Analytic jurisprudence divides into two related areas: substantive and methodological. Until the late 1980s most analytic jurisprudence had been substantive. It focused on producing theories of the nature of law, the relationship between laws (particular legal standards) and law (a system of governance by laws), and the relationship of law to morality and other institutions for regulating human affairs and actions.

Whereas these debates in substantive jurisprudence remain as lively and urgent as ever, analytic jurisprudence has taken a decidedly methodological turn. Jurisprudence is a philosophical theory of the nature of law, not a historical, economic, or sociological one. But how can philosophy shed light on law? The conventional answer is that philosophy aims to uncover the nature of law.

But how can philosophy help uncover the nature of law? Since H. L. A. Hart, at least, the most prominent answer has been that philosophical theories...