Natural Law and Modern Society presents a new theory of natural law, grounded in the thought of Saint Thomas Aquinas, aimed at answering questions relevant to the world of today: from the nature of morality and ethics to the theory of law, obligation and political authority; from the domestic realm to international community. It seeks to elicit from the natural law tradition timeless truths concerning the human condition, in particular the social and political dimensions to human existence. This mode of existence, it argues, is not a problem to be resolved through some permutation of political institutions, but a predicament to be managed. At the heart of the book is the identification of a 'core morality': a set of moral requirements that are foundational to every society at all places and times, as distinct from those standards that are particular to this or that society at some time.