One of the most exciting and potentially fecund developments in contemporary moral philosophy is due to a recent line of thought developed by Stephen Darwall. In The Second-Person Standpoint: Morality, Respect and Accountability, Darwall has defined a novel and interrelated set of concepts – which include those of the “second-person standpoint” and “second-personal reasons” – and has argued that these concepts shed new light on both the nature of moral obligation and the appropriate methods for justifying moral judgments. Because most traditional views of practical reason (including both Kantian and consequentialist views) are rooted in the first and third-person standpoints, Darwall’s work provides a fundamental challenge to a broad range of views in the literature. This article argues that – despite a number of important controversies surrounding Darwall’s underlying account of morality – there are special reasons to think that three of his core claims should have more powerful, more robust, and more uncontroversial applications to the law. Building on these three core claims, this article also develops a novel and highly integrated account of both legal authority and legal legitimacy, which helps to illuminate a number of the law’s otherwise puzzling features. The article also explains why, in light of these facts, there there are special reasons to apply contractualist (as opposed to consequentialist) standards to test for the legitimacy not only of public but also of private law. For those who are unfamiliar with these contemporary developments in moral philosophy, Section I introduces the concepts of the “second-person standpoint” and “second-personal reasons,” and locates them within the larger intellectual landscape in normative theory. Section II presents three core claims that Darwall makes about second-personal reasons, which are – in my view – most relevant to legal theory. Section III then develops a novel set of reasons for extending these core claims to the law, regardless of whether they apply to morality. Section III also develops a novel, and highly integrated, account of legal authority and legal legitimacy, and describes some of the potentially far-reaching applications that this account may have for legal theory. Section IV, finally, discusses some of the primary objections to Darwall’s views on morality – which arise from Korsgaard, James, Wallace, and Watson – as well as from the so-called “philosophical utilitarians.” It argues that these objections ultimately depend on special features of morality, which the law does not share, and that a close examination of these objections can therefore help explain just why these contemporary developments may have more powerful applications to law than to morality. Indeed, there are – in my view – special reasons for both Kantians and philosophical utilitarians (one branch of which includes many members of the law and economics movement) to think that the law is distinctive in ways that invite a fundamentally contractualist (rather than a fundamentally consequentialist) test for its its legitimacy, on distinctive grounds.