Just like astronomers do: building hypotheses in Giorgio Baglivi’s medicine

Thomas Sydenham’s view on methodology in the preface to Observationes medicae (1676) is traditionally considered one of Giorgio Baglivi’s main sources for the reform of medical practice outlined in De praxi medica (1696). This is the case for two crucial aspects: the recovery of observation in medicine and the conception of “natural history of disease”. However, Sydenham and Baglivi have different opinions about the role of hypotheses in medical practice. While recognising the main critical issues about their use, Baglivi tries to provide physicians with some useful instructions for building them: just like astronomers do, hypotheses should be founded on a strong empirical evidence and rejected once they are in discordance with Nature and thus unable to properly explain phenomena. This paper will explore this pivotal aspect of Baglivi’s methodology.