Disjunctive Theory of Perception

Perception: Representation or Relation?

There are two very different ways of thinking about perception. The first one is this. Perceptual experiences are representations: They represent the world as being a certain way. They have content, which may or may not be different from the content of beliefs. They represent objects as having properties, sometimes veridically, sometimes not.

According to the other influential view, perception is a relation between the agent and the perceived object. Perceived objects are literally constituents of our perceptual experiences and not of the contents thereof. Perceptual experiences are not representations. Following John Campbell, we can label these views the representational and the relational view, respectively.

One of the explanatory advantages of describing perceptual experiences as representations is that it allows us to treat veridical and nonveridical cases of perception in similar manner; thus, this could be termed the common factor view. Our beliefs can be incorrect and so can our perceptual experiences. The representational view can give a simple explanation for this: Both beliefs and perceptual experiences can fail to represent correctly; both can misrepresent. I may hallucinate that there is an apple on my desk. In this case, I have a perceptual experience that misrepresents. It represents an apple in front of me but in fact there is no apple in front of me. If we accept the representational view, hallucinations and illusions are considered to be perceptual experiences that misrepresent their objects.

Hence, the representationalist has a neat story to tell when it comes to the relation between veridical and nonveridical experiences. But what can the relationalist say? As the main claim of the relational view is that the perceived token object is a constituent of our veridical perceptual experiences, if we are hallucinating, there is no perceived token object that could be this constituent of our experience: Veridical experience is a relation between the perceiver and the perceived token object. But [Page 256]hallucination cannot be conceived of as a relation, as one of the two relata (the perceived object) is missing. In other words, veridical experience and hallucination are very different (but maybe indistinguishable) experiences.

This relationalist way of accounting for the relation between veridical and nonveridical experiences is called disjunctivism.

What Disjunctivism Entails

We have to be careful about what is meant by the identity or difference of experiences in order to properly interpret the main claim of disjunctivism. What the debate between the disjunctivist and the common factor view is about is whether my veridical experience of a pillow and my indistinguishable hallucination of a pillow are of the same type. But then this disagreement no longer seems very clear, as there are many ways of categorizing experiences as belonging to different types. Even the disjunctivists would agree that we can do so in such a way that the two token experiences would both belong to the same type, say, the type of experiences in general. And even the common factor theorist could say that there are ways of sorting these two experiences into very narrowly defined types so that they end up belonging to different types.

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