Kant's Pre-Critical Possibility Proof for God's Existence as the Ground of Possibility: A Reconstruction

The aim of this paper is to analyze and reconstruct Kant’s possibility proof. By distinguishing real possibility from logical possibility and by appealing to the notion of real absolute necessity, this proof introduces God as the unique necessary being who serves as the ground of all possibilities and who exists with real absolute necessity. The argument is significant both from a historical perspective and in virtue of its implications for modal metaphysics, particularly with respect to the problem of the ground of possibilities and the truthmakers of modal propositions. As such, it has recently received renewed attention in contemporary Kant scholarship. After presenting the conceptual preliminaries, the present study examines four main steps of the possibility proof, following the interpretations and reconstructions developed within contemporary Kant scholarship: (1) the necessity of the existence of a ground for real possibilities; (2) the transition from de dicto necessity to de re necessity (that is, the existence of a necessary being); (3) the demonstration of the uniqueness of this ground; and (4) its simplicity. At each stage, the argument is given a logical reconstruction, the main challenges confronting it are identified, and a number of critical remarks and proposals are offered with a view to refining or revising the formulation and addressing these challenges. In the final section, by presenting a preferred reconstruction of the possibility proof, it is argued that the overall structure of the argument can be rendered shorter and more rigorous in a two-step form, while preserving its core content.