Kant’s Critical Transformation of Rational Cosmology

It is well known that Kant intended to follow the three Critiques with a full system of metaphysics, which, whilst following the structure of traditional Wolffian metaphysics, would possess a new legitimacy bestowed by Kant’s prior critique of pure reason. However, little research has been devoted to reconstructing Kant’s projected metaphysics of nature from his sketches and efforts towards its completion. This project proposes to undertake the first extended study in any language of Kant’s career-long effort to reform the branch of Wolffian ‘special metaphysics’ known as rational cosmology. Rational cosmology sought to conceive of the world as a unified and interconnected whole by means of reason alone. Starting from the eighteenth-century intellectual context, the project provides comprehensive accounts of Kant’s pre-critical rational cosmology, the Critique of Pure Reason’s radical critique of cosmological ideas, and the late return of rational cosmology in Kant’s projected metaphysical system and his Nachlass. The project breaks new ground by treating Kant’s late drafts, the Opus postumum, not in relative isolation from his preceding work but as a continuation of his lifelong engagement with rational cosmology. It demonstrates the unique complexities of a ‘critical’ rational cosmology and reveals the systematic significance of the discipline for Kant’s mature philosophy.