Understanding the transformations in the history of ætiological models means understanding also the changing of the notion of cause. From a historical-epistemological standpoint recent ætiological models broke the monotheistic concept of cause and blurred it in a pluralist pantheon of interacting risk factors, the determinants of health and disease (genetics, behavioral, environmental and social). However, plural ætiology centered on the role of the interaction is not novel in medical history, especially when dealing with hereditary diseases. Since antiquity hereditary matters comprised a variety of causes, or influences (astrological, constitutional, congenital and environmental in general) at the crossroad of the naturenurture interaction. As result of the FIRB project “For a Lexicon of genetics and its degenerations from Hippocrates to ICD-10” emphasizing the dialogue between ancient and modern medical concepts, I discuss here the main shifts of the notion of cause addressing generation and hereditary theories by means of a two step-analysis. In the first part, I will outline the notions of influence and interaction highlighting the main theoretical turning points about medical causality. In the second part, I will review the nature-nurture distinction in the field of heredity underlining the dichotomy between genetic and environmental factors throughout times. As a matter of fact, heredity reveals a most suitable tool for explaining the development of ætiological paradigms in the light of the nature-nurture debate.
