ÁLVARO HADAD FILHO

Like other natural phenomena, the symptoms of diseases present some regularities that make it possible to consider the cases of different individuals as representatives of limited and distinct classes. Nosology is the name given to a scientific branch structured during the 18th century, whose importance to the history of medicine lies in the definition and systematic classification of diseases. The authors that contributed to the formation of nosology advocated that the sensible morbid phenomena, and not their causes, should form the basis of the classification of diseases. They used as their model the works of botanists and the taxonomy of plants, generally based on their visible characteristics. The nosologists adopted some version of empiricism as their philosophical doctrine. So also did the first writers that tried to quantify morbid phenomena. Indeed, many of them have worked on these two different tasks, i.e., classifying and quantifying diseases. In this thesis, we reconstruct the historical development of nosology and medical statistics as autonomous medical disciplines, underlying the relations they share with each other and with philosophical thinking. Following that process, we intend to indicate some forms of production of scientific knowledge that persist in contemporary Western medicine. The classification of diseases is a fundamental prerequisite to their quantification, and the validity of quantitative studies depends on the taxonomy adopted