Abstract
This chapter demonstrates that the law’s social ontology, properly understood, has dramatic implications for the longstanding debate among legal philosophers over the role morality plays in the law. When the debate is confined to discussions of the truthmakers of legal propositions or the criteria of legal validity, the debate can easily be seen to be at an impasse. However, a deeper understanding of the ontology of law may help to settle this debate. The chapter’s contention is that a proper understanding of the way in which institutions like legal systems depend upon collective belief and acceptance for their existence, supports an exclusive positivist picture. Officials and others can be wrong about the application of a rule to a set of circumstances. This can include a mistaken belief that a critical moral principle fixes the correct content or application of the law. It is the very fact that the legal system is constituted by their articulated beliefs that makes it the case that the content of the system cannot depend upon something that makes those beliefs correct or incorrect.