‘Hermeneutics and law’ begins with natural law in Greco-Roman culture and God’s moral law of Christendom. It then explains legal positivism as espoused by John Austin (1790–1859) and the more democratic ideal of Herbert L. A. Hart (1907–92). For Hart, society operates two sets of legal rules: primary rules that tell us not to steal or not to kill, and secondary rules ‘of recognition’ by which primary positive law is recognized and applied in a regulated manner. Critics of legal positivism—legal realism and natural law—are discussed, before concluding that a legal judgment involves more than the mere application of rules. To judge is to interpret.