Dworkin versus Hart Revisited: The Challenge of Non-lexical Determination

A fundamental task for legal philosophy is to explain what makes it the case that the law has the content that it does. Anti-positivists say that moral norms play an ineliminable role in the determination of legal content, while positivists say that they play no role, or only a contingent one. Increasingly, scholars report finding the debate stale. This article hopes to freshen it by, ironically, revisiting what might be thought its opening round: Dworkin’s challenge to Hartian positivism levelled in The Model of Rules I. It argues that the underappreciated significance of Dworkin’s distinction between rules and principles is not that Hart’s model cannot allow for the existence of legal principles, but that it cannot make sense of their operation. Hart’s model posits that legal rules are determined in a rule-like (‘lexical’) way, whereas legal principles contribute to rules in a manner that is at least partly non-lexical. The upshots of this reinterpretation are: first (against most positivists) that Dworkin’s challenge does require some reworking of Hart’s positivist theory; and second (against most anti-positivists) that the reworking required to meet Dworkin’s challenge does not necessitate positivism’s abandonment.