There was a time when people did not resort to risk to understand or calculate their health condition; they simply lived, caught diseases and then, one day, they just died; or so it seems today. Even doctors—traditionally more aware of their personal casuistry than of the global context—did not pay much heed to statistical refinements. That time is gone forever. Today, probability calculation appears as the very core of clinical and epidemiological research; even geneticists and other basic scientists often offer risk estimates. Furthermore, a good part of medical decisions are actually based on risks and benefits assessments. When recommending a treatment, performing a biopsy or applying a specific procedure, contemporary doctors have to consider the risks for each patient. In a way, they are the advisers and managers who assess the risks revealed by a host …