In this part, I provide a theory of social morality that requires those who would be moral to be other-regarding in the way that I have described, and I justify that theory on the basis of Kantian/Rawlsian ethics. In Chapter Three, I provide an overview of the theory, building on my claim that individual decisions that are other-regarding lead to a social system that is efficient, fair, and socially stable, and I describe the sense in which this theory is both economic and corrective. Chapter Four then explores the foundation of this social morality in Kantian ethics, demonstrating that the categorical imperative not only establishes the deontological duty to be other-regarding but also requires resort to a form of consequentialism to operationalize the notion that people should not use others as means to their own ends. Chapter Five then employs Rawls's device of the veil of ignorance to allow us to analyze which consequences are appropriately considered when an actor is other-regarding.