Disjunctivism in philosophy of perception asks whether perceptions and hallucinations differ fundamentally in kind. The article argues that if a perception could have been a hallucination with the same content, the difference between them would depend on the external world, not the mind. Perceptions have a double existence—both intentional and natural—and allow indefinite perspectival transformations due to their informational link to objects. On this basis, a disjunctivist position is ascribed to Kant. The authors also contend that perceptions, unlike hallucinations, carry their own epistemic warrants, applicable to both humans and non-rational animals.
The human standpoint is distinguished from that of non-rational animals, and contrasts with the God's eye viewpoint of traditional metaphysics. The author draws distinctions between lower and higher representations of objects based on cognitive involvement. Space and time are presented as human forms of intuition rather than Newton's absolute sensoria, leading to Kant's distinction between appearances and things in themselves. However, the author defends a deflated version of Kant's transcendental idealism, advocating for a special variety of direct realism in philosophy of perception. Even within empirical realism, space can be seen as a form of perceiving, as perceptual content is organized spatially and mirrors a perceived scene.