Abstract

Two essential periods may be identified in the early stages of the history of vitamin D-resistant rickets. The first was the period during which a very well known deficiency disease, rickets, acquired a scientific status: this required the development of unifying principles to confer upon the newly developing science of pathology a doctrine without which it would have been condemned to remain a collection of unrelated facts with very little practical application. One first such unifying principle was provided by the notion of hygiene; while the blanket explanations provided by this notion alone were much too general to enable rickets to achieve scientific status, it did point out the need to look for specific external causes for the disease and to examine the life-style and dietary habits of the patients. The second phase of the conceptualization of the disease was the assumption of a specific cause — that is, using concepts developed in the area of infectious diseases. This was made possible by fundamental similarities between deficiency and infectious diseases, in spite of their apparent differences. Both types of illness have some of the characteristics of what Georges Canguilhem calls the ontological representation of disease as opposed to dysharmonic representations, which primarily concern the endocrine diseases. It is precisely this shift from one to the other manner of perceiving ill health that enabled the identification of the vitamin D-resistant rickets. Conceptualization of the notion of vitamin D resistancy required that the conditions causing the disease be looked for within the organism rather than outside it; this was thus the first time that endocrine concepts were applied to studying the physiology of vitamin D.The history of resistant rickets therefore represents an interesting model for understanding the growth of biomedical knowledge. It allows the development of a number of more general ideas on the question of the relationship between biology and medicine and on the thorny problem of specificity in medical thinking. As far as this topic is concerned it can be seen that there was an ongoing exchange between medical and biological thinking during the initial period up until 1937, and that one could deny any such specificity in medical thinking during this same period. Albright, for example, used human diseases as spontaneously produced models for experimental biology. It was also more feasible for an experimental biologist to administer toxic doses than for a clinician to do so.What, then, if any, is the place of the specificity of medical thinking in this history? The fact that medicine is characterized not only by it ccognitive content78 but also by its final aim, which is to restore health, makes it necessary to take factors other than objective knowledge into consideration. This is particularly evident in two aspects of medicine, therapeutics and nosology, and in approaching the notion of pathological individuality.Therapeutic activity has a largely empirical approach. Many drugs, such as cod-liver oil, were discovered empirically. Treatment often in the past, and still now, has proceeded by trial and error, upon no established theoretical basis. At this level the relationship between biology and medicine is roughly comparable to that between science and technology79 \3- that is, it is impossible to reduce either therapeutics or technical activities to the simple application of basic science. In this sense, the application of vitamin D to vitamin-resistant rickets is quite typical. Further-more, in the case studied here, the therapeutic activity heralds a definite breaking away from the medicatrix naturae of conventional medicine dating back to ancient times, and it embodies a new concept of the organism and of disease: no longer can the diseased organism be thought of as merely having a perturbed equilibrium requiring restoration by means of a natural style of medicine. On the contrary, vitamin D resistance is an obstacle that indicates profound biological dysfunction, to be rectified only by means of an extremely aggressive and therefore dangerous therapy. The therapy thus serves to reveal the severity of the dysfunction, thereby leading inevitably to conceptual innovation. This sheds light on the theoretical innovations of which the therapeutic activity is capable.Therapeutic activity is also influenced by notions of health and illness, normal and pathological states, none of which may be determined entirely objectively. For example, the term healing as used by Albright in the case of resistant rickets that he described may be discussed in this light.Nosology, or the classification of diseases, depends largely on the description of clinical syndromes, which are themselves mainly based on subjective elements (discomfort, disability, or the extent of a patient's suffering). The advent of pathological anatomy at the beginning of the nineteenth century disrupted classification by introducing the concept of localized anatomical lesions81-and, hence, an element of material objectivity \3- into nosology. Radiological examination further complicated matters by enabling the equivalent of an autopsy on living matter. Lastly, biological examination complicated nosology by showing that biological anomalies may exist in human beings without necessarily leading to a pathological condition. Medical thinking can choose to combine all these elements to describe a disease, but can also separate them and retain only a few, or a single one, according to requirements - as did Albright.The notion of biological and pathological individuality is fundamental to the development of medical thinking. Whatever its theoretical origin, medical thinking has since ancient times incorporated the idea that each individual reacts differently to the same treatment and his own specific pathological tendencies. I mentioned earlier that in the history of vitamin D-resistant rickets the notion of rachitic tendency reflected this type of thinking. After 1937, this history progressed by successively separating new individual entities, affecting smaller and smaller groups of individuals in each case. In other words, the need to understand and to define individual illness more closely required the development of new concepts and the construction of new individual categories of disease linking these concepts to older clinical, radiological, and biochemical elements