This book conceptualizes international law as an expression of practical reason, focusing on the genesis of modern international law in the essence of the concept of sovereignty. Utilizing the philosophical method of R.G. Collingwood, the essence of sovereignty is sought in a dialectical model drawn from the philosophy of David Hume. John Martin Gillroy transcends conventional social scientific method, political theory, and its understanding of global governance to make the study of the philosophical underpinnings of international law accessible, grounded, and practical. This book provides analytic tools for understanding globalization, international legal thought, legal theory, and political philosophy, offering engaging insights on a complex field of study. It outlines the first of three arguments describing the evolution of international law as a manifestation of practical reason through an application of philosophical method to the source, locus, and scope of the concept of sovereignty. It moves from a dialectic balance favoring utility, to a balance dominated by legal right, and finally to a dialectic of duty to humanity and nature.

The book transcends conventional social scientific method, political theory and its understanding of global governance to make the study of the philosophical essence of the international legal system fully accessible.