The history of the research on peptic ulcer disease is characterized by a premature abandonment of the bacterial hypothesis, which subsequently had its comeback, leading to the discovery of Helicobacter pylori—the major cause of the disease. In this paper we examine the received view on this case, according to which the primary reason for the abandonment of the bacterial hypothesis in the mid-twentieth century was a large-scale study by a prominent gastroenterologist Palmer, which suggested no bacteria could be (...) found in the human stomach. To this end, we employ the method of digital textual analysis and study the literature on the etiology of PUD published in the decade prior to Palmer’s article. Our findings suggest that the bacterial hypothesis had already been abandoned before the publication of Palmer’s paper, which challenges the widely held view that his study played a crucial role in the development of this episode. In view of this result, we argue that the PUD case does not illustrate harmful effects of a high degree of information flow, as it has frequently been claimed in the literature on network epistemology. Moreover, we argue that alternative examples of harmful effects of a high degree of information flow may be hard to find in the history of science. (shrink)

The history of the research on peptic ulcer disease is characterized by a premature abandonment of the bacterial hypothesis, which subsequently had its comeback, leading to the discovery of Helicobacter pylori – the major cause of the disease. In this paper we examine the received view on this case, according to which the primary reason for the abandonment of the bacterial hypothesis in the mid-twentieth century was a large-scale study by a prominent gastroenterologist Palmer, which suggested no bacteria (...) could be found in the human stomach. To this end, we employ the methodof digital textual analysis and study the literature on the etiology of PUD published in the decade prior to Palmer’s article. Our findings suggest that the bacterial hypothesis had already been abandoned before the publication of Palmer’s paper, which challenges the widely held view that his study played a crucial role in the development of this episode. In view of this result, we argue that the PUD case does not illustrate harmful effects of a high degree of information flow, as it has frequently been claimed in the literature on network epistemology. Moreover, we argue that alternative examples of harmful effects of a high degree of information flow may be hard to find in the history of science. (shrink)

Throughout the first half of the twentieth century the research on peptic ulcer disease focused on two rivaling hypothesis: the “acidity” and the “bacterial” one. According to the received view, the latter was dismissed during the 1950s only to be revived with Warren’s and Marshall’s discovery of Helicobacter pylori in the 1980s. In this paper we investigate why the bacterial hypothesis was largely abandoned in the 1950s, and whether there were good epistemic reasons for its dismissal. Of special (...) interest for our research question is Palmer’s 1954 large-scale study, which challenged the bacterial hypothesis with serious counter-evidence, and which by many scholars is considered as the shifting point in the research on PUD. However, we show that: The perceived refutatory impact of Palmer’s study was disproportionate to its methodological rigor. This undermines its perceived status as a crucial experiment against the bacterial hypothesis. In view of this and other considerations we argue that the bacterial hypothesis was worthy of pursuit in the 1950s. (shrink)

In 1983, Dr. J. Robin Warren and Dr. Barry Marshall reported finding a new kind of bacteria in the stomachs of people with gastritis. Warren and Marshall were soon led to the hypothesis that peptic ulcers are generally caused, not by excess acidity or stress, but by a bacterial infection. Initially, this hypothesis was viewed as preposterous, and it is still somewhat controversial. In 1994, however, a U. S. National Institutes of Health Consensus Development Panel concluded that infection appears (...) to play an important contributory role in the pathogenesis of peptic ulcers, and recommended that antibiotics be used in their treatment. Peptic ulcers are common, affecting up to 10% of the population, and evidence has mounted that many ulcers can be cured by eradicating the bacteria responsible for them. (shrink)

The corpse of a high-ranking male official was unearthed in the 1975, and important archaeologic discoveries were claimed. The exact year of his funeral was 167 BC. Autopsy revealed that the man had peptic ulcer disease. His naked body exposing genitalia and post-dissection stitches, with the dissected-out intestines and brain lying alongside, is now exhibited in a formalin-impregnated viewing glass tank in a museum .Meanwhile a 2000-year-old clothed female corpse is on display in another museum. In 1971, workers (...) in …. (shrink)

What is W. V. O. Quine’s relationship to classical pragmatism? Although he resists the comparison to William James in particular, commentators have seen an affinity between his “web of belief” model of theory confirmation and James’s claim that our beliefs form a “stock” that faces new experience as a corporate body. I argue that the similarity is only superficial. James thinks our web of beliefs should be responsive not just to perceptual but also to emotional experiences in some cases; Quine (...) denies this. I motivate James’s controversial view by appealing to an episode in the history of medicine when a researcher self-experimented by swallowing a vial of bacteria that at the time had not been studied in much detail. The researcher’s commitment to his own as-yet untested hypothesis was based in part on emotional considerations. Finally, I argue that Quine’s insistence that emotions can never be relevant to adjusting our web of belief reflects a tacit holdover of one of logical positivism’s crucially anti-pragmatist commitments—that philosophy of science should focus exclusively on the context of justification, not the context of discovery. James’s emphasis on discovery as a (perhaps the) crucial locus for epistemological inquiry is characteristic of pragmatism in general. Since Quinean epistemology is always an epistemology of justification, he is not happily viewed as a member of the pragmatist tradition. (shrink)

"This is a wonderful book! In "How Scientists Explain Disease," Paul Thagard offers us a delightful essay combining science, its history, philosophy, and sociology.

Hospital admission and mortality statistics suggested that peptic ulcer reached a peak prevalence in the mid-1950s. During the Second World War, against this background of serious and common pathology, an epidemic of dyspepsia afflicted both service personnel and civilians alike. In the absence of reliable diagnostic techniques, physicians struggled to distinguish between life-threatening illness and mild, temporary disorders. This article explores the context in which non-ulcer stomach conditions flourished. At a time when fear was considered defeatist and (...) overt psychological disorder attracted stigma, both soldiers and civilians exposed to frightening events may have unconsciously translated their distress into gastrointestinal disorders. While the nature of army food was initially identified as the cause of duodenal ulcer in servicemen, the pre-war idea that conscientious and anxious individuals were at high risk gathered support and fed into post-war beliefs that this was a stress-related illness. Diet continued to be employed as a means of management at a time when the nation was preoccupied by food because of the constraints imposed by rationing. The peptic ulcer phenomenon set much of the medical agenda for the war years and conflicted with the commonly held view that the British people had never been healthier. (shrink)

According to van Fraassen, constructive empiricism (CE) makes better sense of scientific activity than scientific realism (SR). I discuss a recent episode in biomedical research - investigations about Helicobacter Pylori and its relation to peptic ulcer. CE's expedient to cope with it is a sort of belief substitution. I argue that replacing realist beliefs by empiricist surrogates (as-if beliefs) could accommodate scientists' expectations and behavior. Nonetheless, theoretical agnosticism could hardly motivate scientists to focus just on the observational consequences (...) derived from the theory at issue. Contrary to van Fraassen, I conclude then that, concerning scientific practice, realist beliefs cannot be considered as a gratuitious surplus which should be rejected. (shrink)

Hospital admission and mortality statistics suggested that peptic ulcer reached a peak prevalence in the mid-1950s. During the Second World War, against this background of serious and common pathology, an epidemic of dyspepsia afflicted both service personnel and civilians alike. In the absence of reliable diagnostic techniques, physicians struggled to distinguish between life-threatening illness and mild, temporary disorders. This article explores the context in which non-ulcer stomach conditions flourished. At a time when fear was considered defeatist and (...) overt psychological disorder attracted stigma, both soldiers and civilians exposed to frightening events may have unconsciously translated their distress into gastrointestinal disorders. While the nature of army food was initially identified as the cause of duodenal ulcer in servicemen, the pre-war idea that conscientious and anxious individuals were at high risk gathered support and fed into post-war beliefs that this was a stress-related illness. Diet continued to be employed as a means of management at a time when the nation was preoccupied by food because of the constraints imposed by rationing. The peptic ulcer phenomenon set much of the medical agenda for the war years and conflicted with the commonly held view that the British people had never been healthier. (shrink)

In 1983, Dr. J. Robin Warren and Dr. Barry Marshall reported finding a new kind of bacteria in the stomachs of people with gastritis. Warren and Marshall were soon led to the hypothesis that peptic ulcers are generally caused, not by excess acidity or stress, but by a bacterial infection. Initially, this hypothesis was viewed as preposterous, and it is still somewhat controversial. In 1994, however, a U. S. National Institutes of Health Consensus Development Panel concluded that infection appears (...) to play an important contributory role in the pathogenesis of peptic ulcers, and recommended that antibiotics be used in their treatment. Peptic ulcers are common, affecting up to 10% of the population, and evidence has mounted that many ulcers can be cured by eradicating the bacteria.. (shrink)

My description of the cognitive processes involved in the discovery, development, and acceptance of the bacterial theory of ulcers might have left the impression that science is all in the mind (Thagard, forthcoming-b). But only part of the story of the bacterial theory of ulcers is psychological. This paper discusses the important role of physical interaction with the world by means of instruments and experiments, and the equally important role of social interactions among the medical researchers who developed the theory. (...) The main questions I want to answer are the following: 1. What instruments contributed to the development and acceptance of the new theory? 2. What kinds of experiments contributed to the development and acceptance of the new theory? 3. How did theorizing and experimentation interact in the development of new experiments and hypotheses? 4. How did social processes such as collaboration, communication, and consensus contribute to the development and widespread acceptance of the bacterial theory of ulcers? I conclude with a sketch of science as a complex system of interacting psychological, physical, and social processes. (shrink)

This study seeks to advance the understanding of controversy resolution in science. I take as a case study conceptualization and treatment of ulcer disease. Analysis of causal accounts and effective treatments illustrate the ways in which competing parallel research programs in medicine embody opposing social, political, and economic forces which are bound to the epistemological dimensions of scientific controversy (e.g., standards of evidence, reference, and inference), and which in turn shift perception of the burden of proof. The analysis illustrates (...) the ways in which (1) medical diagnoses create as much as discover useful distinctions and (2) epistemic and non epistemic values divide scientists into competing research programs, as well as (3) the ways in which these structures often effectively prevent scientific controversy closure. (shrink)

Human microbiome research makes causal connections between entire microbial communities and a wide array of traits that range from physiological diseases to psychological states. To evaluate these causal claims, we first examine a well-known single-microbe causal explanation: of Helicobacter pylori causing ulcers. This apparently straightforward causal explanation is not so simple, however. It does not achieve a key explanatory standard in microbiology, of Koch’s postulates, which rely on manipulations of single-microorganism cultures to infer causal relationships to disease. When Koch’s postulates (...) are framed by an interventionist causal framework, it is clearer what the H. pylori explanation achieves and where its explanatory strengths lie. After assessing this ‘simple’, single-microbe case, we apply the interventionist framework to two key areas of microbiome research, in which obesity and mental health states are purportedly explained by microbiomes. Despite the experimental data available, interventionist criteria for explanation show that many of the causal claims generated by microbiome research are weak or misleading. We focus on the stability, specificity and proportionality of proposed microbiome causal explanations, and evaluate how effectively these dimensions of causal explanation are achieved in some promising avenues of research. We suggest some conceptual and explanatory strategies to improve how causal claims about microbiomes are made. (shrink)

Human microbiome research makes causal connections between entire microbial communities and a wide array of traits that range from physiological diseases to psychological states. To evaluate these causal claims, we first examine a well-known single-microbe causal explanation: of Helicobacter pylori causing ulcers. This apparently straightforward causal explanation is not so simple, however. It does not achieve a key explanatory standard in microbiology, of Koch’s postulates, which rely on manipulations of single-microorganism cultures to infer causal relationships to disease. When Koch’s postulates (...) are framed by an interventionist causal framework, it is clearer what the H. pylori explanation achieves and where its explanatory strengths lie. After assessing this ‘simple’, single-microbe case, we apply the interventionist framework to two key areas of microbiome research, in which obesity and mental health states are purportedly explained by microbiomes. Despite the experimental data available, interventionist criteria for explanation show that many of the causal claims generated by microbiome research are weak or misleading. We focus on the stability, specificity and proportionality of proposed microbiome causal explanations, and evaluate how effectively these dimensions of causal explanation are achieved in some promising avenues of research. We suggest some conceptual and explanatory strategies to improve how causal claims about microbiomes are made. (shrink)

Human microbiome research makes causal connections between entire microbial communities and a wide array of traits that range from physiological diseases to psychological states. To evaluate these causal claims, we first examine a well-known single-microbe causal explanation: of Helicobacter pylori causing ulcers. This apparently straightforward causal explanation is not so simple, however. It does not achieve a key explanatory standard in microbiology, of Koch’s postulates, which rely on manipulations of single-microorganism cultures to infer causal relationships to disease. When Koch’s postulates (...) are framed by an interventionist causal framework, it is clearer what the H. pylori explanation achieves and where its explanatory strengths lie. After assessing this ‘simple’, single-microbe case, we apply the interventionist framework to two key areas of microbiome research, in which obesity and mental health states are purportedly explained by microbiomes. Despite the experimental data available, interventionist criteria for explanation show that many of the causal claims generated by microbiome research are weak or misleading. We focus on the stability, specificity and proportionality of proposed microbiome causal explanations, and evaluate how effectively these dimensions of causal explanation are achieved in some promising avenues of research. We suggest some conceptual and explanatory strategies to improve how causal claims about microbiomes are made. (shrink)

For decades, aged care facility residents at risk of pressure ulcers (PUs) have been repositioned at two-hour intervals, twenty-four-hours-a-day, seven-days-a-week (24/7). Yet, PUs still develop. We used a cross-sectional survey of eighty randomly selected medical records of residents aged ≥ 65 years from eight Australian Residential Aged Care Facilities (RACFs) to determine the number of residents at risk of PUs, the use of two-hourly repositioning, and the presence of PUs in the last week of life. Despite 91 per cent (73/80) (...) of residents identified as being at risk of PUs and repositioned two-hourly 24/7, 34 per cent (25/73) died with one or more PUs. Behaviours of concern were noted in 72 per cent (58/80) of residents of whom 38 per cent (22/58) were restrained. Dementia was diagnosed in 70 per cent (56/80) of residents. The prevalence of behaviours of concern displayed by residents with dementia was significantly greater than by residents without dementia (82 per cent v 50 per cent, p = 0.028). The rate of restraining residents with dementia was similar to the rate in residents without dementia. Two-hourly repositioning failed to prevent PUs in a third of at-risk residents and may breach the rights of all residents who were repositioned two-hourly. Repositioning and restraining may be unlawful. Rather than only repositioning residents two-hourly, we recommend every resident be provided with an alternating pressure air mattress. (shrink)

The aim of this study was to illuminate nurses’ reflections on obstacles to and possibilities for providing care as desired by people with malodorous exuding ulcers. Six nurses who took part in a previous study were interviewed. The participants were shown an illustration with findings from a study that elucidated the meaning of living with malodorous exuding ulcers. They were asked to reflect on the obstacles to and possibilities of providing the care desired by the patients. Twelve audio-recorded transcribed interviews (...) were analysed using qualitative content analysis. Our interpretations of participants’ reflections on the obstacles and possibilities while caring for such patients revealed one theme: striving to ‘do good’ and ‘be good’. The obstacles were formulated as subthemes: experiencing clinical competence constraints, experiencing organizational constraints, experiencing ineffective communication, fearing failure, and experiencing powerlessness. The possibilities were formulated by the subthemes: spreading knowledge about ulcer treatments, considering wholeness, and creating clear channels of communication. A multiprofessional team could overcome the identified obstacles and provide structure, competencies, commitment and support to ‘do good’ for patients and ‘be good’ nurses. (shrink)

For decades, aged care facility residents at risk of pressure ulcers have been repositioned at two-hour intervals, twenty-four-hours-a-day, seven-days-a-week. Yet, PUs still develop. We used a cross-sectional survey of eighty randomly selected medical records of residents aged ≥ 65 years from eight Australian Residential Aged Care Facilities to determine the number of residents at risk of PUs, the use of two-hourly repositioning, and the presence of PUs in the last week of life. Despite 91 per cent of residents identified as (...) being at risk of PUs and repositioned two-hourly 24/7, 34 per cent died with one or more PUs. Behaviours of concern were noted in 72 per cent of residents of whom 38 per cent were restrained. Dementia was diagnosed in 70 per cent of residents. The prevalence of behaviours of concern displayed by residents with dementia was significantly greater than by residents without dementia. The rate of restraining residents with dementia was similar to the rate in residents without dementia. Two-hourly repositioning failed to prevent PUs in a third of at-risk residents and may breach the rights of all residents who were repositioned two-hourly. Repositioning and restraining may be unlawful. Rather than only repositioning residents two-hourly, we recommend every resident be provided with an alternating pressure air mattress. (shrink)

Newly developed techniques for anaesthesia and asepsis made it possible for surgeons to attempt operative attacks on diseases which had been previously incurable. The period around the turn of the century is sometimes portrayed as one of very active development of new surgical methods. This activity has been seen as a result of fertile scientific thinking. It is demonstrated in the paper that it was in fact a barren period with a prolonged adherence to an anatomical concept as the basis (...) for problem solving. It is described in terms of Kuhnian periods of normal activity and crisis. It took about fifty years before theory and practice were harmonized under a physiological concept and real progress was made. (shrink)