One skeptical challenge to the authority of reason is that the rational forms we use to conceive the world are illicitly imposed upon the world by us. In this book, Andrew Werner closely analyzes that threat to the authority of reason, suggests that many contemporary responses to the threat fail to answer it, and argues for the particular importance and value of Hegel's response. Werner develops an original account of Hegel's method and an original interpretation of his justification and construction of the categories of substance and causality, and shows how Hegel responds both to Hume's argument that we cannot give any justification for the objective validity of these categories, and to Kant's instructive but ultimately insufficient attempt to vindicate these categories. His bold study articulates and illuminates the radical systematic implications of Hegel's thought in the fields of metaphysics and epistemology.