewise, the reader is impressed byits significance. The mutually favorable emotions seem to validate the story—and foster asimilar story the next time.
Moreover, when cast in a grand scale, a story is more easily interpreted as representing all science. For Lawson, at least, this is explicit: Harvey's reasoning should illustrate animportant principle about science generally. These narratives of science, then, are "mythic"in proportion, both cognitively and affectively. Ultimately, this monumentalism amplifiesthe importance of the story—and whatever "moral" it contains.
A second architectural feature of myths in science is idealization. The case-histories exemplify phenomena about storytelling familiar to psychologists: sharpening and leveling(Gilovich, 1991, pp. 90 – 94): What the speaker construes to be the gist of the message is emphasized or "sharpened,"whereas details thought to be less essential are de-emphasized or "leveled." Qualifications are lost. Extremes emerge. What remains is a black-and-white image ofscience, rendered quite literally in the case of the peppered moths. The intermediate insulariamoths are leveled. So, too, are the logistics of field tests. Meanwhile, the contrast betweenthe Birmingham and Dorset woods is sharpened. So, too, is the clarity of the experimentalcontrol. In Semmelweis's case, the intellectual and social contexts directly relevant toassessing his claims are not just leveled, but razed. Mendel's and Harvey's precursors areleveled, while the scientific heroes are sharpened. Sharpening and leveling for the sake oftelling a "good story" easily leads to misleading oversimplification.
One particular consequence of simplified narratives is a streamlined plotline. The multi- ple lineages of thought and action that characterize a web of history (Figure 1) are reducedto a single timeline. Stories, like those about penicillin, are reduced to the "essentials"linking the past to the present. Fleming's role becomes sharpened. Duchesne's and oth-ers' become leveled. Although many will acknowledge that science involves trial anderror, stories of science rarely include blind alleys (except for dramatic effect). The re-sulting sequence of events, leading item by item to the discovery and then to its mean-ing to us today, is all too easily interpreted as inevitable. Historians have long criticizedWhiggism: interpreting (or rewriting) history as leading to—and justifying—current statesof affairs (Butterfield, 1959; Kuhn, 1970, pp. 136 – 143). Whiggism is conventionally con-strued as a political bias. Here I am suggesting, instead, that it may also be due to rhetoricalbias. The storytelling tendency to sharpen and level leads to minimizing plotlines andexcluding the alternatives. Hence, the narratives understate the uncertainty and misleadabout the process as it moves forward. Teaching about the nature of science would sufferaccordingly.
As stories are shaped to heighten their apparent informativeness, certain types of details will tend to be lost. The particulars of the discovery—details of time, place and culture,contingencies of personality, biographical background, coincident meetings, etc.—becomesecondary. For example, the myths highlight "positive" contributions. Errors or "failures"are eclipsed. Mendel's 15 "confusing" pea traits are forgotten. Harvey's microcosm analogyis discounted. The story about Semmelweis frequently omits all the possibilities that he firstconsidered, then (critically) ruled out. All these details seem to drag down the plot. In a goodstory, the pace is exhilarating. As a result, stories tend to preserve just the elements neededto justify the outcome narratively. Indeed, this might seem appropriate if one intends thehistory as a lesson in the nature of science.
The stories of science thereby become idealized and universalized, in accord with their monumental status (above). Although the achievement of any given mythic scientist issingular, their methods are cast as transcending their particular occurrences (Milne, 1998, pp.
178 – 179). They illustrate a method of science, writ large. Here, the details or contingenciescannot be too important, lest they subvert the general lesson. Consequently, the idealizednarratives foster the conventional school philosophy of a scientific method, in the sense ofan algorithm guaranteed to find the truth. Bauer (1992) profiled well many deficits in thestandard account of "the scientific method." He even labeled it a "myth." Yet Bauer did notconsider the role of narratives. In my view, the persistence of perceptions of an algorithmicscientific method is strongly linked to the attractiveness of the myths that sustain it. Bymyths, of course, I mean the narratives of science in which it is inscribed. Telling thesestories surely perpetuates the mythic method by embodying it. But I suggest further that thestorytelling tendencies may themselves be a source of the problem. In my view, educatorsshould reconsider the power and impact of these narratives.
The power of the idealization in narrative is especially evident in the various errors it generates. While the stories are all about history—events that happened—they sometimesdrift into stories of what "should" have happened. Witness Harvey's imagined prediction ofcapillaries. Or Mendel's Second Law. Or Fleming's posture on penicillin's use for humans.
Sometimes, the desire for a cozy story may overtake the historical facts. Simplification mayseem inevitable in education. Simple concepts, even if flawed by overgeneralization, seemessential foundations. However, this leaves educators with the additional responsibility ofarticulating how such simple concepts can "lie" (Allchin, 2001a).
While method is unquestionably important in science, the mythic structure oversimplifies the process. It seems flawless. When coupled with the monumental scale, it overstates theguarantee on the claims it generates. With no place for error, except as pathology, theprocess appears more efficient than it actually is. In failing to understand the work ofscientists, people sometimes expect too much of science. Like Wells (Case 2) perhaps,they can feel betrayed when science does not perform according to the idealized account.
Recently, several individuals have sued scientists for making mistakes (Steinbach, 1998).
What fostered such a stark frame of mind that expects science never to err? Did textbookaccounts of famous discoveries help shape their thinking? Virtually all the recent calls topromote "scientific literacy" appeal to the role of science in social decision-making. Mostsuch issues are quite complex. They often deal with scientific uncertainty and incompleteand/or conflicting results (Anand, 2002). Yet partisans of a particular view appeal to sciencein simplistic black-and-white terms (nicely profiled in Martin's account of the fluoridationcontroversy [Martin, 1991] and in Toumey's analyses of creationism, cold fusion and HIV-testing [Toumey, 1996]). Their expectations seem to echo the idealized classroom-histories.
Again, there is opportunity for more research on how public sentiment about science isrelated to the implicit promise of scientific myths. In seeking to remedy misimpressionsabout science, as recommended in recent reforms, applications of history of science shouldbe a solution, not a source of the problem.
A third element of the mythic architecture is literary techniques whose purpose is enter- tainment and persuasion. One may enhance a story's power to engage and persuade withmany rhetorical devices—that is, literary constructs or familiar plot patterns. They intensifyimages, heighten drama, and deepen the aesthetic response. They make a story more com-pelling, possibly even more persuasive or believable. Through their emotional effect, thestories become more memorable. I suspect, this is one reason why the culture perpetuatesthe myths even though they are false or misleading: simply because we remember them andenjoy telling and re-telling them (Milne, 1998, p. 177). But it is all in the literary craft: thestyle, the plot construction, relationships among characters, word choice, etc. Among theserhetorical devices—and I hope that this phrase enters the lexicon of science educators—onemay list • The thrill of the moment of discovery (the stereotypical light-bulb cartoon) • The surprise of chance • The reward of integrity (loyalty to evidence, resistance to social prejudice) • Shame (for example, challenging an ultimately correct idea) Truth always triumphs, but typically only after dramatic conflict. The "aha!" phenomenondeserves special note. Nothing drives a discovery plot quite like a well framed "eureka!" For added effect, it comes in the wake of despair. Another very strong rhetorical device,epitomized in melodrama, is amplifying the good by contrasting it with the bad: hero versusadversary, scientist versus suppressor of the truth, Harvey versus Galen, Semmelweis versushis Austrian critics, Darwin versus Lamarck, Lavoisier versus the phlogistonists, Galileoversus the Church, and so on. I hope the concept of rhetorical devices becomes a standard andfamiliar element in educating teachers. Good teachers, I think, understand what elementsmake stories persuasive—and manage them responsibly in their own storytelling.
Explanatory and Justificatory Narrative
The final element that makes these histories mythic is their explanatory role. They are not "just" stories of science. They are "just-so" stories of science. Like Kipling's fables—"Howthe Leopard Got His Spots," etc. (Kipling, 1902)—they explain a certain outcome throughnarrative. Every history—every story—has an implicit "lesson," or moral. Historical talesof science implicitly model the scientific process by showing how a series of events leads toa certain result: in our cases, a renowned scientific finding. The narrative inherently couplesprocess and product. As idealized accounts, most are rational reconstructions and serve tojustify the authority of the scientific conclusion. Right method, right ideas. Wrong method,wrong ideas. The story of a discovery explains, narratively, the methods of science and,hence, the authority of science.
The architecture of scientific myths, then, ultimately serves a function of explaining and justifying the authority of science. The elements conspire together to collapse the nature ofscience into an all too familiar just-so story of "How Science Finds the Truth": • All experiments are well designed and forestall any mistakes.
• Interpreting evidence is unproblematic, and yields yes-or-no answers.
• Achievement relies on privileged intellect. (Scientists are special, extraordinary peo- ple, whose authority is beyond question.) • Science leads surely and inevitably (and uniquely) to the truth, without uncertainty or error. (Anything less abandons objectivity and reduces to relativism.) No one need critique these features yet again. They have also already been labeled as"myth" (Bauer, 1992). I wish to highlight, however, how they tend to derive legitimacyfrom the explanatory power of the narratives. Because of the monumental scale, the re-sulting authority is monolithic. Because of the idealization, simple method seems suffi-cient to account for all scientific achievement. Because of the rhetorical devices of affec-tive drama, the features, however misleading, are immensely persuasive and emotionallycommanding.
Myths of science also exhibit another important, related feature of classical mythology.
Traditional myths often explain natural phenomena—e.g. the movement of the sun, theseasons, the rainbow, etc.—through the actions of human-like gods. While appearing tointerpret nature, the myths also, conversely, inscribe human behavior in nature. Thus, themyths function implicitly to legitimize certain actions or norms of human conduct by fram-ing them as "natural." In a similar way (especially clear in Harvey's case), particular viewsof science benefit by being inscribed in history. The historical tale is not just an illustration.
It is a persuasive tactic. The author's view of scientific norms seems to emerge naturally from the history. Here, the myth's lessons derive status from the recognized value of histor-ical scientific achievements. But the act of persuasion is not betrayed by any "arguments."The story conceals the rhetorical work. The reader focused on the story sees the historyand the norms as real causes. Unless trained, they rarely see the framework for compos-ing the story. This is why histories are more potent cognitively than mere descriptions ofsciences and its methods. The architecture is invisible. Sometimes even to the storytellersthemselves.
Myths of science are myths, not just idle stories, because their architectures—the syn- drome of elements including monumentalism, idealization, rhetorically crafted drama—areall designed to explain and buttress the unqualified authority of science.
In the Introduction section, I suggested that educators need to replace the types of history that students learn. It is the mythic "classroom histories" that mislead students. They distortthe nature of science, even as they purport to show how science works (see Footnote 8).
They are pseudohistory of science (Allchin, 2001c). Like pseudoscience, they foster falsebeliefs about science—especially about the nature and limits of scientific authority. Onemight imagine that the only solution would be to purge science textbooks—and the cultureat large—of all historical error. However, such a utopian goal is hardly necessary. Nor doesevery teacher need expert credentials in history at the outset—although educators mightsurely seek guidance from professional historians. Educators might begin with two simplestrategies, profiled below. First is reflexivity. With just a few powerful analytic tools and afew good examples, one may recognize the rhetoric of myth for what it is. Second, teachersmay profit from a small repertoire of discrepant myths: stories that break the conventionsof mythic storytelling in science and may (like any anomaly) provoke rethinking and leadto deeper understanding.
First, then, we should equip teachers (and students) with the tools to recognize and deal with the misleading myths they will inevitably encounter. The cases above are examples.
In addition, teachers new to history may rely on a few brief maxims to help evaluate anyhistory. For example (based on the analysis above): Suspect simplicity. Beware vignettes.
Embrace complexity and controversy. Discard romanticized images. Do not inflate genius.
Mix celebration with critique. Scrutinize retrospective science-made. Revive science-in-the-making. Explain error without excusing it. And above all respect historical context (seeCase 5). (Note that these maxims focus on the rhetoric of science stories rather than onthe "nature of science" directly.) For those who like mnemonic devices, one may expressthe "SOURCE" of the problem and the "SOURCE" of the solution as summarized inFigure 2. Thus, while we may not ever eradicate mythic narratives about science, one mightnevertheless be able to neutralize them. Analytical tools empower teachers to recognizemyths and regulate their effect.
Figure 2. Comparison of sample features characterizing mythic history and history that portrays nature of science
more informatively, using the mnemonic "SOURCE."
Second, teachers may benefit from alternative stories of science that break the norms of the mythic structure and hence begin to expose the conventions at work. One core of themythic architecture is a simple narrative formula for science right methods ⇒ right conclusion Viewing scientific methods as foolproof is a caricature, of course. Science proceeds by trialand error, we often hear. Everyone seems willing to acknowledge that science is fallible. Thismeans, of course, acknowledging that scientists can err. It means acknowledging honestlythat good scientists can err—even Nobel Prize winners (Darden, 1998). We cannot gentlyexcuse the errors or explain them away, as in the myths. Nor can we cast all mistakes inscience as fraud or as aberrant pathology (e.g., Dolby, 1996; Langmuir, 1989; Rousseau,1992; Youngson, 1998). It is not just that scientists lapse from some ideal method. The"right" methods do not always yield right ideas. Sometimes right methods ⇒ wrong conclusion Hence, even a single case of fallibility, well articulated, may serve as a corrective to themythic caricature. Ideally, educators should introduce some histories that chronicle how ev-idence at one time led reasonably to conclusions that were only later regarded as incorrect(Hagen, Allchin, & Singer, 1996, pp. 116 – 127). This is how teachers can explain the limitsof science without vague handwaving about skepticism or tentativeness. They must helpundo the myth-conception and show how doing science can, on occasions, lead to error. Wemust explain the error, not excuse it (Allchin, 2001b). Ideally, educators will also show whatallowed scientists later to recognize a mistake and remedy it. Narratives of error and recoveryfrom error, I claim, convey both what justifies and what limits scientific conclusions.
Myths of science are unquestionably seductive. They tempt the teacher eager to engage students. They entertain. On the surface, they seem to inform. These are reasons why themythic forms of the history of science already haunt the classroom and our culture at large.
But they are misleading. They do not promote understanding of the process of science ornature of science. Contrary to reform claims (see Introduction), having more of them solvesnothing.
We need to promote less mythic narrative frameworks instead. While less monumental, they may still be equally dramatic and humanly inspiring. While less idealized, they may stillserve as modest exemplars (in concert with others) for understanding the process of science.
Other rhetorical devices may evoke responses: the excitement of opportunities, the suspenseof persistent uncertainty, the reward of hard work, the surprising significance of "trivial"events, the tension of even-handed debates, the tragic consequences of human limitations,and the aesthetic of resolving error. The new stories will celebrate insight achieved throughperseverance, creative interpretation of evidence, and shrewd insights enabled by depthof experience. They will reflect how scientific conclusions are assembled, how they arechallenged, how error can occur and how knowledge is sometimes revised. Alternativenarratives of science need not reduce the greatness of scientific achievement. But, ideally,they will also portray equally both the foundations and limits of scientific authority andfoster deep understanding of the nature of science. Effective histories of science will avoidengendering myth-conceptions.
The author thanks Art Stinner, Steve Fifield, Alan Gross, participants of the Fourth InternationalSeminar for History of Science and Science Education, and three anonymous reviewers. The authorenjoyed support from the Herbert P. and Alice W. Bailey Trust.
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