The Philosophy of Customary Law

Although many modern philosophers of law describe custom as merely a minor source of law, formal law is actually only one source of the legal customs that govern us. Many laws grow out of custom, and one measure of a law’s success is by its creation of an enduring legal custom. Yet custom and customary law have long been neglected topics in unsettled jurisprudential debate. Smaller concerns, such as whether customs can be legitimized by practice or by stipulation, stipulated by an authority or by general consent, or dictated by law or vice versa, lead to broader questions of law and custom as alternative or mutually exclusive modes of social regulation, and whether rational reflection in general ought to replace sub-rational prejudice. Can legal rules function without customary usage, and does custom even matter in society?

The Philosophy of Customary Law brings greater theoretical clarity to the often murky topic of custom by showing that custom must be analyzed into two more logically basic concepts: convention and habit. James Bernard Murphy explores the nature and significance of custom and customary law, and how conventions relate to habits in the four classic theories of Aristotle, Francisco Suarez, Jeremy Bentham, and James C. Carter. He establishes that customs are conventional habits and habitual conventions, and allows us to better grasp the many roles that custom plays in a legal system by offering a new foundation of understanding for these concepts.

James B. Murphy is Professor of Government at Dartmouth College, where he teaches courses in jurisprudence and political philosophy. His research interests include: Aristotle, jurisprudence, semiotics, political economy, and the philosophy of education. He has received grants and fellowships from the N.E.H., the A.C.L.S., the Earhart Foundation, The Manhattan Institute and the Pew Charitable Trusts. He previously authored The Moral Economy of Labor: Aristotelian Themes in Economic Theory and The Philosophy of Positive Law. He co-edited, with Richard O. Brooks, Aristotle and Modern Law (2003), Augustine and Modern Law (2011), and Aquinas and Modern Law (2013). He has also co-edited with Amanda Perreau-Saussine, The Nature of Customary Law (2007). He has published scholarly articles in Political Theory, The Review of Politics, The Review of Metaphysics, Semiotica, The Thomist, TheAmerican Journal of Jurisprudence, The American Catholic Philosophical Quarterly, Revue Internationale de Philosophie, and Social Philosophy and Policy.