Kant's Critique of Skepticism in the Fourth Paralogism

Abstract

In this paper, I elicit a successful Kantian argument against skepticism from the Fourth Paralogism in the A-edition. The skeptical argument can be summarized as follows. A subject can know the existence of perceptual object only if he can infer "This perceptual experience has the property which distinguishes it from hallucination" (Inference Thesis). However, such a property cannot be found (Indistinguishability Thesis). Therefore, a subject cannot know the existence of perceptual object.
Two approaches against this argument can be distinguished. The first is to reject the Indistinguishability Thesis, but it fails because it falls victim of phenomenalism. I argue that the second and the defendable Kantian argument is to reject the Inference Thesis.