How Practices Make Principles and How Principles Make Rules

One of the most fundamental questions in general jurisprudence concerns what makes it the case that the law has the content that it does. It is the job of theories of legal content to provide answers. This article offers a novel positivist theory of legal content. According to the theory it calls “principled positivism,” legal practices ground legal principles, and legal principles determine legal rules. This two-level account of the determination of legal content differs from Hart’s celebrated theory in two essential respects: in relaxing Hart’s requirement that fundamental legal notions depend on judicial consensus; and in assigning weighted contributory legal norms—“principles”—an essential role in the determination of legal rights, duties, powers, and permissions. Drawing on concrete examples from American statutory and constitutional law, the article shows how the version of positivism that it introduces and defends betters Hart’s in meeting the most formidable challenges to positivism that Dworkin marshaled. The article also explains why the revisions it advances matter, legally as well as philosophically.