Perceptual illusionism is the view that perceptual experience is, in general, radically illusory. That is, perceptual experience presents objects as having certain sensible properties and standing in certain sensible relations, but nothing in the subject’s environment has those properties or stands in those relations. This paper makes the case for perceptual illusionism by showing how a broad set of philosophical and scientific considerations converge to support illusionism about the full range of sensible properties and relations. After clarifying the illusionist thesis, (...) I set out the argument in three parts. First, I briefly make the case for an illusionist view of color. I then argue for illusionism about the spatial/temporal properties presented in experience on the assumption that some “radical” view of space (and/or time) is correct—that is, some view according to which nothing like our ordinary three-dimensional space (or four-dimensional spacetime) exists at the fundamental level. Finally, I argue that there is a strong case for illusionism even if all radical views turn out to be false. (shrink)

It is common for an object to present different colour appearances to different perceivers, even when the perceivers and viewing conditions are normal. For example, a Munsell chip might look unique green to you and yellowish green to me in normal viewing conditions. In such cases, there are three possibilities. Ecumenism: both experiences are veridical. Nihilism: both experiences are non-veridical. Inegalitarianism: one experience is veridical and the other is non-veridical. Perhaps the most important objection to inegalitarianism is the ignorance objection, (...) according to which inegalitarianism should be rejected because it is committed to the existence of unknowable colour facts. The goal of this paper is to show that ecumenists are also committed to unknowable colour facts. More specifically, I argue that, with the exception of colour eliminativism, all major philosophical theories of colour are committed to unknowable colour facts. (shrink)

This is the Stanford Encyclopedia of Philosophy entry on the contents of perception.