Legal philosophers have been preoccupied with specifying the differences between two systems of normative guidance that are omnipresent in all modern human societies: law and morality. Positivists propose a solution to this ‘Demarcation Problem’ according to which the legal validity of a norm cannot depend on its being morally valid, either in all or at least some possible legal systems. The proposed analysis purports to specify the essential and necessary features of law in virtue of which this is true. Yet, (...) the concept of law is an ‘artefact concept’, that is, a concept that picks out a phenomenon that necessarily owes its existence to human activities intended to create it. Artefact concepts, even simple ones like ‘chair’, are notoriously resistant to analyses in terms of their essential attributes, precisely because they are hostages to human ends and purposes, and also cannot be individuated by their natural properties. Twentieth-century philosophy of science dealt with a kindred Demarcation Problem: how to demarcate epistemically reliable forms of inquiry from epistemically unreliable ones, that is, how to demarcate science from pseudo-science or nonsense. Like the legal philosophers, they sought to identify the essential properties of a human artefact (namely, science). They failed, and spectacularly so, which led some philosophers to wonder, ‘Why does solving the Demarcation Problem matter?’ This essay develops the lessons for legal philosophy from this episode and its philosophical aftermath, and concludes that, in order not to become embroiled in pointless Fullerian speculations about the effects of jurisprudential doctrines on behaviour, we should abandon the Demarcation Problem in jurisprudence. (shrink)