Complexion of the Members, Complexion of the Body, in Late-Medieval Scholastic Medicine

According to the medical theory of the Middle Ages, every individual had a general complexion for its whole body, but at the same time each organ had a specific complexion, determined by its anatomy, its function, and, of course, the individual. The problem of the relationship between those two types of complexion was, therefore, crucial for the medical practitioner: could a shift in the complexion of the body have an effect on a single organ? Could a change in the complexion of one member alter the general functioning of the body? And what were the interactions between the separate complexions of the various organs? All these questions, which had only briefly been tackled by Galen in his Tegni, began to be systematically addressed by physicians at the end of the thirteenth century. Some thinkers started to write specific treatises on the subject, often called De resistentiis, dealing with the “resistance” (or “counter-operations”) of particular complexions between them. The present paper deals with the origins of this debate, highlighting the role of Gentile da Foligno (d. 1348), and shows how the discussion evolved in the following century. Thus, the aim is to present an overlooked medical debate on complexion while proposing a reflection on the way in which scientific problems can come into being and how they can evolve.