Abstract:

Kant's Modal Metaphysics examines Kant's views on the nature of possibility, actuality and necessity. In Chapter 1 I discuss Kant's pre-Critical rejection of the theory of possibility shared by Leibniz, Wolff and Baumgarten. I highlight two principles that are decisive for Kant's metaphysics of modality: the distinction between what is logically self-consistent and what is really possible, and the claim that existence/actuality is unanalyzable. In Chapter 2 I reconstruct Kant's own positive pre-Critical metaphysical theory of real possibility, focusing on the concept of a 'ground of possibility' and his novel argument for the existence of God. In Chapter 3 I move from the pre-Critical to the Critical period and argue that Kant's 'metaphysics of experience' in the Critique of Pure Reason is motivated by a problem about modal knowledge. In Chapter 4 I argue that Kant distinguishes between the agreement of an object with our forms of experience and the real possibility of the object: Kant does not conflate the a priori with the necessary, either intensionally or extensionally. Chapter 5 discusses Kant's Critical stance towards his pre-Critical proof of the existence of God, and argues that, for Kant even in the Critical period, one can intelligibly raise the question of the modal status of non-sensible objects, things in themselves. Throughout the dissertation, I emphasize the continuity of Kant's pre-Critical and Critical theorizing about modality, without neglecting what is distinctive about the Critical method in metaphysics.