Details in Galileo’s Mechanism of Inertia as New Intellectual Historical Insights

In the twentieth century, although evident and remarkable works correctly studied Galileo’s Inertia, giving fundamental insights, they did not grasp the nuances of Galileo’s concept, idea and mechanism of Inertia in its intellectual subtlety. Galileo offered crucial insights on the concept of inertia, and there are many studies on this subject. We think that much investigation remains before the processus of Galileo’s scientific thought is complete, and we can fully appreciate both his uncertainties and understandings in the field. We think that a full understanding of some aspects of Galileo’s concept of inertia is lacking. We try to fulfil this gap. This paper deals with Galileo’s conceptualisation of Inertia as presented in the First Two Days of Dialogo sopra i due massimi sistemi del mondo tolemaico e copernicano (1632) and Last Two Days of Discorsi e dimostrazioni matematiche intorno a due nuove scienze (1638). Our work consists in three main parts: scientific, historical, and historiographical.(1) After introducing Inertia scientifically, we present it into historical research from its embryonic statements respectively as Impetus, laws and incorporated into Principle of virtual laws. (2) We historically analyse Galileo’s inertial paths, showing how, in specific physical–geometrical circumstances, his ideas confront both circular and rectilinear Inertia. (3) We examine and discuss some of the most influential histo-riographical contributions in the range of Galileo’s Inertia––and––his mechanics. Our paper intends to offer an additional analysis on the subject within the history of physics––and––intellectual history of ideas, including both the relationship between physics–mathematics and the current historiographical debate.