Hugo Grotius
Dutch jurist, political philosopher, theologian and statesman (Huig de Groot, 1583–1645), an intellectual prodigy who entered Leiden University at eleven and accompanied a diplomatic mission to the French court at fifteen, distinguishing himself while still young as one of the most precocious scholars of his time, before pursuing a career in the service of the Dutch Republic that ended with him sentenced to life imprisonment on religious-political grounds — linked to tensions between orthodox Calvinists and moderate Arminians — and, in a celebrated episode, escaping from Loevestein Castle prison in 1621 hidden inside a chest of books, thanks to the ingenuity of his wife Maria van Reigersberch. Generally regarded as the father of modern international law, his masterwork, On the Law of War and Peace (1625), written during his subsequent exile in Paris, for the first time coherently systematised a body of law applicable to relations between sovereign states even in the absence of any common superior authority, rigorously distinguishing between the justice or injustice of the causes of war (ius ad bellum) and correct or incorrect conduct during the conflict itself (ius in bello), and laying the conceptual foundations of all subsequent international humanitarian law. Philosophically, Grotius developed a secularised theory of natural law, formulated in his famous and controversial 'etiamsi daremus' hypothesis — that the principles of natural law would hold even if (per an impossible hypothesis) God did not exist, since they derive from the rational and social nature of human beings themselves — a decisive contribution to the process by which legal and political philosophy became autonomous from revealed theology, a process that would characterise all of later political modernity. Also the author of an influential defence of the freedom of the seas (Mare Liberum, 1609), originally written as a legal brief in favour of Dutch commercial interests against the Portuguese monopoly in the Indies, Grotius exerted decisive influence on later thinkers as diverse as Hobbes, Locke, Pufendorf and Kant.