Conceptions of Health & Disease

1. Conceptions of Health & Disease ISD I – E/H/HL Session 1 April 14, 2003

2. Overview • Since you’re in the early days of the ISD course, it’s a good time to consider the concepts of disease & health • How should we conceive of them? • The main question for this part of the session: Are these descriptive or normative notions? • i.e., is a value judgment made whenever judgments about health and disease are made or are these simply objective, value-free descriptions of a patient?

3. Some Examples • Which of the following are examples of disease or ill health? Which are neither? • AIDS • Senility • Extremely short stature • SARS • Colour blindness • Starvation

4. Why Does Defining Health & Disease, Matter? • The basic concepts we work with often shape our thinking in ways we might not expect • This idea will be explored at several points in the term 2. Significance for the scope of medicine • Medicine is generally thought to be in the business of promoting health, curing disease, etc. • Thus the limits of disease, health, etc. set the limits of medicine • Consider, e.g., the debate about whether alcoholism is a disease

5. Two Examples • Contrast • “Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.” (Preamble to the WHO Constitution) • “Health is a state of physical well-being” (Daniel Callahan) • Notice the huge difference in the scope of health care implied by the two definitions

6. The Relationship between Disease & Health • Are disease and health logical opposites? I.e., is health just the absence of disease? • This doesn’t allow for degrees of healthiness • Does being healthy really require the complete absence of disease? • If so, we’ll either need a fairly restrictive definition of disease or else no one will ever be healthy

7. Three Approaches to Defining Disease & Health • In terms of statistical normalcy/ abnormality • In terms of proper biological functioning • In normative terms

8. Normative vs. Non-normative Conceptions of Disease & Health • What’s at stake in the argument about whether disease and health are normative concepts? • Some claim that medicine cannot be objective unless its basic concepts are value-judgment free • However, recall that some think value judgments can be objectively true or false • If you accept that (at least some) value judgments are objectively correct, this usually limits your discomfort with the idea that health & disease are normative concepts

9. Statistical Normalcy/Abnormality • Healthy conditions are statistically normal conditions • Diseases are statistically abnormal conditions • Is this plausible? • This idea is often appealed to, but clearly flawed • Abnormal tallness is a disease? • Unusual hair or eye colour constitutes a disease?

10. Proper Function • “health consists in our functioning in conformity with our natural design as determined by natural selection” (66) • If an organ “loses the capacity to perform the function for which it was designed by evolution…, the condition is indicative of disease” (66) • Is this plausible?

11. Problems with Proper Function • The very idea seems to anthropomorphize evolution. • Does it make sense to talk about function where there’s no conscious designer? • Notice: this problem goes away if you accept the existence of God as active creator • Even if we speak loosely about function, couldn’t there be normal diseases? • E.g., Consider that aging might be very useful from an evolutionary point of view • Would this mean no diseases as a result of ‘ordinary’ aging?

12. Normative Conceptions of Health & Disease • A normative conception claims “it is impossible to decide whether a particular state of affairs represents health or disease without some reference to values” (68) • Culver & Gert: “it is not dysfunction but the perceived evil associated with dysfunction that is at the heart of the meaning of disease.” (69) • Such a conception may also draw on ideas of function or abnormality, but it is value judgments that are claimed to be at the heart of judgments about disease or health • Is this plausible?

13. So What? • Most of the time, the fact that health & disease are value-laden terms is not problematic since most of the time we agree about how to evaluate a particular condition • E.g., heart problems = bad • Problems do arise, however, in some cases in which there are disagreements about how we should evaluate a particular condition • E.g., deafness • homosexuality • p.m.s.

14. The Point • None of this suggests that there is anything fundamentally wrong with the concepts of disease & health • It does suggest that it is a mistake to think the concepts are purely descriptive • They have a normative element we should be aware of

15. A Further Question • Even if we accept that the concept of disease has normative elements, it still remains for us to come up with a precise definition of disease • Two Competing Conceptions of Disease • Disease entity • Focuses on the existence of a discrete, physical disease entity • Clinical ‘entity’ • Conceives of disease in functional terms