For the past four decades, Anglo-American legal philosophy has been preoccupied – some might say obsessed – with something called the “Hart–Dworkin” debate. Since the appearance in 1967 of “The Model of Rules I,” Ronald Dworkin's seminal critique of H. L A. Hart's theory of legal positivism, countless books and articles have been written either defending Hart against Dworkin's objections or defending Dworkin against Hart's defenders. Recently, in fact, there has been a significant uptick in enthusiasm for the debate from its already lofty levels, an escalation no doubt attributable to the publication of the second edition of The Concept of Law, which contained Hart's much anticipated, but alas posthumous, answer to Dworkin in a postscript. Predictably, the postscript generated a vigorous metadebate about its cogency, with some arguing that Hart was wrong to reply to Dworkin in the way that he did and others countering that such criticisms of Hart are unfounded.

In this essay, I will not take sides in this controversy over Hart's reply to Dworkin. I will be interested, rather, in a more preliminary matter, namely, in attempting to set out the basic subject matter of the debate. My chief concern, therefore, will be to identify the core issue around which the Hart–Dworkin debate is organized. Is the debate, for example, about whether the law contains principles as well as rules? Or does it concern whether judges have discretion in hard cases?