ABSTRACT
This chapter examines Alberico Gentili’s contribution to the secularization of the law of nations. A prominent early modern Italian legal theorist and practicing lawyer, Alberico Gentili designed a solid framework for the law of nations based on three pillars: the Greco-Roman idea of natural law, the Justinian compilation of Roman law, and the then novel Bodinian notion of sovereignty. Gentili freed the law of nations from excessive scholastic influences and theological importations, avoiding metaphysical developments and overly subtle dialectics. Providing some new arguments, he removed religion as a valid reason for conflict and war, he advocated for the legitimacy of non-Christian regimes, especially the Ottomans, and he tried to fix the tenuous lines of separation between jurisprudence and theology and between the internal forum and external forum of canon law. His world-famous saying—silete theologi in munere alieno!—commands the theologian not to be involved in other people’s business and was claimed centuries later by the jurisprudence of European public law to argue in favor of the secularization of the law, beyond the limits Gentili himself intended.
