Clinical Judgment

of Medicine and other periodicals over the past decade. Dr. Feinstein's aim is nothing less than to induce doctors to think in new ways. He hopes that one result of his proposed revolution in clinical thinking will restore to clinical medicine the status it has lost owing to the explosive growth of molecular biology. He traces at length the growth and change of clinical investigation in this country, the changing role of the clinical investigator, first as medicine's handmaiden, later (and now) as master of the house, and the impact of the new breed of clinical investigator on medical teaching. He is not happy with what he sees. He finds the clinician distrustful of the new science and too willing to lean on vague artistic principles airily described as "clinical judgment" in the old sense. He finds the "modern" clinical investigator trying, sometimes without adequate training, to study molecules while he allows his clinical skills to wither and ignores the problems which only he has the training and skills to investigate. Feinstein convincingly exposes unreason all about us. He points out forcibly that we don't really know what we are doing when we try to evaluate such things as the natural history of disease or the results of various kinds of treatment for all sorts of disorders. The two major defects underlying our ineptitude in these matters are that we haven't learned to classify diseases in a way that will provide us with homogeneous populations to study, and that we persist in adhering to pathological classifications when we should be using clinical ones. For example, we should be studying the subgroup of young, white male patients who have myocardial infarction with shock but without congestive heart failure, not just a heterogeneous lump of people with myocardial infarction. Only in this way might we hope to find out if anti-coagulation "for myocardial infarction" is any good or not. (We still don't know after more than 20 years). The method Feinstein offers is the application of Boolean algebra and of Venn diagrams to facilitate the intellectual management of overlapping populations and groups. His exposition of the mathematics is clear and even exhilarating, and he shows how these applications have clarified obscurities in the course and treatment of acute rheumatic fever and the natural history of bronchogenic carcinoma. It is a great pity that Dr. Feinstein's enormously important message is buried in such …