Anglo-American philosophy of law is at a turning point in its short history.1 A peculiar tradition, dominated – like, arguably no other realm of philosophy on the contemporary scene – not only by one philosopher (H. L. A. Hart), but by one book (The Concept of Law, 1961; 2nd edition in 1994), it is one that, for the last fifty years, has been responding, sometimes passionately in favour, and sometimes passionately against, Hart’s surprising2 magnum opus.3 A Hart-inspired map of the discipline has those close to the core engaging directly with Hartian problematics, and thus participating in such popular contemporary debates as the quarrel between soft and hard positivism, the plausibility of the right answer thesis, the conventionality of the Rule of Recognition, and the explanatory scope of the concept of a legal system as the union of primary and secondary rules. Those on the penumbra, from this perspective, include those with less obvious a stake on how to interpret Hart, including the institutionalists and neo-institutionalists,4 the discourse theorists,5 the autopoieisis theorists,6 the American and Scandinavian legal realists, and the various kinds of non- or post- formalists and legal naturalists.7 This is not yet to mention all who would find a hard time fitting onto this map altogether, including those engaged in anthropology and sociology of law, law and literature, law and the humanities, law and policy, feminist legal theory, and increasingly, law and psychology, and law and neuroscience.8