This chapter illuminates a different sense in which Gentili’s work was influenced by humanist sensibilities. Differentiating between legal humanism (the mos Gallicus) on one hand and rhetorical humanism on the other, it argues that Gentili did not subscribe to the rigid historical approach to legal sources as practised by the French humanist proponents of the mos Gallicus. Nor is the core significance of humanism in Gentili’s writings directly related to his substantive stance on questions of the law of war, such as the issue of the legitimacy of pre-emptive warfare. It relates instead to the importance of the studia humanitatis and of the participation in the revival of classical learning, especially literature and poetry. Exploring the relationship in Gentili’s writings between poets, especially Vergil, and the substance of his laws of war, the chapter acknowledges that poetry could not strictly serve as a source of law, yet emphasizes the importance of Vergil and other poets for Gentili’s laws of war. In showing that poetry for Gentili went far beyond mere ornament, the chapter significantly enlarges standard international law-oriented understandings of Gentili’s use of textual sources.