Balthasar de Ayala

Abstract

Balthasar de Ayala attended the University of Louvain and later served as advocate-general of the army of King Philip II in the Netherlands. He finished his only book, De iure et officiis bellicis et disciplina militari, in 1581, and died of unknown causes in 1584, at the age of 36. Ayala’s treatise reflects the intellectual culture of Louvain, in which both scholastic and humanist jurisprudence were practiced. The work is influenced by Jean Bodin, but Ayala theorizes the Bodinian state within the higher unity of the Holy Roman Empire. With four editions, Ayala’s work served jurists and canonists as an authority on the laws of war throughout the seventeenth and eighteenth centuries. Ayala’s contemporary relevance centers upon his strict application of a formal criterion of belligerency. Without abandoning a moral conception of “just war” (bellum iustum), Ayala insists that only a sovereign state can engage in hostilities as a “just enemy” (iustus hostis). Insurgents are to be treated as outlaws.