The precise nature and role in medical practice of disease, health, illness, wellbeing, and associated notions such as sickness and wholeness, are fervently debated in the current medical literature (Boyd, 2000). For example, Germund Hesslow (1993) claims that the distinction between health and disease is "irrelevant" for medical practice, since a disease is not required for soliciting medical attention.' The purpose of the following chapter is not to provide a definitive answer or solution to the debate but rather to explore the possibilities of an answer or a solution in order to clarify further the debate. As Lawrie Reznek contends, philosophy is germane to the discussion concerning the nature of disease: "Philosophy cannot cure disease, but it certainly can cure inappropriate disease attribution" (1987, p. 11). It is in this spirit that I undertake a discussion of the notions of illness and wellbeing.
The participants in the debate can be divided into two camps: the naturalists and the normativists. According to naturalists, disease and health are descriptive concepts that can be used to define the objective and real state or condition of a person. These concepts are strictly neutral to any personal or social values. According to the normativists, however, these concepts depend upon personal and social values. Reflecting these values, normativists often utilize terms like "illness" and "wellbeing" to define a person's subjective or constructed state or condition. In general, biomedical practitioners champion naturalistic notions of disease and health, while humanistic or humane practitioners advocate normativist notions of illness and wellbeing.
The biomedical model is responsible for the predominant conceptions of disease and health that inform the practice of medicine in the industrialized west. Disease is consigned to dysfunction or lost of a body part, while health is defined with respect to the (absence of the) disease state. A person is healthful if no palpable disease is present or requires treatment. Health, then, is a default state and is what keeps one from enlisting a physician's services. These notions of disease and health have certainly contributed to the quality-of-care crisis. By reducing the patient to a diseased body part, the patient's suffering and existential concerns are often ignored and go unaddressed by the biomedical practitioner.
Humanistic or humane modifications of the biomedical model attempt to include the patient's suffering and existential concerns as part of the illness experience and to address them through therapeutic procedures. For humanistic models, health is not a default state but is defined in positive terms, often with respect to a person's wellbeing or wholeness. The humane practitioner's concern is not just the absence of disease in the patient but adoption of a lifestyle that promotes being well both physically and mentally (and, at times, spiritually). In addition the distinction between the biomedical and humanistic or humane models vis-a-vis mental health and illness is explored, when appropriate.
4.1 Disease or Illness
According to the biomedical model, the nature of disease, as well as health, can be defined in terms of the material and physical. "There is an objectivity about disease," according to Marshall Marinker, "which doctors must be able to see, touch, measure, smell" (1975, p. 82). Disease, whose cause can be identified by scientific investigation and clinical diagnosis, is an objective and real state that is reduced to a material or physical entity or condition.
This reductive notion of disease is evident in medical dictionaries. For example, in the twenty-sixth edition of Stedman's Medical Dictionary, the first definition of disease reads: "An interruption, cessation, or disorder of body functions, systems, or organs" (Stedman, 1995, p. 492). Even mental or behavioral disease is reduced to the biochemical and physiological operations of the brain. "Biomedical dogma," according to Engel, "requires that all disease, including `mental' disease, be conceptualized in terms of derangement of underlying physical mechanisms" (1977, p. 130). This notion of disease is predominate in the biomedical model and influences its conception of health. As noted already, health, even mental health, is simply a default state that represents the absence of disease.
While the biomedical physician is concerned with the patient's disease state, the humane physician is solicitant for or empathetic over the patient's illness and the suffering associated with it. Cassell distinguishes between disease and illness, accordingly: "Diseases... are specific entities characterized by disturbances in structure or function of any part, organ, or system of the body. Illnesses... afflict whole persons and are the set of disordered functions, bodily sensations, and feelings by which persons know themselves to be unwell" (1991, p. 49). Physicians should not deal exclusively with disease as an objective entity but with the sick person: "the object of the physician's search, the disease entity, does not exist in concrete reality but is merely an abstraction without independent existence. The only thing the clinician can work on (a paradox for medical science) is this sick person" (Cassell, 1991, p. 108).
In the remainder of this section, the various conceptions of disease, including the ontological, physiological, evolutionary, and genetic conceptions, are discussed first, followed by a discussion of the humanistic or humane model's conception of illness.
Traditionally, there are two conceptions of disease: the ontological and the physiological. The ontological conception is concerned with disease causing entities, while the physiological conception involves deviation from functional norms. Christopher Boorse furnishes the best known, if not the most recognized and controversial, physiological conception of disease based on the notion of "species design." Two additional conceptions of disease have recently been championed in the literature-the evolutionary and genetic-with the genetic conception taking center stage, especially with the inception of the human genome project. Although no one conception captures completely the nature of disease, these conceptions provide, according to biomedical practitioners, a means for distinguishing disease states from defects, deformities, and disabilities.
220.127.116.11 Ontological Conception
According to the ontological conception, "diseases are things, entities with a separate existence from the person who has them" (Cassell, 1991, p. 77). But, as Engelhardt argues, the ontological conception is ambiguous in terms of referring either to a thing (ens) or to a logical type: "Medical ontology in the strong sense refers to views in which disease is conceived of as a thing, a parasite, in contrast with `Platonic' views of disease entities in which diseases are understood as unchanging conceptual structures" (1975, p. 128).
In the strong sense, a disease entity is an infectious agent that invades a host or patient and directly causes the disease condition. These agents may be, for example, a pathogen, virus, parasite, or bacterium. According to Rudolf Virchow (1821-1902), however, a distinction must be made between the disease entity itself (ens morbi) and the entity as cause of a disease (causa morbi)-for the disease entity may be present without disease symptoms (Virchow, 1958). In the weak sense, there are disease patterns, in terms of symptoms, which "are interpreted as enduring disease types often without an immediate connection to a particular theory of material disease entities" (Engelhardt, 1975, p. 129).
The best known example of the ontological conception is the germ theory of disease. The germ theory was first proposed at the end of the nineteenth century and was instrumental in explaining many deadly infectious diseases that no longer plague the industrial west because of the discovery of antibiotics. Recently, however, bacteria that cause infectious diseases are becoming resistant to antibiotics (Le Fanu, 2002).
According to the germ theory, disease, especially infectious disease, is the result of a microorganism that is able to overcome the body's immunological defense system and thereby damage the patient's tissues and organs. For example, septicemia, which was called the putrid disease, was shown to be due to a "septic vibrio" (an oxidase-positive, gram-negative bacillus) from infected organisms (Pasteur, 1996). Of course, the discovery of penicillin and its first clinical use on a forty-three year old policeman in 1941 revolutionized medicine in that infected patients could be successfully cured with antibiotics (Le Fanu, 2002).
18.104.22.168 Physiological Conception
Traditionally, the physiological conception of disease is contrasted with the ontological conception. From the physiological point of view, disease, which is an abstract concept, should not be confused with a concrete object. According to the physiological conception, disease is deviation from a functional norm or general regularity. The laws of physiology are essential for understanding the pathological nature of a diseased state. Thus, diseases are "more contextual than substantial, more the result of individual constitutions, the laws of physiology and the peculiarities of environment, than the result of disease entities" (Engelhardt, 1975, p. 131).
The basis of the physiological theory of disease is the notion of normality. Edmond Murphy has identified several of kinds for normality, especially in terms of statistical variation. The first is "a metrical variate with a particular probability density function that is conveniently described by some such term as `Gaussian"' (Murphy, 1997, p. 145). The next two kinds involve a class representative such as an average or a mode and the frequently experienced in a class such as the ordinary. Many physiological processes vary within a normal range of measured values. For example, normal blood pressure ranges from 90-140mmHg for systolic pressure and from 60-90 mmHg for diastolic pressure. Depending on one's physical activity, the pressure varies within this range and returns to normal under resting conditions. If the pressure is outside the normal range under resting conditions, then it may indicate a disease or pathological state. The laws governing these physiological processes are part of the homeostatic mechanisms that ensure stable bodily functions (Cannon, 1939).
In the mid 1970s Christopher Boorse proposed a physiological notion of disease, in which he initially made a distinction between disease and illness. Disease, according to Boorse, interrupts specific functions performed by members of a species and is a value-free concept. Illness, however, involves personal or individual and social or cultural values in that disease is generally "undesirable" (Boorse, 1975, p. 61). In other words, disease is a natural concept and therefore theoretical while illness is a normative concept and therefore practical. The normative conception of disease among philosophers of medicine, according to Boorse, reflects a "psychiatric turn" that misrepresents the "physiological" basis of disease.
Boorse ultimately refined the above conception of disease in terms of normal function: "A disease is 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" (1977, p. 567). This conception hinges on the meaning of "normal functional ability." This refers to members of a "reference class," i.e. "a natural class of organisms of uniform functional design," who contribute in a typically statistical way to the survival and reproduction of the species (Boorse, 1977, p. 562). Functionality depends not on the function's causal history, as advocated by Larry Wright, but on its contribution to a goal (Boorse, 1976).
Boorse (1987) later recasts the conception of disease in terms of a normalpathological distinction, especially in terms of function. Again, the distinction is a naturalistic one and the pathological is defined in terms of statistically suboptimal functioning of a part. "A condition of a part or process in an organism is pathological," according to Boorse, "when the ability of the part or process to perform one or more of its species-typical functions falls below some central range of the statistical distribution for that ability in corresponding parts or processes in members of an appropriate reference class of the species" (1987, p. 370).
Boorse eventually called his naturalistic conception of disease (and health) the "biostatistical theory" (BST), "a name emphasizing that the analysis rests on concepts of biological function and statistical normality" (1997, p. 4). Disease is an inability of species members to conform to the notion of "species design." Species design involves
the internal functional organization typical of species members, which (as regards somatic medicine) forms the subject matter of physiology: the interlocking hierarchy of functional processes, at every level from organelle to cell to tissue to organ to gross behavior, by which organisms of a given species maintain and renew their life
(Boorse, 1997, p. 7).
A disease or pathological state, then, is disruption of a part-function at some level of the above hierarchy.
Although Boorse's notion of disease has been criticized from a variety of perspectives, critics are particularly adverse-from an evolutionary perspective-to his notion of "species design."' For example, Jozsef Kovacs (1998) insists that Boorse's notion does not take into consideration the change of species design over geological time. In fact, there is a substantial "time lag" between the design of a species and the changing environment, such that "species design does not always mean health, but it can represent-by the dramatic changes of the environmentdisease and death" (Kovacs, 1998, p. 32). In other words, current species design is usually out of step with changes in the environment. Moreover, there is never an ideal species design to which individuals comport but rather a significant variability that maintains adaptability vis-n-vis changing environments (van der Steen and Thung, 1988).
22.214.171.124 Evolutionary Conception
Evolutionary biology provides another approach to defining abnormality and disease. According to Randolph Nesse, a statistical approach is inadequate to determine what is normal; rather, what is required is "nothing less than a complete knowledge of what the body is for, how it works, and, especially, how it came to have its current form" (2001, p. 38). The design and function of the body are the result of evolutionary processes, especially by means of adaptation though natural selection. Over the course of the species evolution vis-n-vis the body, specific adaptive mechanisms evolved to defend the body against, for example, microorganisms that would compromise the body's integrity and thereby reduce the organism's fitness, especially in terms of reproductive capacity.
According to the evolutionary conception of disease, disease is defined in terms of adaptive mechanisms. In other words, disease is the result of maladaptation, e.g. to ward off a microorganism that would cause the body serious harm or even death. "Failure to express a defense in response to a challenge," for Nesse, "results in a disease" (2001, p. 38). Consequently, evolutionary mechanisms shape normality and its maintenance; and, disease is then defined as "a disadvantageous difference from the normal" (Nesse, 2001, p. 41).
The evolutionary conception of disease has important ramifications for understanding the nature of disease, especially in terms of the body's defenses to diseaseproducing conditions and agents. According to Nesse, evolutionary processes like natural selection "should shape mechanisms that regulate defenses to give optimal benefit" (2001, p. 39). For example, fever is a symptom of many diseases that biomedical practitioners often treat. However, fever is an adaptive mechanism to defend the body against infectious agents like bacteria and viruses. "Medications that block fever," contend Nesse and George Williams, "apparently interfere with the normal mechanisms that regulate the body's responses to infection, with results that may be fatal" (1996, p. 28). Moreover, studies demonstrate that blocking fever in adult rabbits increases their mortality rate. However, Nesse and Williams acknowledge that there are conditions in which blocking fever is necessary.
Although Nesse recognizes that no single definition is adequate, he defines disease in terms of biological or evolutionary function: "An individual has a disease when a bodily mechanism is defective, damaged, or incapable of performing its function" (2001, p. 45). Critics of evolutionary medicine challenge the appropriateness of relying on biological function to determine the disease or health of a person. For example, Anne Gammelgaard argues that biological function derived from evolutionary theory is inadequate to determine function in terms of medical significance: "What is functional from an evolutionary perspective is not necessarily functional from the perspective of the patient. This is primarily due to a difference in the perspective from which doctors and evolutionary biologists consider bodily functions" (2000, p. 112). In other words, healthcare professionals are concerned with the welfare of the individual patient while the evolutionary biologists investigate the biological fitness of a unit of selection, which may not necessarily be important to any particular organism's health.
126.96.36.199 Genetic Conception
With the inception of the genetic revolution in the twentieth century a "geneticisation" of the conceptual basis of medicine occurred, with the rise of a new field of medicine-genomic medicine (Guttmacher and Collins, 2002). One of its chief notions is the genetic conception of disease (Hall, 2005). This conception involves the explanation of disease in terms of mutation in or absence of a gene(s), especially in terms of its products being either defective or missing. "One of the opportunities provided by modern genetic techniques," according to John Bell, "is that it should be possible to clarify the pathogenic basis of many of these disorders, and thereby more clearly define most diseases by mechanism" (1997, p. 1052). Genetic diseases are usually the result of loss of function such as in diabetes; however, there are situations in which it leads to gain of function such as in cancer. Gene mutation may be either sporadic, i.e. the result of changes in the genome of patients' somatic cells during their lifetimes, or hereditary, i.e. inherited from one or both of the patient's parents.
If a single defective gene is responsible and if inherited, then it is a Mendelian disease and follows Mendelian inheritance patterns. These patterns include autosomal dominant or recessive, X-linked dominant or recessive, and Y-linked. There are roughly 5,000 Mendelian traits in humans, with hundreds of Mendelian diseases (McKusick, 1998). The classic Mendelian disease, and the first disease described as "molecular," is sickle cell anemia (Feldman and Tauber, 1997). Sickle cell anemia is due to defective hemoglobin in erythrocytes (Stuart and Nagel, 2004). In 1956, Vernon Ingram and J. Hunt demonstrated that sickle hemoglobin's sequence contains a valine in place of normal hemoglobin's glutamic acid (Ingram, 2004).
If there is more than one gene involved then it is a non-Mendelian or polygenetic disease (Williamson, 1988). Most polygenetic diseases are also multifactorial in that the environment plays a critical role in the disease's expression. In other words, part of the disease's origins may be due to inheritance while the remainder may be the result of environmental factors. Thus, many common diseases, such as cancer, diabetes, hypertension, and atherosclerosis, involve the interaction between the genes and the environment. The inherited genes predispose a patient to a given disease but are only expressed under certain environmental conditions. For example, lung cancer has a familial component that can be realized by cigarette smoking (Kiyohara et al., 2002).
Cancer is a prime example of a polygenetic or multifactorial disease. A combination of oncogene activation and tumor suppressor gene inactivation is required for tumorigenesis. However, Robert Weinberg, from the Whitehead Institute at MIT, and Douglas Hanahan, from the University of California at San Francisco, after reviewing the current literature concerning carcinogenesis, proposed a new paradigm to guide research in the twenty-first century. Rather than explaining cancer with just a few mutated genes, they argued that it is a complex and multifaceted disease that exhibits at least six different "hallmarks" (Hanahan and Weinberg, 2000). These include self-sufficiency in growth signals, insensitivity to antigrowth or growth-inhibitory signals, tissue invasion and metastasis, limitless replicative potential, sustained angiogenesis, and evading apoptosis or programmed cell death. Hanahan and Weinberg (2000) advocate a heterotypic cell biology, in which cancer cells recruit normal cells to form a mature tumor. Recently, defects in the extracellular matrix have also been proposed as etiological factors in carcinogenesis (Marcum, 2005c).
Finally, a class of genetic diseases that represent mutations to genes located on the circular pieces of DNA in mitochondria has been investigated intensely over the past decade (Taylor and Turnbull, 2005). Mitochondria are organelles found in eukaryotic cells that are responsible for aerobic respiration or oxidative phosphorylation. They are maternal in origin, since paternal mitochondria are destroyed during fertilization. The inheritance of mitochondrial genes exhibits a non-Mendelian pattern. The mitochondrial genes encode for over a dozen proteins and associated RNA machinery involved in cellular respiration. Mitochondrial diseases include a form of dementia called MELAS, which stands for mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes, and a form of epilepsy called MERRF, which stands for myoclonus epilepsy with ragged red fibers. In addition, the eye disease, Leber's hereditary optic atrophy, results from mutations to mitochondrial genes, which is also the case for Pearson's syndrome-an inherited bone marrow failure syndrome. Although progress is being made with respect to understanding mitochondrial diseases, there are few if any therapeutic modalities to treat them.
Humanistic or humane practitioners reject the abstract notion of disease for a concrete notion of illness. For example, Cassell (1991) points out two problems with biomedical conceptions of disease. The first is that biomedical practitioners look at each disease as the result of a single, unique cause. Although infectious diseases are often the result of a single microorganism, however, many diseases-such as cancer and heart disease-have multiple causes. There is certainly no single cause that is responsible for many chronic diseases. In addition, the etiology of many diseases is embedded in a society's cultural fabric. According to Cassell, illness cannot "be completely understood apart from personal lifestyle and the social setting in which it occurred" (1991, p. 14). For example, the sharp rise in lung cancer after the First and Second World Wars reflected the socially accepted practice of a previous generation's habit of cigarette smoking.
The second problem, according to Cassell, is that function, for the biomedical model, is simply a result of structure, such that a change in function or a dysfunction reflects a change in structure. The issue is that structure is an artificial construct or a moment in time, while illness is dynamic in which the pathophysiology unfolds over time.
Cassell (1991) contrasts the ontological view of disease with a physiological or process-oriented view and claims that there is no adequate system for understanding the nature of disease. He goes on to challenge the reader: "I think you will be unable to come up with any definition that is not so vague as to be useless as a practical guide to action" (1991, p. 92). Kenneth Boyd (2000) agrees that notions such as disease and illness are ambiguous but contends that this is because they are based on values. Lester King (1954) also agrees that the nature of disease is imprecise, although he contends that the imprecision is based on the fact that disease conditions generally follow a range. For example, what constitutes the normal blood hemoglobin is not a precise number but rather a range.'
According to King, disease is a purely artificial notion. What makes something a disease is not only the biology but also our social values: "Disease is the aggregate of those conditions which, judged by the prevailing culture, are deemed painful, or disabling, and which, at the same time, deviate from either the statistical norm or from some idealized status" (King, 1954, p. 197). Ultimately, diseases are not "things in the same sense as rocks, or trees, or rivers. Diseases represent patterns or relationships" (King, 1954, p. 199). Of course, this position raises the ontological issue of a pattern's or a relationship's reality, which King resolves by embedding it within a cognitive framework.
George Agich also rejects a value-neutral theory of disease, especially Boorse's functional theory of disease. Agich claims that freedom is the main value by which to evaluate the notion of disease: "Underlying all criteria of disease is the view that what is proper to human beings is bound up with freedom or rational free agency since pain, deformity and dysfunction of various kinds all restrict the individual's capacity to act. The reference to freedom" he continues, "has an interesting and important implication in connection with the problem of disease language, for it implies that many goals are possible not simply those typical at any given time" (1983, p. 37). The possibility of these goals is not strictly biological but also social.
Agich next applies the value of freedom as a hermeneutical principle to interpreting Boorse's theory: "On Boorse's view, `disease' is a description of a deficiency in typical species functions where `function' means `a standard causal contribution to a goal actually pursued by the organism'; my suggestion is that if the phrase `goals actually pursued by the organism' is understood in social terms and in terms of freedom rather than biologically (since medicine concerns human disease), then the breadth of possibilities regarding disease as well as the value-laden character of disease judgments will become apparent" (1983, p. 37). Agich concludes that Boorse's theory is too simple and fails to capture the complexity of disease and its personal and social dimensions.
Caroline Whitbeck also subscribes to a value-laden notion of disease and bases her notion on psycho-physiological processes. To that end she defines disease, in general terms, as "an instance of the sort of psycho-physiological process that people wish to be able to prevent or terminate" (Whitbeck, 1978, p. 211). Moreover, this notion of disease is relative to a cultural context, with respect to what people want and expect to be able to do. "Thus," concludes Whitbeck, "the judgment as to what types of processes constitute a disease depends on a value judgment of the societal group, rather than upon either the judgment of the person afflicted, or simply upon the judgment of the professional whom the society has charged with developing and applying preventive and therapeutic measures" (1978, p. 211). Finally, she cites with approval Mervyn Susser's distinction between disease as organic or mental dysfunction and illness as the subjective or conscious awareness of the dysfunction. What makes the awareness possible are the social values that dictate appropriate behavior.
In addition, K.W.M. Fulford (1989) proposes a value-laden notion of disease, since conceptually medicine is fundamentally evaluative and not factual in nature. Fulford contrasts a "reverse" view of the relationship between disease and illness with the "conventional" view. In the latter view, a value-free concept of disease is primary to a value-laden notion of illness, of which it is a subclass. In the reverse view, illness is primary to disease. "In medicine," argues Fulford, "just as illnessthe patient's direct experience of something wrong-normally precedes a clinical diagnosis of what is wrong in terms of particular diseases, so, in the logic of medicine it is `illness' which comes first" (1989, pp. 262-263).
What makes illness logically prior to disease, according to Fulford, is that the former is based on the notion of action failure, while the latter is based on a notion of dysfunction. Action failure involves an inability of persons to carry out their "intentional doings." For example, Fulford claims that delusions are not cognitive dysfunctions in which the patient believes what is factually false but that delusions result from an inability of the patient to provide satisfactory justification for an action.
Finally, the phenomenological model of the body has important implications for the patient's experience of illness. Illness is not so much the dysfunction of a mechanized body or body part within a machine-world, as it is the disruption of an embodied subject's lifeworld: "illness must be understood not simply as the physical dysfunction of the mechanistic, biological body but as the disorder of body, self and world (of one's being-in-the-world)" (Toombs, 1993, p. 81). Illness, then, results in an awareness of the body as separate and foreign that stands out over and against (ek-stasis) the normal course of life.'
No longer, claim phenomenologists, does the suffering patient go about everyday life without conscious awareness of the body's constraints and limitations. That constrained body, in terms of its spatial and temporal dimensions, imposes itself upon a patient who is ill. Illness often expands the temporal scale and collapses the spatial domain in which the sick body is lived (Toombs, 1993). For example, a routine activity, such as combing one's hair, which normally takes little time, takes much longer, when an arm is broken.
As a broken tool thwarts the builder's plans so to the ill body disrupts the patient's plans. This is not to say that the body is a tool in a strict sense and that the ill body consequently is a broken tool, but the analogy of the ill body as a broken tool does capture the impact illness has on the patient's experience of the body: "it would be wrong to call the body parts tools since they are also part of Dasein as self. They are not only a part of the totality of tools, but also, as lived (leibliche), they belong to the projective power of the self' (Svenaeus, 2000, p. 109).5 The objectification of the phenomenological body, however, differs from the objectification of the biomechanical body. In the former the patient is an object but one that is situated in a unique lifeworld as an embodied subject, while in the latter the patient is an object located in a common machine-world as a disembodied person.
4.2 Health or Wellbeing
Part of the problem with the biomedical model's definition of disease and health is that medicine is more often a practical rather than a theoretical discipline: "medicine and its concepts of `disease' and `health' are bound up with medical practice and the interests of doctors and patients as well as with advances in science" (Brown, 1985, p. 326). Humanistic or humane practitioners criticize the biomedical model because it brackets the patient's existential concerns associated with the illness experience, which are often critical for a patient's recovery. "Illness," according to Marinker, "is a feeling, an experience of unhealthy which is entirely personal, interior to the person of the patient" (1975, p. 82).6 Illness then is a more expansive concept than disease, in that the patient may not present with the symptoms of a disease but still be ill.
So too health is not simply a default state with respect to a disease state, for humanistic or humane practitioners. Rather, it is defined in positive terms of wellbeing. Finally, the interests and values of the patient and the physician are critical for defining health as wellbeing, just as they were needed to define illness by humane practitioners. In the remainder of this section, the biomedical notion of health is discussed followed by an examination of the humanistic notion of wellbeing.
Biomedical practitioners often explicate the notion of health in negative terms as the absence of disease, in terms of either the expression of the disease entity or the conditions of the diseased state. This negative definition of health is evident in many medical dictionaries. For example, in the twenty-sixth edition of Stedman's Medical Dictionary, the first definition of health reads: "The state of the organism when it functions without evidence of disease or abnormality" (Stedman, 1995, p. 764).
Stedman's dictionary and other medical dictionaries also include mental health as part of their overall definition of health. For example, the thirty-seventh edition of Black's Medical Dictionary claims that "good health may be defined as the attainment and maintenance of the highest state of mental and bodily vigor of which any given individual is capable" (Macpherson, 1992, p. 265). Moreover, even mental health is reducible in terms of material, physical entities and conditions and is explicated in terms of the absence of mental disease. Thus, the notion of health-whether physical or mental-is defined traditionally and predominantly as the absence of a disease-a material state-and thus represents a default state.
Boorse distinguishes between two notions of health. The first is a theoretical notion, in traditional terms, as the absence of disease. He develops this traditional notion with respect to the notion that disease is sub par functioning vis-a-vis optimal species design: "health is normal functioning, where the normality is statistical and the functions biological" (Boorse, 1977, p. 542). The theoretical notion is a value-free concept, because it is based on biological facts.7 The second notion of health is practical and is defined as "roughly the absence of any treatable illness" (1977, p. 542). This notion is not as ideal as the theoretical notion and is therefore inadequate for developing a robust conception of health."
Boorse develops his functional account of health based on the Aristotelian notion of teleology and the modern notion of goal-directedness. The intuition he uses to frame this account is that "the normal is the natural" (1977, p. 554). Importantly, health is not based on personal or social values and therefore is not a normative concept. To that end, Boorse defines health accordingly: "Health in a member of the reference class is normal functional ability: the readiness of each internal part to perform all its normal functions on typical occasions with at least typical efficiency" (1977, p. 555). The reference class again refers to the species, while function refers to contributing to a goal. Health is a species related notion in that it is an ability of species members to conform to species design: "We have supposed that the basic notion is `X is a healthy Y'-that it is by comparing X with its reference class Y that one distinguished the way X does function from the way it ought to" (Boorse, 1977, p. 562). It then is the absence of disease, which is the inability to conform to such design.
For Boorse health is the organism's normal functioning, especially in terms of its physiology or the function of its parts. He further develops his notion of health in terms of "grades of health." The base upon which these grades are founded is the distinction between being dead or alive. From there he makes further distinctions between well and ill, therapeutically abnormal and normal, diagnostically abnormal and normal, pathological and theoretically normal, and finally suboptimal and positive health. Positive health he now defines as "superhealth beyond the already utopian goal of complete normality" (Boorse, 1987, p. 366). Such health would be one to two standard deviations from the normal, as the right-hand tail of a distribution graph for the efficiency of a part's function. However, health is normal functioning vis-n-vis species design and, therefore, the definition of health as the absence of disease is a truism.
Wellbeing is the normative conception of health and reflects the values of a particular culture and, therefore, includes the peripheral dimensions of medical practice (Boorse, 1987). For example, cosmetic surgery may not be required for maintenance of a part's efficient functioning but may reflect social values of beauty that enhance the overall wellbeing of a person. Engelhardt also defines health as a normative concept but distinguishes it from a moral sense of right and wrong: "Though health is good, and though it may be morally praiseworthy to try to be healthy and to advance the health of others, still, all things being equal, it is a misfortune, not a misdeed, to lack health" (1975, p. 125). Thus, health or wellbeing is a metaphysical notion, such as beauty or goodness and not necessarily a moral or factual state of being. One does not blame another for loss of good health but sympathizes with him or her for the misfortune. The notion of health is also descriptive, according to Engelhardt, and it is this dual nature of health as normative and descriptive that often results in ambiguous definitions of health and wellbeing.
The World Health Organization provides the standard and oft-quoted definition of health, in terms of wellbeing: "Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity" (1948, p. 35). Engelhardt (1975), however, finds this definition of health or wellbeing problematic because of its ambiguity. The issue is how to define the norms that constitute a person's wellbeing. Moreover, the term "complete" is also problematic: "if health is a state of complete physical, mental and social well-being, can anyone ever be healthy?" (Engelhardt, 1975, p. 126). Ultimately, health is "a regulative ideal of autonomy directing the physician to the patient as person, the sufferer of illness, and the reason for all the concern and activity" (Engelhardt, 1977, p. 139).
The ambiguous nature of health-especially in terms of wellbeing-is to be expected, since health depends upon our values of what constitutes wellbeing (King, 1954). For King, health is "the state of well-being conforming to the ideals of the culture, or to the statistical norm" (1954, p. 197). Since wellbeing is a value judgment, besides being a biological state, it is only partly derived from the statistical norm. Thus, the correspondence between health and wellbeing is not one to one: "The sense of well-being frequently correlates with what we mean by health, but the correlation is not high. Certainly a sense of well-being does not preclude the presence of disease, while the absence of such subjective feelings does not indicate disease" (King, 1954, p. 196).
Whitbeck also subscribes to a notion of health as value-laden and as positive in terms of a person's wellbeing: "health, rather being something that happens or fails to happen to a person in the way that diseases and injuries do, is the ability to act or participate autonomously and effectively in a wide range of activities" (1981, p. 616). This ability to act, however, involves more than functional capacities but also involves the integration of intentional capabilities to attain the goals and interests of the individual person. There are then several components that make up Whitbeck's notion of health or wellbeing. The first is the physical fitness of the functional capacities, especially in terms of avoiding disease. The second is wholeness, in which intentional capabilities are integrated with physical fitness. The final two components include "having a generally realistic view of situations, and having the ability to discharge negative feelings" (Whitbeck, 1981, p. 620).
Carol Ryff and Burton Singer (1998a) champion a notion of wellbeing in terms of positive health. They base their notion on three principles. The first is that positive health is fundamentally a philosophical and not a medical issue. To that end, they examine "the goods" required for living a healthful life. The next principle is that the mind and body are intimately connected and influence each other, especially in terms of health and wellbeing. The final principle is that "positive human health is best constructed as a multidimensional dynamic process rather than a discrete end state. That is, human well-being is ultimately," Ryff and Singer conclude, "an issue of engagement in living, involving expression of a broad range of human potentialities: intellectual, social, emotional, and physical" (1998a, p. 2).
Ryff and Singer (1998b) also identify four essential features of positive human health: "(a) leading a life of purpose, embodied by projects and pursuits that give dignity and meaning to daily existence, and allow for the realization of one's potential; (b) having quality connection to others, such as having warm, trusting, and loving interpersonal relations and a sense of belongingness; (c) possessing selfregard, characterized by such qualities as self-acceptance and self-respect; and (d) experiencing mastery, such as feelings of efficiency and control" (1998b, p. 69).
Finally, Lennart Nordenfelt (1993, 1995) proposes a notion of health in contrast to Boorse's notion, which he calls "the welfare theory of health." He establishes the notion on action theory, in which a person's health is defined in terms of an ability to achieve specific goals that are tantamount to good health. These goals include "the vital goals of man" and they are not reducible to a person's basic needs or to specific personal goals. Rather, Nordenfelt defines a vital goal as "a state of affairs that is necessary for the realization of this person's state of minimal long-term happiness" (1995, p. 213). Happiness is not a singular concept that pertains just to a person's emotional state but is a multifaceted one that also includes the intention and object of those emotions.
Nordenfelt then defines the welfare notion of health in terms of a person's vital goals vis-n-vis happiness: "A is completely healthy, if and only if A is in a bodily and mental state which is such that A is able to realize all his or her vital goals, given accepted circumstances" (1995, p. 212). Health is an evaluative notion or an "ideological judgment" that depends on a person's notion or judgment of what constitutes a healthful, happy life. However, the welfare notion of health is not relative, since the "accepted circumstances" do not reflect only a person's judgment but also include social judgment as well. "It is a challenge to health care and to traditional medical education in general," according to Nordenfelt, "to incorporate insights about existential states and their role as determinants and constituents of health" (1993, p. 284).
The nature of disease and health or of illness and wellbeing depends on the metaphysical position ascribed to by the medical practitioner and, often by default, by the patient. If the patient is a body-machine made up of or reducible to various parts, then disease is an entity or a condition that results from a malfunctioning body part and thereby hinders the efficient running of the body-machine. Health is the absence of any such malfunctioning, although once a year the body-machine may need a check-up.
However, if the patient is a person, who strives to find meaning in the world, then, besides biological malfunction, the patient experiences the "ev-ill" effects of or the existential angst associated with the "dis-eased" state. Health involves more than the absence of a malfunctioning part or body. It also includes the overall wellbeing of the person.
Finally, it is not surprising that there is a quality-of-care crisis in modern medicine, given its understanding of disease and health. Patients are not simply body-machines but persons with concerns and fears about their physical and mental (and for some spiritual) being-in-the-world. The humanistic or humane notions of illness and wellbeing certainly take into consideration these concerns and fears.