The continuing existence and operation of the traditional law of Aboriginal and Torres Strait Islander peoples has – relatively recently – been explicitly acknowledged in Australian law. In emerging case law on the subject, the High Court of Australia has confirmed the common law recognition of the survival of Indigenous Australian law. However, in determining what it is that is recognized by the common law – in interpreting Indigenous Australian ‘traditional laws and customs’ – the High Court has disregarded the (...) knowledge reposed in those with authority or expertise in Indigenous Australian law, relying instead upon concepts and assumptions from the jurisprudence of English legal philosopher, HLA Hart. The influence of Hart’s theory in the Australian High Court’s interpretation of Indigenous Australian ‘traditional laws and customs’ is problematic, because it contains an obvious pre-legal–legal dualism reminiscent of the ‘state of nature’ – ‘civil society’ mechanism that was instrumental in the application of terra nullius to Australia. At the heart of The Concept of Law lies the notion of progression from a ‘primitive community’ with only primary rules, to an advanced legal system with a combination of both primary and secondary rules. In this article, I investigate how Indigenous Australians are positioned in relation to Hart’s pre-legal–legal dualism. I examine the ‘primitive’, pre-legal society in The Concept of Law, and its counterpart, the advanced legal system, to analyze the position of Indigenous Australian societies and law in Hart’s scheme. Finally, I analyze the construction of the dualism and consider its impact on the High Court’s interpretation of Indigenous Australian ‘traditional laws and customs’. (shrink)