Abstract
One aspiration of an analytic jurisprudential theory is to provide an account of how legal obligations arise, including the legal obligation of judges to apply only legally valid norms when adjudicating cases. Also, any fully adequate theory should enable a solution to a ‘chicken-egg’ puzzle regarding legal authority: legal authority can exist only in virtue of rules that authorize it, but such rules require a legal authority as their source. Which came first? This article argues that it is difficult to see how a particular type of positivist theory (featuring a fundamental norm that plays certain roles) can solve the puzzle and also account for the aforementioned adjudicative duty. The challenge can be framed in terms of the need to be able to derive a legal ‘ought’ (applying to courts) from only ‘is’-statements expressing social facts, where the requisite derivation cannot rely on what John Searle has called ‘institutional facts’.