Last week I reread Owsei Temkin’s classic essay from 1963, “The scientific approach to disease: specific entity and individual illness,” for a course I am co-teaching on individuality and medicine. (I have not found the Temkin essay online. If you would like a copy of it, put a request in the comments section.) In it, Temkin distinguishes between the “ontological” and the “physiological” concepts of disease. An ontological approach treats diseases as specific entities—“things” that exist out in nature and befall humans and other creatures. The best example of an ontological approach to disease is the germ theory: the notion, developed by Pasteur, Koch, and others in the late 19th century, that many common diseases are caused by microbes. An ontological approach treats diseases as static; curing disease entails getting rid of the thing that causes it. An ontological approach gave us some of the greatest triumphs of twentieth century medicine: penicillin, the polio vaccine, the triple-drug AIDS therapy.
In contrast, a physiological disease concept treats illness as a process. Temkin also calls this a “biographical” or “historical” concept of disease. A physiological approach is individualized; it treats disease as a unique constellation of disease agent, heredity, experience, and local conditions. In its extreme form, it treats every case as different, because no two individuals have the exact same circumstances. Temkin shows how this approach characterized ancient Greek and Roman medicine, and illustrates how the two, ontological and physiological, have been in dynamic interplay down through the centuries.
Thinking about how to explain this distinction to my students, it occurred to me that ontological diseases are nouns, while physiological diseases are verbs. Objects versus processes; things versus actions. This is a little bit crude, but as a mnemonic it works well to remind one of the fundamental distinction Temkin makes. It’s important to remember that these are not properties of the diseases, but of one’s approach to disease.
Catching up on The Daily Show last night I saw an interview with USC professor David Agus, author of the new book, The End of Illness. Near the beginning of the interview, Agus uses exactly this concept. He says,
We look at diseases as one little factor…You have cancer. You have heart disease. Well to me, those diseases are verbs. You are cancering. You are heart diseasing. And I want to take you from a disease state, the other direction.
After a long and successful run in the twentieth century, the ontological approach to disease has recently ceded the limelight to the physiological disease concept. Genomic medicine is all about individualized or personalized medicine. It promises to end “one size fits all” medicine and treat patients as individuals once again. Individualized medicine is also about prevention—about identifying and stopping disease before it starts. Indeed, Agus segues immediately from diseases-as-verbs to prevention: “And I want to prevent illness.” The physiological approach to disease, individualized medicine, is intimately bound to this notion of disease prevention.
Prevention seems an unassailably benevolent goal; however, in this age of intensive medical management and a potent biochemical, pharmaceutical therapeutic style, prevention also means the erosion of the patient as a medical actor. We all become patients. Your health needs to be managed from birth to death, probably with an armamentarium of drugs designed to forestall a battery of diseases for which you have risk factors.
Agus seems to say that everyone should take a physiological approach, that all cancer and all heart disease, and perhaps even all diseases are verbs. But Temkin concludes his essay by insisting that neither the physiological nor the ontological approach is “correct.” Rather, one must treat a given disease ontologically or physiologically (or perhaps in some combination), depending on whether one is a patient, a doctor, a researcher, a public health worker, or what have you.
It is a marvelous example of how a historical approach to biomedicine—even from an essay half a century old—can deepen our understanding of current events in science, health, and disease.
Temkin, Owsei. “The Scientific Approach to Disease: Specific Entity and Individual Illness.” In Scientific Change: Historical Studies in the Intellectual, Social and Technical Conditions for Scientific Discovery and Technical Invention from Antiquity to the Present, edited by AC Crombie. 629-47. NY: Basic Books, 1963. Reprinted in The Double Face of Janus, Johns Hopkins, 1977.
See also Rosenberg, C. E. “What Is Disease? In Memory of Owsei Temkin.” Bull Hist Med 77, no. 3 (Fall 2003): 491-505
Interview with David B. Agus by Jon Stewart, http://www.thedailyshow.com/watch/thu-february-2-2012/david-agus