Kant’s Cosmological Critique: Rational Cosmology and the Development of the Critical Philosophy

How can mere thoughts reliably guide both scientific investigation and our moral actions? This question is at stake in Kant’s theory of the positive role of ideas of reason in the Transcendental Dialectic of the Critique of Pure Reason. Recent scholarship has emphasized that Kant’s Dialectic chapter does not only make a negative argument about the futility of metaphysical psychology, cosmology and theology; the Dialectic also outlines a positive conception of reason, an account of the sources of metaphysical thinking, and a theory of how reason guides systematic empirical science. However, no extended study in English has yet examined how rational cosmology and its object, the idea of the ‘world’, fit into this picture.

This project fills this gap by investigating Kant’s appropriation of prior cosmology in the critical period. Firstly, I explain Kant’s perplexing account of how the idea of the world can guide natural-scientific investigation and moral action. Secondly, I argue that Kant subtly transforms cosmological doctrines when placing the notion of the unity of the understanding and reason at the heart of the critical philosophy. I ground these claims on the historical context: the debates over cosmology among Kant’s immediate predecessors, and Kant’s conception of cosmology in the pivotal 1770 dissertation.