Abstract: Illusions are thought to make trouble for the intuition that perceptual experience is "open" to the world. Some have suggested, in response to the this trouble, that illusions differ from veridical experience in the degree to which their character is determined by their engagement with the world. An understanding of the psychology of perception reveals that this is not the case: veridical and falsidical perceptions engage the world in the same way and to the same extent. While some contemporary vision scientists propose to draw the distinction between veridical experience and illusion in terms of the satisfaction or non-satisfaction of “hidden assumptions” deployed in the course of normal perceptual inference, I argue for a different approach. I contend that there are, in a sense, no illusions – illusions are as “open” as veridical experiences. Percepts lack the kinds of intentional content that would be needed for perceptual misrepresntation. My view gives a satisfying solution to a philosophical problem for disjunctivism about the good case/bad case distinction: with respect to illusions, every "bad case" of seeing an X can be equally well construed as a "good case" of seeing some Y (different from X). -/- .
Comment: Background reading on direct realism and sense data.