To understand our current world crises, it is essential to study the origins of the systems and institutions we now take for granted. This book takes a novel approach to charting intellectual, scientific, and philosophical histories alongside the development of the international legal order by studying the philosophy and theology of the Scientific Revolution and its impact on European natural law, political liberalism, and political economy. Starting from analysis of the work of Thomas Hobbes, Robert Boyle and John Locke on natural law, the author incorporates a holistic approach that encompasses global matters beyond the foundational matters of treaties and diplomacy. The monograph promotes a sustainable transformation of international law in the context of related philosophy, history, and theology. Tackling issues such as nature, money, necessities, human nature, secularism, and epistemology which underlie natural lawyers' thinking, Dr García-Salmones explains their enduring relevance for international legal studies today.