Brian Leiter

Serious doubts about nonreductive materialism — the orthodoxy of the past two decades in philosophy of mind — have been long overdue. Jaegwon Kim has done perhaps the most to articulate the metaphysical problems that the new breed of materialists must confront in reconciling their physicalism with their commitment to the autonomy of the mental. Although the difficulties confronting supervenience, multiple-realizability, and mental causation have been recurring themes in his work, only mental causation — in particular, the specter of epiphenomenalism — has really captured the interest of philosophers in general in recent years.This growing attention has spawned a large body of literature, which it is not our aim here to explore or assess. Rather, we want to call attention to what we believe is a new and quite different argumentative strategy against epiphenomenalism voiced in some recent articles by Tyler Burge and Stephen Yablo. Each has challenged two central assumptions of the existing mental causation debate.

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

Contemporary moral psychology has been dominated by two broad traditions, one usually associated with Aristotle, the other with Kant. The broadly Aristotelian approach emphasizes the role of childhood upbringing in the development of good moral character, and the role of such character in ethical behavior. The broadly Kantian approach emphasizes the role of freely chosen conscious moral principles in ethical behavior. We review a growing body of experimental evidence that suggests that both of these approaches are predicated on an implausible view of human psychology. This evidence suggests that both childhood upbringing and conscious moral principles have extraordinarily little impact on people's moral behavior. This paper argues that moral psychology needs to take seriously a third approach, derived from Nietzsche. This approach emphasizes the role of heritable psychological and physiological traits in explaining behavior. In particular, it claims that differences in the degree to which different individuals behave morally can often be traced back to heritable differences between those individuals. We show that this third approach enjoys considerable empirical support - indeed that it is far better supported by the empirical data than are either the Aristotelian or Kantian traditions in moral psychology.