Brian Leiter

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

This chapter offers a new interpretation of Nietzsche’s argument for moral skepticism, an argument that should be of independent philosophical interest as well. On this account, Nietzsche offers a version of the argument from moral disagreement, but, unlike familiar varieties, it does not purport to exploit anthropological reports about the moral views of exotic cultures, or even garden-variety conflicting moral intuitions about concrete cases. Nietzsche, instead, calls attention to the single most important and embarrassing fact about the history of moral theorizing by philosophers over two millennia: namely, that no rational consensus has been secured on any substantive, foundational proposition about morality. Persistent and apparently intractable disagreement on foundational questions, of course, distinguishes moral theory from inquiry in the sciences and mathematics. According to Nietzsche, the best explanation for this disagreement is that, even though moral skepticism is true, philosophers can still construct valid dialectical justifications for moral claims because the premises of different justifications will answer to the psychological needs of at least some philosophers and thus be deemed true by some of them. The chapter concludes by considering various attempts to defuse this abductive argument for scepticism.

The seven original essays included in this volume from 2000, written by some of the world's most distinguished moral and legal philosophers, offer a sophisticated perspective on issues about the objectivity of legal interpretation and judicial decision-making. They examine objectivity from both metaphysical and epistemological perspectives and develop a variety of approaches, constructive and critical, to the fundamental problems of objectivity in morality. One of the key issues explored is that of the alleged 'domain-specificity' of conceptions of objectivity, i.e. whether there is a conception of objectivity appropriate for ethics that is different in kind from the conception of objectivity appropriate for other areas of study. This volume considers the intersection between objectivity in ethics and objectivity in law. It presents a survey of live issues in metaethics, and examines their relevance to theorizing about law and adjudication.

This article revisits the author’s influential account of Nietzche as a philosophical naturalist. It identifies the sources of Nietzsche’s position in the German naturalism of the mid-nineteenth century, in particular the work of Friedrich Lange. His naturalism is, however, “speculative” in that he postulates causal mechanisms not confirmed by science. Nietzsche’s ambition to explain morality naturalistically coexists with a “therapeutic” ambition to induce some readers to escape from morality. The article also addresses doubts that might arise against reading Nietzsche as a naturalist.