This thesis focuses on the entire Machiavellian diplomatic carteggio (Legazioni, Commissarie, Scritti di governo). This correspondence reflects cultural practices of writing and all the sociolinguistic transformations they cover. The methodology is a combination between traditional philological methods and computer technology (Digital Humanities and Digital Studies): it is the intersection of these disciplinary fields I have conceived a software to analyze my corpus (Machiato). The argument of the the political instability has been developed in three stages: analyzing the upheavals triggered by the proliferation of conflicts; the impact of war on the conception of Stato as on practices and finally, multiplication and confusion of temporalities of the political world. Individuals are forced to reduce the time of speculation and theorizing to respond to the state of emergency, a state of permanent war. The LCSG allow to identify the steps in the construction of the Machiavellian perspective and more specifically, the various attempts to found the practice including insecurity, not as a source of disorientation but as specificity of action in politics.