The unique coincidence of Renaissance, Humanism, and Reformation fostered the adaptation of Galilei's mathematical method within the legaI realm. Due to the artistically communicated il stato-reference, the Bodinan focus on legislative primacy, the enriched legal interpretations by mos gallicus-minds, and the usus modernus-interest in locaI statutes' rational validity mathematics amounted to an epistemological key - also in law. According to the Quattrocento's new subjectivity an individual mathematical 'acquisition' of nature and philosophy set the tone for voluntary and legal self-formation beyond medieval canon restraints on traded (de Medici) wealth.