The health sector's use of big data no longer comes as a surprise. Our lives are marked by death rates, demographic curves, national averages, and distributions of gender, profession, and age. Numbers have taken on even more importance in the current health crisis, for want of greater scientific understanding. Medical statistics have become the primary tool in political decision-making. There is a history behind this computational episteme. It began with the interpretation of 16th century death records and has been transforming over time ever since. In every era, it has connected the state of mathematical knowledge to medical practice, and to a political vision of public health.