Debates on the Nature of Disease

One of the central debates in the field of philosophy of medicine concerns the nature of disease. There are many different positions with interesting and subtle differences, but they are usually divided into two types: naturalist views which separate disease from health on the basis of purely natural, biological facts, and normativist views, which distinguish disease from health at least partly by appeal to value, of what is good and what is bad for the person involved. 

The paradigm naturalist view is that of Christopher Boorse (1977). According to him, what makes a body diseased is that it is not functioning properly, as compared against bodies of the same age and sex. So, for instance, a person with tuberculosis is diseased, in virtue of the fact that their lungs are no longer able to perform their proper function, as measured by, for instance, reduced oxygen extraction compared to the average person. 

And the most prominent normativist view is that of Rachel Cooper (2002). According to her, a bodily state is one of disease when it is bad for the person in that bodily state, that person is unlucky to be in that bodily state, and ameliorations to this state of affairs can at least in principle be hoped for from medicine. So what makes the person with tuberculosis diseased, according to her, is that their pulmonary state is not good for them, that they are unlucky to be in this state, and that medical intervention might help. 

As is commonplace in analytic philosophy, much of the debate consists in the presentation of counterexamples (“but an unwanted pregnancy is a bodily state that isn’t good for one, that one is unlucky to be in, and that might be remedied by medical intervention—yet it’s not a disease!”) and modifications to the various theories in response, the refutation of claims made about one’s theories (for instance, Elselijn Kingma 2007 shows that the appeal to proper function and comparisons to a statistical norm are both value-laden, such that Boorse’s view doesn’t count as thoroughly naturalist in the sense of being strictly biological and therefore value-free), and refinements of coarse distinctions (thus Alex Broadbent 2019 distinguishes between something being value-free and something being objective, in the sense of perspective-invariant: the same from all points of view—as he remarks, these are independent and conflated in the debate). That is, much of the discussion takes the parameters of the debate for granted and digs in, so to speak. 

What interests me here is why this debate is had at all. Not what conscious or unconscious drives propel people to engage in this debate, but what is at stake in the question of what makes a bodily state healthy or diseased. 

In a recent paper, Harriet Fagerberg shows that, contrary to what many in this debate conceive of themselves as doing, they are not engaged in conceptual analysis. Conceptual analysis is the task of coming to understand what we mean when we apply various concepts, here, the concept of disease. She argues that people engaged in this debate do not seem particularly interested in how words like “disease” are actually used, and indeed use various words quite interchangeably (“disease”, “disorder”, “illness”, “malady”), and she concludes that despite their own claims, what is at stake here is not the linguistic question of how people apply concepts. Rather, she suggests, it is the metaphysical question of what kind of thing disease is, what cluster of real properties diseases have in common.

But the participants of the debates do not claim merely to be doing conceptual analysis. In fact, both Boorse and Cooper begin their famous papers by remarking on the political stakes of the debate. Thus Boorse writes: 

On our view disease judgments are value-neutral, which is our second main result [after the differentiation between theoretical health, absence of disease, and practical health]. If diseases are deviations from the species biological design, their recognition is a matter of natural science, not evaluative decision. (Boorse 1977: 542–3) 

He considers it a “main result”, that his theory settles the source of diseases’s “recognition” as natural science. In a similar vein, Cooper begins her paper by talking of its political implications: 

Whether a condition is considered a disease often has social, economic and ethical implications. Are psychopaths evil or sick? Should the NHS pay for the treatment of nicotine addiction? Is it right for shy people to take character-altering drugs? All these debates may be seen to depend on whether the conditionsare diseases, and developing an account of disease may be hoped to help us in addressing such questions. (Cooper 2002: 263) 

Now, neither Boorse nor Cooper develop this political thread any further. Instead, they immediately retreat to the seemingly apolitical realm of what Cooper calls “philosophical work” (263): Boorse announces that his “goal in this paper is to analyze health and disease as understood by traditional physiological medicine” (542) and Cooper presents hers as “attempt[ing] to clarify notions of disease” (263). And this seemingly apolitical realm is where they remain until the end; hence Fagerberg’s sense that they both take themselves to be concerned with linguistic questions. 

But their initial suggestion that it is political reasons that drive not just the development of their individual views but indeed the very frame of the debate strikes me as lucid. What is at stake in the naturalism/normativism debate about the nature of disease is, I think, the political question of who gets help, who gets support, who gets funds, who gets compassion; and not just that but who and what decides it. It is a hallmark of the pragmatist tradition, broadly construed, to consider that the stakes of things are contained in their use. And what use does it have, exactly, to distinguish disease from non-disease? In the case of specific diseases, the answer is clear. Distinguishing tuberculosis from non-tuberculosis serves to determine a course of action: which kind of infection control measures to take, which treatments to begin, which variables to keep under surveillance, how to evaluate the risks to one’s survival, how to relate to various aspects of one’s life, and so on. 

But what use might lumping all diseases together have? Dealing with illness requires resources. The costs can be enormous and wide-ranging: the cost of medical care (including doctors’ fees, medications, fees associated with dispensing treatment like infusions, injections, etc.), of paramedical care (physical and psychological therapy, assistance with activities of daily living, costs of specialised nutrition and food supplements, all sorts of specialised equipment), and of partial or complete reduction in work capacity, from the symptoms themselves, and/or from the gigantic administrative and organisational load of living with a disease. The question arises of who supplies these resources: of who incurs these costs. And contained within our concept of disease, as Cooper acknowledges in the citation above, is the idea you are entitled to these resources if you are sick. If you are sick, you should (in some sense of should) get medical treatment, assistance with tasks, a pension to replace lost wages. What is at stake in the question of whether someone’s bodily state is one of disease or not, is whether or not this person is entitled to this support. 

We should understand the disease debate then, not as an apolitical metaphysical question, but as an epistemic question (that, in Boorse’s words, of the “recognition” of disease) embedded in a political context which has major material consequences for people’s lives. Indeed, in the background of this debate on the nature of disease, we find a very real sorting process, performed by state and private (healthcare and insurance) institutions working in tandem. People come in contact with these institutions, and they are sorted into sick and not-sick, and treated (or not) accordingly. This sorting process, it bears remarking, has consequences beyond the economic realm: whether people are classified as sick by these institutions often has a significant impact not only on their self-conception, but also on the way they are conceived of and therefore acted with by kith and kin. It has profound and wide-ranging ramifications for people’s lives, including for their survival. 

Even though, as far as I’m aware, none of the participants in the debate on the nature of disease reference this sorting process, any perspicuous reader aware of the political discourse around illness and disability can recognise it as informing the various views defended in the debate: discussions arise again and again of whether this or that account would rule this as a disease, where this is something widely taken to be something for which a person should receive no support. Moreover, regardless of the authors’ intentions, discussions of whether people who claim to be sick really are sick appear chiefly in and saturate the political, medical, and popular discourse around accommodations, financial support, and the availability of medical care. Whether they intend to or not, participants in the debate of what distinguishes disease from non-disease speak to the question of who should get the support only sick people are thought to deserve. 

According to Boorse, bodily states should be sorted into ones of disease and ones of non-disease by whether there is biological dysfunction. This suggests that a task of sorting people into “really sick” and “not actually sick” should proceed by examining whether biological dysfunction can be identified. This is roughly the status quo. In order to be recognised as sick and therefore eligible for whatever meagre supports are made available by the state and insurance companies, one has to go through an extensive, invasive, exhausting, and dehumanising process of demonstrating biological dysfunction considered significant enough by the institutions in question to warrant said support. 

A significant issue with this process is that biomedical knowledge is at best incomplete, such that there likely are dysfunctions that cannot currently be detected by the best available science, that is, diseases by the naturalist’s own lights that would be wrongly classed as non-diseases—like epilepsy was before the EEG, or multiple sclerosis before the MRI. (It should be remarked here that many if not most illnesses branded “medically unexplained” by institutions eager to deny people benefits are not at all unexplained in the sense that biological dysfunctions cannot be detected. In myalgic encephalomyelitis for instance, the illness from which I suffer, significant immune, metabolic, and vascular dysfunctions are well-documented.)

Cooper’s normativist account fares better in this regard. According to her, the sick (those then who should receive support) are those whose bodily state is bad for them. Thus the question of whether a biological dysfunction can be detected does not arise. She explains that whether one’s bodily state is bad for one isn’t always known by oneself: one might for instance have a so-far asymptomatic illness that will go on to cause suffering or shorten one’s life. One can then learn through biomedical exploration that one is sick. But one can also know that one is sick if for instance, one lives with chronic physical suffering. Thus determining whether someone is sick may but need not involve biomedical investigation: sometimes, a person’s testimony may be enough. 

A sorting process predicated on this kind of account of disease would avoid the significant difficulties of the naturalism-based account concerning people whose ills are not easily detectable by current means of biomedical investigation. But critics will object that a process that allows self-reporting opens the door for false reports; indeed Cooper herself raises this possibility: 

Sick people may both be stigmatised and receive certain social benefits. Thus people are often motivated to either consciously lie or to deceive themselves regarding whether or not they are sick. (2002: 273) 

The political dimension of the debate on the nature of disease should be evident now: we have made our way to the widespread inflammatory rhetoric that depicts sick and disabled people as potential liars, fakers, and malingerers, not actually sick as certifiable by a doctor but pretending for supposed gains. This is the kind of rhetoric employed by right-wing governments across the world to justify ever increasing restrictions on life-sustaining and life-improving support for disabled people, including misery payments on which people cannot survive, and are forced instead to depend on mutual aid, personal wealth, or die. 

The debate between the naturalist and the normativist accounts of disease ultimately boils down to a difference of political orientation. On the one hand, we have a view that insists on what Ellen Samuels calls biocertification: “the massive proliferation of state-issued documents purporting to authenticate a person’s biological membership in a regulated group” (2014: 9). On the other, we have a view that allows for some autonomy, agency, and self-knowledge on the part of people with recalcitrant bodies. 

But both views are formulated within a particular frame: that outlined above of the public/private assortment of institutions that decides who gets support. To some, this will be appealing: a set of institution exists to fulfil the needs of the population, by providing care to those who need it—the question arises then of who they are. To others however, myself included, it will fall significantly short of what we dream of and struggle for: a world where care is no longer rationed and distributed by the state, but communised and abundant, the collective work and project of us all. In the world we try to bring into existence, the question of who is sick and who isn’t doesn’t arise in the same way, because care isn’t predicated on need, given to some and withheld from others, such that there remains a reason to determine whether someone e.g. has tuberculosis, since the care we will want to give them will depend sensitively on that, but not whether someone is sick as opposed to non-sick, since care will be shared to all. 

Now, where does all this leave us, as far as naturalism is concerned? We have seen that attempts to appeal to naturalist views within the debate on the nature of disease amount to accusations of malingering in disguise. Yet the same people, myself included, who categorically reject these views in that context, are thorough naturalists about their illnesses. This is because, for us, naturalism is not a debate to be had, to be opposed to normativism, to be weaponised in service of biocertification and the attendant abandonment of sick people. No, naturalism is assumed, it is a framework within which we think, because it is the only framework within which it is fruitful to think of illness, when the question isn’t whether we deserve life-sustaining and life-improving support (a question we do not ask ourselves, but is only ever imposed on us), but how do we get better. 

—— 

NB. Outlines of others’ views are written from memory and old informal notes, and with significantly reduced cognitive function. Please excuse and point out any errors. 

References 

Broadbent, A. (2019) Health as a Secondary Property. British Journal for the Philosophy of Science, 70: 609–627. 

Boorse, C. (1977) Health as a Theoretical Concept. Philosophy of Science, 44: 542–573. 

Cooper, R. (2002) Disease. Studies in the History and Philosophy of Biological and Biomedical Sciences, 33: 263–282. 

Fagerberg, H. (2023) What We Argue about when We Argue about Disease. Philosophy of Medicine, 4(1): 1–20. 

Kingma, E. (2007) What Is it to Be Healthy? Analysis, 67(2): 128–133. 

Samuels, E. (2014) Fantasies of Identification: Disability, Gender, Race. New York University Press.