A Relational Moral Theory provides a new answer to the long-standing question of what all morally right actions might have in common as distinct from wrong ones, by drawing on neglected resources from the Global South and especially the African philosophical tradition. The book points out that the principles of utility and of respect for autonomy, the two rivals that have dominated Western moral theory for about two centuries, share an individualist premise. Once that common assumption is replaced by a relational perspective that has been salient in African ethical thought, a different comprehensive principle focused on harmony or friendliness emerges, one that is shown to correct the blind spots of the Western principles and to have implications for a wide array of applied controversies that an international audience of moral philosophers, professional ethicists, and similar thinkers will find attractive.