The past three decades have witnessed the emergence, at the forefront of political thought, of several Kantian theories. Both the critical reaction to consequentialism inspired by Rawlsian constructivism and the universalism of more recent theories informed by Habermasian discourse ethics trace their main sources of inspiration back to Kant's writings. Yet much of what is Kantian in contemporary theory is formulated with more or less strict caveats concerning Kant's metaphysics. These range from radical claims that theories of justice must be political, not metaphysical, to more cautious calls for replacing Kant's metaphysics with a more modest ontology, for instance, one informed by the relatively recent linguistic turn in philosophy. The volume will consist of thirteen state-of-the-art essays which explore the relationship between politics and metaphysics in Kant and Kantian political philosophy. All essays will be published for the first time in this volume and will be preceded by an Introduction from the editors. Given the current legitimation crisisA" of modern liberal democracies, the purpose of the collection as a whole is to revisit the question concerning the role of metaphysics in moral and political philosophy and to suggest new perspectives on the question of legitimation.