Philosophy Research Seminar - Andrew Stephenson

Andrew Stephenson (University of Southampton)

Existence, Modality, and Imagination in Kant: Lessons from Barcan

This paper considers Kant’s theory of modality in light of a debate in contemporary modal metaphysics and modal logic concerning the Barcan formulas. The comparison provides a new and fruitful perspective on Kant’s complex and sometimes confusing claims about possibility and necessity. The starting point for the comparison is the famous dictum that existence is not a real predicate, which is shown to be intimately connected to the view encoded in the Barcan formulas. Kant’s views on what he distinguishes as three different kinds of modality are then considered in light of this connection: logical, material (or physical), and real (or metaphysical). The first two cases are relatively straightforward. It is argued that Kant would reject the view encoded in the Barcan formulas for logical modality but accept it for material modality. For each case, there is textual evidence as well as both a philosophical and a formal corollary. The hardest case is that of real modality. This case raises a puzzle concerning how, according to Kant, we can know whether something non-actual is nevertheless really possible. A solution is proposed based on Kant’s account of the imagination as a capacity for intuition ‘without the presence of the object’ and it is argued that Kant’s idealism provides an explanation of how the imagination can form the basis of a modal epistemology in this way - a more secure explanation than recent imagination-based epistemologies of modality, but at what cost?