This meticulously researched book addresses a central question of analytical and philosophical jurisprudence: What is positive law? Throughout his analysis, James Bernard Murphy, author of The Moral Economy of Labor: Aristotelian Themes in Economic Theory (New Haven: Yale University Press, 1993), contrasts positive law with the other two kinds of law that constitute the triad of legal concepts - natural law and customary law. Although they are treated at length in this work, Murphy states in the preface that he intends to write a companion volume on natural law and customary law, "thus completing the foundation of philosophical jurisprudence" (p. x). It is an ambitious project, but Murphy is up to the task. Murphy displays a vast knowledge of analytical jurisprudence, of the history, sociology, and anthropology of law, as well as of linguistics (study of language is the fundamental analytical tool employed by Murphy). The Philosophy of Positive Law is a searching examination of the concept of positive law - apparently the first such book length study - in the works of four seminal legal philosophers, Plato, St. Thomas Aquinas, Thomas Hobbes, and John Austin (along with "eminent" and contemporary scholars thereof), allowing Murphy to draw magisterial conclusions about the jurisprudence of positive law.
Bromberg, Howard. Review of The Philosophy of Positive Law: Foundations of Jurisprudence, by J. B. Murphy. Rev. of Metaphysics 60, no. 3 (2007): 675-6.