Abstract
This article argues that Rawls’ history of ethics importantly contributes to the advancement of ethical theory, in that it correctly situates Kantian constructivism as an alternative to both sentimentalism and rational Intuitionism, and calls attention to the standards of objectivity in ethics. The author shows that by suggesting that both Intuitionist and Humean doctrines face the charge of heteronomy, Rawls appearsto adopt a Kantian conception of practical reason. Furthermore, Rawls follows Kant in assuming that ethical objectivity can be vindicated only if the productive and constructive powers of reason are acknowledged. The author accounts for this assumption against the background of Kant’s moral psychology, and examines Intuitionist and Humean rejoinders. Contrary to a common view, the author arguesthat because of its claims on the nature of moral agency and the sovereignty of practical reason, Kantian Constructivism sets the standards of ethical objectivity higher than its alternatives, and is more ambitious and more demanding than the realist conception of objectivity.