Abstract
The article examines the evolution of public health legislation in Italy from the Unification to the approval of the Crispi-Pagliani law, one piece of the Crispi reform agenda, which contributed to the modernization of the country and the reduction of the mortality rate. Initially, health reforms faced political resistance due to the difficulty of accepting state intervention in the private lives of individuals. However, scientific discoveries profoundly changed the sensitivity and political narrative on the issue of health. Through the analysis of parliamentary debates, the article highlights how scientific knowledge led the government to enact a law for the protection of public health, eventually advocating for the creation of a Ministry of Health.