How should we act? How should the world be organised? This new anthology on Kant's practical philosophy guides the reader from the general question of the nature of reasons and rationality in Kant's philosophical system to the Kantian task of promoting justice and peace at the global level. Contributions in this volume show how the Kantian idea of reason as a source of normativity is grounded, and which implications and applications the Kantian approach might bring about. The volume covers three areas: meta-ethics, political thought and theory, and applied politics. Although these are different spheres of thought, they are interconnected in an fundamental way through Kant's account of normativity as derived from reason. The volume provides an overview of recent debates in Kant scholarship and ground-breaking new applications of Kant's theory to current affairs.