What is desert? The aim of this book is to give an analysis of this notion. Starting from Feinberg's seminal paper, the argument goes on to Chisholm, 18th-century British Rationalism, and Kant, who developed the concept of propriety that is the foundation of the concept of desert and the key to understanding it. Beyond the analysis, the concept of desert is applied to two problems of moral philosophy, punishment and moral residue, that can be solved only by means of this notion. Desert is an indispensable moral concept we do well to understand clearly and to incorporate into our moral practice.