ArgumentAt the end of the seventeenth and beginning of the eighteenth century, ageing was specifically a medical issue. Indeed, on the one hand, ageing is a normal process of living; on the other hand, old age often entails specific pathologies. Is it really possible to dissociate old age from pathology? If so, how can we think of old age and explain both the necessity and the normality of it? If not, what is the cause of this dysfunction? Modern medical controversies (...) argue along the lines of the respective partisans ofiatromecanism, empirical medicine, and animist medicine. Furthermore, it progressively appears that the issue of aging must also be addressed within the social field, where old age is affected by sanitary, economic, and strategic conditions. Indeed, doctors, economists, and philosophers even tried to assess old age quantitatively with new methods of arithmetic. Thus, in this paper, we want to draw what constitutes the systems of knowledge of old age as a medical category located at the borderlines between epistemological, practical, and social challenges. (shrink)