Perceptual Illusions

"Things often go awry. Indeed, things can go awry in our beliefs, our actions, our emotions, and, of course, our perceptions. According to one popular philosophical theory, when things go wrong in perception, discrepancies between the world and its appearance occur. Although objects in the world have certain properties, they nevertheless appear to have other properties. For example, they seem to have shapes that they do not; their manifest colors, sizes, and weights are not their actual ones; and their perceived locations are at odds with their real ones. However, the claim that illusions are discrepancies between the objects in the world and their appearances can be questioned on two grounds. On the one hand, notions of apparent and real property are not quite clear. On the other, myriad examples have been put forward to show that a discrepancy between an appearance and reality is neither a necessary nor a sufficient condition for a perception to count as illusory. But the notion of perceptual illusion is something that the philosopher does not want to abandon. The authors contributing to this volume, while rejecting the idea that an illusion is a discrepancy of appearance and reality, think that illusions involve errors that produce some kind of inconsistency. And so, they argue, although the popular theory of perceptual illusions has gone awry, it can be amended"--Publisher's description, back cover.