The Routledge Companion to Philosophy of Medicine

Miriam Solomon, Jeremy R. Simon, Harold Kincaid, Miriam Solomon, Jeremy R. Simon, Harold Kincaid

• Publisher: Routledge
• Year: 2016
• eBook ISBN: 9781317519843
• Topic: Philosophy
• Subtopic: Philosophy History & Theory

The Routledge Companion to Philosophy of Medicine is a comprehensive guide to topics in the fields of epistemology and metaphysics of medicine. It examines traditional topics such as the concept of disease, causality in medicine, the epistemology of the randomized controlled trial, the biopsychosocial model, explanation, clinical judgment and phenomenology of medicine and emerging topics, such as philosophy of epidemiology, measuring harms, the concept of disability, nursing perspectives, race and gender, the metaphysics of Chinese medicine, and narrative medicine. Each of the 48 chapters is written especially for this volume and with a student audience in mind. For pedagogy and clarity, each chapter contains an extended example illustrating the ideas discussed. This text is intended for use as a reference for students in courses in philosophy of medicine and philosophy of science, and pairs well with The Routledge Companion to Bioethics for use in medical humanities and social science courses.

Part I
General Concepts

1
The Concept of Disease

Dominic Sisti and
Arthur L. Caplan

Introduction

“What is disease?”

This simple question has vexed philosophers of medicine, yet has been overlooked entirely by bioethicists, physicians, and epidemiologists, with the exception of a rare few. On the one hand, dozens of philosophical theories paint starkly different pictures of the essential nature of disease. On the other hand, most bioethicists, policy makers, and clinicians take disease to be a given—the things we call diseases exist as such, they are bad, and they should, if possible, be treated or eliminated. Conversely, health is, quite simply, often thought to be the absence of disease.

It is across this landscape—from fine-grained analyses to straightforward pragmatism—that a multitude of perspectives on the nature and importance of the concept of disease coexist. This chapter offers a survey of this landscape and specific examples that illustrate the confusing nature and ambiguous applications of the concept of disease. We begin with a historical sketch and then examine contemporary philosophical theories of disease. To demonstrate the way these theories shape empirical realities, we offer cases across a range of medical specialties to illustrate theoretical perspectives.

From there we discuss both the clinical and health policy dimensions of the concept of disease. The concept of disease serves many purposes—identifying behavior that requires control, supporting excuses for absence from work or school, creating eligibility for benefits, and serving as the basis for exculpation in the eyes of the law. We pay particular attention to the complicated nature of psychiatric disease or disorder and lay out the significant practical stakes that depend upon the underlying theoretical orientation of disease.

Historical Thumbnails

The quest to “carve nature at its joints” and provide answers to the titular question of this chapter may be found in the metaphysics and epistemology of classifications of antiquity. Various approaches to categorizing the maladies of human existence are found in the Hippocratic Corpus and in the writings of Plato, Aristotle, and Galen (Hippocrates, 1780, Jowett, 1925, Chadwick, 1983). For the better part of two millennia, classical humoral explanations prevailed. Imbalances in the four basic substances of the body—blood, black and yellow bile, and phlegm—caused disease and disability. The medieval theological constructions of disease by the likes of Maimonides and Aquinas both drew upon the classicists and additionally characterized various diseases in terms of moral failing (Caplan et al., 2004).

The Renaissance polymath and occultist, Paracelsus, rejected humoral models of disease and instead developed a nosology based on external substance or “poisonous” causes (Caplan et al., 1981, Porter and Rousseau, 2004). Descartes, whose anatomical studies complemented his conception of the human organism as an ensouled machine, reframed the concept of disease in a more modern way. Disease was considered a mechanical dysfunction or external attack on the body and a deviation in the teleological functioning of the automatic motions of the body.

Throughout history, the question about the nature of psychiatric disease and mental disorder preoccupied physicians and philosophers alike. Phillipe Pinel aimed to parallel his methodical systematizing of medical and mental illness with that of Hippocrates. He drew upon the philosophies of Locke and Condillac in developing a system of psychopathology that was based upon empirical observation and fact-finding (Charland, 2010). To Pinel, the various mental disorders emerged from a single kind of mental alienation. He believed that sudden, often unexpected reversals in life arising “from the pleasure of success to an overwhelming idea of failure, from a dignified state—or the belief that one occupies one—to a state of disgrace and being forgotten” could bring on “mental alienation” or mania—what we might term today depression or anxiety (Gerard, 1997).

Around the same time, an exceptionally detailed and empirically based psychiatric nosology is presented in Kant’s Anthropology from a Pragmatic Point of View (Kant, 2006). In Anthropology, Kant constructs a highly accessible nosology that was not geared for physicians but might have been useful to philosophers and individuals interested in self-treatment (Frierson, 2009). He defines two general forms of mental disorder that affect the cognitive faculty: melancholia and derangement. The first is a milder form of mental illness that is treatable, whereas the latter seems to include severe psychotic syndromes, bipolar illness, and egosyntonic disorders (Sisti, 2012).

Formal systems of post-humoral nosology find their origin in the work of Thomas Sydenham; disease classification and diagnosis slowly evolves toward what is basically the mainstream view today—an understanding that infectious agents or internal mechanisms cause localized acute or chronic dysfunctions. William Harvey’s cardiovascular findings and Morgangni’s nosology set up the foundations of understanding diseases as tissue and organ specific—a way of thinking that would prove exceptionally valuable with the later advent of germ theory (Baronov, 2008).

The 19th century saw the emergence of scientific medicine and careful observation in both empirical research and in the categorization of ailments. Claude Bernard, Rudolf Vichow, and Walter Cannon developed theories of disease based on physiological findings related to inflammation, cancerous cell growth, and the loss of homeostasis.

The renewal of interest in the concept of disease in the second half of the 20th century may have in part emerged out of a new and applied ethics and philosophy of science that used biomedicine as both a source of puzzling cases and as a professional substrate (Toulmin, 1982). Some argued that a clarification of the basic concepts of medicine—disease, illness, health, disability, etc.—would be necessary for sorting out clinical and health policy problems (Daniels, 1985).

Clinicians who examined the concepts of health and disease began to recognize deep problems in the ways clinicians equivocated in their use of these terms. Members of the first generation of biomedical ethicists sought to build a new philosophy of medicine within which a more coherent theory of disease and health served a critical role. Edmund Pellegrino, for example, wrote early nosological tracts on osseous lesions that foreshadowed over a half-century of scholarship in the philosophy of medicine and bioethics (Pellegrino et al., 1971). Pellegrino’s conceptual work on the concept of disease fit within his overall project on defining the special, if not sacred, relationship between the virtuous physician and his patient (Pellegrino, 2008). He states that “clarification of medicine’s basic concepts is as much a moral as an intellectual obligation.… [C]onfusion about the nature of health and disease is ultimately confusion about the concept of medicine itself” (Pellegrino, 2004).

Today there are dozens of philosophical theories on the concept of disease, from which has emerged a complex classification-of-classifications debate. The most common is to distinguish between naturalism and normativism. For example, Hofmann illustrates that across the complex array of these many accounts, theories on the concept of disease fall within two broad categories—real essence and nominal essence accounts (Hofmann, 2001). Ereshefsky helpfully adds a third category and groups the theories into the broad categories of naturalist, normativist, and hybrid (Ereshefsky, 2009). This is the tripartite division we will follow in our discussion.

Naturalism

Disease naturalism is the general view that the concept of disease reflects an objective reality about cell, organ, or system function or dysfunction. Physician J. G. Scadding introduced a foundational naturalistic theory grounded upon a biostatistical concept of disease. To Scadding,

A disease is the sum of the abnormal phenomena displayed by a group of living organisms in association with a specified common characteristic or set of characteristics by which they differ from the norm for their species in such a way as to place them at a biological disadvantage.

(Scadding, 1968)

Christopher Boorse, echoing Scadding, developed and defended the most widely discussed contemporary naturalist theory. Boorse claims that the concept of disease is grounded in the

autonomous framework of medical theory, a body of doctrine that describes the functioning of a healthy body, classifies various deviations from such functioning as diseases.… This theoretical corpus looks in every way continuous with theory in biology and other natural sciences, and [is] value-free.

(Boorse, 1975)

Disease is defined by Boorse as

a type of internal state which is either an impairment of normal functional ability, i.e. a reduction of one or more functional abilities below typical efficiency, or a limitation on functional ability caused by environmental agents.

(Boorse, 1977)

As such, Boorse argues that diseases are recognizable against the objective backdrop of species-typical function—a concept he borrowed and refined from Scadding. Thus, the epistemic core of Boorse’s theory of disease is statistical—determining species typicality is an empirical question. Boorse has labeled his particular brand of naturalism the “biostatistical theory.” Biological dysfunction is both necessary and sufficient for defining disease.

Boorse draws a distinction between the concepts of disease and illness. He defines the concept of illness as a subclass of disease: those diseases that carry with them “certain normative features reflected in the instructions of medical practice” are considered illnesses (Boorse, 1975). To support the claim that the concept of disease is value-free, Boorse reminds us that we typically do not claim that plants or animals suffer from an illness. Rather, we describe plants and animals as simply afflicted by a disease. Potato blight, for example, renders its host diseased, not ill. One might ask, “What about cases of animal companions who are ‘sick’ or ‘ill’?” Boorse might respond that in those cases where we refer to animals, such as pets, as being sick or ill, it is in the context of a personal relationship, where we, acting as a companion and caregiver, bring to bear certain values we hold about the animal—for example, that it deserves treatment by a veterinarian.

Second, Boorse recognized that the ascription of illness grants the sufferer “special treatment and diminished moral accountability.” Thus, illness is a morally laden concept, whereas the concept of disease is, he maintains, completely value-free. According to Boorse (1975), “A disease is an illness only if it is serious enough to be incapacitating, and therefore is: (1) undesirable for its bearers; (2) a title to special treatment; and (3) a valid excuse for normally criticizable behavior” (Boorse, 1975).

Since Boorse’s theory was advanced in the 1970s, a plethora of objections have appeared. Some accuse Boorse of covert normativism by questioning the “evaluative” nature of his terminology—that the concept of function itself smuggles values because it is the product of choice on a range of things to examine (Fulford, 2001). Others deny the possibility that objective evaluations of species-typical functioning are possible.

Key objections turn on the possibility of asymptomatic individuals who present with dys-functions or infectious agents. Are infertile individuals who do not wish to have children diseased or in any way disordered? Should individuals who have rare mutations in a suite of genes, but who are not experiencing any effects of those mutations, be considered to have a disease? Should carriers of HIV, who experience no symptoms of HIV/AIDS, be thought to have a disease (Wakefield, 2014)? Boorse has replied comprehensively and repeatedly to these and other objections (Boorse, 1997, Boorse, 2014).

Like Boorse, Lennart Nordenfelt argues that the word “disease” is simply an empirical statement and not to be taken as an evaluation of a person’s state. But, Nordenfelt’s holistic theory of health is different in the way it treats disease. Whereas Boorse works his way upward from diseases defined in terms of biostatistical deviations, Nordenfelt argues that we should work in reverse by first recognizing the suffering and the lived experience of illness and then move to examine the underlying cause of such suffering to reveal the disease state (Norden-felt, 2007). This approach is resonant of Canguilhem’s theory of health, disease, and illness (Nordenfelt, 2007).

Clouser, Culver, and Gert provide a distinctly different account of disease, substituting the concept of “malady” for disease. According to the authors,

a person has a malady if and only if he or she has a condition, other than a rational belief or desire, such that he or she is suffering, or at increased risk of suffering, an evil (death, pain, disability, loss of freedom or opportunity, or loss of pleasure) in the absence of a distinct sustaining cause.

(Clouser et al., 1981)

The idea here is that certain ontic evils—the authors draw explicitly on Aquinas—are objectively and universally bad. This malady account includes values but only insofar as those values are considered objective and universal; rational persons would agree that suffering, pain, injury, and death are bad and ought to be avoided. But how can an assessment of objective values be reasonably made? Who are these so-called rational persons, and how can their values be identified in a pluralistic world? Should certain maladies that predispose one to self-injury, seizure, or hallucination—such as schizophrenia or epilepsy—but that are valued in a particular culture for spiritual reasons count as objectively evil? Clouser, Culver, and Gert’s account is very close to toppling over into normativism.

Normativism

The key feature of normativist theories of disease is that they all reject the possibility that objective necessary and sufficient conditions can be found to identify diseases as such. To express this position positively, normativist theories all con...

Table of contents

• Cover
• Title
• Copyright
• CONTENTS
• List of Contributors
• Introduction
• PART I General Concepts
• PART II Specific Concepts
• PART III Research Methods: (a) Evidence in Medicine
• PART III Research Methods: (b) Other Research Methods
• PART IV Clinical Methods
• PART V Variability and Diversity
• PART VI Perspectives
• Index