ABSTRACT
This chapter argues that Rousseau’s account of how to identify and to justify the most basic moral principles in Du contrat social belongs to a neglected though important branch of natural law theory, one inaugurated by Hume (and later augmented by Kant and by Hegel). This branch of natural law theory is a distinctive kind of moral constructivism which is altogether independent of moral realism and its alternatives, and yet identifies and justifies strictly objective basic moral principles. Cognitivism about basic moral principles is provided by this view through its account of justification, rather than by appeal to moral truth or truth-makers. I designate this approach ‘Natural Law Constructivism’. I detail the theoretical context within which to reconsider natural law aspects of Rousseau’s theory of justice. The Euthyphro question poses a basic dilemma in moral theory, which raises an issue about the relation between artifice and arbitrariness. This issue about arbitrariness highlights the significance of Hume’s key insight into the prospect of Natural Law Constructivism, and how this type of theory addresses Hobbes’ insight that our most fundamental moral problems are problems of social coordination. These problems raise the issue about the extent to which a social contract theory is substantive, because contractual agreement plays a constitutive role in identifying or justifying basic normative principles, or instead is merely expository, because a theory assigns no such constitutive role to contractual agreement. This latter kind of social contract theory may instead be a natural law theory. I argue that Rousseau’s Du contrat social is of this latter kind. To do so, I systematically re-examine the core of Rousseau’s theory of justice and then highlight Rousseau’s Natural Law Constructivism, distinguishing it from prudentialist and other (merely) instrumental forms of reasoning and justification.
