Perceptual Illusions : Philosophical and Psychological Essays

Things often go awry. Indeed, things can go awry in our beliefs, our actions, our emotions, and, of course, our perceptions. When things go awry in our perceptions, illusions occur. One popular philosophical theory argues that illusions are discrepancies between the world as it is and how it appears: although objects have certain properties, they nevertheless appear to have others. 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. The claim that illusions are discrepancies between objects in the world and their respective appearances can be questioned .Notions of apparent and real property are not quite clear; moreover 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. The notion of perceptual illusion is among those that philosophers are not prepared to relinquish. And so, they argue, although the popular theory of perceptual illusions has gone awry, it can be amended.