Nineteenth-century medical advances were entwined with a conceptual innovation: the idea that many cases of disease which were previously thought to have diverse causes could be explained by the action of a single kind of cause, for example a certain bacterial or parasitic infestation. The focus of modern epidemiology, however, is on chronic non-communicable diseases, which frequently do not seem to be attributable to any single causal factor. This paper is an effort to resolve the resulting tension. The paper criticises (...) the monocausal model of disease, so successful in the nineteenth century. It also argues that a multifactorial model of disease can only be satisfactory if it amounts to more than a mere rejection of the monocausal model. A third alternative, the contrastive model, is proposed and defended on the grounds that it links the notions of disease and of general explanation, while avoiding the philosophical naiveties and practical difficulties of the monocausal model. (shrink)

This paper is on dangerous human experimentations with drugs against trypanosimiasis carried out in the former German colonies of German East Africa and Togo. Victory over trypanosomiasis could not be achieved in Berlin because animals were thought to be unsuitable for therapeutic laboratory research in the field of trypanosomiasis. The colonies themselves were necessarily chosen as laboratories and the patients with sleeping sickness became the objects of therapeutical and pharmacological research. The paper first outlines Robert Koch's trypanosomiasis research in the (...) large sleeping sickness laboratory of German East Africa and then focuses on the escalating human experiments on trypanosomiasis in the German Musterkolonie Togo, which must be interpreted as a reaction to the starting signal given by Robert Koch in East Africa. (shrink)