«Scientific Myth-Conceptions DOUGLAS ALLCHIN Minnesota Center for the Philosophy of Science and Program in History of Science and Technology, ...»
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 reconstructing its cause. Why would he have even suspected the cadaveric material? Perhaps he already had 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 diminish Semmelweis’s stature. In a sharp dichotomy, the evidence favors Semmelweis exclusively, while “unscientiﬁc” factors (must?) bias his critics. Authors cast the negative response as permeated with personal prejudice and social ideology. Some commentators note that Semmelweis was Hungarian and portray him as a victim of Austrian xenophobia. They disregard the contemporary intellectual context, however. Vienna was then viewed as “the Mecca of Medicine.” Therapeutic caution had emerged, correcting earlier excesses of bloodletting, purgatives, etc. (Johnston, 1972). Our modern practices of diagnostics and loose bandaging of wounds began here. Many thus found Semmelweis’s results empty. He did not identify what caused the disease, for example. Without knowing the cause, one could easily err—and be diverted from searching for the real cause. With no concept of germ theory (still decades away), Semmelweis’s peers may thus have responded to his conclusions cautiously for good reasons. But this does not contribute to either building sympathy for the protagonist or 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 encourages the 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 balances in science (because it led, in retrospect, to the right answer). When the same system leads to skepticism about ideas we now consider right, one tends to ﬁnd only conservatism and condemn it. What seems to matter is not proﬁling the process of peer review—for better or worse—but matching the outcome with a method that justiﬁes it. Right answer?: right method. Wrong answer?: wrong method. It ﬁts an easy narrative formula.
SCIENTIFIC MYTH-CONCEPTIONS 339 In this episode, the rejection of Semmelweis is typically overstated. In fact, hospitals across Europe widely (although not universally) instituted handwashing. Semmelweis was not as neglected as the typical story suggests. But suppressing this heightens the drama of vindication. The story can trumpet the triumph of science and truth, contrasted against social 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 served as adequate excuse for dismissal. Here, the narrative tends to interpret his whole life narrowly through 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 the sense of tragedy. Our best evidence indicates that guards beat him while he was trying to escape an insane asylum, leaving lethal injuries and infected wounds. But this ending is not very powerful rhetorically. Ideally, a story ends in uplifting triumph or cathartic tragedy.
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 HARVEYFinally, 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 own to its “natural place,” but was propelled by the action of the heart. Moreover, blood is not merely used up in the extremities. Rather, it continues to ﬂow as in a natural cycle. Harvey’s conceptual achievement was certainly recognized by his peers, although, one might note, not without some particular disputes. He also epitomized the emergence of experimental investigation 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 the centrality of hypothetico– deductive reasoning in science. But why history? Here, history is a critical persuasive tactic. By inscribing the philosophical perspective into the work of a renowned scientist, an author gives it the semblance of “naturalness” or authority (recall Sapp’s comments on Mendel, Case 1). An imaginary example simply does not carry the same cachet. In this case, Harvey is ﬁrst established as the desired authority by dramatizing
his discovery (Lawson, 2000, p. 482):
Galen’s theory of blood ﬂow was virtually unquestioned for nearly 1500 years until 1628 when the English physician William Harvey... published a book.” 6 Here, the monumental time scale (over a millennium!) functions to impress us with the scale and singularity of the achievement. Yet this apparently modest statement collapses contributions 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 1603 each claimed that blood follows the “pulmonary transit,” although each for a different 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 with the research itself, a point echoed below.
340 ALLCHIN reason.7 All questioned Galen’s authority. And each introduced new ideas about circulating blood ﬂow. Moreover, with wider scope, one ﬁnds that Ibn al-Naﬁs discussed pulmonary blood ﬂow in the 1200s, during the Golden Age of Arabic science. Cultural slight and historical details aside, the magnitude of Harvey’s achievement has been grossly exaggerated. Here, a reader can see more clearly how the inﬂated genius (Cases 1, 3, 4) is part of a persuasive strategy. The implicit lesson for the reader?: Harvey possessed some special form 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 believed that blood must ﬂow from the heart to the lungs, and that some blood ﬂowed back to the other side of the heart, but he also reasoned that blood might permeate the septum of the heart 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 had criticized Galen on this very point based on his observations decades earlier.) The uninformed reader never learns that Galen was a pioneer in dissection. He hardly would have advanced such a claim foolishly, in absence of any observation whatsoever. Here, Galen, as straw man, ﬁlls the narrative role of adversary, or villain. We never learn how Galen might have reasoned, nor why his ideas were respected for so long. Indeed, the question does not even 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 bold
implications of his theory:
If... the blood ﬂows away from the heart in the arteries, and If... 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 years after 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 reconstruct the reasoning knowing that capillaries exist. When I began teaching, I encountered this story about Harvey’s prediction and I believed it. I had not yet read Harvey’s original work. In his classic De motu cordis, Harvey describes how blood percolates in the lungs and 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 a later publication (A Second Disquisition to John Riolan). Harvey did not reason blindly. He had dissected many “lesser” animals that have hearts but no blood vessels (“open circulatory systems,” in our terminology). He had observed directly that connections were not needed.
Harvey did not predict capillaries. That misattribution eclipses the 17th-century perspective in which he reasoned. Yet it ﬁts the narrative goal of framing Harvey as a scientiﬁc hero who champions a certain style of reasoning.
Harvey supposedly further exercised if – then reasoning to frame numerous tests, as described in his landmark book. But this means reading Harvey as plainly describing the investigative process, rather than trying to persuade his readers. Indeed, it is not too difﬁcult to discern Harvey’s own rhetorical strategy. He offers numerous demonstrations, such as 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. Cesalpius linked the pulmonary circuit to thinking about cycles in nature and chemical distillation (resonating with Fludd’s interpretation, see later).
SCIENTIFIC MYTH-CONCEPTIONS 341 the one portrayed in the renowned ﬁgure of ligatured arms. These are not “tests” in the
sense 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 for the science itself, with misleading results. Narratively, however, a method is only justiﬁed by 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-scale planetary patterns should be echoed in smaller-scale physiological systems (p. 482).
This is the microcosm–macrocosm concept of the chemical philosophy, shared by Robert Fludd, a close friend of Harvey’s. The analogy also extended to chemical reactions, strengthening the analogical resonance. Harvey used this image throughout his book, sometimes explicitly as an argument. He described the heart as the sun of the microcosm, giving warmth and life to the body. That seems very strange to us today – and decidedly “unscientiﬁc.” Yet historians document that this analogy was integral to Harvey’s very reasoning. Some may want to discount that this microcosm worldview could lead Harvey to “discover” something we now regard as true. No doubt because the analogy is false by today’s standards. Attributing it to Harvey appears to lessen his status as a scientist. But it is coupled with Harvey’s achievement. It is essential if we want to understand scientiﬁc reasoning, and portray it faithfully to students. But in Lawson’s article, the analogy is only curtly acknowledged, then abandoned as peripheral. The historical facts, even about reasoning, seems secondary to the persuasive aims of the “historical” narrative.