Medical Epistemology

I argue that the concept of normality in medical research and practice is inextricable from that of ambiguity. I do so in the context of Edmund Pellegrino's call for a renewed reflection on medicine’s basic concepts and by drawing on work in critical disability studies concerning Deafness and body integrity identity disorder. If medical practitioners and philosophers of medicine wish to improve their understanding of the meaning of medicine as well as its concrete practice, they should take seriously the import (...) and centrality of ambiguity. (shrink)

The paper will compare two methods used in the design of diagnostic strategies. The first one is a method that precises predictive value of diagnostic tests. The second one is based on the use of Bayes’ theorem. The main aim of this article is to identify the epistemological assumptions underlying both of these methods. For the purpose of this objective, example projects of one and multi-stage diagnostic strategy developed using both methods will be considered.

The paper deals with the procedure of explaining the secondary immune response. First, the basic concepts of the mechanistic account of explanation developed by Machamer, Darden and Craver will be considered. Subsequently, I will focus on the concepts describing the activation of the elements of the immunological system viewed as a signal decoding process. The analysis will make it possible to argue for the thesis that the explanations of the secondary immune response, formulated in immunology, aim to describe the possible (...) procedures of simplifying the signal decoding process. The following considerations will make it possible to show the specificity of the mechanistic explanations formulated in immunology, and to demonstrate their significance for medical sciences. (shrink)

Population health has recently grown from a series of loosely connected critiques of twentieth-century public health and medicine into a theoretical framework with a corresponding field of research—population health science. Its approach is to promote the public’s health through improving everyday human life: affordable nutritious food, clean air, safe places where children can play, living wages, etc. It recognizes that addressing contemporary health challenges such as the prevalence of type 2 diabetes will take much more than good hospitals and public (...) health departments. -/- Blending philosophy of science/medicine, public health ethics and history, this book offers a framework that explains, analyses and largely endorses the features that define this relatively new field. Presenting a philosophical perspective, Valles helps to clarify what these features are and why they matter, including: searching for health’s “upstream” causes in social life, embracing a professional commitment to studying and ameliorating the staggering health inequities in and between populations; and reforming scientific practices to foster humility and respect among the many scientists and non- scientists who must work collaboratively to promote health. -/- Featuring illustrative case studies from around the globe at the end of all main chapters, this radical monograph is written to be accessible to all scholars and advanced students who have an interest in health—from public health students to professional philosophers. (shrink)

Contemporary reasoning about health is infused with the work products of experts, and expert reasoning about health itself is an active site for invention and design. Building on Toulmin’s largely undeveloped ideas on field-dependence, we argue that expert fields can develop new inference rules that, together with the backing they require, become accepted ways of drawing and defending conclusions. The new inference rules themselves function as warrants, and we introduce the term “warranting device” to refer to an assembly of the (...) rule plus whatever material, procedural, and institutional resources are required to assure its dependability. We present a case study on the Cochrane Review, a new method for synthesizing evidence across large numbers of scientific studies. After reviewing the evolution and current structure of the device, we discuss the distinctive kinds of critical questions that may be raised around Cochrane Reviews, both within the expert field and beyond. Although Toulmin’s theory of field-dependence is often criticized for its relativism, we find that, as a matter of practical fact, field-specific warrants do not enjoy immunity from external critique. On the contrary, they can be opened to evaluation and critique from any interested perspective. (shrink)

What constitutes clinical reasoning is a disputed subject regarding the processes underlying accurate diagnosis, the importance of patient‐specific versus population‐based data, and the relation between virtue and expertise in clinical practice. In this paper, I present a model of clinical reasoning that identifies and integrates the processes of diagnosis, prognosis, and therapeutic decision making. The model is based on the generalized empirical method of Bernard Lonergan, which approaches inquiry with equal attention to the subject who investigates and the object under (...) investigation. After identifying the structured operations of knowing and doing and relating these to a self‐correcting cycle of learning, I correlate levels of inquiry regarding what‐is‐going‐on and what‐to‐do to the practical and theoretical elements of clinical reasoning. I conclude that this model provides a methodical way to study questions regarding the operations of clinical reasoning as well as what constitute significant clinical data, clinical expertise, and virtuous health care practice. (shrink)

Explores the ethical issues faced by GPs in their everyday practice, addressing two central themes; the uncertainty of outcomes and effectiveness in general practice and the changing pattern of general practitioners' responsibilities.

This article analyses the phenomenon of epistemic injustice within contemporary healthcare. We begin by detailing the persistent complaints patients make about their testimonial frustration and hermeneutical marginalization, and the negative impact this has on their care. We offer an epistemic analysis of this problem using Miranda Fricker's account of epistemic injustice. We detail two types of epistemic injustice, testimonial and hermeneutical, and identify the negative stereotypes and structural features of modern healthcare practices that generate them. We claim that these stereotypes (...) and structural features render ill persons especially vulnerable to these two types of epistemic injustice. We end by proposing five avenues for further work on epistemic injustice in healthcare. (shrink)

Part of a symposium devoted to ‘Prediction, Understanding, and Medicine’, in which Alex Broadbent argues that the nature of medicine is determined by its competences, i.e., which things it can do well. He argues that, although medicine cannot cure well, it can do a good job of enabling people not only to understand states of the human organism and of what has caused them, but also to predict future states of it. From this Broadbent concludes that medicine is (at least (...) in part) essentially a practice of understanding and predicting, not curing. In reply to this bold position, I mount two major criticisms. First, I maintain that the reasons Broadbent gives for doubting that medicine can cure provide comparable reason for doubting that medicine can provide an understanding; roughly, the best explanation of why medicine cannot reliably cure is that we still lack much understanding of health and disease. Second, I object to the claim that a practice is medical only if it facilitates understanding and prediction. Although Broadbent has brought to light certain desirable purposes of medicine that are under-appreciated, my conclusion is that he has not yet provided enough reason to think that understanding and prediction are essential to it. Instead of supposing that medicine has an essence, in fact, I suggest that its nature is best understood in terms of a property cluster. (shrink)

The first part of a symposium devoted to Alex Broadbent's essay titled ‘Prediction, Understanding and Medicine’, this article notes the under-development of a variety of issues in the philosophy of medicine that transcend bioethics and the long-standing debates about the nature of health/illness and of evidence-based medicine. It also indicates the importance of drawing on non-Western, and particularly African, traditions in addressing these largely metaphysical and epistemological matters.

Increasing philosophical attention is being directed to the rapidly growing discipline of evidence-based medicine. Philosophical discussions of EBM, however, remain narrowly focused on randomization, mechanisms, and the sociology of EBM. Other aspects of EBM have been all but ignored, including the nature of clinical reasoning and the question of whether it can be standardized; the application of EBM principles to the logic, value, and ethics of diagnosis and prognosis; evidence synthesis ; and the nature and ethics of placebo controls. Philosophical (...) analysis in each of these areas has the potential to enhance the discussion of EBM methodology and practice. (shrink)

Over the past seven decades, randomised controlled trials (RCTs) have revolutionised clinical research and achieved a gold standard status. However, extending their use to evaluate complex interventions is problematic. In this paper we will demonstrate that complex intervention RCTs violate the necessary premises that govern the RCTs logic and underpin their rigour. The lack of blinding, heterogeneity of participants, as well as poor treatment standardisation and difficulty of controlling for confounders, which characterise complex intervention RCTs, can potentially be profoundly detrimental (...) to their integrity. Proponents of this approach argue that matching “real world” circumstances, while maintaining the randomised design, enhances external validity. We counter this argument by pointing out that an inverted U relation exists between internal and external validity, and thus relaxing the experimental conditions beyond a certain threshold can potentially paradoxically render the RCT externally invalid, i.e. its results cannot be used anywhere. We shall illustrate the inappropriate use of RCTs to evaluate community treatment orders and propose an alternative epistemic model that is based on mechanistic reasoning and Cartwright's capacity concept. (shrink)

We survey several ways in which the structures and norms of medicine and healthcare can generate epistemic injustice.

The requirement of randomization in experimental design was first stated by R. A. Fisher, statistician and geneticist, in 1925 in his book Statistical Methods for Research Workers. Earlier designs were systematic and involved the judgment of the experimenter; this led to possible bias and inaccurate interpretation of the data. Fisher's dictum was that randomization eliminates bias and permits a valid test of significance. Randomization in experimenting had been used by Charles Sanders Peirce in 1885 but the practice was not continued. (...) Fisher developed his concepts of randomizing as he considered the mathematics of small samples, in discussions with "Student," William Sealy Gosset. Fisher published extensively. His principles of experimental design were spread worldwide by the many "voluntary workers" who came from other institutions to Rothamsted Agricultural Station in England to learn Fisher's methods. (shrink)

Values-Based Medicine (VBM) is the theory and practice of clinical decision-making for situations in which legitimately different values are in play. VBM is thus to values what Evidence-Based Medicine (EBM) is to facts. The theoretical basis of VBM is a branch of analytic philosophy called philosophical value theory. As a set of practical tools, VBM has been developed to meet the challenges of value diversity as they arise particularly in psychiatry. These challenges are illustrated in this paper by a case (...) study of the differential diagnosis between delusion and religious experience. In a traditional model of scientific medicine, such challenges would be expected to become less pressing with advances in medical science. Philosophical value theory suggests, to the contrary, that scientific progress, through opening up an ever-wider range of choices, will increasingly bring the full range and diversity of human values into play not just in psychiatry but in all areas of medicine. The future, then, for medicine, is an integrated model in which VBM and EBM are equal partners in a genuinely human discipline. (shrink)

The purpose of this chapter is to describe what we see as several important new directions for philosophy of medicine. This recent work (i) takes existing discussions in important and promising new directions, (ii) identifies areas that have not received sufficient and deserved attention to date, and/or (iii) brings together philosophy of medicine with other areas of philosophy (including bioethics, philosophy of psychiatry, and social epistemology). To this end, the next part focuses on what we call the “epistemological turn” in (...) recent work in the philosophy of medicine; the third part addresses new developments in medical research that raise interesting questions for philosophy of medicine; the fourth part is a discussion of philosophical issues within the practice of diagnosis; the fifth part focuses on the recent developments in psychiatric classification and scientific and ethical issues therein, and the final part focuses on the objectivity of medical research. (shrink)

Harms of medical interventions are systematically underestimated in clinical research. Numerous factors—conceptual, methodological, and social—contribute to this underestimation. I articulate the depth of such underestimation by describing these factors at the various stages of clinical research. Before any evidence is gathered, the ways harms are operationalized in clinical research contributes to their underestimation. Medical interventions are first tested in phase 1 ‘first in human’ trials, but evidence from these trials is rarely published, despite the fact that such trials provide the (...) foundation for assessing the harm profile of medical interventions. If a medical intervention is deemed safe in a phase 1 trial, it is tested in larger phase 2 and 3 clinical trials. One way to think about the problem of underestimating harms is in terms of the statistical ‘power’ of a clinical trial—the ability of a trial to detect a difference of a certain effect size between the experimental group and the control group. Power is normally thought to be pertinent to detecting benefits of medical interventions. It is important, though, to distinguish between the ability of a trial to detect benefits and the ability of a trial to detect harms. I refer to the former as power-B and the latter as power-H. I identify several factors that maximize power-B by sacrificing powerH in phase 3 clinical trials. If a medical intervention is approved for general use, it is evaluated by phase 4 post-market surveillance. Phase 4 surveillance of harms further contributes to underestimating the harm profile of medical interventions. At every stage of clinical research the hunt for harms is shrouded in secrecy, which further contributes to the underestimation of the harm profiles of medical interventions. (shrink)

Measuring the effectiveness of medical interventions faces three epistemological challenges: the choice of good measuring instruments, the use of appropriate analytic measures, and the use of a reliable method of extrapolating measures from an experimental context to a more general context. In practice each of these challenges contributes to overestimating the effectiveness of medical interventions. These challenges suggest the need for corrective normative principles. The instruments employed in clinical research should measure patient-relevant and disease-specific parameters, and should not be sensitive (...) to parameters that are only indirectly relevant. Effectiveness always should be measured and reported in absolute terms (using measures such as 'absolute risk reduction'), and only sometimes should effectiveness also be measured and reported in relative terms (using measures such as 'relative risk reduction')-employment of relative measures promotes an informal fallacy akin to the base-rate fallacy, which can be exploited to exaggerate claims of effectiveness. Finally, extrapolating from research settings to clinical settings should more rigorously take into account possible ways in which the intervention in question can fail to be effective in a target population. (shrink)

To be effective, a medical intervention must improve one's health by targeting a disease. The concept of disease, though, is controversial. Among the leading accounts of disease-naturalism, normativism, hybridism, and eliminativism-I defend a version of hybridism. A hybrid account of disease holds that for a state to be a disease that state must both (i) have a constitutive causal basis and (ii) cause harm. The dual requirement of hybridism entails that a medical intervention, to be deemed effective, must target either (...) the constitutive causal basis of a disease or the harms caused by the disease (or ideally both). This provides a theoretical underpinning to the two principle aims of medical treatment: care and cure. (shrink)

Evidence hierarchies are widely used to assess evidence in systematic reviews of medical studies. I give several arguments against the use of evidence hierarchies. The problems with evidence hierarchies are numerous, and include methodological shortcomings, philosophical problems, and formal constraints. I argue that medical science should not employ evidence hierarchies, including even the latest and most-sophisticated of such hierarchies.

Whipple disease is a rare, infectious, disease first described from a single case by Whipple in 1907. As well as characterising the clinical and pathological features of the condition, Whipple made two suggestions regarding its aetiology. These were either than the disease was caused by an infectious agent, or that it was of metabolic origin. As the disease is now thought to be caused by infection with the bacterium Tropheryma whipplei, historical reviews of the history of the disease typically mention (...) only the first of these suggestions. In this paper, we therefore revisit Whipple’s other theory. We argue that a diverse and often successful research programme was developed around this mechanism of disease causation which gave rise to many useful findings on the condition. In the later parts of this article, we then turn to discuss the surprising neglect of this period of Whipple disease research in the current literature, and conclude by offering a brief reconstruction of this early history suitable for use in a technical context. (shrink)

Despite the increasing recognition that heuristics may be involved in myriad scientific activities, much about how to use them prudently remains obscure. As typically defined, heuristics are efficient rules or procedures for converting complex problems into simpler ones. But this increased efficiency and problem-solving power comes at the cost of a systematic bias. As Wimsatt showed, biased modelling heuristics can conceal errors, leading to poor decisions or inaccurate models. This liability to produce errors presents a fundamental challenge to the philosophical (...) value of heuristic analyses. Heuristics may be powerful and efficient procedures, but their practical value for science and epistemology is significantly mitigated if we do not have a principled methodology for knowing how to use them wisely. In this essay, I extend Wimsatt’s analyses to argue that this challenge for a heuristic methodology can be met by appealing to second-order, or meta-, heuristics—that is, practical guidelines that prescribe the appropriate conditions for a first-order heuristic’s use. 1 Introduction2 Background3 Heuristics and Meta-heuristics4 A Hierarchical Model and Three Applications4.1 Decision making in emergency medicine4.2 Mathematical explanation in physics4.3 Resilience in ecological management5 Conclusion. (shrink)

Hierarchies of evidence are an important and influential tool for appraising evidence in medicine. In recent years, hierarchies have been formally adopted by organizations including the Cochrane Collaboration [1], NICE [2,3], the WHO [4], the US Preventive Services Task Force [5], and the Australian NHMRC [6,7]. The development of such hierarchies has been regarded as a central part of Evidence-Based Medicine, a movement within healthcare which prioritises the use of epidemiological evidence such as that provided by Randomised Controlled Trials. Philosophical (...) work on the methodology of medicine has so far mostly focused on claims about the superiority of RCTs, and hence has largely neglected the questions of what hierarchies are, what assumptions they require, and how they affect clinical practice. This thesis shows that there is great variation in the hierarchies defended and in the interpretations they are, and can be, given. The interpretative assumptions made in using hierarchies are crucial to the content and defensibility of the underlying philosophical commitments concerning evidence and medical practice. Once this variation is been identified, it becomes clear that the little philosophical work that has been done so far affects only some hierarchies, under some interpretations. Modest interpretations offered by La Caze [11], conditional hierarchies like GRADE [12-14], and heuristic approaches such as that defended by Howick et al. [15,16] all survive previous philosophical criticism. This thesis extends previous criticisms by arguing that modest interpretations are so weak as to be unhelpful for clinical practice; that GRADE and similar conditional models omit clinically relevant information, such as information about variation in treatments’ effects and the causes of different responses to therapy; and that heuristic approaches lack the necessary empirical support. The conclusion is that hierarchies in general embed untenable philosophical assumptions: principally that information about average treatment effects backed by high-quality evidence can justify strong recommendations, and that the impact of evidence from individual studies can and should be appraised in isolation. Hierarchies are a poor basis for the application of evidence in clinical practice. The Evidence-Based Medicine movement should move beyond them and explore alternative tools for appraising the overall evidence for therapeutic claims. (shrink)

This is a response to the response by Robyn Bluhm to my paper, and I am again arguing for a limited role of capacities in psychiatry, given the current scientific uncertainties.

Cartwright and Munro argued that extrapolation of findings from randomized controlled trials to other settings can be difficult because information about the underlying causal structure and subgroups is often not available. They advocated the use of ‘capacities’ – that is fixed causal contributions – in predicting effects of interventions. In psychiatry, it is often not possible to determine what the fixed causal contributions are and one can only establish ‘approximate capacities’. However, using ‘approximate capacities’ does imply a different way of (...) evaluating health services, especially combined interventions. In health service research, if different studies, randomized controlled trials or other designs, have given different outcomes, the best way to investigate the effectiveness of a particular way of service organization is not to conduct more randomized controlled trials. It is preferable to study the effects of certain elements of the complex intervention, which have been tested before in other settings, that is investigating ‘approximate capacities’. One should check whether the separate elements do form a part of the complex intervention in practice and whether they have the same effect as in other studies and if not, why not. This enhances knowledge about the underlying causal structure and increases the possibility of extrapolation of the findings. (shrink)

MALARIA, SCIENCE AND SOCIETY IN FERRARA FROM THE MIDDLE AGES TO THE NINETEENTH CENTURY -/- In this paper it is outlined the history of malaria in Ferrara and its suburbs, from ancient times up to the nineteenth century. It is considered the issue of malaria in Roman times, during the Middle Ages and the Renaissance, the discovery of quinine, the first scientific studies made at the University of Ferrara, the first analysis about the causes and the spread of the disease. (...) The conditions of backwardness of Ferrara society are considered, especially of the people living in the countryside, and the most common medical knowledge. Statistics about the spread of malaria after the unification of Italy are resumed. Problems of environmental recovery are taken into account. Scientific progresses due to positivism and to the doctors who faced the first anti-malarial campaigns, bringing their testimonies. The essay ends up with the reorganization of public health and places of health care in modern hospitals all over the province of Ferrara. (shrink)

In medicine and the social sciences, researchers must frequently integrate the findings of many observational studies, which measure overlapping collections of variables. For instance, learning how to prevent obesity requires combining studies that investigate obesity and diet with others that investigate obesity and exercise. Recently developed causal discovery algorithms provide techniques for integrating many studies, but little is known about what can be learned from such algorithms. This article argues that there are causal facts that one could learn by conducting (...) a large study but which could not be learned by combining many smaller studies. Moreover, I characterize the frequency with which combining many studies increases underdetermination and exactly how much information is lost. 1 Introduction2 Causal Inference from Observational Data3 Piecemeal Causal Inference4 The Extent and Frequency of the Problem of Piecemeal Induction5 Conclusion. (shrink)

This paper considers the view that medicine is both “science” and “art.” It is argued that on this view certain clinical knowledge – of patients’ histories, values, and preferences, and how to integrate them in decision-making – cannot be scientific knowledge. However, by drawing on recent work in philosophy of science it is argued that progress in gaining such knowledge has been achieved by the accumulation of what should be understood as “scientific” knowledge. I claim there are varying degrees of (...) objectivity pertaining to various aspects of clinical medicine. Hence, what is often understood as constituting the “art” of medicine is amenable to objective methods of inquiry, and so, may be understood as “science”. As a result, I conclude that rather than endorse the popular philosophical distinction between the art and science of medicine, in the future a unified, multifaceted epistemology of medicine should be developed to replace it. (shrink)

Acupuncture, the traditional Chinese practice of needling to alleviate pain, offers a striking case where scientific accounts in two cultures, East and West, diverge sharply. Yet the Chinese comfortably embrace the apparent ontological incommensurability. Their pragmatic posture resonates with the New Experimentalism in the West--but with some provocative differences. The development of acupuncture in China (and not in the West) further suggests general research strategies in the context of discovery. My analysis also exemplifies how one might fruitfully pursue a comparative (...) philosophy of science that explores how other cultures investigate and validate their conclusions about the natural world. (shrink)

Although American philosophers and physicians are generally familiar with the writings of Claude Bernard (1813–1878), especially his Introduction to the Study of Experimental Medicine (1865), the medicial epistemology of Georges Canguilhem, born in 1904, is virtually unknown in English speaking nations. Although indebted to Bernard for his conception of the methods to be employed in the acquisition of medical knowledge, Canguilhem radically reformulates Bernard's concepts of ‘disease’, ‘health’, ‘illness’, and ‘pathology’. Contemporary exhortations to medical professionals and medical students that they (...) “pay more attention to the whole patient” take on significance in working through the writings of Canguilhem; of crucial importance is the relation that obtains between a patient's unique symptomatology and the proper drug regiment that is required. (shrink)

This exchange of correspondence with a critic provides helpful explanations of aspects of the paper "On Evidence, Medical and Legal" by the same authors.

In the contemporary biomedical literature, every disease is considered genetic. This extension of the concept of genetic disease is usually interpreted either in a trivial or genocentrist sense, but it is never taken seriously as the expression of a genetic theory of disease. However, a group of French researchers defend the idea of a genetic theory of infectious diseases. By identifying four common genetic mechanisms (Mendelian predisposition to multiple infections, Mendelian predisposition to one infection, and major gene and polygenic predispositions), (...) they attempt to unify infectious diseases from a genetic point of view. In this article, I analyze this explicit example of a genetic theory, which relies on mechanisms and is applied only to a specific category of diseases, what we call “a regional genetic theory.” I have three aims: to prove that a genetic theory of disease can be devoid of genocentrism, to consider the possibility of a genetic theory applied to every disease, and to introduce two hypotheses about the form that such a genetic theory could take by distinguishing between a genetic theory of diseases and a genetic theory of Disease. Finally, I suggest that network medicine could be an interesting framework for a genetic theory of Disease. (shrink)

It is often said that clinical research and the practice of medicine are fraught with uncertainties. But what do we mean by uncertainty? Where does uncertainty come from? How do we measure uncertainty? Is there a single theory of uncertainty that applies across all scientific domains, including the science and practice of medicine? To answer these questions, we first review the existing theories of uncertainties. We then attempt to bring the enormous literature to bear from other disciplines to address the (...) issue of uncertainty in clinical research and medical practice. Our main and overarching goal is to review and classify uncertainties in clinical medicine. (shrink)