On the concept of disease

2

  Abstract:  3

Introduction   4

  For a new concept of disease  6

  The antiquity and the objective reality of pathological conditions  8

  Complexity theory and a new concept of health and disease  10

  The Individual level and the reality of lesions  12

  Population level and abstract construction of diseases  14

  Diseases at the ecosystem level  16

  Defining disease  17

  Literature  19

3

Abstract:

A new concept of disease is proposed under the Systems Theory of Levels of Complexity. The objective reality of pathological lesions and organic and mental dysfunctions is admitted as characteristic of the individual level of organization. Diseases, though, are defined as social constructs of collective nature. Current definitions of disease fail to recognize the fact that diseased and diseases belongs to distinct levels of complexity. The question of anachronism in diagnosing pathological conditions in the past is addressed.

Key words:

diseases; levels of complexity; systems theory; anachronism; social constructs.

Acknowledgments:

Márcia Grisotti and Márcia Pfuetzenreiter read, discussed, and commented on this text. With Adriana Mohr and François Delaporte I kept lively discussions concerning some philosophical and practical issues related to realism and social constructivism. Stephen M. Sacks encouraged the writing of an earlier version of this article and offered valuable comments.

4

Introduction

Defining disease and health is both a necessity and a challenge. It has been attempted by anthropologists, sociologists, philosophers, biologists, and medical doctors. The very need for a definition has been questioned recently (Hesslow, 1993), but a clear theoretical concept and an operational definition are certainly needed. Seedhouse (1993) and Nordenfelt (1993a, 1993b) justified that need not only as a matter of purely philosophical speculation and applied philosophical research, but also for pragmatic reasons, as a reference for legal litigations and health care policies. It is also a requisite to allow doctors and patients to understand each other.

A growing body of literature addresses this question, but a thorough bibliographic review will show that the failure to distinguish between phenomena pertaining to distinct levels of complexity has so far confused the actual issue and led frequently to fruitless arguments.

Inventions and discoveries like the world of microbes in the 17 ^th Century, the cell in the 19 ^th Century, and the molecular basis of biological phenomena in the 20 ^th Century, certainly improved our knowledge of health and disease. But phenomena taking place at lower levels of complexity - those of the molecules and the cells - had little influence upon our philosophical conceptualization of health and disease at the individual or higher levels.

Recently, Temple et al. (2001) proposed a new definition of disease. Their approach did little to improve on previous attempts. For them, disease is a state that places individuals at increased risk of adverse consequences. If we adopt their definition, we would be forced to recognize that getting old qualifies and also, for that matter, driving a car, getting married, breathing, eating, or simply, being born: all those states carry a "risk of adverse consequences". They failed to recognize that disease is not an attribute of a patient, but a generalization from a large number of particular, individual observations. Sasz (2002) remarked on the narrow, sometimes indistinct limits that separates morality, sin, and crime, reaffirmed his polemic opinion of 1961

5

of the inexistence of mental diseases. He also showed how tradition and respect for religious beliefs and norms affect social views and legal dispositions. Saz reduced disease to one of its components, when he sustains that disease is a biological process that occur in our bodies, a vision reminiscent of the old conception of Littré and Robin (1858).

6

For a new concept of disease

A simple and direct answer is not sufficient to take into consideration all the complex aspects involved in the conceptualization of disease.

A historical approach may be of help. The historian of medicine may follow several avenues of inquiry. He may produce a historiography of discoveries. A paradigmatic example is the revision of the currently accepted views concerning the discovery of Chagas disease, published by Delaporte (1999). He may analyze the changing concepts and diagnostic procedures concerning a certain disease in medical literature, from the past to present times. An example is the recent change in the etiologic explanation of gastric ulcers, from a presumed inflammatory condition of psychosomatic nature to be treated with anti-acids and dieting, to a bacterial infection responsive to antibiotics. Wilson (2000) explored this venue showing it to be a domain of historical investigation of its own right, distinct from - though by no means independent of - such more familiar history-of-medicine themes as the history of anatomy [...]. Or else, he may be interested in the identification of diseases in early descriptions, travelogues, reports and chronicles of explorers. (Hudson, 2001). Yet another venue is to make retrospective diagnoses in an attempt to fit early descriptions of ailments or anomalies found in fossil, prehistoric or historical remains into current categories of diseases. This type of reseach falls into the special fields of paleopathology and paleoparasitology. An example is the search for the influenza virus of 1918 in corpses frozen in ice or preserved in collections of pathological specimens. Some authors criticize such attempts as anachronistic while others find merit in these regressive efforts (Jardine, 2000). A bitter argument surrounded the identification of tuberculosis as the cause of death of Ramsés II (Latour, 1998). This argument was taken over by hard-line relativists and post-modern social constructivists who denied the existence of the reality of scientific facts, as merely mental constructs, and as valid as any other alternative explanation. Zoologists and botanists, though routinely include a chapter in their taxonomic papers in which they disentangle nomenclatorial problems not unlike those encountered by historians of diseases without any qualms concerning anachronism. To identify an animal