When first published twenty years ago, The Logic of Medicine presented a new way of thinking about clinical medicine as a scholarly discipline as well as a profession. Since then, advances in research and technology have revolutionized both the practice and theory of medicine. In this new, extensively rewritten edition, Dr. Murphy includes changes to show how these different areas of scholarship may affect details of "the logic of medicine" without compromising its fundamental coherence. New to this edition are discussions (...) of the challenge of the flood of new empirical data, new ideas in genetics, molecular biology, homeostasis, pathogenesis, cancer, aging, and Alzheimer's disease. Murphy also comments on such new theoretical topics as dynamic systems, chaos, and fractals and their impact on the burgeoning fields of philosophy and practice of medicine. Written with medical students in mind, the book includes a glossary, many new examples, and problems for solutions with comments on each. An entirely new chapter deals with modeling. Clinicians and researchers will also find the principles thought-provoking and illuminating. (shrink)

This paper examines the way in which causal relations are understood in the dominant model in contemporary medicine. It argues that the causal relation is not definable in terms of the condition relation, but that in general for conditions of an occurrence to be among its causes they must answer instrumental interests in a certain way, and there are further criteria for distinguishing 'the' cause of a disease (i.e., its etiological agent) from other causal factors, which are based upon instrumental (...) interests peculiar to medicine. It also argues that diseases are complex processes of which both clinical and underlying patho-physiological manifestations are proper parts (as contrasted with effects). (shrink)

, Lawrie Reznek argues that disease is not a natural kind term. I raise objections to Reznek's two central arguments for establishing that disease is not a natural kind. In criticizing his a priori, conceptual argument against naturalism, I argue that his conclusion rests on a weaker argument that appeals to the empirical diversity in the symptoms and manifestations of disease. I also raise questions about the account of natural kinds which Reznek utilizes and his point that conventions for classification (...) are excluded by there being natural kinds. Keywords: Disease, natural kind, value judgement CiteULike Connotea Del.icio.us What's this? (shrink)

It is argued that the common definition of diagnosis as the determination of the nature of a disease is misleading. Many diagnoses are not the names of disease entities. This finding reflects the integral relation of the diagnostic task to the rest of clinical reasoning. Diagnosis has no separate goal of its own, in particular it does not have the goal of determining the nature of a disease. Instead, diagnosis contributes to the general goals of clinical medicine. Any attempt to (...) model diagnostic reasoning abstracted from the rest of clinical reasoning will yield an inadequate representation of diagnosis. Such a distortion of medical reasoning will blind us to whatever implications an adequate epistemology of medicine may have for an understanding of the relation between theoretical and practical knowledge in other contexts. (shrink)

I argued that a value-free account of our concept of disease cannot be given. Part of this argument consisted in showing that diseases as a class do not constitute a natural kind. To understand this, we need only see that we define and classify conditions into diseases and non-diseases not in terms of their causes but in terms of their effects. While no philosophical position is watertight, the arguments overwhelmingly favour the conclusion that diseases do not constitute a natural kind. (...) Keywords: Disease, natural kind, value-laden CiteULike Connotea Del.icio.us What's this? (shrink)

The study of mental illness by the methods of molecular genetics is still in its infancy, but the use of genetic markers in psychiatry may potentially lead to a Virchowian revolution in the conception of mental illness. Genetic markers may define novel clusters of patients having diverse clinical presentations but sharing a common genetic and mechanistic basis. Such clusters may differ radically from the conventional classification schemes of psychiatric illness. However, the reduction of even relatively simple Mendelian phenomena to molecular (...) genetics has been shown to be a surprisingly complex and problematic enterprise. Mental illnesses exist at many levels of including social, environmental, and developmental interactions. Reductionistic shifts in the classification of such a disease entity will have to address the interlevel dynamics that take place within the structure of theories of mental illness. The question of how molecular analysis of psychiatric disease will impact on the structure of existing theories and classification systems is the central topic of this paper. (shrink)

The problem of disease definition is related to theproblem of proving that a certain agent is thenecessary cause of a certain disease. Natural kindterms like ‘rheumatoid arthritis’ and ‘AIDS’ refer toessences which are discoverable rather thanpredeterminate. No statement about such diseases isa priori necessarily true. Because theories onnecessary causes involve natural kind semantics,Koch's postulates cannot be used to falsify or verifysuch theories. Instead of proving that agent A is thenecessary cause of disease D, we include A in atheoretical definition of (...) D, take this to representthe real meaning of ‘D’, and discard thepretheoretical definition. This is illustrated byKoch's own attempt to prove he had discovered thenecessary cause of tuberculosis. Methodologicalarguments about disease causation require a clear viewof our use of diagnostic terms. Medical lexicographersshould do more to provide such a view. (shrink)

Since the microbiological revolution, most infectious diseases have been defined and classified according to an etiologic criterion, i.e. the identification of single, external necessary causes (for example, Mycobacterium for tuberculosis). This is not the case with cancer. Not only external necessary causes of cancer have not been identified, but also the morphological classification cannot be based on univocal criteria. Although neoplasia and anaplasia appear to be universal attributes of cancer, these events are only quantitative. Neoplastic growth can be fast or (...) slow (development may take weeks or years), and tissue pathologies are difficult to detect from normal tissue in some cancers but are obvious in others. Common special properties of anaplasia appear to be concealed in the wide range of morphologies. In the absence of a coherent morphological definition, and of external necessary causes (such as bacteria for infectious diseases), a mechanistic definition could be adopted. However, unless molecular biology discovers specific mechanistic steps in carcinogenesis, which indicate the existence of necessary events in carcinogenesis, we cannot adopt a univocal (monothetic) definition of cancer. The alternative is to use a polythetic definition, according to Wittgenstein's model of a long rope twisted together out of many shorter fibres. (shrink)