Disjunctivism

Disjunctivism is a theory within the philosophy of perception that offers an account of how perception can provide us with knowledge of the external world. At its core, disjunctivism claims that perceptual experiences are not all of a single kind. Instead, disjunctivists argue that perceptual experiences are either veridical (accurately representing an external object) or illusory/hallucinatory. When we have a veridical perceptual experience, we are in a direct and non-inferential relation to the object of our perception. This means that, in such cases, the experience itself is constituted by the object being perceived. In contrast, illusory or hallucinatory experiences are different in kind and do not involve such a direct relation to reality.

A key motivation for disjunctivism is its ability to provide a straightforward explanation of how perception can be infallible, at least in cases of veridical perception. If seeing a tree is, in the actual case, a matter of being directly presented with the tree itself, then it is impossible to see a tree and not see a tree. This contrasts with theories that view perceptual experience as involving a common subjective state, whether the perception is accurate or not. Disjunctivists argue that attempts to find a common subjective property shared by both veridical and non-veridical experiences fail to capture the fundamentally different nature of these experiences. The world is either as it appears, or it is not, and there is no intermediate subjective state that can be used to bridge the gap.