This article explores the New Testament's critique of Old Testament law, a genus of positive law. It looks at the applicability of that critique to modern ecclesiastical law: The article identifies three common misconceptions about the view of the New Testament concerning Old Testament law, and then sets out what the New Testament does say about Old Testament law, principally from the writings of St Paul. The principles underlying the New Testament's critique are established. The critique is made not on natural law grounds but on pragmatic and utilitarian grounds. The grounds of the critique are (i) the efficacy of the law to achieve its true intent; and (ii) the extent to which human beings exaggerate the usefulness of Old Testament law.