R. H. Helmholz, "Natural Law in Court: A History of Legal Theory in Practice" (Harvard UP, 2015)

R. H. Helmholz's book Natural Law in Court (Harvard UP, 2015) serves as a guide to the uses of natural law in the past. It shows how lawyers, judges and jurists used natural law to reason and argue about all areas of the law, be they procedural or substantive. Far from being a polemic, this book delves into the legal record of multiple countries to compare, contrast and shed light on the role natural law played in actual legal disputes. Due to the renewed interest in natural law today, this book serves as an important counter-point to legal thinkers who too often rely on purely philosophical or theoretical notions of natural law in their arguments to show how natural law was (and potential can be) deployed to make effective legal arguments in actual legal proceedings.